Ch. 20: Electrical Fires & Emergencies Flashcards
(290 cards)
1
Q
Ch. 20: Norman – Electrical Fires & Emergencies
(NC #1)
___ is the power that moves industry and provides us with convenience in our daily life:
A
Electricity
2
Q
Ch. 20: Norman – Electrical Fires & Emergencies
(NC #2)
Electricity is actually a moving force that travels through (3) materials, in the form of electron transfer from one molecule to another:
A
- Solid
- Liquid
- Gaseous
3
Q
Ch. 20: Norman – Electrical Fires & Emergencies
(NC #3)
To simplify the ID of the various phases of the force that are at work – labels are attached to them. Bear in mind, that although numerous terms are used, its actually:
A
The same force being described in different forms.
4
Q
Ch. 20: Norman – Electrical Fires & Emergencies
(NC #4)
Electricity has pressure – known as:
A
- Electromotive force -or-
* Electrical potential difference.
5
Q
Ch. 20: Norman – Electrical Fires & Emergencies
(NC #5)
Electricity has pressure, known as electromotive force or electrical potential difference, and is measured in:
A
Volts
6
Q
Ch. 20: Norman – Electrical Fires & Emergencies
(NC #6)
(Norman uses comparison of electricity to water): Electricity’s friction loss - which is the measure of the resistance that it meets is measured in:
A
Ohms
7
Q
Ch. 20: Norman – Electrical Fires & Emergencies
(NC #7)
- The flow rate in water is referred to in terms of:
- In electricity, it is called:
A
- Gallons per minute.
* Amperes (amps for short)
8
Q
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #8)
Amperage (amps) can be thought of as being:
A
The amount of electricity that a wire is carrying.
Similar to how many gallons per minute a hose is flowing.
9
Q
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #9)
Amperage is determined by the:
A
- The amount of voltage the conductor is delivering -and-
* The resistance that the wire or object in the path of the current is offering.
10
Q
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #10)
Amperage → T or F – You can tell how much current a wire carries by looking at it:
A
False – Cannot tell
11
Q
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #11)
- Amperage ¬¬→ Assume all wires carry sufficient current to:
- It takes far less than ___ amps passing through your body to kill you:
A
- Kill.
* 1 amp.
12
Q
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #12)
Voltage → Can be described as the pressure that:
A
Forces electrical current through the lines that carry it.
Similar to the way we use pressure to move water.
13
Q
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #13)
Voltage → As with amperage, you cannot tell the amount of voltage a wire is carrying by looking at it. Voltage can vary in the same size wires. High voltages increase the tendency of electricity to:
A
Arc to ground across an open space
14
Q
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #14)
Voltage → Is the following statement true – ‘it is the amps that kill, not the voltage.’
A
Not entirely true and can be misleading.
15
Q
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #15)
Voltage → (CFPC) – It is true that level of amperage does the damage, current passing through a body requires ___ to cause the amps to flow:
A
Adequate amperage
this is why high-voltage levels are dangerous
16
Q
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #16)
Voltage → The presence of high-voltage is usually accompanied by the presence of:
A
High-amperage
17
Q
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #17)
Voltage → ‘it’s the amps that kill, not the voltage’ – The high voltage does not do the damage, but what accompanies it does. The danger posted is relative & depends on many variables that can be present – such as:
A
Potentially lethal – regardless of the labels associated with them.
18
Q
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #18)
Voltage → It is wise & prudent to treat all electrical emergencies as potentially ___.
A
Potentially lethal – regardless of the labels associated with them.
19
Q
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #19)
Voltage → Most of the situations that a FF will encounter involve various elements of the ___ system, and the power company’s labels can be misleading to the layperson.
A
Power distribution
20
Q
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #20)
Voltage → Many utilities refer to anything less than ___ as “low” voltage:
A
600 volts
21
Q
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #21)
Resistance → Can be thought of in terms of the ___ offered to the electricity:
A
Resistance to flow
(Norman’s analogy → a cracked nozzle provides resistance to water flow – consequently, there is little volume (amperage) delivered. If nozzle fully open or removed entirely – less resistance to flow & volume delivered (amps) increases.
22
Q
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #22)
Resistance occurs due to the:
A
Material of the conductor
23
Q
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #23)
Resistance → Occurs due to the material of the conductor. Materials that are good conductors offer little resistance to flow, while poor conductors – offer high resistance. Many ___ are poor conductors:
A
Rubber & plastic compounds
24
Q
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #24)
Resistance → Good conductors of electricity include:
A
Copper – and other metals
25
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #25)
FF boots (either leather or rubber) are not good ___, bc many of the compounds they contain:
Insulators
26
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #26)
Dry skin isn’t a good conductor – but the amount of pressure behind a high-voltage line can force electricity through even a poor conductor. When skin is ___, it becomes a good conductor:
* Does not permit electricity to flow –
| * Bc there is a break in the circuit wire, or an open switch.
27
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #27)
Resistance → Open circuit – An open electrical circuit (does or does not) permit electricity to flow because:
* Does not permit electricity to flow –
| * Bc there is a break in the circuit wire, or an open switch.
28
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #28)
Resistance → Short circuit – When a electrical ___, it becomes a short circuit:
When an electrical circuit’s normal path has been interrupted – it become a s/c.
Permitting current to flow through a path it was not intended to travel.
29
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #29)
Resistance → Utility ground – This is:
* The wiring installed by the utility companies –
| * That permits electricity to flow back in to the system and then into the earth (or ‘ground’).
30
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Terminology (NC #30)
Resistance → House ground – Wiring called house ground is:
* Installed by an electrician when building a house.
* The house ground permits electricity to flow back into the earth (or ground) in the event that the utility ground is broken or ‘open.’
31
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #31)
Most electricity is produced by ___, in facilities that use fuel as the source of energy. Sources of energy include:
• Generators
* Coal
* Oil
* Gas
* Nuclear
32
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #32)
Most electricity is produced by generators, in facilities that use fuel as a source of energy (coal, oil, gas, nuclear). This electricity is generally produced at __ volts:
13,000
33
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #33)
Upon leaving the generating station, electricity travels through transformers, that increase its voltage to:
138,000 – 345,000 volts
34
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #34)
* 20-1: The ___ station is responsible for the quality of live we enjoy today:
* This power moves out of the plant over large-capacity uninsulated conductors carrying upwards of ___ volts:
* Power generating station
| * 300,000 volts.
35
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #35)
Upon leaving generating station, electricity travels through transformers (that increase its voltage to?). This step is taken in preparation for:
* Moving the current over great distances –
* To the areas where it will be distributed.
* BC – high-voltage current travels more efficiently than low-voltage current.
36
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #36)
(CFPC) – Once at that point of the distribution, other transformers reduce the voltage to:
* 4,000 – 33,00 volts.
* Produced at – 13,000 volts.
* Transformers – 138k – 345k volts.
* Reduced – 4k – 33k.
37
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #37)
20-2: The neighborhood substation takes power from very-high voltage transmission lines & reduces it to ___ or ___ voltages:
Midrange or distribution
38
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #38)
20-2 (cont): The neighborhood substation takes power from very-high voltage transmission lines & reduces it to midrange or distribution voltages, commonly ___ volts:
27,000 volts
39
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #39)
20-2 (cont): Neighborhood substation – The silver ‘pipes’ about ‘14’ off of the ground, are actually:
* Buss bars –
* High voltage conductors.
* (Power must be removed from the facility before fire or emergency operations can safely be conducted inside)
40
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #40)
(Cont. From NC #36) – The electricity is then fed through a grid of cables & transformers that take it right to the customer’s door – On the way, the voltage is further stepped down to ___ volts normally used in the home or the office:
120 or 240
41
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #41)
The most important thing for FFs to be aware of in regard to the transmission system is that:
High voltage wires are not insulated.
42
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #42)
The most important thing for FFs to be aware of in regard to the transmission system is that high voltage wires are not insulated. That is also true of ___ on outdoor stations:
Buss bars (sometimes called bus bars)
43
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #43)
With electricity, the ___ is increased to push more of the power through the carrier:
Pressure (volts)
44
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #44)
When electricity reaches its destination, ___ convert it to match consumers’ needs:
Transformers
45
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #45)
When electricity has performed its function at the appliance or light bulb, it:
Returns to its source – via a return wire.
| not unlike water – which when its been used, finds its way into the sewer system to ultimately return to its source
46
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #46)
(CFPC) – As with water deliver, the ___ changes to maximize the efficiency of the delivery system, and this conversion is made at, or close to, the use location to match the need:
Mode of transport
47
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #47)
20-3: Typically the ___ (higher or lower) a wire is on a pole, the lower the voltage.
Lower
| dangling high-voltage wires could energize a telephone or cable tv wire w/ deadly current
48
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #48)
* 20-3 (cont): Utility pole – The top wires may carry more than ___ volts:
* ___ & ___ are indicators of high voltage:
* 13,000 volts.
| * Number & size of porcelain insulators.
49
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #49)
Keep in mind – size of the electrical transmission line will vary. A carrier of the same potential (voltage) may be of different sizes, depending on:
The substance from which it is made – such as copper or aluminum alloy.
50
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #50)
(CFPC) – This is unlike water carriers, where the size (diameter) of the conduit is the primary factor in transmission for:
Pressure & FL calculations
(rather than the construction & substance of the hose).
51
Section: The Power Distribution System (NC #51)
(CFPC) In electricity, the relationship of the diameter of the transmission pressure isn’t a strong consideration. W/ cables, problems of burst lengths & FL are also not strong factors (as w/ water in comparison), so high very ___ can be generated & used to provide more power potential over large distances at greater economy:
High pressures (kilovolts)
| Summarize this NC
52
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #52)
It would be (accurate or inaccurate) to state that the larger the line, the higher to voltage:
In accurate
53
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #54)
The old notion of ‘the larger the line, the higher its voltage’ is no longer a rule of thumb that can be relied upon, although the size of any ___ that can be seen on a line can give an indication of the relative voltages involved:
Size of any insulators
54
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #55)
The larger it ___, the higher the voltage is a valid indicator.
Insulator
55
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #56)
* F20-5: Transmission towers are insulated from the___ volts in the wires by porcelain insulators:
* T/F – The wires themselves are not insulated:
* 345,000.
| * T – Wires are not insulated.
56
Ch. 20: Norman – Electrical Fires & Emergencies
Section: The Power Distribution System (NC #57)
From a safe distance, look at any equipment that is attached to the line; it may be marked with the:
Normal operating voltage
57
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Hazards (NC #58)
There are 2 main hazards from electricity:
Electrocution & burns
58
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Hazards (NC #59)
Electrocution results from electrical currents interfering with:
The normal currents within the body – that cause the heart to contract & relax.
59
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Hazards (NC #61)
Electricity can cause paralysis of the muscles needed for breathing, resulting in asphyxiation, or the contraction of the muscles, forcing the body to:
* ‘Freeze’ in its position –
| * Often in continuing contact with the conductor.
60
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Hazards (NC #62)
Electrocution is affected by several variables, the; (5):
* Amount of energy passing through body.
* The size of the contact point.
* The path E takes to enter/exit the body.
* The duration of the current flow.
* The condition of the skin (dry, wet or if the skin is broken).
61
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Hazards (NC #63)
High-current flows though the body, either due to ___ or ___ cause rapid death:
* High-voltages -or-
| * Low resistances (wet or broken skin).
62
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Hazards (NC #64)
The amount of current flow through the body required to produce injury or death is very small. Table 20-1 → (NC 64-69):
1 milliamp = ___ of an amp:
1 milliamp (ma) = 1/1,000 of an amp
63
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Hazards (NC #65)
Table 20-1 → Alternating current (AC) flow hazard to humans:
1 – 5 ma (results in):
Tingling sensation
64
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Hazards (NC #66)
Table 20-1 → Alternating current (AC) flow hazard to humans:
5 - 10 ma (results in):
Pain
65
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Hazards (NC #67)
Table 20-1 → Alternating current (AC) flow hazard to humans:
15 ma (results in):
Level where muscle contraction prevents letting go of a wire in the hand.
66
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Hazards (NC #68)
Table 20-1 → Alternating current (AC) flow hazard to humans:
>50 ma (results in):
• Loss of muscle control.
• Cessation of the heart & respiratory functions.
• Death.
67
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Hazards (NC #69)
2 important factors that help determine whether a person survives a contact with electricity:
* The size of the contact point &
| * The path electricity takes through the body to ground.
68
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Hazards (NC #70)
Current that enters or exits through the head directly impacts:
The brain and nervous system
69
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Hazards (NC #71)
Current that enters one side of the body and traverses the chest to exit is likewise severe, as it impacts:
The heart & other vital organs
70
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Hazards (NC #72)
Current that enters an extremity & exits before it travels the length of that extremity could result in less injury to the ___ organs:
Systemic organs
71
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Hazards (NC #73)
Systemic organs include:
* Heart
* Lungs
* Brain
72
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Hazards (NC #74)
Current that enters an extremity & exits before it travels the length of that extremity could result in less injury to the systemic organs, but could still produce a ___ that could be life threatening:
Severe injury (explosive amputation)
73
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electrical Hazards (NC #75)
Duration of contact also plays a role – A longer duration ___ will likely produce greater damage:
Current flow
74
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #76)
Electricity also causes burns – the current flowing through the body produces 1 type of burn. T or F → Direct contact & current flow are not necessary to cause severe injury:
True
75
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #77)
Burns can also result from an electrical arc. An arc occurs whenever:
An electrical circuit is interrupted
| examples – turning a light switch on/off, a wire that touches the ground
76
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #78)
___ is a good example of the power of electric arc.
Arc welding
(being sufficient to melt steel & permit it to form a continuous pool to weld the 2 pieces of steel together as it passes)
77
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #79)
It is usually the presence of a ___, or the result of it, that triggers the response of FFs:
Arc
78
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #80)
An arc is caused by:
Current trying to jump an opening to reach ground.
79
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #81)
An arc is caused by the current trying to jump across an opening to reach ground. In high-voltage conductors, the current can jump ___ ft or more (cont. on NC):
3 ft or more
80
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #82)
An arc is caused by the current trying to jump across an opening to reach ground. In high-voltage conductors, the current can jump 3’ or more, depending on:
* Moisture content of the air,
* Electrical potential -and-
* Type of conductor.
81
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #83)
(CFPC) – That is why all ladders and all other equipment must be kept at least ___ feet from overhead power lines.
10’
82
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #84)
The arc also produces ___ that can damage the skin and eyes:
Ultraviolet rays
83
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #85)
If an arc is occurring or is possible, avoid looking directly at the source, since permanent damage to the ___, similar to that which occurs with welding, can occur:
Eyes
84
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #86)
(Reason why) FFs & utility personnel are cautioned not to turn any light switches on or off or on at suspected gas leaks, as well as not pull battery cables at an auto accident where gasoline vapors are present:
* Arcs that occur in presence of a flammable atmosphere –
| * Can ignite the flammable vapors.
85
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #87)
An arc can generate enough heat to melt metal and spatter the liquid. ___ heat from the arc itself, or the hot metal droplets can ignite combustibles – resulting in a more common Class A type fire:
Radiant
86
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #88)
If 2 energized lines of different potential come in contact with one another – as may be the case w/ an uninsulated overhead line, or a deteriorated underground cable, ___ will usually occur:
An arc
87
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #89)
The space that an arc can jump varies with (3):
* The conductor,
* The air moisture -and-
* The amount of voltage.
88
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #90)
An arc can occur between 2 downed lines if they are ___, or they can arc to ground:
They are close enough to each other
89
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Elements of the System That Affect FFs (NC #105)
The distribution of electricity includes a combination of:
* Transformers, with –
| * High & low-power carriers (cont. on nc)
90
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #91)
Static electricity can (also) create electric arcs. Static charges accumulate when 2 like substances:
* Create friction by passing one another in contact -or-
| * While being separated.
91
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #92)
(CFPC) – When the charged object is close enough to an uncharged object, and the ___ is reduced enough, a spark will jump the gap in an attempt to follow the laws of physics and neutralize the charge:
Air space insulation
92
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #93)
___ is 1 very common occurrence of static arcing:
Lightning
| Can ignite structures & kill people who are in the path of the discharging current
93
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #94)
T / F → Static arcs, as those you build in your clothes are strong enough to ignite flammable liquids & gases:
True
94
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Electric Arcs (NC #95)
Static arcs, as those you build in your clothes are strong enough to ignite flammable liquids & gases. ___ permits the static charge to drain away as it is produced, thereby preventing the charge strong enough to create an arc:
Proper grounding
95
Ch. 20: Norman – Electrical Fires & Emergencies
(NC #96)
___ is the result of current being dissipated to ground as it travels from a source:
Voltage gradient
96
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Voltage Gradient (NC #97)
If high-voltage wire is in contact with the ground, or in a puddle, the current is being dissipated into:
The soil
97
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Voltage Gradient (NC #98)
If high-voltage wire is in contact with the ground, or in a puddle, the current is being dissipated into the soil. The soil dissipates at various rates depending on:
* Moisture content
* Soil type &
* Wiring within them.
98
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Voltage Gradient (NC #99)
(CFPC) – At the point of contact, the amount of voltage that will be present will be very close to:
Whatever voltage the wire is delivering – farther away, from POC, less voltage will be present as more current is absorbed by the ground.
99
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Voltage Gradient (NC #100)
F20-8: The voltage gradient from a downed high-voltage line radiates (how and from where):
* Outward –
* From the poc – but not necessarily evenly in an evenly spaced radius, bc;
* Differences in conductivity of the soil.
* (Damp locations have higher current flows than dry – flow increases as source is approached)
100
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Voltage Gradient (NC #101)
A person approaching the scene will initially contact these lower voltage areas & receive increasing voltages as h/s gets closer. The nearer as person gets to the wire, the greater the ___ that is present between each step:
Differences in the amount of current
101
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Voltage Gradient (NC #102)
(CFPC) – If you get close enough, you may feel a:
Tingling sensation – as the current passes up 1 leg & then travels out the leg that is farther away from the source.
102
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Voltage Gradient (NC #103)
If you get close enough, you may feel a ‘tingling sensation’ as the current passes up 1 leg & then travels out the leg that is farther away from the source. This danger sign is a warning that:
You are about to get a real shock
103
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Voltage Gradient (NC #104)
The difference in the amount of current flow increases dramatically as the source is approached. If you encounter the tingling sensation, immediately (actions):
* Stop your forward advance.
* If possible – lift 1 foot clear of the ground to interrupt the current flow.
* Hop away from area on 1 foot - until clear.
* DO NOT – grab any objects for support; as they may provide better ground through your body do your feet.
104
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Elements of the System That Affect FFs (NC #105)
The distribution of electricity includes a combination of:
* Transformers, with –
| * High & low-power carriers (cont. on nc)
105
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Elements of the System That Affect FFs (NC #106)
The distribution of electricity includes a combination of transformers with high and low-power carriers, arranged in ___ grid systems:
Series and parallel
106
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Elements of the System That Affect FFs (NC #107)
FD purposes – only concerned w/ the aspects of the system that will affect us, either through:
Fire potential or shock hazard
107
Ch. 20: Norman – Electrical Fires & Emergencies
Sec. Elements of the System That Affect Firefighters (NC #108)
Carriers vary in voltage potential, depending on the:
Stage of the transmission
108
Ch. 20: Norman – Electrical Fires & Emergencies
Sec. Elements of the System That Affect Firefighters (NC #109)
A transmission line voltage will likely exceed _____ volts.
8,000
109
Ch. 20: Norman – Electrical Fires & Emergencies
Sec. Elements of the System That Affect Firefighters (NC #110)
Distribution line voltage will carry potentials of ___ volts:
601 – 8,000 volts
110
Ch. 20: Norman – Electrical Fires & Emergencies
Sec. Elements of the System That Affect Firefighters (NC #111)
Low voltage potentials range up to and include ___ volts:
600
111
Ch. 20: Norman – Electrical Fires & Emergencies
Sec. Elements of the System That Affect Firefighters (NC #112)
Terminology used by utility companies can be misleading to the layperson. Even ‘low voltage’ can be fatal. As FFs are concerned, ___ carriers are to be considered potentially fatal, regardless of how they are described:
All distribution system carriers
112
Ch. 20: Norman – Electrical Fires & Emergencies
Sec. Elements of the System That Affect Firefighters (NC #113)
Voltage cannot always be determined by:
* The size of the line,
* Its position on the pole, -or-
* Its position in the manhole vault.
113
Ch. 20: Norman – Electrical Fires & Emergencies
Sec. Elements of the System That Affect Firefighters (NC #114)
The introduction of ___ & ___ now allow small diameter cable to carry higher voltage, so you cant use line to determine voltage:
* Alloys -and-
| * Winding techniques.
114
Ch. 20: Norman – Electrical Fires & Emergencies
Sec. Elements of the System That Affect Firefighters (NC #115)
FDs are most often concerned with areas of the distribution system where ___ are made:
• Changes in voltages are made.
* Such as →
* Substations,
* Transformers,
* Junctions of cables that are found in manholes or overhead structures like utility poles.
115
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #116)
The safety of the operating personnel is paramount. The tactical position is generally:
Defensive – until the power is shut down
116
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #117)
The need for an offensive attack is rare and will be only be justified if:
Human life is at stake
117
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #118)
Remember, with this type of incident, damage was done prior to our arrival, and our concern is:
The protection of exposures.
118
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #119)
Generating station fires & emergencies – Emergencies in power generator stations are infrequent, but due to the nature of these facilities, they can be serious events because of:
* The size of the structures,
* The number of people that occupy these facilities,
* The nature of the hazards they contain (HV equipment, flammable liquid, high-pressure gas, steam lines)
119
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #120)
Generating station fires & emergencies – The oldest transformer oils might be contaminated with ___, which break down into deadly dioxin when heated:
* PCBs (polychlorinated biphenyl)
| * Use of SCBA at fires involving electrical installations should be mandatory – even outdoors.
120
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #121)
Generating station fires & emergencies – In a generating station, ___ (4) are used to heat water to several hundred degrees (cont. on nc):
* Coal,
* Oil
* NG -or-
* Nuclear fuel.
121
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #122)
Generating station fires & emergencies – In a generating station, coal, oil, NG or nuclear fuel are used to heat water to several hundred degrees, turning it into steam at over ___ psi. Steam used to __:
* 400
| * Turn turbines to generate electricity.
122
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #123)
(CFPC) – The steam is used to turn turbines to generate electricity, usually at about ___ volts and millions of amps:
13,000 volts
123
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #124)
Generating station fires & emergencies – A leak of such high-pressure steam creates:
* Scalding temps – from which bunker gear cannot provide protection.
* Tremendous shrieking noise – blocks verbal cmmu for 100s of ft in vicinity.
* Produces a cloud on condensing water vapor – obscures vision.
124
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #125)
(CFPC) – To compound the problem, in the immediate vicinity of the leak, the steam can be ___:
Invisible.
125
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #126)
Generating station fires & emergencies – The generators are a cooled with:
Hydrogen
(A lighter than air gas, so flammable that often ignites immediately in the event of a leak – w/ only the energy of the escaping gas as the ignition source)
126
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #127)
When hydrogen burns, it is a very ___ flame, that can be nearly invisible during daytime:
Pale
127
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #128)
The generated electricity (from generating station – water heated to steam, steam used to turn turbines to generate electricity) is then fed to:
Transformers
128
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #129)
The generated electricity (from generating station – water heated to steam, steam used to turn turbines to generate electricity) is then fed to transformers, with their cooling oils, to be stepped up to ___ volts:
138,000 – 345,000 volts
129
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #130)
Generating station fires & emergencies – Large, solid, metal bars that are not insulated carry the electricity throughout the plant. Bars are called:
* Buss bars –
| * Sometimes mistakes for overhead pipes or other construction.
130
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #131)
It is not necessary to touch the buss bars to be electrocuted; merely being within their electric fields (which can extend ___), is all it takes:
10’ from the bar
131
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #132)
In most power station plants, the ___ (who) has access to an emergency operations cabinet:
Watch general supervisor.
132
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #133)
The emergency operations cabinet contains information such as station diagrams, system & relay drawings, log books, a current list of all equipment containing __ and charts that show ___:
* Lists – PCBs.
| * Charts show emergency posts & jobs for all staff (in large power plants can be 100+ people)
133
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #134)
Generating station fires & emergencies – The watch general supervisor knows which equipment is live & can order it to be de-energized. FD should have arrangements to meet the watch supervisor in a pre-designated area outside the plant. The WS or other knowledgeable utility rep. should:
* Brief the fire officers,
* Escort them to the incident site,
* Provide FD w/ information & cooperation until incident has ended.
* (same should be followed for smaller staffed substations)
134
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #135)
Generating station fires & emergencies – In unstaffed stations, fire personnel should:
* Wait outside until knowledgeable utility representatives arrive.
* There is no civilian life hazard at unstaffed stations – only FF life hazard.
135
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #136)
Generating station fires & emergencies – No FF shall ever enter a power plant or substation without:
Being escorted by a knowledgeable utility representative.
136
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #137)
Other hazards (generating stations) may contain – Large open spaces with few areas of ___ during an emergency:
Refuge
Floors that are often open grate materials, exposing upper levels to rising heat, smoke or fire.
137
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #138)
* Other hazards (generating stations) may contain – ___ that may be remotely started:
* ____ for cutting & welding:
* Moving equipment
| * Compressed gas cylinders
138
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #139)
Actions to be taken – FFs responding to fires/emergencies at generating stations should observe the following procedures – assume ___ position.
Assume defensive position.
139
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #140)
FFs responding to fires/emergencies at generating stations - observe the following procedures – assume defensive position. Do not enter the plant or substation until:
* The arrival of the power company supervisory representative –
* Unless – human life is in jeopardy.
* (await arrival at location outside of hazard area)
140
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #141)
Fires/emergencies at generating stations, observe the following procedures –
• Do not enter ___ w/ out representative:
• Stretch a line to supply:
• Carry no ___ tools:
* Fenced areas
* Facility’s standpipe & sprinkler system if present – but don’t enter until verified it’s a safe area.
* Metal tools – leave halligan & metal tools outside.
141
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #142)
Fires/emergencies at generating stations, observe the following procedures – Do not under any circumstances, bring ___ inside the gate of the generating station:
* Metal ladders or metal tools.
| * No ladders, even wooden ones should be supported by metal superstructures.
142
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #143)
Fires/emergencies at generating stations, observe the following procedures – Ensure all handlines are equipped with ___ tips:
Fog
143
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #144)
Fires/emergencies at generating stations, observe the following procedures – Ensure ___ are deployed and tied off to outside areas if entry in to be made where there’s a potential for obscured visibility, such as smoke/steam leaks”
Search lines
144
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #145)
Fires/emergencies at generating stations, observe the following procedures – list them:
* Defensive position.
* Don’t enter plant or fenced off areas.
* Stretch line to standpipe or sprinkler system – if safe to enter area.
* No metal tools or ladders.
* Fogs on handlines.
* If enter – search lines deployed & tied outside.
145
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #146)
Typically these incidents fall into 1 of the 3 following categories:
* Generating station fires & emergencies,
* Transformer fires,
* Manhole fires.
146
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #147)
Transformer fires – change the current of the of electricity that flows through them, usually either:
Increasing or decreasing the voltage
147
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #148)
Transformer fires – In the process of changing the voltage, transformers produce heat. To remove or cool the transformer, most are filled with:
A cooling, non-conducting liquid
148
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #149)
(CFPC) – Liquid is ___ based. And in the event of a overheating or other mishap, this oil can leak and ignite:
Oil based
149
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #150)
* A transformer fire is primarily an ___ fire:
* Might be recognized by the ___ it produces:
* Oil fire.
| * Large quantity of black smoke.
150
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #151)
* Transformer fires – Large transformers can contain ___ gallons of oil:
* Creating a Class ___ fire if they ignite:
* 20,000 gallons.
| * Class B fire.
151
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #152)
Transformer fires – In the past, some oils used in transformers were PCB based. All oil should be presumed to be ___ until testing shows otherwise:
Contaminated with PCBs.
152
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #153)
Transformer fires – PCB oil creates a serious ___ incident is the oil leaks.
Hazardous material
153
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #154)
Transformer fires – PCB oils that are involved in a fire break down into deadly ___ & ___:
dioxin & dibenzofurans
(full use of PPE including SCBA is mandatory at a transformer fire – even outdoors. Exposed personnel and equipment may require decontamination)
154
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #155)
Actions at transformer fires – In all cases, units arriving at what is suspected to be a transformer fire should do the following, the 1st step is to:
Isolate the area and perform a size up
155
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #156)
Actions at transformer fires – Units arriving at a transformer fire should do the following – Notify ___ of the conditions and request:
* Dispatcher –
* Request response of the utility to shut down power.
* Going through dispatcher usually provides a tape-recorded verification of cmmu.
156
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #157)
Actions at transformer fires – Units arriving at a transformer fire should do the following →
Assume a ___ position:
Defensive
157
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #158)
Actions at transformer fires – Units arriving at transformer fires should do the following: Assume a defensive position – Position apparatus with the potential for ___ in mind. Try to park ___ if possible:
* Contamination.
| * Upwind and uphill of the incident.
158
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #159)
Actions at transformer fires – Secure a water supply water supply and stretch precautionary handlines or master streams as conditions dictate. Avoid directing water at ___. Water can be used to protect ___:
* The actual transformer – until assured by the utility or knowledgeable bldg personnel (in case of private transformers inside bldgs) that power has been removed.
* Exposures
159
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #160)
Actions at transformer fires – Units arriving at a transformer fire should do the following – Consult with utility company representatives before attempting:
Extinguishment
160
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #161)
Actions at transformer fires – Units arriving at a transformer fire should do the following – Once power has been removed, use ___ to extinguish the oil fire:
Dry chemical or foam
161
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #162)
Actions at transformer fires – Units arriving at a transformer fire should do the following – Examine adjacent structures for:
Fire or smoke
162
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #163)
Actions at transformer fires – Units arriving at a transformer fire should do the following – Do not begin overhauling until advised by the utility of the definite nature of:
The oil (PCB or non-PCB)
163
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #164)
Units arriving at a transformer fire should do the following → Consider using ___ personnel for a preliminary check of the oil type & for overhauling. Request ___ to verify the oil type:
* Hazmat personnel
| * The utility
164
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #165)
Actions at transformer fires – If a transformer is atop a pole (in addition to previous procedures) the following should be done: Establish a ___ from any falling power line potential:
Safety zone
165
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #166)
Actions at transformer fires – If a transformer is atop a pole (in addition to previous procedures) the following should be done: Make no attempt to extinguish the fire unless:
* It exposes cross members -or-
| * It could result in wire breakage.
166
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #167)
Actions at transformer fires – If a transformer is atop a pole (in addition to previous procedures) the following should be done: If necessary to extinguish – use:
* A fog or foam stream -or-
| * A dry chemical extinguisher.
167
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #168)
Actions at transformer fires – If a transformer is atop a pole (in addition to previous procedures) the following should be done: The fire is essentially a confined Class __ fire:
Class B
168
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #169)
* (CFPC) - Use the reach of the hose stream, remaining outside of the safety zone at least ___ ft from energized equipment.
* ___ ft if using solid streams or foam nozzles on other than spray pattern.
* 25 feet
| * 40 feet
169
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #170)
Actions at transformer fires – If a transformer is atop a pole (in addition to previous procedures) the following should be done: Stretch a line to protect ___:
Exposures.
But do not enter the safety zone until you have verified that all power has been removed.
170
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #171)
F20-11: Pole mounted transformers contain combustible oil. Once the oil ignites, the equipment is a total loss, protection of (3) are the only considerations:
* Responders,
* Public,
* Exposures.
* (Once power is removed, fire can be extinguished like any Class B fire)
* (NC 155 – 171 are transformer fire procedures)
171
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #172)
In many urban areas, the most frequent response to electrical emergencies is to:
Manhole fires
172
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #173)
Manhole fires → In many urban areas, the most frequent response to electrical emergencies is to manhole fires. The most common fire that we deal with occurs in:
The winter – when salt has been spread on snow & ice mixes with the runoff and finds its way into the manholes.
173
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #174)
The most common fire that we deal w/ occurs in the winter, when salt has been spread on snow & ice mixes with the runoff and finds its way into the manholes. Here it:
* Contacts some electrical circuits,
* And acts to short circuit these lines,
* Igniting a fire or creating an arc.
174
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #175)
Manhole fires → The ‘rumbling’ noise we hear at manhole fires is an:
Ongoing electrical arc
175
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #176)
Manhole fires → In most manhole fires, the fire is confined to:
* The wire insulation &
| * Any rubbish at the bottom of the vault.
176
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #177)
Manhole fires → Manholes contain a variety of high and low voltage equipment, but there are relatively few ___ in street manholes:
Transformers
177
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #178)
* Manhole fires → Most often transformers are found in ___:
* With covers made of (material & shape):
* Vaults.
| * Square or rectangular covers made of steel grating or concrete.
178
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #179)
Manhole fires → Covers – The entire cover must be lifted off to replace a defective transformer, so there are usually ___ over transformer vaults to permit easy access:
Very large, multipart covers
179
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #180)
20-12: Manholes or street vaults are scenes of many electric fires, especially in the winter. Protect exposures, especially where:
* Underground cables enter the basement of nearby bldgs.
| * Beware of high CO levels – which can lead to serious explosions when the gas ignites.
180
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #181)
Manhole fires → Fires burning in underground conduits and manholes produce large quantities of deadly:
CO – which follows the conduits to the bldgs & other manholes.
181
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #182)
Manhole fires → Nearby bldgs can accumulate deadly quantities of CO & other toxic gases from the burning ___, which presents a serious threat to firefighting personnel.
Polyvinyl chloride (PVC) insulation.
182
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #183)
Manhole fires → CO & toxic gases in manhole fires – These gases form a ___ when they contact the mucous membranes and lung tissue:
Hydrochloric acid (HCL)
183
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #184)
Manhole fires → (CFPC) - These gases form a HCL when they contact the mucous membranes and lung tissue. This HCL may be pulled deep into the ___, where serious long-term injury may occur:
CO
| with HCL present, it takes less of a dose of CO to be fatal
184
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #185)
Manhole fires → The presence of HCL in the lungs also causes a greater susceptibility to the effects of ___:
CO
| with HCL present, it takes less of a dose of CO to be fatal
185
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #186)
Manhole fires → Monitor CO levels in adjoining buildings, particularly the ___:
Cellars, and if detected, check the upper floors.
Wear SCBA while performing such examinations.
186
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #187)
Manhole fires → The danger of an explosion from a buildup of CO, a combustible gas with an extremely wide explosive range (which is?), is always present:
12 – 75%
187
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #188)
Manhole fires → (CFPC) – The force of these explosions can be tremendous, sufficiently powerful to blow 300 lb manhole covers, more than ___ feet in the air:
30’
188
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #189)
Manhole fires → Since wires & cables run from manhole to manhole through ___, all of the nearby manholes are interconnected:
Underground ducts or conduits
(if there’s smoke issuing from 1 manhole, treat nearby manholes with caution).
189
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #190)
Actions to take at manhole fires → When arriving; do the following – Establish a safety zone around:
All involved and adjacent manholes
190
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #191)
Actions to take at manhole fires → When arriving; do the following – Verify that your apparatus is:
Not parked over any manhole covers, and that personnel stay clear as well.
191
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #192)
Actions to take at manhole fires → When arriving; do the following – Notify ___ of the conditions, and request response of:
* Dispatch
| * Utility
192
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #193)
Actions to take at manhole fires → When arriving; do the following – Check adjacent bldgs for possible extension through:
Conduits
193
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #194)
(CFPC) – Use TIC to check for heat – the presence of heat in the ___ would indicate possible fire extension, and must be monitored closely:
Fuse service panel
194
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #195)
Actions to take at manhole fires → When arriving; do the following – Do not touch electrical panels with ___ when performing an examination:
The inside part of your hand
(a charged conduit could send an electric shock through your body, causing the muscles in your hand to contract & freeze in place, gripping the energized conduit)
195
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #196)
Actions to take at manhole fires → When arriving; do the following – Electrical conduits, if a manual examination must be made, use:
The back of your hand.
Expect high CO levels and wear your mask
196
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #197)
Actions to take at manhole fires → When arriving; do the following – Secure a water supply & stretch precautionary lines as conditions dictate, avoid directing any water into the manhole until:
* Authorized by utility personnel.
| * A wet manhole could endanger the service technician entering the hole.
197
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #198)
Actions to take at manhole fires → Standby and await arrival of utility. If forced to move through area containing electrical hazards, where smoke or other conditions prevent visibility, (proceed how):
* Move slowly, with your –
* Arms outstretched in front of you, and –
* Palms turned back in toward your body.
* (if outstretched hands contact a live power source, involuntary muscle contraction that occurs should pull arms back – breaking contact & limiting duration of current flow).
198
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #199)
There’s rarely a life hazard inside a manhole. In the event of an occupied manhole, standard ___ practices should be followed:
Confined space rescue
199
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Operational Procedures & Strategies (NC #200)
In the event of an occupied manhole cover on fire, the extreme risks to rescuers & the extremely remote possibility of survival of occupants must prevent entry until:
* The fire is extinguished -and-
| * You have verified that the power has been removed.
200
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Open Ground in Structures (NC #201)
Electricity requires a continuous path from its source, through the bldg wires, and then back to its source via:
The utility’s ground wire
201
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Open Ground in Structures (NC #202)
Electricity requires a continuous path from its source, through the bldg wires, and then back to its source via the utility’s ground wire. If this pathway is interrupted, a ___ results:
Short circuit
202
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Open Ground in Structures (NC #203)
To guard against electrical shock to anyone who contacts a device that has short-circuited, each building is provided with a:
* Separate path to ground,
| * That the electricity can flow through to dissipate harmlessly.
203
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Open Ground in Structures (NC #204)
Many FFs are familiar with the wire that is attached from the electrical panel to the building’s cold water pipe – this is the ___ wire:
Building’s emergency ground wire
204
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Open Ground in Structures (NC #205)
Many FFs are familiar w/ the wire that is attached from the electrical panel to the building’s cold water pipe – this is the building’s emergency ground wire. Normally there (should or shouldn’t be) current flowing through these lines:
There shouldn’t be
205
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Open Ground in Structures (NC #206)
(CFPC) – In the event that a broken wire has interrupted the normal path of the utility’s ground circuit, these house appliance grounds are designed to:
Prevent dangerous current flow through other paths that might start fires of cause electrocution.
206
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Open Ground in Structures (NC #207)
If the ___ wire is also interrupted, there may be no safe path to the ground:
House ground wire
207
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Open Ground in Structures (NC #208)
FFs have encountered parts of bldgs, such as metal ceilings, steam pipes & other metal fixtures that have been electrically charged. The current flowing through these unintentional conductors can be as large as what the ___ carries:
Building service – hundreds of amps
And can result in heat sufficient to ignite nearby combustibles.
208
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Open Ground in Structures (NC #209)
20-15: Loose connections and open grounds can result in the energizing of equipment that was never meant to carry electricity. A ___ helps detect such stray voltage.
TAC – Tester Alternating Current
209
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Open Ground in Structures (NC #210)
FFs might recognize the open ground condition from the:
* Dimming of light fixtures in affected structure,
* The presence of sparks at the contact point of metallic objects,
* The overheating of the building’s electrical service wires – if the over current protection (fuses or circuit breakers) has not functioned.
210
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Open Ground in Structures (NC #211)
Units encountering open grounds should take these actions → 1st - Attempt to open the building’s:
* Individual branch electrical breakers or fuses, reducing the load gradually, then,
* Only after all branch circuits are open,
* Open the main circuit breaker or switch.
* A large current flow may make this difficult or create a dangerous arc (PPE)
211
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Open Ground in Structures (NC #212)
Units encountering open grounds should take these actions → Stretch handlines to affected structure, notify utility & examine surrounding structures – if affected, shut down their electric service. Be aware:
* In some old bldgs, 2 bldgs may share a single ground wire.
* If shutting off the electricity in 1 attached bldg has not stopped the flow of current, consider shutting down the service in the adjoining bldg.
212
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Open Ground in Structures (NC #213)
The unpredictable nature of electrical current demands that FFs do not attempt ___ to such circuits. Only action necessary to:
* Repairs or alterations.
| * Protect life & prevent fire extension of fire should be taken pending the arrival of electrical utility personnel.
213
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Exposed Wires at the Base of Lampposts (NC #214)
A common response is a report of exposed wires at the base of the lamppost – At times this may be accompanied by reports from citizens that they are:
Getting shocked when they touch the pole.
214
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Exposed Wires at the Base of Lampposts (NC #215)
(CFPC) – Units receiving such reports should 1st:
* Isolate the hazard area -and-
| * Conduct a visual examination for the cause.
215
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Exposed Wires at the Base of Lampposts (NC #216)
Avoid touching the pole or wires without proper protection. These wires can contain upward of ___ volts:
227 volts
216
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Exposed Wires at the Base of Lampposts (NC #217)
A member wearing ___ may wrap visibly exposed wired with electrical tape to reduce the danger to unsuspecting passersby, and replace the wires within the base of the pole.
Lineman’s gloves
| attempt to secure the cover to prevent contact by unsuspecting civilians
217
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Exposed Wires at the Base of Lampposts (NC #218)
(CFPC) – Tape of area immediately around the pole to avoid contact by civilians, and notify the utility via the dispatcher.
-Empty-
218
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Exposed Wires at the Base of Lampposts (NC #219)
Often the cause of these incidents is:
People illegally tapping into the base of the pole to steal electricity.
(you may observe extension cords or other wires strung from the pole to an adjoining structure – notify dispatch to advise utility, do not attempt to cut or disconnect these wires unless they pose an immanent danger).
219
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #220)
FFs are often called to the scene of downed power lines, often as a result of:
Automobile accidents.
When approaching, be vigilant for wires that may be lying on the ground.
220
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #221)
20-16: Responders to reports of wires down should do a careful ___ survey before approaching the vicinity of the reported problem. Especially (when):
* Window survey
| * At night or in bad weather – its possible to step out of cab onto an energized wire.
221
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #222)
20-16 (cont): FFs located downed telephone wire – After examining it to ensure that is has not crossed high-voltage lines, the hazard should be isolated from the public by:
Taping and elevating before securing it in place.
222
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #223)
Use a light to examine the area immediately around the apparatus b4 climbing down from the apparatus at the scene of:
* Autos that struck a pole -or-
* Reports of wires down.
* (likewise – do not step off of the apparatus into a puddle of water that may be contact w/ a downed wire)
223
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #224)
On arrival, size up the scene, determining the need for additional fire/rescue units, utility crews, EMS, PD, and so forth based on:
* Nature of incident,
* Life hazard -and-
* The ability of units to isolate the area or control the hazard.
224
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #225)
* Treat all electrical wires as ___:
* Isolate the area, keeping pedestrians, civilian vehicles & apparatus out of the danger area. Use __ to ID danger zone:
* Live wires.
| * Barrier tape.
225
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #226)
The danger area for downed wires is defined as:
The area in all directions that is at least as large as the length of wire in question.
(Ex – if wire down between 2 utility poles that as 100’ apart – danger area should be at least 100’ in all directions from the pole(s) that the wire is hanging from)
226
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #227)
If utility poles are involved, sudden failure of a pole or its ___ could cause a domino effect, toppling other poles.
Supporting guy wires
227
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #228)
Do not approach or touch any (5) that may be energized:
* Person
* Object
* Electrical parts
* Puddles of water
* Wet ground
228
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #229)
If a utility crew is required, the IC should contact them through dispatch and give as much information as possible, including:
* The location,
* The # of the utility pole if possible,
* Description of the condition
229
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #230)
Rescuers must be aware that in the event of a downed utility pole or wires, other wires such as TV, phone, fire alarm cables & other so-called low voltage wires could be:
In contact with, and energized by, high-voltage wires.
230
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #231)
The 1st tactical consideration is to:
* Define the perimeter of the operation, by;
* Establishing a safety zone, that is –
* 1 full span greater than the affected area.
231
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #232)
20-17: The 1st action to take after sizing up the scene is to:
Isolate the area around downed power lines.
Keep spectators and nonessential personnel out of the danger zone.
232
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #233)
Safety zone – This is done to reduce the possibility of the downed line ___ into spectators or rescue personnel standing by.
* Dancing.
| * A downed line can be dancing, arcing or just lying still.
233
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #234)
Isolate the area extending back to ___ for all but essential personnel:
The next pole
234
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #235)
20-18: Energized high-voltage can whip around violently, propelled by an electric charge – Initial responders should isolate the area at least:
* 1 full wire span away from any break.
* (that is the area between the next utility poles – since that’s the potential danger zone a whipping zone can contact)
* (same rule applies to burning wires, transformers atop poles)
235
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #236)
Actions to take a DPL → 1st step is:
* Isolate area –
* Use apparatus to detour traffic and request PD for assistance w/ crowd control.
* Use barrier tape to indicate danger area.
236
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #237)
Actions to take a DPL → Immediately after confirming that electrical wires are down & creating a hazard, have the ___ notified:
Utility – thorough the dispatcher
237
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #238)
Actions to take a DPL → Expect high-voltage wires to:
Arc and whip violently.
Provide a large danger zone to protect against anyone being caught by a sudden change in conditions.
238
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #239)
Actions to take a DPL → A wire that appears lying quietly, apparently ‘dead’ can suddenly become very active when:
* The insulation on it burns away -or-
| * Becomes wet by rain.
239
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #240)
* Actions to take a DPL → Stretch a handline equipped with a ___ nozzle:
* Keep at least ___ ft away from any electrical equipment when operating any handline:
* Fog
| * 25’
240
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #241)
Actions to take a DPL → If its necessary to utilize a solid tip nozzle, remain at least ___ ft from any energized equipment:
* 40’
| * 25’ if using a fog nozzle.
241
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #242)
Power lines in contact w/ people → 20-19: In the event that its necessary to approach a live wire (to save a life), extra precautions are required, those are:
* Wear full fire PPE &
* Tested utility lineman’s gloves.
* And use a hot-stick if available to secure the wire (lift wire clear of victim or vehicle to minimize arcing, back away slowly – pulling wire toward safety, keep self & wire out of puddles.
242
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #243)
Power lines in contact w/ people → Trained & properly equipped FFs may use a properly tested ___ to remove wires from direct contact with a victim or vehicle:
Hot stick
243
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #244)
Power lines in contact w/ people → If use hot stick – secure the hot stick around the wire by placing a clamp under the wire and:
Twisting the body of the stick clockwise, until the clamp tightens around the wire.
244
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #245)
Power lines in contact w/ people → Hot-stick procedures:
* Once wire cleared with clamp, lift wire.
* If possible back away from victim, walking with the wire.
* (Be aware – wire can spring in any direction w/ out warning)
* Try to keep hot stick between self and wire at all times.
245
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #246)
Power lines in contact w/ people → Hot stick procedures (cont):
* Quickly lift wire to reduce amount of arcing & resultant burns to the victim.
* Protect your eyes by not looking at wire as its being lifted.
* If possible – leave wire in contact with ground to permit as much of the current as possible to continue to flow ground through that route, rather than arcing.
246
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #247)
Power lines in contact w/ people → If, due to a life-threatening situation, it becomes necessary to cut the line, do so at:
Both snapped ends
(both ends could be energized if an alternate feeder arrangement is set up – similar to a hydrant grid system for water supply)
247
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #248)
Power lines in contact w/ people → Cutting the line – Secure the wire in place with ___ to prevent it from whipping up at you when it is cut:
* Hot stick -or-
| * A nonconductive object such as long, dry, wooden boards.
248
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #249)
Power lines in contact w/ people → Cutting the line – Anyone approaching a live wire for this purpose, should be (wearing):
* Full PPE,
* Approved lineman’s gloves,
* Tested wire cutters (not bolt cutters).
249
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #250)
Power lines in contact w/ people → Cutting the line – Cut through only 1 conductor at a time. When approaching a downed line, if a tingling sensation is perceived in the feet, this is an indication that the surrounding ground is:
* Highly energized, with a;
* Voltage gradient.
* (In this case – imperative that power be shut down b4 further action is taken)
250
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #251)
Power lines in contact w/ people → Do not approach wires unless there is a:
Imminent hazard to savable human life
251
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #252)
Power lines in contact w/ people → Permit only properly ___ members to approach the incident scene:
* Trained and protected.
| * (Full PPE, lineman’s gloves, hot stick)
252
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #253)
Power lines in contact w/ people → Do not touch the victim or electrical parts that may be energized either:
Manually or with a tool that may be a conductor.
253
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #254)
Wires down on vehicles → If the wire is down over a car with people in it, have the people (in the car do what):
* Remain in the car,
| * Clear of any metal parts – until power is removed.
254
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #255)
• Wires down on vehicles - If the driver is able to move the vehicle, direct h/h to:
* If vehicle cannot move & no-life threatening situations exits, do not:
* Drive the vehicle out from under the wires.
* Attempt to remove the occupants until the lines are deactivated.
255
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #256)
Wires down on vehicles → If fire threatens the occupants, direct them to:
Jump clear of the vehicle without touching the car & ground at the same time.
THIS WAS A TEST QUESTION
256
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #257)
Wires down on vehicles → If injured people are trapped in a car that is in contact with wires, direct them to:
* Remain in the vehicle,
* Clear of any metal parts – until power is removed.
* (Do not allow rescuers near vehicle until power has been removed)
257
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #258)
* Wires down on vehicles - Always stretch a ___ (line & nozzle) to deal with a potential fire:
* But be aware of:
* 1¾” handline w/ a fog nozzle.
| * Potential runoff – keep all personnel out of the water.
258
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #259)
Wires down on vehicles → Injured people trapped in a car – In the event that a life threatening condition requires their immediate removal & a hot stick is not available, the line might be removed by using a:
A dry rope
259
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #260)
Wires down on vehicles → Using a dry rope to remove a line (on a car w/ injured people w/ life threatening conditions that require their immediate removal) – rope must be dry – this technique cannot be used during rainy or damp weather:
* One weighted end of rope is thrown under the wire – to allow a rescuer on the far side to retrieve the rope.
* Then, other end of rope is thrown over the wire.
* M on far side then retrieves this end and walks backwards – pulling wire off vehicle & toward himself.
260
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #261)
Wires down on vehicles → Using a dry rope to remove a line (on a car w/ injured people w/ life threatening conditions that require immediate removal) – the presence of ___ around the site may remove this option:
* Spilled gasoline.
| * As any spark could create a far worse situation for the victim.
261
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #262)
Using a dry rope to remove a line (on a car w/ injured people w/ life threatening conditions that require immediate removal) – presence of gasoline around the site; actions are:
* Flush spilled gasoline away with fog nozzle from a safe location &
* Cover gasoline with foam.
262
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #263)
Wires down on vehicles → (CFPC) – Gasoline around fuel scene; flush spilled gasoline away w/ fog & cover with foam. No physical contact w/ the vehicle should be made as the individual would become:
The path to ground – and electrocution would result.
| if necessary – wire could be cut
263
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #264)
Wires down on vehicles → In the event that an apparatus contacts a wire during an operation, FFs on or inside the apparatus are safe, provided they:
* Are not in contact with the wire or the arc it produces -and-
* Do not make contact with a ground.
264
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #265)
In the event that an apparatus contacts a wire during an operation, FFs on or inside the apparatus are safe, provided they aren’t in contact with the wire or arc it produces and do not make contact w/ a ground. Ground could be:
* Aerial of another apparatus,
* A fire escape,
* Or the actual ground itself.
265
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #266)
Wires down on vehicles → Apparatus contacts a wire during an operation – Dismounting the apparatus while in contact w/ both the energized apparatus & the grounded object would cause the FF to become:
The conductor through which the electricity would flow – would result in electrocution.
266
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #267)
Wires down on vehicles → Apparatus contacts a wire during an operation – Those individuals who are on an energized vehicle are safe because they:
Are part of the circuit.
| Again, however, there is a serious danger from the arc flash the results from power lines contacting metal objects
267
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #268)
(CFPC) – If FFs provide a link to the ground, they can severely injured or killed. This should not be construed to mean that if an apparatus is already grounded, that the individual on the ___ would be safe:
Ground making contact
268
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #269)
Wires down on vehicles → The path of electricity can follow a ___ path:
Parallel
269
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #270)
Wires down on vehicles → Rule for safety is to avoid all contact if on an ___ object:
Energized
270
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Downed Power Lines (NC #271)
Wires down on vehicles → Keep all apparatus at least ___ feet away from all wires:
10’
271
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #272)
Common electrical problem involves overheated ___ light ballasts, which often don’t give off visible smoke until later in the emergency:
Fluorescent
272
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #272)
Common electrical problem involves overheated ___ light ballasts, which often don’t give off visible smoke until later in the emergency:
Fluorescent
273
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #274)
Light ballasts contain a cooling oil that gives off an oily smell when it is overheated. On older types, this was often ___ oil, so you should wear SCBA when handling these seemingly minor incidents:
PCB
274
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #275)
Locating the defective unit can be complicated by the height of the fixture, ___ can be used that allow a FF, standing on the floor, to search rapidly along the rows of light fixtures:
TICs or other types of heat scanner devices
275
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #276)
Without a heat scanner, FFs (will locate defective ballast by):
Must physically inspect each fixture
276
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #277)
Physically inspecting each ballast – The search can be narrowed by following a few visual hints, begin by looking for:
* Begin by looking for fixtures w/ intact bulbs that are glowing faintly.
* (Fixtures w/ out bulbs won’t have flow of current & usually aren’t the problem)
* (Fixtures that are operating correctly can be the source of the problem, but not as common as dim fixtures)
277
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #278)
(CFPC) Physically inspecting each ballast – The search can be narrowed by following a few visual hints – Look at fixtures for defects. ___ or ___ indicates a problem:
* Dark-colored oil on the outside of the fixture -or-
| * Dark-colored oil on the light diffuser of a recessed type.
278
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #279)
Visual hints – On surface-mounted fixtures, a ___ indicates soot-deposits:
Dark smudge around the sides, particularly near the vent.
279
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #280)
(Physically inspecting each fixture) – As a last resort, ___ each fixture:
Feel
280
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #281)
Feel - A normal ballast will be __.
Feel - A defective unit will be ___:
* Normal – warm to touch.
| * Defective – hot.
281
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #282)
Once defective unit (ballast) has been identified, take steps to isolate it. First:
* Ensure there hasn’t been any ignition of nearby combustibles -and-
* Prevent any further flow of the current.
282
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #283)
Once defective unit has been identified, take steps to isolate it. 1st ensure there hasn’t been any ignition of nearby combustibles & prevent any further flow of the current. This generally entails:
* Gaining access to the ballast,
* Feeling around it for abnormal heating, -and-
* Opening the electric circuit.
283
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #284)
Once defective unit (ballast) has been identified, take steps to isolate it. Steps taken:
* 1st – ensure there’s been no ignition of nearby combustibles & prevent any further flow of current.
* Shut off power to fixture –
* Remove all bulbs –
* Open cover – dc all wires leading to ballast
* Cover exposed ends of black & white wires w/ electrical tape or wire nuts.
* Examine nearby combustibles for hidden fire.
284
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #285)
Electrical fires are common occurrences that can usually be handled easily. To locate the source of the problem, consider:
* Where the smell was first detected –
| * Then, examine all devices in the area that are on, or had recently been on.
285
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #286)
(CFPC) Locating the problem – It often pays to leave the power on until the source is located. Turn power off, if it endangers members or occupants.
-BLANK-
286
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #287)
* If the electrical equipment is on fire, as opposed to being merely overheated, use ___ agents:
* Preferably an agent that won’t:
* Nonconductive extinguishing
| * Damage the equipment or compound the cleaning problem.
287
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #288)
If the electrical equipment is on fire, as opposed to being merely overheated, use nonconductive extinguishing agents. ___ & newer clean agents are well suited for this:
CO2
288
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #289)
If the electrical equipment is on fire, as opposed to being merely overheated, use nonconductive extinguishing agents. ___ shouldn’t be used because of their effect on the earth’s ozone layer:
Older halon extinguishers
289
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Overheated Ballast (NC #290)
If the electrical equipment is on fire, as opposed to being merely overheated. ___ as soon as possible once the source is located.
* Disconnect the power.
* Turning the power off may cause fire to self-extinguish –
* Alleviating need for an extinguishing agent.
290
Ch. 20: Norman – Electrical Fires & Emergencies
Section: Conclusion (NC #291)
* (3) are useful tools for lifesaving purposes – don’t rely on them:
* Always assume all wires to be:
* Linemen’s gloves, mats, sleeves. (THIS WAS ON TEST)
| * Live, high-voltage conductors.
