Eps And Res Flashcards
(199 cards)
1
Q
As the battery discharges the internal resistance will?
A
Rise
2
Q
As the battery becomes more loaded the terminal voltage will
A
Fall
3
Q
EP systems are often necessary in a facility where?
A
A large number of people congregate
4
Q
Having a EP system will allow _____________ equipment to operate and _________ ______________ in the even of an emergency
A
Vital
Safe evacuation
5
Q
Generators are used for what kind of loads
A
Large capacity loads
6
Q
Batteries are less complex than generators and are used in what kind of applications
A
Small to medium applications
7
Q
Devices that convert chemical energy into electrical energy are called?
A
A cell
8
Q
When several cells are connected together they become a
A
Battery
9
Q
The output of a battery depends on both the __________ within and
A
Material within
How they are connected
10
Q
The two different materials that a cell is made of is called?
A
Electrodes
13
Q
______________ causes the internal resistance to increase during and when the battery is discharged
A
Sulphation
14
Q
When testing a battery the voltage shouldn’t drop below _______ during test
A
9.6v
15
Q
A __________ is how much energy that a battery can store
A
Amp hour
16
Q
A amp hour is calculated from?
A
The maximum sustained ampacity drawn from a fully charged battery over a time period of 20 hours
17
Q
If a battery can sustain 10A for 20hoirs is would have an amp hour rating of
A
200 amp hours
18
Q
If a battery can sustain 30A for 20 hours the amp hour rating would be
A
600 amp hours
19
Q
Besides amp hours ______________ is another measurement of battery capacity
A
Reserve capacity
20
Q
If a 12v battery can supply 25A for 100min the serve capacity would be
A
100 RC
21
Q
Reserve capacity is less common than?
A
Amp hours
22
Q
The _____________________ specification provides a measurement of the starting power of a battery at -18c under a load (amps) for 30 seconds with the end voltage maintained at 1.20 vpc (7.2v
A
Cold cranking amps
23
Q
___________ batteries are made with softer plates which convert chemical energy to electric energy much faster than deep cycle
A
Start
24
Q
__________________ is similar to ________________ but is performed at a warmer 0c instead of -18c
A
Marine cranking amps
Cold cranking amps
25
Q
The idea of marine cranking amps is
A
You don’t need to start a boat if the lake is frozen
26
Q
For any specific battery the MCA will be about _____ % greater than CCA because of increased temperature
A
20%
27
Lead acid batteries have ________________ and __________ electrodes and _______________
Lead and lead dioxide
Sulpheric acid
28
In lead acid battery both the electrodes and electrolyte both turn into
Lead sulphate
29
In a lead acid the electrolyte loses ____________ and becomes like _____________
Hydrogen
Water
30
In a lead acid during discharge the plates become ____________ and the charge gets ____________
Larger
Smaller
31
_________________ are used between plates to prevent short circuits in lead acid batteries
Separators
32
__________ at the bottom catch shed material from the plates on a lead acid battery
Ribs
33
What are the three types of lead acid batteries
Flooded or wet cells
Gel cells
Agm absorbed glass mat cells
34
What kind of lead acid battery had space between plates that is filled with a matt like material that holds electrolyte liquid
Agm or absorbed glass mat
35
Gel and agm batteries are ________________ technologies
Sealed off
36
Agm or gel lead acid batteries are ________________ free
Maintenance free
37
Gel or agm batteries are sometimes called
VRLA or valve regulated lead acid
38
If you run a current through a lead acid in the opposite direction the chemical action is
Reversed
39
When charging a lead acid battery the __________ go back to their original material and the _____________ gets stronger
Plates
Electrolyte
40
For a 12v battery the charging voltage would be about
14.2 - 14.5vdc
41
__________________ is always released when charging a lead acid battery
Hydrogen
42
___________________ may occur through the vents on a lead acid
Hydrogen gassing
43
Another name for specific gravity is
Relative densityb
44
To determine the level of charge in a battery we check the _____________________ of the electrolyte
Specific gravity
45
The ___________________ is the measure of the amount of acid contained in the water
Specific gravity
46
Whater has a SG of __________
1.000
47
A ____________ is used to measure the specific gravity
Hydrometer
48
Fully charged battery will have a specific gravity about __________ or ________ times heavier than water and a voltage of about ______v
1280 or 1.28
13.2v
49
A fully discharged battery would have a specific gravity of about _______ or less and a ______v
1150
11.9v
50
SG reading should be taken at ______C
25⁰C
51
When the _________________ we decrease our readings on a hydrometer
Temperature falls
52
When the _______________ we increase or readings on a hydrometer
Temperature rises
53
On a hydrometer each degree away from _____ we increase or decrease our SG rating by _____
25
.7
54
Generally batteries should be used at recommended temps of
25-27⁰C
55
In _________ temperature locations the capacity improves as chemical activity increases for a battery
High
56
In high temps for batters _______________ can occur
Overheating
57
In high temperatures _________________ and ___________ resistance go up
Evaporation
Internal
58
At high temps batteries have a tendency to _______________
Self discharge
59
High temps on batteries cause _______________ and voltage
Reduced life
60
Batteries in low temps ____________ decreases as _______________ activity decreases
Capacity
Chemical
61
Low temps for batteries ____________ can occur
Freezing
62
In low temps for batteries overall shelf life ______________
Increases
63
A batteries plates should always be _____________ with ___________
Covered
Electrolyte
64
If battery electrolyte is low add
Distilled water
65
If battery level is low due to spillage add
Sulpheric acid
66
Ration of sulpheric acid to water for a battery is
3:1
67
When mixing water and water how should it be poured
always add acid to water
68
Use ________________ and ___________ to clean battery terminals
Baking soda and water
69
Battery _____________ causes ________ resistance in your circuit and can lead to short circuits or premature battery failure
Corrosion
High
70
___________ battery terminals regularly
Tighten
71
For large battery banks use ___________ for representation on the health of the bank
Pilot cells
72
_________ cells are selected and tested to determine the charge or discharge current state for the entire battery bank
Pilot cells
73
Typically ________ pilot cells are selected and periodically rotated
5-7
74
Should visually inspect all connections as part of a ___________________ for battery banks
Maintenance program
75
Keep ___________ handy for lead acid spills
Baking soda
76
For ni cad spills use ___________
Vinegar
77
Ventilate battery rooms for buildup of _________________
Hydrogen gas
78
What battery has robust build that can take overcharge, over discharge and even a short circuit and is virtually indestructible
Nickel iron ni-fe
79
What battery has been long used in mining operations because of their ability to withstand vibration high temps and other physical stress
Nickel iron ni-fe
80
What battery is environmentally benign in that they do not contain hazardous materials
Nickel iron ni-fe
81
What battery has a hard time keeping a charge bully and very expensive
Nickel iron ni-fe
82
What battery operated poorly at low temps
Nickel iron ni-fe
83
What battery when overcharged, gasses and loses electrolyte volume
Nickel iron ni-fe
84
What battery can you not use a hydrometer because the electrolyte density never changes
Nickel iron ni-fe
85
How do you determine the state of charge of a nickel iron battery
Use a dc voltmeter on cells while under load to determine state of charge
86
What are the voltages for fully charged average charge and required charge for a nickel iron battery
1.37
1.2
1.0
87
What battery was seen as improvement for ni-fe batteries
Nickel cadmium ni-cd
88
What battery can hold it's charge well had a good life cycle and perform well at low temperatures
Nickel cadmium ni-cad
89
What battery has thinner plate design that's made for portable size batteries
Nickel cadmium ni-cad
90
What battery suffers from memory effect, holding less charge over time
Nickel cadmium ni-cad
91
What battery is a disaster to the environment and humans leading to being banned
Nickel cadmium ni-cad
92
What battery is seen as the future
Lithium ion or li
93
What battery has high energy density, tiny memory effect and low self discharge as all benefits
Lithium ion LI
94
What kind of battery comes in many shapes and sizes including lightweight options or power tools
Lithium ion LI
95
__________ batteries can be dangerous as they contain flammable electrolyte that is pressurized
Lithium ion
96
What battery if it has exposure to heat reduces battery life and could lead to thermal runaway and cell combustion
Lithium ion
97
What battery contains fail safe circuitry that disconnects the battery when the voltage is above cell safe range
Lithium ion
98
What is a lithium ion batteries safe range
3-5.2v/cell
99
What battery is considered less toxic than others and safe for landfills
Lithium ion
100
What is the difference between a primary and secondary cell
Secondary can be recharged
101
The SG of a fully charged lead acid battery would be
1280
102
The no load terminal voltage of a fully charged six cell lead acid battery would be
13.2v
103
Acid added to battery making it's specific gravity 1650 would cause?
Formation of hard sulphates
104
Sulfation is most likely caused by?
Too low water level
105
A lead acid battery when stored for long time would be stored how?
Full and charged
106
The 12v lead acid battery consists of _____ cells
6
107
The 12valkaline battery consists of ____ cells
8
108
What battery has a thermal release feature
Lithium ion
109
In regards to charging terms what is the first charge after a battery is filled with electrolyte
Initial charge
110
In regards to charging terms what is it when you restore a battery after it has been used or sitting
Normal charging
111
In regards to charging terms when you supply a charge to batteries and connected loads
Float charging
112
In regards to charging terms what is it when you ensure plates are de-sulphatef after bulk (constant voltage)
Absorption
113
In regards to charge terms: elevated charge voltage to equalize cells and remove residual sulphation
Equalization
114
What kind of charging is when:
Outputs rated current allowing charge to build fast. Voltage increases as charge builds.
Constant current
115
What is the preferred charging for nickel cadmium
Constant current
116
What kind of charging:
-outputs preset voltage level to prevent overcharging
-current decreases as charge builds
Constant voltage
117
How long does level 1 evse take to charge an ev
16hours
118
How long does level 2 charging of an ev take
3.5 hours
119
How long does a dc fast charging take to charge an ev
30 minutes
120
What ev charger is typically 120v
Level 1
121
What ev charger is the slowest how many km and hour
Level 1 8km/hour
122
What ev charger is considered a trickle
Level 1
123
What ev charger has a low installation cost
Level 1
124
A level 2 ev charger uses higher __________________ and __________________
Voltage and current
125
Level 2 ev chargers have _____________________ and programming
More involved installation
126
Level 2 charges charge _________ times faster than level 1
5-7
127
Level 2 chargers charge about __________ km and hour
24-40
128
Dc fast level 3 use about _______ vdc to directly charge batteries
480vdc
129
Dc fast ev chargers are ______________ and very ______________
Much larger and very expensive
130
What ev charger isn't seen in residential markets
Dc fast level 3
131
Why are dc fast level 3 more efficient
Don't need rectification and no acdc conversion losses
132
PV systems typically use a _____________ to make it more useful to household items
Inverter
133
High quality inverters can give efficiencies of about ______%
90%
134
Most common back up for a PV system is a
Diesel or propane generator
135
During the day the PV array provides
Power to loads and battery top up
136
3 different types of PV systems
Stand alone
Hybrid systems
Grid connected
137
What are two main types of grid connected PV systems
Utility interface
Utility interactive
138
What kind of PV grid connected system:
-Solar energy is stored in battery bank
-provides some or all of the buildings electrical needs
-low batteries=building transfer to utility
Utility interface
139
What kind of grid connected PV system:
-no storage
-excess energy fed to utility grid
Utility interface
140
Describe islanding
Undesirable condition where a distributed generation power source such as a PV system continues to transfer power to the utility grid during a utility outage
141
Some benefits of a grid connected PV system
Simple to install
Low capital cost
No requirement for local storage
142
Cons of a grid connected PV system
More expensive inverter required
Utility approval process
143
Bc hydro has ____________ which means they buy back power the same price they sell it
Net metering
144
Meter base:
Used for single phase applications
4 jaw
145
Meter base:
Single phase application with a connection for neutral
5 jaw
146
What jaw type gives higher accuracy In measuring unbalanced loads and is more common on homes fed from 3 phase network
5 jaw
147
Meter base:
Used for 3 phase
7 jaw
148
What are three factors that determine any PV modules power output what are they
Load impedance
Solar irradiance
Cell temperature
149
PV modules are ____________ and ______________ limited devices
Voltage and current
150
A ____________ is a high efficiency dc to dc converter that presents an optimal electrical load to a solar panel or array and produces a voltage suitable for the load
Maximum power point tracker
Mppt
151
What controller will look at the output of an array and compare it to the battery voltage
Mppt
Maximum power point tracking
152
Efficiency of a mppt
92-97%
153
A mppt gains _________% in winter and __________% in summer
30-45%
10-15%
154
Solar power available per unit area is
Solar irradiance
155
Solar irradiance is measured in
W/m²
156
Peak irradiance at sea level=
This is referred to as?
1000w/m²
One sun or peak sun
157
When solar cells are tested the standard condition is _______ at ________⁰C
1 sun
25⁰C
158
Modern PV inverters have two flavours what are they
Modified square wave
Sine wave
159
____________ inverters are most common on pv systems cheaper but not as efficient
Modified square wave
160
What inverter type causes more harmonic distortion in a system due to extra step produces
Modified square wave
161
In a _____________ inverter motor pumps will draw more current florescent lights may be dimmer or hum and digital clocks will tend to run faster as some parts of the sine wave are above 60hz
Modified square wave
162
A ________________ is a generic term used to describe devices that orient various payloads toward the sun. Like PV panels or reflectors
Solar tracker
163
A _______________ for a PV system requires no power and accurately tracks the sun throughout the day
Passive tracker: closed loop system
164
In a solar array many cells are connected ____________
In series
165
_______ of array coverage can result in ______ reduction of output
10%
90%
166
Azimuth in modern times is nearly always measured from the ________ in former times was common to refer from the _______
North
South
167
_________________ is the angle between magnetic north and true north
Magnetic declination
168
A _________________ is used to measure the solar irradiance on the planar surface and is a sensor that is designed to measure the solar radiation flux density
Pyranometer
169
A ______________ is an instrument for direct measurement of solar irradiance. And converts heat into an electrical signal for tracking the sun
Pyrheliometer
170
____________ are photovoltaic materials that are used to replace conventional building materials in parts of the building envelope such as the roof skylights or facades
Bipv
Building integrated photovoltaic
171
Solar panels must be bonded so?
That the panels can be removed without disconnecting the bond of the other panels
172
Why do you need batteries for a PV system
For energy storage
Periods of no or little sun
Prevent fluctuations
173
The cycle life of the battery is the number of times it can be discharged and recharged before it's storage capacity is reduced to _______
80%
174
The greater the _______ the shorter the batteries cycle life
DOD
Depth of discharge
175
Battery life ____________ as temperature _____________
Decreases
Increases
176
_______________ protect the batteries from overcharge
Charge controllers
177
____________ disconnect the PV array when the battery is fully charged
Charge controllers
178
More expensive ____________________ will also disconnect the batteries before they are discharged too low
Charge controllers
179
Do not ____________ into electronics or PV panels
Megger
180
Stand by power supplies come in what three forms
Dual radial feeds
Batteries and UPS
Emergency generators
181
Generators can be started then switched using an
Automatic transfer switch
182
A generator usually takes about ___________ to come online
8-15seconds
183
What generator fuel has problems with extreme temperatures
Propane
184
What generator fuel has faster start time but becomes unstable over time
Gasoline
185
What generator fuel is the most popular but slow start time
Diesel
186
Generators must be located
As close as possible to the main power supply
187
Generators must mount on?
Vibration pads
188
Generators must avoid areas of abnormally _________ or ___________________ for ease of starting
High or low temperatures
189
If a generator is kept outside it must be equip with a
Block heater
190
________________ are typically mounted at the alternator end of a generator
Control panel
191
When parelleling generators what must be the same
Terminal voltage
Frequency
Phase sequence
Phase displacement
192
Synchronized generators must have ________ protection
Rpr
Reverse power replays
193
The standby generator should be run for at least ____________ to ensure reliable starting
30min/week
194
It is preferred to test run a generator at at least ______ load or _______ if possible
40%
Full
195
What does test running do for a generator
Booster charge batteries
Cleans carburetor or fuel injectors
Keeps all parts lubricated
Brings engine up to operating temp
Removes a y condensation from crankcase
196
During an exercise of a generator you should observe and record
Oil pressure
Battery charging ammeter
Fuel level
Voltage and current levels
Frequency under load
Crank time
197
What style transfer switch overlaps the two sources for 0.1 seconds
Closed transition transfer switch
198
What can be used to help in synching up parellel systems to a grid
A synchroscooe
199
If you needed a transformer for a parellel system that has a line to line voltage of 208v 3 phase what size step down transformer would you need for the system
240v 1 phase x2
200
A defective batters voltage will remain ___________ when load is off
Low
201
A _____________ is a measurement or classifications of a batteries capacity
Amp hour
