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Electrical - Level 4 > Modern Building Systems > Flashcards

Modern Building Systems Flashcards

1
Q

What is Structured Cabling?

A

Telecommunications wiring in buldings

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2
Q

What was structured cabling originally?

A

Plain Old Telephone Service (POTS)

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3
Q

What does structured cabling include?

A
  • Telephone/fax
  • Television
  • Video
  • Security
  • HVAC
  • Automation
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4
Q

What is the connection point called where electricians take over the wiring?

A

Demarcation

Also known as Network Interface Device, Node zero, and Telco Room

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5
Q

What are the 4 networks?

A
  • Internet Service Provider (ISP)
  • Wide Area Network (WAN)
  • Local Area Network (LAN)
  • Municipal Area Network (MAN)
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6
Q

What does a municipal area network for?

A

Civil (sewer and water) and emergency services

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7
Q

What is ISP wiring typically provided by?

A

twisted pair, coax, fibre or a combination

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8
Q

What may Node Zero include?

A

modems (modulator, demodulator), routers, splitters, switches (data), cross connects (punch down blocks), control panels, radios

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9
Q

What can LAN wiring include?

A

twisted pair, coax or fibre (even power wiring) but generally refers to CAT5e, CAT 6, CAT6a, U.T.P.

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10
Q

What is “convergence” refer to?

A

the integration of various media (voice, video, data) onto common medium (U.T.P., coax, fibre)

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11
Q

What are the 3 types of twisted pair wiring? What do they carry?

A
  • Unshielded twisted pair (U.T.P.)
  • Shielded twisted pair (S.T.P.) - each indiv. pair is shielded
  • Screened twisted pair (Sc.T.P.) - all pairs have overall shield
    They carry “balanced” signals with half the signal on each conductor
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12
Q

Are signals out of phase?

A

yes, by 180°

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13
Q

What are the 4 components of a coaxial cable?

A
  • Core
  • Dielectric (insulation)
  • Shield
  • Jacket
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14
Q

How is the signal carried in a coaxial cable? How is the shield bonded?

A
  • the entire signal is carried on the center core

- shield is bonded at both ends

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15
Q

What is the purpose of the shield in a coaxial cable?

A

reduce outside signals from ingressing onto the core, and provides a return path for the signal

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16
Q

How is a quad shield shielded?

A

foil, braid, foil, braid for improved shielding

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17
Q

What are the core materials used, for what purposes and at what Hz?

A 
Solid Copper (usually) - closed circuit TV (CCTV) and audio and video signals (approx 5-55 MHz)
Copper Claded Steel - community antenna TV (CATV), satellite TV (950-1450 MHZ)
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18
Q

What does the core gauge depend on?

A

Frequencies and Distance required

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19
Q

cable specific connectors are required based on what?

A
  • Radio Grade
  • Shielding Configuration
  • Jacketing
  • Characteristic Impedance
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20
Q

What does the dielectric insulation between the core and shield determine?

A

the “characteristic impedance” of the cable with its capacitance

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21
Q

Does the length of the cable have affect on its impedance?

A

NO

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22
Q

What is the impedance dependant on?

A

Frequency dependant and varying slightly over the intended frequency range

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23
Q

What must have the same characteristic impedance? What will occur if they do not?

A

All components (transmitters, splitters, cable, connectors, receivers) or else losses will occur (reflected signal cancelling out the main signal)

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24
Q

What are typically ohms of Radio Transmitters, data modems (coax) and CATV systems?

A

Radio transmitters and data modems = 52 or 50 ohms

CATV systems = 75 ohms

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25
Q

The impedance of a cable is severely affected by any disturbance of the dielectric. List some examples of what could do this?

A
  • A kink in a coax renders it destroyed
  • Excessive pulling tension
    Max 80 lbs for good RG-6
    Max 25 lbs for CAT5e
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26
Q

The shield may be what in coaxial cable? What do double shielded cables have?

A
  • Braided 92% copper or tinned copper
  • Foil 100%
    Double shielded cables have both
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27
Q

What are Baluns?

A
  • balanced to unbalanced matching transformers

- HDMI extenders are sometimes called baluns

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28
Q

Coax connectors are labelled as what?

A

“F” connectors

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29
Q

Coax couplings are labelled as what?

A

“F-81” connectors

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30
Q

What are the two standards for Twisted Pair Balanced Systems? What do they specify? (EIA & TIA)

A
  • Electronics Industry Association
  • Telecommunications Industry Association
    They specify the “category” of cabling
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31
Q

What is Power Over Ethernet?

A

44 - 57 Vdc (48V nominal) over our ethernet cabling

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32
Q

Power over Ethernet switches and routers or power inserting equipment are used for what?

A
  • Phones
  • Cameras
  • Tstats
  • Remote data switches
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33
Q

What are U.T.P. connectors called?

A

Registered Jack

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34
Q

What are the properties of RJ 11 U.T.P.s?

A

6 pole 4 conductor bus paralleled

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35
Q

What are the properties of RJ 12 U.T.P.s?

A

6 pole 4 conductor straight thru (no sharing)

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36
Q

What are the properties of Ethernet RJ 45s?

A

8 pole 8 conductor

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37
Q

Explain Simplex Communication systems?

A
  • Info is sent in 1 direction only
  • Source to receiver
  • ex: broadcast radio
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38
Q

Explain Half Duplex Communication systems?

A
  • Info is sent in both directions but only 1 at a time
  • each direction shares a common channel
  • ex: Two-way radios
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39
Q

Explain Full Duplex Communication systems?

A
  • Info is sent in both directions at same time
  • Two channels required, 1 for each direction
  • ex: Telephone system
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40
Q

What is a Decibel (dB) ?

A

a ratio with a logarithmic (exponential) scale. Sound level, voltage and power levels are often compared using dB’s

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41
Q

What is Thermal Noise? (atmospheric noise, cable noise, receiver noise)

A

Random electron movement thru any conductive materials with ohms creates random voltages at random frequencies

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42
Q

What is thermal noise directly proportional to?

A

Temperature and has a flat frequency response

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43
Q

All frequencies with equal amplitude = ?

A

White noise

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44
Q

Explain Slope?

A

In regards to frequency response, all cables will have more attenuation (losses) at higher frequencies

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45
Q

What do some amplifiers have to compensate and provide more gain at higher frequencies?

A

Slope Adjustment

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46
Q

What is Signal to Noise ratio?

A

the ratio in dB of signal to noise

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47
Q

What must analog systems have in regards to Signal to Noise?

A

Signal to noise ratio must be very good or noise is noticeable

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48
Q

Explain signal to noise ratio in digital systems

A

Signal to Noise ratio can be lower because the receiver need only determine 1s and 0s

49
Q

What does a very poor SNR result in?

A

High bit error rate (BER) and causes signal dropouts/pixelation

50
Q

What are splitters/combiners?

A

Coax (unbalanced) signals are split into multiple receivers (transmitters can be combined thru the same units)

51
Q

What power would you expect for a 1 into 2 splitter?

A

1/2 power to each outlet

52
Q

What should you do if using a splitter with more outlets than required?

A
  • Terminate unused outlets with a 75 ohm termination
53
Q

What is automatic gain control?

A

Receivers have automatically adjustable amplifiers in their circuitry to compensate for reasonable variances in signal power

54
Q

What will happen if you add a splitter to an automatic gain control?

A

AGC will increase

55
Q

What will happen if you amplify the signal in automatic gain control?

A

AGC will decrease

56
Q

What must automatic gain control systems be ‘balanced’ with? Why?

A

Must be balanced with amplifiers or power continuation devices (PADs) to supply signal strength towards the center of the AGC range

57
Q

What are the 6 types of physical topologies?

A
  1. Linear Bus
  2. Star Network
  3. Ring
  4. Tree
  5. Mesh
  6. Hybrid
58
Q

Linear Bus Advantages and Disadvantages?

A

Adv: Easily disconnect nodes without disrupting service
DIsadv: Not reliable if trunk cable is down everyone is down

59
Q

Star Network Adv. & disadv. ?

A

Adv: Easy to add additional devices with no service interruption
Disadv: Hub represents a single point of failure, not reliable

60
Q

Ring Adv & Disadv?

A

Adv: performs better under heavy network load & server does not need to manage connectivity to each device
Disadv: 1 bad workstation & system is down. Making any changes will affect network operation

61
Q

Tree Adv & Disadv?

A

Adv: easy to add more nodes, reliable network and some level of redundancy with multiple servers
Disadv: overall length of each segment limited to 100m, more difficult to wire than other topologies

62
Q

Mesh Disadv ?

A

Expensive to have this if it is a physical connection

63
Q

What is a hybrid topology?

A

a combination of two or more topologies

64
Q

What are the two types of protocol?

A
  1. Ethernet

2. Token Ring

65
Q

What are some advantages of Fibre Cable?

A
  • Operate at high speeds
  • Large carry capacity
  • Signals can be transferred further
  • Immune to RFI & EMI
  • Light weight
  • Costs much less to maintain
66
Q

What are single-mode characteristics?

A
  • Narrow Core
  • Higher bandwidth for long distances
  • More expensive than multi-mode and more difficult to terminate
  • 5.8 micron glass core
  • Uses lasers
67
Q

Multi-mode characteristics?

A
  • Wider core or more fibres
  • Higher bandwidth for shorter distances
  • In long runs, multiple light pulses (modes) can distort and deliver incomplete data
  • 60 micron glass core
  • uses LEDs
68
Q

25 Pair cable colour codes:

A

5 Tip colours : White, red, black, yellow, violet

5 Ring colours: blue orange green brown slate (grey)

69
Q

What is I.D.C. and what is it considered?

A

Insulation Displacement Connector

Considered gas proof

70
Q

What are normal voltages for POTS?

A

On hook = 48 VDC
Off hook = approx. 9 VDC
Ringing = approx. 90-110 VAC

71
Q

How many cables max for velcro straps? Why?

A

15-20 to avoid crosstalk

72
Q

Tips for using conduit?

A
  • 100’ max between pull points
  • Two 90° bends between pull points
  • Ream Conduit
  • Insulated bushings
  • Must have pull strings or ropes
  • 40% fill max
  • Firestop may be required
73
Q

Cable tray tips:

A
  • 50% max fill
  • Access important, 1’ above required
  • Metal trays bonded to ground
74
Q

Cable placement tips:

A
  • 25 lbs-ft max
  • Bend radius = 10x diameter multipair, 4x diameter horizontal
  • 3” from power sources
  • leave 18” at outlets and connection points
75
Q

What are the types of punchdown blocks?

A
  • 66 type
  • 110 type
  • BIX type
76
Q

How much should you untwist conductors for cat5e and cat6?

A

1/2” max for cat5e

1/4” max for cat6

77
Q

what is the most popular punchdown block?

A

110 type

78
Q

What block is used when space is an issue?

A

BIX type

79
Q

What is BLOGB?

A

colour identification for 8 conductor cable

Blue, Orange, Green, Brown

80
Q

What is Permanent Link testing?

A

(basic link) cable run from cross-connect or patch panel to work area outlet

81
Q

What is Channel Testing?

A

tests not only the cable, but all hardware, patch cords, cross-connect wiring, etc..

82
Q

Explain Certification testing for length? What test tool is used?

A
  • 568 cables must be less than 90m in link and 100m in channel
  • Done with a “time Domain Reflectometer”
  • Tester sends out a pulse, waits for an echo and measures the time it took for the trip
83
Q

Explain an Attentuation test?

A

measures the signal loss from one end of the link to the other, the smaller the dB the better

84
Q

Explain a crosstalk test?

A
  • Measured at both ends (NEXT & FEXT), larger the dB the better
85
Q

What is crosstalk? What helps prevent this?

A
  • Unplanned transfer of data from one pair to another
  • twist rates help prevent within cable
  • shielding helps prevent between cables
86
Q

What is Attentuation to Crosstalk ratio?

A

measurement of how much more signal than noise exists in the link
larger the dB the better

87
Q

What is some essential info for cabling install?

A
  • Plans
  • Entrance facilities
  • Equipment rooms
  • Telecom closets
  • Telecom equipment
  • Spaces and pathways
  • Work area outlets
88
Q

What division are telecom specs in?

A

16 and possibly 17

89
Q

When should conduit be used?

A
  • When required by code
  • If outlet boxes are permanent
  • Cable security required
90
Q

What is an Inner/Subduct?

A

Non-metallic pathway within a pathway

91
Q

What are some types of cable trays?

A
  • Ladder cable tray
  • Basket tray
  • Rollout tray
92
Q

What are some underfloor systems?

A
  • Underfloor duct embedded in concrete
  • Cellular floor
  • Raised access floor
  • Ceiling pathway
93
Q

What are some methods of supporting cables?

A
  • J-hook
  • Plywood backboards
  • Tywraps
  • Velcro
94
Q

What connector does LAN use?

A

BNC (bayonet mount)

95
Q

In power of ethernet, what is the max amps per conductor?

A

1.3A

96
Q

what is PSE?

A

Power sourcing equipment

97
Q

what is PD?

A

Powered device

98
Q

What are the 5 purposes of Security systems?

A
  1. Deterrence
  2. Prevention
  3. Detection
  4. Response
  5. Apprehension
99
Q

What are the 3 categories of the Onion Skin Approach of security and their properties?

A
  1. Perimeter Protection - Door contacts, Beam break
  2. Space Protection - Motion detectors, the “back-up”
  3. Spot Protection - Last line of protection, placed around the object (lock)
100
Q

What does Power over Ethernet allow?

A

Allows appliances to receive power as well as data over existing LAN cabling

101
Q

What is Central Equipment in Nurse Calls? what does it house?

A

Brain of the system

Houses programming and cct boards, power supplies and terminal blocks

102
Q

What is the Dome light?

A

Visual annunciation just outside the room requiring assistance

103
Q

What is a zone lamp?

A

in hallway to direct nurse to room requiring assistance

104
Q

What are the different priority levels and their properties?

A 
High = Flashing red or blue, 60 PPM, code blue
Medium = Flashing white, 30 PPM, toilet shower etc..
Low = Steady white, 6 PPM with tone every 10s, patient station
105
Q

What are some different kinds of detectors for security?

A
  • Magnetic Contacts
  • Passive Infrared
  • Microwave Detectors
  • Dual Tech Devices
  • Photoelectric Beam detectors
  • Glass breaks
  • Shock sensors
106
Q

What are the two styles Magnetic Contacts come in?

A
  • Surface mount and Recessed
107
Q

What are some advantages and disadvantages or PIRs?

A
  • Very versatile
  • Quad element PIR will eliminate false alarms
  • Has hazards for false alarms such as heaters, reflective glass, sources of whitelight
108
Q

Advantages and Disadvantages of Microwave Detectors?

A 
Advantages: 
- sense motion towards the detector
- longer range than PIR
- Unaffected by ambient conditions
Disadvantages:
- Subject to interference from other microwaves
- sensitive to flouresent lights
- Must adjust range so they dont look for movement outside
109
Q

Explain Dual Tech detectors?

A
  • rely on two sensing methods

- Majority Microwave/PIR

110
Q

What is the most common intrusion circuit?

A

closed loop

111
Q

What type of supervision does the closed-loop provide?

A

open-circuit supervision

112
Q

What happens if the loop is shorted in a closed loop application?

A

it will not detect an alarm as the contacts have been bypassed

113
Q

what are the 4 basic closed-loop circuits?

A
  1. Two-wire
  2. two-wire with EOL
  3. Four wire
  4. Four wire ULC
114
Q

What is commonly used in lower security applications such as residential alarms? Why?

A

Two-wire as it provides only partial supervision and are easily defeated

115
Q

What is popular in higher-security applications such as commercial buildings?

A

Two-wire with EOL

116
Q

What is the four-wire loop also called?

A

double circuit or HI/LO loop

117
Q

How are the loops wired and is there current in its secure position? When is the four-wire loop most used?

A

HI loop is +
LO loop is -
no current flow in secure position
Most used in installations using window foil

118
Q

What is the four-wire ULC recognized as and by who?

A

High-level security by the Underwriters Laboratories of Canada

119
Q

What must the contacts be in a four-wire ULC system?

A

must be Form C which = SPDT, with N.O. and N.C. contacts

Electrical - Level 4 (8 decks)

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