electrical Flashcards
(52 cards)
1
Q
- phenomenon; manifestation
- Principally made up of atoms (electron, proton, neutron)
A
Electricity
2
Q
2 General Classes
A
Dynamic and Static
3
Q
flow in an electric circuit
A
ELECTRIC CURRENT
4
Q
- Flows in one direction (- to +)
- Uniform in strength
- Battery/dry cell
2 types: continuous/pulsating (fluctuating)
A
DIRECT CURRENT (DC)
5
Q
- Reverses direction of flow at regular intervals
- Reverses in direction
- Frequency: 60 cps (60 Hertz)
- Phase: SP/3P
- 230VAC, 60Hz, SP
A
ALTERNATING CURRENT (AC)
6
Q
- Fixed polarity
- Steady (continuous)
- Varying in magnitude (fluctuating)
- Steady value
- Easier to MEASURE
- 1.5 VOLTS
A
DIRECT CURRENT (DC)
7
Q
- Reverse Polarity
- Varies between reversal
- Stepped up or down
- Easier to AMPLIFY
- 110 VOLTS
A
ALTERNATING CURRENT (AC)
8
Q
Path for electric current w/ EMF applied
A
ELECTRIC CIRCUIT
9
Q
Force which causes movement of electricity in a conductor
A
Electromotive Force (EMF)
10
Q
Electrical layout
A
Circuit Diagram
11
Q
Broken, incomplete, disconnected
A
Open Circuit
12
Q
Complete; Continuous path
A
Close Circuit
13
Q
Bridging
A
Short Circuit
14
Q
Circuit branching
A
Shunt
15
Q
Relationship of EMF, Current, Resistance
A
OHM’s LAW
16
Q
Current (Amperes)
A
I
17
Q
EMF (Volts)
A
V
18
Q
Resistance (Ohms)
A
R
19
Q
EMF; pressure or force; Voltmeter
A
Voltage (Volts)
20
Q
Inherent in wires (conductor); Ammeter
A
Amperes (Amps)
21
Q
Current-carrying capacity (w/o undue heating)
A
Ampacity
22
Q
Friction; inherent in insulator/Ohmmeter
A
Ohms
23
Q
Does not consume electricity
A
DEVICE
24
Q
Rate of power; power consumption;
A
WATT
25
Any one time
Watt Meter
26
periodic; KWH Meter/
Watt-Hour Meter
27
AC generator
ALTERNATOR
28
M.E to E.E.
GENERATOR
29
E.E. to M.E.
MOTOR
30
Electrochemical; electrolysis
BATTERY
31
Nonrenewable
Primary
32
Lines that run along highways and major roads
1500+ customers restored
Ciscuit
32
The source of electricity
Generating station
32
Rechargeable
Secondary
32
High voltage power lines that run cross country
25000+ customers restored
Transmission lines
32
Distribute power to several circuits
Up to 6000 customers restored
Substation
33
These serve smaller groups of customers and neighborhoods from the main circuits
50+ customers restored
Tap Lines
33
Reduces power to usable voltage levels
1-8 customers restored
Individual Transformers
34
Power supplied to a building through a service entrance. Three
heavy wires (drop), extend from utility pole overhead wires are
fastened to the structure and spliced to service entrance wires that enter a conduit through a service head; rigid conduit must
be used
SERVICE ENTRANCE (SE - AERIAL)
35
Three wires are placed in a rigid conduit. An underground
service conduit is brought to the meter socket. An USE includes
a watt- hour meter, main breaker, and lightning protection.
UNDERGROUND SERVICE ENTRANCE (USE)
36
Offers low resistance
Conductors
37
Prevents flow of electric current
Insulators
38
Channel
Raceways
39
Delivered through a distribution panel, or service panel.
SERVICE DISTRIBUTION
40
READ
SYSTEM COMPONENTS OF BUILDING
Category 1. WIRINGS AND RACEWAYS
Conductors – offers low resistance
Insulators – prevents flow of electric current
Raceways - channel
Category 2. POWER HANDLING EQUIPMENTS
Transformer, Switchboard/Switchgear, Panel board, Service
Switch/Safety Switch, Circuit Breaker/Fuse
SERVICE DISTRIBUTION – delivered through a distribution panel, or service panel.
Category 3. UTILIZATION EQUIPMENTS – actual use
Fixtures, Switches, Convenience Outlets, Branch Circuits
41
From the distribution panel, electricity is routed to the building
through branch circuits. Each circuit delivers electricity to a
limited number of outlets or devices and protected with a circuit
breaker.
BRANCH CIRCUITS
42
Branch circuits are divided into three types by the PEC:
lighting circuits
small-appliance circuits
individual circuits
43
underfloor raceway
- conventional installation
cellular metal floor raceway – rib decking/raised floor system
cellular concrete floor raceways – T-joist/ precast concrete slab with built in pipes
Floor Raceway
44
- Power and Control Tray
- Cable (TC)
- Busbar
- Cable bus
Ceiling Raceway
45
H-frame – 1000 kva
Cluster mounted – 225 kva
Pad mounted – 120V to 240V
Outdoor Transformers
46
voltage to voltage
TRANSFORMER
47
READ
Dry Type – pad mounted; switchboard
Askarel – synthetic non-flammable liquid
Oil-insulated – for transformer vault
Transformer Rating: stepped up/stepped down
