Electrical Power Distribution
Forms of Energy
All forms of energy fall under two categories
POTENTIAL
KINETIC
Stored energy or energy
of position
(gravitational)
Energy of motion (motion of waves,
electrons, atoms, molecules, and
substances)
Work
Work is done when a force that is applied to
an object moves that object. The work is
calculated by multiplying the force by the
amount of movement of an object (W = F * d).
Power
Electrical Power is measured in
Watts (W) or kWatts (kW)
W = joule per second
Power Generation
Power Transmission Lines
Power Generation and Transmission
Electrical Systems
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Incoming Service - Power
Switchgear / Distribution Equipment
Feeders
Grounding
Motor Br. Branch/Equip. Connect
Emergency Generators / ATS / UPS
Lighting Fixtures / Lighting Control
Devices - Lighting
Devices - Power
Lighting Branch
Power Branch
Fire Alarm System
Site Lighting
Telephone / Data Conduit
Incoming Service - Telephone
Electrical Terms
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Utility Power XFMR
Switchboard
Panelboard
Motor Control Center
Disconnect Switch
Transformer
Circuit Breaker
Feeder
One-Line Diagram
Equipment Connection
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Branch Circuit
Homerun
Receptacle
Switch
Automatic Transfer Switch
Generator
UPS
Electrical Symbols
Service Equipment
 Service equipment is the electrical equipment that
constitutes the main control and means of power cutoff to
the electric service (normally Power Company supply)
brought into the building.
10
Incoming Service - Power
 All buildings have an electrical service.
 Primary service (utility company) is shown on the one-line
diagram.
 A utility transformer is installed outside the building on a
pad (site drawing) or pole.
11
Incoming Service - Power
12
Incoming Service - Power
13
Common Electrical Distribution Systems
14
Common Electrical Distribution Systems
Common Electrical Distribution Systems
Common Electrical Distribution Systems
Common Electrical Distribution Systems
Common Electrical Distribution Systems
1φ2W, 240 Vac
1φ3W, 120/240 Vac
3φ3W, 240 Vac
3φ3W, 240 Vac corner ground delta
3φ4W, 208Y/120 Vac
3φ4W, 480Y/277 Vac
3φ3W, 480 Vac
3φ4W, 600Y/347 Vac
3φ3W, 600 Vac
2W, 250 Vdc
3W, 125/250 Vdc
120 x 3 = 208 V
277 x 3 = 480 V
Residential Power Distribution
Commercial and Industrial Power Distribution
Utility Primary Transformer
In-Coming Service - Power
23
Carpenters International Training Fund
Program 3 – 8
Feeders
Incoming Service – power feeders
24
One-Line Diagram
Power Distribution System Equipment
Power Distribution System Equipment
Switchboard
30
Main Distribution Board (MDB)
Main Distribution Board (MDB)
32
Main Switchboard (MSB)
Switchboard
Incoming Section
Meter Main Section
Distribution Section
Circuit Breakers
Fusible Switches
Grounding
Bonding
Switchboard
Incoming Section
Meter Main Section
Distribution Section
Circuit Breakers
Fusible Switches
Grounding
Bonding
In-Coming Service - Power
Incoming Section
Meter Main Section
Distribution Section
Circuit Breakers
Fusible Switches
Grounding
Bonding
Switchboard
Incoming Section
Meter Main Section
Distribution Section
Circuit Breakers
Fusible Switches
Grounding
Bonding
Switchboard
Incoming Section
Meter Main Section
Distribution Section
Circuit Breakers
Fusible Switches
Grounding
Bonding
Switchboard
Incoming Section
Meter Main Section
Distribution Section
Circuit Breakers
Fusible Switches
Grounding
Bonding
Switchboard
Incoming Section
Meter Main Section
Distribution Section
Circuit Breakers
Fusible Switches
Grounding
Bonding
Switchboard
Incoming Section
Meter Main Section
Distribution Section
Circuit Breakers
Fusible Switches
Grounding
Bonding
Panelboard
42
Panelboard
MCB
MLO
43
Panelboard
Panelboards
Lighting, appliances, motor/equip
Main Breaker
Enclosed
Disconnect
Primary
Transformer
[480/277V 3ϕ 4W]
Power
Panelboard
Step-Down
Transformer
[120/208V 3ϕ 4W]
44
Panelboard
45
Motor Control Center (MCC)
Safety Switch - Disconnect Switch
Fusible or Non Fusible
250V or 600V
2 Pole or 3 Pole
30A
60A
100A
200A
400A
600A
800A
1200A
Disconnect Switch
4 & 6-Pole Heavy Duty Safety Switches
Two-speed, two-winding motors
4-pole switches are also used in 3-phase, 4-wire circuits when
a switching neutral is required.
49
Disconnect Switch
Five Guys Burgers and Fries
Accubid Office Building
12
1
4
5
1
4
12
1
3
3
4+1=5
5
9
1
12
4
12
1
3
3
4+1=5
5
9
1
12
4
12
5
1
3
3
4+1=5
5
9
1
12
4
12
1
4
5
1
3
3
4+1=5
5
9
1
1
1
1
1
4
5
1+3
1
3
1
1
1
3
4
4
1
12
4
12
4
4
1
1+1
3
4
4
Accubid Office Building
ACCUBID OFFICE BUILDING
WIRE POWER TERMS – BRANCH CIRCUITS AND MOTORS (Panel Schedule and Motor Schedule)
PNL HB1
Branch Circuits
(8) 20A 1P
(10) #12
(3) #10
H
6#12
N
2#10
G
1#12
2#12
1#10
1#12
H
H
H
N
H
H
H
N
G
Maximum Number of Conductors in a ½" EMT Conduit = (9) #12
NEC Annex C, Table C.1
Accubid Office Building
ACCUBID OFFICE BUILDING
WIRE POWER TERMS – BRANCH CIRCUITS AND MOTORS (Panel Schedule and Motor Schedule)
PNL H1
Branch Circuits
(8) 20A 1P
Motor and Equip
FPB
3#10, #12 G
x8
UH-1
3#12, #12 G
x1
H
6#12
N
2#10
G
1#12
2#12
1#10
1#12
(10) #12
(3) #10
Accubid Office Building
ACCUBID OFFICE BUILDING
WIRE POWER TERMS – BRANCH CIRCUITS AND MOTORS (Panel Schedule and Motor Schedule)
PNL H1
Branch Circuits
(8) 20A 1P
H
6#12
N
2#10
G
1#12
2#12
1#10
1#12
Motor and Equip
FPB
3#10, #12 G
x8
(8) #12
(24) #10
UH-1
3#12, #12 G
x1
(4) #12
(22) #12
(27) #10
(10) #12
(3) #10
Accubid Office Building
ACCUBID OFFICE BUILDING
WIRE POWER TERMS – BRANCH CIRCUITS AND MOTORS (Panel Schedule and Motor Schedule)
PNL L1
Branch Circuits
(45) 20A 1P
Motor and Equip
70A 2P 22/24
50A 2P 26/28
WH-1
E3.1
2#12, #12G
Accubid Office Building
ACCUBID OFFICE BUILDING
WIRE POWER TERMS – BRANCH CIRCUITS AND MOTORS (Panel Schedule and Motor Schedule)
PNL L1
Branch Circuits
(45) 20A 1P
Motor and Equip
70A 2P 22/24
50A 2P 26/28
WH-1
E3.1
2#12, #12G
H
6#12
N
2#10
G
1#12
3#12
1#10
1#12
2#4, 1#8
2#8, 1#10
x7
(56) #12
(16) #10
(3) #8
(2) #4
(53) #12
(15) #10
Accubid Office Building
ACCUBID OFFICE BUILDING
WIRE POWER TERMS – BRANCH CIRCUITS AND MOTORS (Panel Schedule and Motor Schedule)
PNL HT (H2, H3, & H4)
Branch Circuits
(5) 20A 1P
H
5#12
Motor and Equip
FPB
3#10, #12 G
x7
(7) #12
(21) #10
EF-1
3#12, #12 G
x1
(4) #12
(17) #12
(23) #10
N
2#10
G
1#12
(6) #12
(2) #10
Accubid Office Building
ACCUBID OFFICE BUILDING
WIRE POWER TERMS – BRANCH CIRCUITS AND MOTORS (Panel Schedule and Motor Schedule)
PNL LT
Branch Circuits
(11) 15A 1P
Motor and Equip
WH-1
2#12, #12G
Accubid Office Building
ACCUBID OFFICE BUILDING
WIRE POWER TERMS – BRANCH CIRCUITS AND MOTORS (Panel Schedule and Motor Schedule)
PNL LT
Branch Circuits
(11) 15A 1P
Motor and Equip
WH-1
20A 2P
2#12, #12G
(16) #12
(4) #10
H
6#12
N
2#10
G
1#12
5#12
2#10
1#12
(13) #12
(4) #10
Accubid Office Building
Takeoff: Distribution
Accubid Office Building
Takeoff: Distribution
Accubid Office Building
Takeoff: Distribution