PEC 2

Common types:

(1.) 240/120V. Single-phase, 3 wire (2.) 4007230V (Or 480/277V), Three-phase, 4-wire

conductors on Poles

- 300 mm minimum, where not placed on racks or brackets - Horizontal climbing space:

DISTRIBUTION CENTER

- a point at which energy is divided among feeders or branch circuits or combination of both, and where over current devices are usually loaded.

Appliance Branch Circuit

- supplies energy to one or more outlets to which appliances) are to be connected. - Permanently connected lighting fixtures ONLY if part of an appliance

Multiwire Branch Circuit

- supplies only line-to neutral connected loads - Consist of two or more ungrounded conductors THAT HAVE a potential difference between them, and a Grounded conductor having equal potential difference between it and each ungrounded conductor of the circuit and which is connected to the neutral grounded) conductor of ihe system.

over 600V, open individual conductors

-14.0 mm? Copper or 22.0 mm? Aluminum over 600V, for cable - 8.0 mm? Copper or 14.0 mm? Aluminum

maximum permitted ampere rating

. Branch circuits shall be rated in accordance with the or setting of the overcurrent device.

600

. Running open wiring on insulators, MI or MC cable, messenger-supported wiring, conductors in raceway, and other approved means on the outdoor building surfaces is permitted for circuits operating at a maximum of volts nominal.

22.54KW

. The service feeder capacity necessary to provide six 5 kW household electric clothes dryer is

15A & 20A Branch Circuits

1. Lighting units, other utilization equipment, and/ or combination of both 2. One cord-and plug- connected utilization equipment * Maximum Rating (80%) of branch circuit ampere rating 3. Utilization equipment fastened in place *Maximum Rating (50% of branch circuit ampere rating)

From either circuit

100 mm minimum

up to 600VI up to 15m, (50 ft):

5.5 mm? (2.6 mm dia.) Copper or 8.0 mm? (dia) Aluminum up to 600v, onger than 15m (50 ft) - 8.0 mime Copper or 14.0 mm= Aluminum

80%

A 15A or 20A branch circuit shall be permitted to supply lighting units and other utilization devices. The rating of any one cord-and plug connected appliances shall not exceed a certain percentage of the branch circuit rating. What is this percentage?

nonlinear

A 3-phase, 4-wire, wye connected, power system used to supply power to loads may necessitate that the power system design allows for the possibility of high harmonic neutral currents.

line-to-neutral loads

A multiwire branch circuit shall supply only

outlet

A point in the wiring at which current is taken to be used in some equipment

SPACING & CLEARANCE

A. Open Conductor Spacing, 600V, Nominal or less B. From either circuit C. conductors on Poles

feeder

A__________________refers to the circuit conductor between the service equipment and the branch circuit over current device.

COMMUNICATION CONDUCTORS

Below Power Conductors - -same as power conductors -no requirement Alone- D. Clearance Above Ground E. Clearance Over Roofs, up to 600V F. Clearance From Building Openings G. Clearance From Fire Ladders H. Clearance From None-Building or None-Bridge Structures

POWER CONDUCTORS

Below communication Conductors ---750 mm (2.5ft) -Over 300 Y Alone or Above Communication Conductors 300V or less.----- ..--600 mm (2.0 ft) "Over 300V -750 mm (2.5 ft)

30

Bored holes in wood members, for cable or raceway-type wiring shall be bored so that the edge of the holes is not less than mm from the nearest edge.

90 deg C

Branch circuit conductors within 75 mm of ballast in a ballast compartment shall have a rated insulation temperature NOT Tess than what value?

300 mm

Communication wires and cable shall be separated by at least what distance from service drops of electric light and power conductors that are NOT installed in raceway or in a cable?

30A Branch Circuit

Fixed lighting units with Heavy duty lamp. holders in other than dwelling unit/s or utilization equipment in any occupancy one cord- and plug-connected utilization Equipment Maximum Rating: 80% of branch circuit ampere rating

Feeder Minimum Size

For specified Circuits Must NOT be less than 30 Amp where the load supplied consists of any of the following number and type of circuits: 1. Two or more 2-wire branch circuit supplied by 2-wire feeder 2. More than 2-wire branch circuits supplied by 3-wire feeder 3. Two or more 3-wire branch circuits supplied by 3-wire feeder 4. Two or more 4-wire branch circuits supplied by 3-phase, 4-wire feeder

one

In general, a building or other structure served shall be supplies by only service(s).

3 000

Open conductors on insulators shall be covered when they are within _________mm of a building.

900

Power conductors on poles, below communications conductors shall maintain a spacing distance of

600

Running open n wiring on insulators, maximum voltage s, messenger-supported wiring, conductors in raceway, and other approved means on the outdoor building surfaces is permitted for circuits operating at a maximum of volts nominal.

2 400 m

Service conductors shall have vertical clearance of not less than above the roof surface.

125%

The branch circuit conductors that supply one or more units of data processing systems shall have an percent of the total connected load. ampacity NOT more than

feeder

The circuit conductors between the service-entrance equipment or isolated generating plant and the branch circuit overload devices

55 A

The feeder conductor ampacity _______________the feeder conductors carry the total load supplied by service-entrance conductors with an ampacity of or less

200

The minimum feeder load allows for show-window lighting expressed in volt-amperes per linear foot shall be

125 %

The minimum feeder-circuit conductor size, before the application of any adjustment or correction factors, shall have an allowable ampacity not less than the non-continuous. load plus of the continuous load.

5 %

To provide reasonable efficiency of operation, the voltage drops for feeders exceeding at the farthest outlet of power, heating, and lighting loads, or combinations of such loads.

5 %.

Total voltage drop on both feeders and branch circuit to the farthest outlet to provide reasonable efficiency of operation shall not exceed

5 500

Voltage shall not exceed 600 volts between conductors. on branch circuits supplying only ballasts for electric-discharge lamps in tunneis with a height of not less than mm

14.00 mm square

What is the minimum size of aluminum or copper clad aluminum conductors. used as service entrance, conductors?

24 A

Where receptacles are connected to a 30A branch circuit, the maximum allowable cord-and plug connected load shall NOT be more than Amperes

25 A

Which of the following is not a standard classification for a branch circuit supplying several loads?

FESTOON LIGTHING

a string-ofoutdoor lights suspended between two points - in all spans exceeding In mi. the conductors shall be supported by messenger wire. The messenger wire shall be supported by strain insulators - its overhead conductors shall not be less than 3.5 m= ( 2.0 mm dia

Feeder

all circuit conductors between the service equipment, the source of separately derived system, or other power supply source and the final branch circuit overcurrent device

BRANCH CIRCUIT-CLASSIFICATION

classified in accordance with the maximum permitted ampere rating or setting of the branch circuit OCP: 15A, 20A, 30A, 40A. & 50A.

Outside Branch Circuits and Feeders

covers electric equipment and wiring for the supply of utilization equipment located on or attached tO the outside of public and private buildings. minimum-size of conductors, with overhead span of:

40A & 50A Branch Circuits

for dwelling units: Cooking appliances that are fastened in place in any occupancy (single/ multifamily)

Feeder Minimum Rating

not lower than required to supply the computed load and before the application of any adjustment or correction factors, shall have an allowable ampacity not less than the non-continuous load plus 125 % of the continuous load

Sub feeder

originate a distribution center other than the service equipment or generator switchboard and supply one or more other distribution panel boards, branch circuit panel boards, or branch circuit.

Open Conductor Spacing, 600V, Nominal or less

see T 2.30.4. 12 (c) page 151 PEC 2009

General Purpose Branch Circuit

supplies a number of outlets of (lighting land appliances

Individual Branch Circuit

supplies only ONE utilization equipment

BRANCH CIRCUIT

the circuit conductors between the final over current device protecting the circuit and the outlets

Recommended Basic Limitations on Voltage Drop

they are sized to prevent exceeding a 3 %,voltage drop @t the farthest outlet of power, heating, and lighting loads, or combination of such loads for reasonable efficiency of operation