E2 Services, Feeders, Branch Circuits 2

Question 1

What is the minimum ampacity required for a service entrance conductor supplying a single commercial occupancy with a calculated load of 175 amperes?

Accepted Answer

175 amperes

Answer

150 amperes

Answer

200 amperes

Answer

225 amperes

Question 2

Per NEC Article 230, how many sets of service entrance conductors are permitted to supply a single building from a single service drop?

Accepted Answer

Up to six sets under specific conditions

Answer

Only one set is always required

Answer

No more than two sets

Answer

Unlimited sets with POCO approval

Question 3

A commercial feeder supplies a panelboard with a total computed load of 92 amperes. What is the minimum conductor ampacity allowed?

Accepted Answer

92 amperes

Answer

90 amperes

Answer

100 amperes

Answer

110 amperes

Question 4

What NEC section governs the minimum size of branch circuit conductors for general lighting loads?

Accepted Answer

NEC 210.19

Answer

NEC 215.2

Answer

NEC 230.42

Answer

NEC 310.15

Question 5

A 120/240V, single-phase service for a commercial building requires a grounded (neutral) conductor. Per NEC 230.42, the neutral must have an ampacity of at least:

Accepted Answer

The full unbalanced load

Answer

Half the line conductor ampacity

Answer

The same ampacity as the largest ungrounded conductor

Answer

70% of the phase conductor ampacity

Question 6

Which wiring method is NOT permitted for service entrance conductors installed inside a building?

Accepted Answer

Open wiring on insulators through a dry area

Answer

Rigid metal conduit (RMC)

Answer

Electrical metallic tubing (EMT)

Answer

Type SE cable in a dry location

Question 7

For a 208Y/120V, 3-phase, 4-wire feeder with a computed load of 115 amperes per phase, what is the minimum ampacity for each ungrounded feeder conductor?

Accepted Answer

115 amperes

Answer

100 amperes

Answer

110 amperes

Answer

125 amperes