CEP CEP Power Systems & Distribution

Question 1

In a 3-phase, 4-wire wye system operating at 208/120V, what is the voltage measured between any two hot legs?

Accepted Answer

208V

Answer

120V

Answer

240V

Answer

277V

Question 2

A distribution transformer rated 75 kVA at 480V–208/120V is loaded to 80% of capacity. What is the approximate load in amperes on the secondary 208V side?

Accepted Answer

208A

Answer

180A

Answer

240A

Answer

277A

Question 3

What is the primary purpose of a distribution panel's main bonding jumper in a service entrance?

Accepted Answer

To connect the neutral (grounded) conductor to the equipment grounding system

Answer

To limit short-circuit current

Answer

To provide surge protection

Answer

To balance the load across phases

Question 4

When sizing a feeder for a 3-phase motor load, the continuous load must be multiplied by what factor per NEC 215.2?

Accepted Answer

125%

Answer

100%

Answer

115%

Answer

150%

Question 5

A high-leg delta (wild leg) service has three phases. Which color identifies the high leg per NEC 230.56?

Accepted Answer

Orange

Answer

Blue

Answer

Yellow

Answer

Red

Question 6

In power distribution, what does the term 'demand factor' refer to?

Accepted Answer

The ratio of maximum demand to the total connected load

Answer

The efficiency rating of a transformer

Answer

The power factor of the overall system

Answer

The ratio of reactive to real power