ELECTRICAL LEVEL 3 M ODULE 1 LOAD
CALCULATIONS AND BRA NCH FEEDER
CIRCUITS QUESTIONS AND ANSWERS
WITH SOLUTIONS
Question :What is the demand load for one household range
with a nameplate rating of 11.75kW, 240V, 1Ø?
Correct answer:8kW
Question :What is the lighting load on a 120V circuit for six
100W incandescent lights and four fluorescent fixtures with a ballast rating of 1.5A, all operating continuously for 8 hours per day? 13.75A
Correct answer:13.75A
13.75A
Question :What is the load center distance for a 208V, four-
wire, three-phase branch circuit with fixed noncontinuous loads from the source of 60A at 45', 40A at 60', 30A at 75', and 25A at 100'
Correct answer:63.55'
63.55'
Question :What is the load center length for a branch circuit
consisting of noncontinuous loads of 125A at 80', 75A at 110', and 50A at 100'?
Correct answer:93'
93'
Question :What is the load center length for a branch circuit
with noncontinuous loads of 20A at 60' and 50A at 125'?
Correct answer:106.43'
106.43'
Question :What is the load for 55' of show window using the
linear foot method?
Correct answer:13,750VA
13,750VA
Question :What is the motor full-load current for a motor
with a nameplate rating of 50hp, 460V, 3Ø?
Correct answer:65A
65A
Question :What is the required circuit ampacity for a
noncontinuous, three-phase load of 6kW at 208V?
Correct answer:16.65A
16.65A
Question :What is the total ampacity for a 120V branch
circuit consisting of four duplex receptacles rated noncontinuous duty and six duplex receptacles rated continuous duty?
Correct answer:17.25A
17.25A
Question :What is the total load required by the NEC® for
two appliance branch circuits plus a laundry branch circuit?
Correct answer:4,500VA
4,500VA
Question :What size copper conductor would be required for
a 240V, 1Ø circuit supplying a noncontinuous load of 27.5A at a distance of 145', and a maximum voltage drop of 3%?
Correct answer:No. 10
No. 10
Question :When connected to 15A or 20A multi-outlet
general-purpose branch circuits, which of the following shall not exceed 50% of the branch circuit ampere rating?
Correct answer:Fastened-in-place utilization equipment
Fastened-in-place utilization equipment
Question: According to the NEC®, the ampacity of branch
circuit conductors must be derated when there are more than how many current-carrying conductors in a raceway?
Correct answer: 3
Question: Air conditioning overcurrent protective devices
can never exceed what percentage of the motor-rated load current or the branch circuit selection current (whichever is greater)?
Correct answer: 225%
Question: When must conductors be derated when installed
in conduit?
Correct answer: On or above rooftops
Question: At what percentage of the maximum current rating
of the overcurrent device are continuous loads calculated?
Correct answer: 80%
Question: For a given load and length, what should the
branch circuit voltage drop not exceed?
Correct answer: 3%
Question: For resistance welders, what should the rating for
the overcurrent protection device not exceed as a percentage of the primary current rating of the welder?