Electrical Level 3 Module 1 Load Calculations and
Branch Feeder Circuits Q
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? - 3
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)? - 225%
Conductors must be derated when installed in conduit - on or above rooftops
Continuous loads are calculated at what percentage of the maximum current rating of the overcurrent
device? - 80%
For a given load and length, the branch circuit voltage drop should not exceed - 3%
For resistance welders, the rating for the overcurrent protection device should not exceed what
percentage of the primary current rating of the welder? - 300%
Show window lighting is calculated at 200VA per linear foot plus - 125%
The allowable ampacity for eleven No. 12 THHN copper conductors in a cable must be adjusted by -
50%
The load for 10' of multi-outlet assembly used to supply several loads simultaneously is - 1,800VA
The maximum size dual-element fuse for a 40hp, 3Ø, 460V motor with a Design Letter D is - 100A
What is the demand load for one household range with a nameplate rating of 11.75kW, 240V, 1Ø? -
8kW
What is the current-carrying capacity for No. 6 THWN aluminum conductors in conduit run through an
ambient temperature of 38°C? - 44 Amps
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 - 13.75A
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' - 63.55'
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'? - 93'
