Download Electrical Level 3 Module 1: Load Calculations and Branch Feeder Circuits and more Exams Electrical Circuit Analysis in PDF only on Docsity!
Electrical Level 3 Module 1 Load
Calculations And Branch Feeder Circuits
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 motor full-load current for a motor with a nameplate rating of 50hp, 460V, 3Ø?
65A
What is the required circuit ampacity of a noncontinuous, single-phase load of 8.5kW at 277V?
30.69A
What is the required circuit ampacity for a noncontinuous, three-phase load of 6kW at 208V?
16.65A
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?
17.25A
What is the total load required by the NEC® for two appliance branch circuits plus a laundry branch circuit?
4,500VA
What is the voltage drop for a 120V, single-phase, two-wire branch circuit, 100' long, using copper conductors of 6,530 circular mils with a noncontinuous load of 13A? 5.14V
5.14V
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%?
No. 10
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?
Fastened-in-place utilization equipment
