NJATC Load Calculations 2 ā Questions and Answers
Question 1: Per NEC 220.44, what demand factor may be applied to receptacle loads in office buildings that exceed 10,000 VA?
- 100%
- 75%
- 50% (Correct answer)
- 25%
Correct answer: 50%
NEC 220.44 permits a 50% demand factor for receptacle loads in excess of 10,000 VA in commercial occupancies such as office buildings.
Question 2: What is the required calculated load per linear foot of show window lighting per NEC 220.14(G)?
- 100 VA
- 150 VA
- 200 VA (Correct answer)
- 250 VA
Correct answer: 200 VA
NEC 220.14(G) requires 200 VA per linear foot of show window when calculating lighting loads for retail display windows.
Question 3: At what percentage of the continuous load must branch circuit conductors and overcurrent devices be rated per NEC 210.20(A)?
- 100%
- 110%
- 125% (Correct answer)
- 150%
Correct answer: 125%
NEC 210.20(A) requires branch circuit conductors and OCPDs to be rated at not less than 125% of the continuous load.
Question 4: Which formula correctly calculates true power (watts) in a three-phase circuit?
- P = V Ć I
- P = V Ć I Ć 1.732
- P = V Ć I Ć 1.732 Ć PF (Correct answer)
- P = VĀ² / R
Correct answer: P = V Ć I Ć 1.732 Ć PF
Three-phase true power equals line voltage Ć line current Ć ā3 (1.732) Ć power factor.
Question 5: What simplified NEC calculation method can be used for dwelling unit service sizing as an alternative to the standard method?
- Abbreviated Load Method
- Optional Calculation per NEC 220.82 (Correct answer)
- Simplified Feeder Method
- Reduced Demand Method
Correct answer: Optional Calculation per NEC 220.82
NEC 220.82 provides an Optional Calculation that simplifies residential service sizing using a general load per square foot plus specific appliance loads.
Question 6: Per NEC 220.61(B)(1), at what percentage of the ungrounded conductor load may the neutral load for household ranges be calculated?
- 100%
- 85%
- 75%
- 70% (Correct answer)
Correct answer: 70%
NEC 220.61(B)(1) allows the neutral load for household ranges, wall ovens, and cooktops to be calculated at 70% of the ungrounded conductor load.
Question 7: What is the minimum volt-ampere load that must be calculated per NEC 220.14(I) for each general-purpose receptacle outlet in a dwelling unit?
- 90 VA
- 120 VA
- 150 VA
- 180 VA (Correct answer)
Correct answer: 180 VA
NEC 220.14(I) requires 180 VA per receptacle outlet when calculating general-purpose receptacle loads in a dwelling unit.
NJATC Load Calculations 2
Per NEC 220.44, what demand factor may be applied to receptacle loads in office buildings that exceed 10,000 VA?