Journeyman Electrician Exam (NEC)Services, Feeders, and Branch CircuitsMedium
A dwelling unit has a 240V, 8 kW electric range. What is the calculated demand load in amperes for this range, assuming only one range is installed?
- A40 amperes
- B25 amperes
- C33.3 amperes
- D30 amperes
Show answer & explanationAnswer & explanation
Correct answer: C. 33.3 amperes
According to NEC Table 220.55, Column C, for a single household electric range rated 8 kW, the demand factor is 8 kW. The current is calculated as I = P/V = 8000 W / 240 V = 33.33 amperes.
Why the other options are wrong
- A. 40 amperes is too high; it might be considered an overestimation.
- B. 25 amperes is too low; it might be mistaken for other appliance calculations.
- D. 30 amperes is incorrect; the calculation yields a different value.
Electric Range Demand Load
For household electric ranges, the demand load is determined by NEC Table 220.55, which provides a demand factor based on the nameplate rating and number of ranges, then converted to amperes.
- NEC Table 220.55 is specifically for household electric cooking appliances.
- For ranges 12 kW or less, Column C is typically used for a single range.
- Demand load is converted to amperes using I = P/V.
Memory trick: Ranges need a table to shrink their power, then convert to amps.