Journeyman Electrician Exam (NEC)Equipment and DevicesMedium
A journeyman electrician is designing an electrical system for a new commercial kitchen. The kitchen includes multiple fixed electric cooking appliances. What is the demand factor that can be applied to four fixed electric cooking appliances rated 4 kW or more each, according to NEC Table 220.55?
- A40%
- B20%
- C65%
- D30%
Show answer & explanationAnswer & explanation
Correct answer: C. 65%
According to NEC Table 220.55, for four fixed electric cooking appliances rated 4 kW or more each, Column C (for three or more appliances) is used. For 4 appliances, the demand factor is 65%.
Why the other options are wrong
- A. This percentage is not directly applicable for four appliances in Column C of Table 220.55.
- B. This percentage is for a single appliance not exceeding 12 kW.
- D. This percentage is for a single appliance over 12 kW through 27 kW.
Fixed Cooking Appliance Demand Factors
Percentages applied to the total connected load of fixed electric cooking appliances to determine the demand load for service and feeder calculations, as per NEC Table 220.55.
- Used to avoid oversizing electrical systems due to diversity of use.
- Factors vary based on the number of appliances and their individual ratings.
- NEC Table 220.55 provides the specific demand factors.
Memory trick: Table 220.55: Cook up your demand, don't over-plan!