Journeyman Electrician Practice Exam

What is the demand load, in kW, on the ungrounded service-entrance conductors for a single 20,800 watt electric range?

1. 10.4 kW

2. 11.6 kW

3. 12.8 kW

4. 13.6 kW

The correct answer is: 11.6 kW

To determine the demand load on ungrounded service-entrance conductors for a single 20,800 watt electric range, one must use the appropriate demand factors stipulated in the National Electrical Code (NEC) or other relevant standards. Electric ranges are typically subject to demand calculations that consider the maximum load they can draw. For residential electric cooking appliances, the NEC allows for a demand factor that permits the calculation of a lower required service capacity than the total wattage. According to the NEC, for a single range, the maximum demand is usually calculated at 12 kW for the first 12 kW and then applies different factors at higher wattages. In this specific scenario, the full wattage of the range is 20,800 watts, which is equal to 20.8 kW. However, the demand calculation can be adjusted based on the code provisions, which typically apply a demand factor. A common demand factor used here is that the maximum first 12 kW is taken fully into account for demand, with a reduced factor for additional watts. Using the NEC demand factors: 1. The first 12 kW is considered at full demand (12.0 kW). 2. The remaining 8,800