Where it is unlikely that two or more noncoincident loads will be in use simultaneously, which load value is used in computing the total load to a feeder?

• A. Smallest
• B. Largest
• C. Average
• D. Sum of all

Answer: (B)

When sizing a feeder, if several large loads aren’t expected to be on at the same time, you don’t add them all together. You use the largest single load to represent the peak demand. The idea is that those loads are mutually exclusive in practice, so the feeder only needs to be capable of at most that largest demand, not the sum of all possible loads. This keeps feeder sizing economical while still providing enough capacity for the worst-case single heavy load.

For example, if a feeder serves a water heater, a clothes dryer, and a range, and these loads aren’t anticipated to operate simultaneously, the feeder is sized based on the largest of those loads rather than the total of all three. Other smaller or continuous loads can be added as appropriate, but the peak demand is driven by the single largest load.