What percentage of load on the ungrounded conductors is used to figure a feeder or service neutral load for ranges and ovens?

For ranges and ovens, the National Electrical Code (NEC) specifies that the feeder or service neutral load should be calculated based on 70 percent of the load on the ungrounded conductors. This guideline is derived from the understanding that not all cooking appliances will operate at their maximum capacity simultaneously, and they often have multiple circuits that can share the load efficiently.

By applying this percentage, electricians can size the neutral conductors appropriately, minimizing the risk of overloading the system while ensuring safety and compliance with electrical codes. This approach reflects the typical operational characteristics of these appliances, making it a critical aspect of electrical planning for residential settings.

Understanding this calculation not only aids in load management but also ensures that the residential wiring system is capable of handling the expected electrical demands without unnecessary strain or risk of circuit failures.