Feeder and service loads for fixed electric space-heating loads shall be calculated at _____ percent of the total connected load.

• A. 90
• B. 100
• C. 110
• D. 120

Answer: (B)

The main idea is that fixed electric space heating is treated as a full-load responsibility for sizing feeders and services. Because these heaters can be on for long periods and may operate concurrently in cold weather, the calculation uses the total connected wattage at its full rating to ensure the service can handle the worst‑case demand. In other words, you sum the rated watts of all fixed space-heating equipment and use 100 percent of that value for feeder and service sizing. Other types of loads are often reduced by demand factors or diversity, but fixed heating is expected to approach its full load when needed, so no reduction is applied.