Grouch
Senior Member
- Location
- New York, NY
The 2008 NEC, section 424.3(B), states the following:
Branch-Circuit Sizing. Fixed electric space-heating equipment shall be considered continuous load.
The 2020 NEC, section 424.4(B), states the following:
Branch-Circuit Sizing. The branch-circuit conductors for fixed electric space-heating equipment and any associated motors shall be sized not smaller than 125 percent of the load.
Why the change in language? Is it to give us flexibility to size the circuit breaker for a heater at 100%, if we know that the heater will be on for less than 3 hours / not a continuous load? But keep the wiring at 125%, to give us room to upsize the breaker later on in case the heater is then considered a continuous load?
Branch-Circuit Sizing. Fixed electric space-heating equipment shall be considered continuous load.
The 2020 NEC, section 424.4(B), states the following:
Branch-Circuit Sizing. The branch-circuit conductors for fixed electric space-heating equipment and any associated motors shall be sized not smaller than 125 percent of the load.
Why the change in language? Is it to give us flexibility to size the circuit breaker for a heater at 100%, if we know that the heater will be on for less than 3 hours / not a continuous load? But keep the wiring at 125%, to give us room to upsize the breaker later on in case the heater is then considered a continuous load?