Neutral Conductor Sizing (NEC2023)

[Abraham V]

Reviewing Example D2(a). When calculating feeder neutral load, why are the water heater and space heater not counted? Why is the dishwasher counted?

 

[infinity]

Without seeing the calculation I would guess that the two types of heaters do not have a neutral as they are 240 volt loads. Dishwashers are typically 120 volts.

 

[Abraham V]

Without seeing the calculation I would guess that the two types of heaters do not have a neutral as they are 240 volt loads. Dishwashers are typically 120 volts.

The question says, "2.5 kW water heater, 1.2 kW dishwasher, 9 kW of electric space heating installed in five rooms..." along with the rest of the loads that are taken into account. I'm looking for something to specifically tell me whether each is a 240 V or 120V load. I guess I just need time and familiarity.

Thanks!

 

[Elect117]

The question says, "2.5 kW water heater, 1.2 kW dishwasher, 9 kW of electric space heating installed in five rooms..." along with the rest of the loads that are taken into account. I'm looking for something to specifically tell me whether each is a 240 V or 120V load. I guess I just need time and familiarity.

Thanks!

They didn't say it, but those are assumed to be 240V loads. Or at least that is what the problem assumed.

Good Catch.