electric heat

[xara]

I have 9 kva of electric heat in 5 rooms so I multiply by 40% to calculate the load for the service. What size wire do I run to each heater and what size breaker do I use for each heater? And can I have them all on one breaker? In this case do I also multiply by 40%, as I did to calculate the load for the service?

 

[Sierrasparky]

Your post is unclear.
Do you have a total of 9KV of heat or 5 - 9kva heaters?

 

[xara]

9kva spread out between 5 heaters

 

[jumper]

fixed electric space heating are considered as continuous loads for branch circuit sizing and the load must be multiplied by 125%.

424.3(B) Branch-Circuit Sizing.
Fixed electric space-heating
equipment and motors shall be considered continuous load

 

[gadfly56]

Assuming these are 240 volt heaters, it's just under 47 amps for the whole kit-and-kaboodle, so a 50 amp breaker. Assuming they are 5 identical heaters at 1,800 VA each, that makes for a 15 amp two-pole for each unit (actually 9+ amps). Wiring-wise you'd be better off with separate circuits, or no more than two (2) per circuit.

 

[jumper]

Assuming these are 240 volt heaters, it's just under 47 amps for the whole kit-and-kaboodle, so a 50 amp breaker.

:happyno:

424.3 Branch Circuits.
(A) Branch-Circuit Requirements.
Individual branch circuits shall be permitted to supply any volt-ampere or watt-
age rating of fixed electric space-heating equipment for which they are rated.

Branch circuits supplying two or more outlets for fixed
electric space-heating equipment shall be rated 15, 20, 25,
or 30 amperes. In other than a dwelling unit, fixed infrared
heating equipment shall be permitted to be supplied from
branch circuits rated not over 50 amperes