Unit heater

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nizak

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Am I correct in saying that the minimum circuit ampacity for a 6000watt 240 volt single phase unit heater would be 35 amps?

Spec sheet for install says 10 gauge copper wire Wire and 30 amp breaker or fuses.
 
nizak said:
Am I correct in saying that the minimum circuit ampacity for a 6000watt 240 volt single phase unit heater would be 35 amps?

Spec sheet for install says 10 gauge copper wire Wire and 30 amp breaker or fuses.
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6000/240=31.25

Use next lowest standard OCPD = 30

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Is this a heater such as installed in a HVAC unit or ducting or a stand alone plug in type heater ?
 
Stand alone ceiling mounted garage heater. Install specs say hardwired, 30 amp breaker/fuse, and 10 gauge copper wire.
 
May be like a big-box 5 hp air compressor :) your heater gives out the "equivalent" heat of a 6000 watt heater when operating in arctic temperatures with a full moon :D

manufacturers' brochures may stretch things.. physics can't
 
So out of this discussion, I can say that #8 NMB cable and a 35 amp breaker would be the code compliant installation?
 
Looks like the Mfgr probably just takes the wire ampacity and the appropriate breaker or fuses and lists that info.

They do not take into account the additional 25% factor.
 
nizak said:
Looks like the Mfgr probably just takes the wire ampacity and the appropriate breaker or fuses and lists that info.

They do not take into account the additional 25% factor.
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Thus, the question is, "Must we?"

By sheer coincidence, I just got a job that includes a 5kw garage heater. 5000/240 = 20.8333. #12 or #10 nm, and 20- or 30-amp breaker (or 25)?
 
I live in interior Alaska, see temp as low as -70 F. Unless operating ouside , would never see a unit heater run non stop for 3 hrs. Then why call this continious duty load? I would follow mfg instructions and sleep soundly.
 
LRB said:
I live in interior Alaska, see temp as low as -70 F. Unless operating ouside , would never see a unit heater run non stop for 3 hrs. Then why call this continious duty load? I would follow mfg instructions and sleep soundly.
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If it's that cold in the interior, how cold is it outside?! :jawdrop:
 
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