Conflicting and convoluted manufacturer's instructions

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Sparksy93

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Purchased a 5000w heater for my garage, in the manual as I try to match what manufacturers want done, I get conflicting and confusing requirements in my opinion, one says appliance must be connected to current protection device at 32-40 amps. Another portion says use 10 ga wire.
Yet another section says use wires suitable for 75* Celsius, yet shows a little image of 10/2 Romex going into unit, are the manufacturers on crack or am I overthinking it I was originally going to pull 10/2 Romex, and land on a 30 amp breaker as 5000 watts at 240 volts is 20.9 amps last time I checked. Any tips or things I’m missing about this? Seems like they had a vague grasp of the NEC but have put conflicting demands on their instructions.
 
drcampbell

drcampbell

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I'd put an ohmmeter on the element(s) to assure that it's not a 208-volt unit, and double-check the nameplate on the fan motor. (if there is one)
A 30-amp breaker assures that the 10-gauge wire is adequately protected.
If the 32 minimum circuit apmacity is genuine -- and not the result of the instructions being written where 16- and 32-amp circuits are common -- the worst you might be risking is nuisance trips.
 
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paulengr

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Does it have a blower or pure resistance? If so the breaker size is adjusted for the motor inrush. Plus that’s a motor load so size ampacity for 125%, so #12 is just barely too small. Heater rules are kind of strange anyway. Look at Article 440. If you thought 430 was goofy you haven’t seen anything yet.
 
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Sparksy93

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It has a blower motor, I appreciate the insights. Some of your responses conflict though so I expect some duking it out with a definitive winner lol
 
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Sparksy93

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Plus it’s thermally protected? Could I theoretically run 8/2 to it on a 40 amp breaker and know that it would shut itself off before tripping breaker/ burning up?
 
Jraef

Jraef

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32A is a standard breaker size everywhere else in the world EXCEPT North America. It is their equivalent of a 30A circuit corresponding to their metric wire sizing. They converted their 6.0mm2 metric wire size to #10 for us, but failed to understand that we don't have 32A breakers, we have 30A.

Use a 30A, quit fretting about it.
 
GeorgeB

GeorgeB

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Sparksy93 said:
Nice. Alrighty then that explains it then. Wasn’t aware of such breaker sizes like 32 lol
Click to expand...
Much of the industrial world follows a "standard" sequence ... 10, 12, 16, 20, 25, 32, 40, 50, 63, 80 and 100 in sizes. Obviously (?) that sequence can be continued up and down. I think of it as DIN based.
 
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Sparksy93

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Winchester ky
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Electrical technician
GeorgeB said:
Much of the industrial world follows a "standard" sequence ... 10, 12, 16, 20, 25, 32, 40, 50, 63, 80 and 100 in sizes. Obviously (?) that sequence can be continued up and down. I think of it as DIN based.
Click to expand...
I’ll be honest this is speaking above my understanding, the only DIN I know is DIN rail for mounting different transformers or terminals lol
 
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zbang

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