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Water heater calculationsSo when I count calculati

Posted By: watersparkfalls

Water heater calculationsSo when I count calculati - 04/11/19 11:23 PM

My question is I have a 250 gallon Water heater do I calculate at 100% or 125%? This is branch circuit not feeder calculations. Thanks
Posted By: ghost307

Re: Water heater calculationsSo when I count calculati - 04/11/19 11:30 PM

That's a big tank.
Is this for a locker room with showers?
Posted By: watersparkfalls

Re: Water heater calculationsSo when I count calculati - 04/11/19 11:32 PM

OK I see article 422.10 says 125% but where is the code reference to the breaker size one size higher? My water heater is listed at 87 A so 90 A is next standard breaker size.
Posted By: ghost307

Re: Water heater calculationsSo when I count calculati - 04/11/19 11:46 PM

You need to take 125% of the full load current; so it needs to be treated as a 108.75A load.
Make sure to also upsize the wire accordingly.
Posted By: watersparkfalls

Re: Water heater calculationsSo when I count calculati - 04/13/19 04:42 PM

Thanks, ghost.
H20
Posted By: watersparkfalls

Re: Water heater calculationsSo when I count calculati - 04/13/19 04:43 PM

Yeah exactly gym inside google bldg.
H20
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