NEMA 15-50 and NEC 210.8

A

Aistobasbistoc9

Member
Location
Texas
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Engineer
Inspector is wanting the circuit breaker for a 15-50 receptacle to be GFCI rated in a kitchen. I believe NEC 210.8 requires that it be GFCI rated because it falls under 150V to ground or less (and 100A or less). However, is it actually 150V to ground or less, or 250V to ground or less?

Thanks
 
Is this a 208/120v wye-connected supply?

If the circuit feeding it is <=150 volts to ground, the receptacle can't be anything else. And receptacles aren't "GFCI rated" although they might contain GFCI functionality; OTOH they may be GFCI protected.

(I suppose a 15-50 could be wired to a 240v delta-connected supply, but that would add another complexity.)
 
Aistobasbistoc9 said:
Thank you. Are you also saying that on the receptacle itself, it would be 150V to ground or less as well?
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If you don’t know, its your job to check it with a meter.

Some commercial, and industrial buildings were not designed for occupancy, or kitchen additions, without a step down xfmr.
 
Aistobasbistoc9 said:
Thank you. Are you also saying that on the receptacle itself, it would be 150V to ground or less as well?
Click to expand...
If you connected this receptacle to a 208y/120 supply it would be required to have GFCI protection. If you connected it to a corner grounded 240 volt delta it would not.
 
zbang said:
Is this a 208/120v wye-connected supply?

If the circuit feeding it is <=150 volts to ground, the receptacle can't be anything else. And receptacles aren't "GFCI rated" although they might contain GFCI functionality; OTOH they may be GFCI protected.

(I suppose a 15-50 could be wired to a 240v delta-connected supply, but that would add another complexity.)
Click to expand...
Sorry, GFCI protected, not rated.
 
CoolWill said:
If you connected this receptacle to a 208y/120 supply it would be required to have GFCI protection. If you connected it to a corner grounded 240 volt delta it would not.
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Is there a remote GFCI protection device that can be added to a 50A 3Ph receptacle (15-50) that can be mounted in an accessible location bypassing the need for GFCI protection circuit breaker? Square D does not make one for over 10kAIC.
 
I believe Bender and Littelfuse both have stand alone devices. They make various types, so you need to make sure the one you select is listed to UL 943.
 
Ask your inspectors jurisdiction to consider accepting a RCD for this situation.
 
Aistobasbistoc9 said:
Thank you. Are you also saying that on the receptacle itself, it would be 150V to ground or less as well?
Click to expand...
The rule is about your SYSTEM VOLTAGE, not the receptacle. In a residence, you have a 120/240V system. At any hot line to ground, you will measure 120V, which is less than 150V.

The only time this rule would not apply is if, in a commercial or industrial setting for example, you have a 3 phase 480V system, or a 3 phase 240V Delta system. So bottom line, in the areas outlined you now need GFCI protection for all outlets smaller than 100A, which is effectively all outlets.
 
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