i am a home brewer and have recently purchased a 200v 30amp brewing pot (NEMA 6-30p).

I have a 220v 50amp rv receptacle (NEMA 14-50r) with a 50A GFCI double-pole breaker in the main house panel.

I am planning to make a project box that will plug into the rv receptacle to provide power receptacles for the brew pot (NEMA 6-30r) and two NEMA 5-15R for brew pumps. The project box will have a 220v 30amp breaker as well as a 110v 15amp breaker.

My question is in regards to the GFCI service in my main panel. Will it provide adequate protection for the brew pot as well as the pumps?

Do I need the breakers on my project box to also be GFCI?

Thanks in advance for your help.


  • Keep in mind that what when you plug your Xerox machine into 110/220V, you are actually plugging a Minolta copier into 120/240V. There have been two voltage bumps since AC electricity entered the public vernacular 100 years ago. That means if the brewing pot is genuinely 200V (Japan?), this is 20% overvoltage not 10%, so any resistive elements will be at 144% of spec not 121%. It's possible to buck 240V down to 204V if you need that. Aug 18, 2019 at 17:26

1 Answer 1


One GFCI protects it all in your case

Since the feeder breaker is a GFCI, it provides GFCI protection to whatever is connected to it; think of it as providing a "zone of protection", if you will. This is enshrined in the NEC in 215.9:

215.9 Ground-Fault Circuit-Interrupter Protection for Personnel. Feeders supplying 15- and 20-ampere receptacle branch circuits shall be permitted to be protected by a ground-fault circuit interrupter installed in a readily accessible location in lieu of the provisions for such interrupters as specified in 210.8 and 590.6(A).

As a result, you can use regular breakers (or more precisely, unit mount breakers such as Square-D QOUs that are designed to mount to an enclosure directly, instead of to a panelboard interior) in the downstream distribution box, instead of needing to fit it with GFCIs.

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