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A couple of wiring device questions

robby

Member
Aug 25, 2014
642
361
Andover, MA
Preface: I am building a charging kit that contains a long, low gauge extension cord that can be used with various NEMA plugs. For example, I can connect it to a 14-50 to make a 14-50 extension cord, or a 6-20 to make it a 6-20 extension cord. I will be keeping all of these NEMA connectors with my car so that I can use it at any house with any connector I find.

1) I would like to protect myself and my charging kit by placing a GFCI at the front of the chain (closest to the outlet). Does anybody know where I can buy a 250V/40A rated inline GFCI device for less than $250? The closest I can find is a 250V/30A device for $263. Ouch! Why are these so pricy? At that price I can make my own with a small circuit breaker box and GFCI breaker. But I'd rather have something portable. DANIEL WOODHEAD Line Cord GFCI240VAC Voltage Rating, NEMA Plug Configuration30053-0M - Grainger Industrial Supply

2) I need to standardize on a male/female system so that I can quickly change adapters (without having to manually rewire them each time). I am hesitant to use a NEMA standard male/female system because when someone sees a plug like that, it implies a certain voltage/amperage capacity, which could be misleading depending on what connector is on the other end. I will label accordingly but I would rather not create the potential for someone to plug in and get something different than is expected/standardized. Is there any 250V/50A-rated male/female connector system (3-wire, or 2-wire + ground) that I can use to connect these things so there is no ambiguity about the NEMA implications?
 

FlasherZ

Sig Model S + Sig Model X + Model 3 Resv
Jun 21, 2012
7,028
1,017
You could use color-coded camlock connectors... those won't be mistaken.

As for GFCI, the best you're going to do is a small GFCI breaker in a mini 2-space box at the 50A rating. It's largely because there are so few things that require GFI protection at that current.
 

FlasherZ

Sig Model S + Sig Model X + Model 3 Resv
Jun 21, 2012
7,028
1,017
Your best bet is probably to use a standard breaker such as this:

New in The Box Square D QO240GFI QO 2 Pole 40 Amp GFCI Breaker | eBay

You'll need to put it in a small fuse box... this is the smallest I could find with a few minutes of googling...

Square D QO 70 Amp Main Lug Load Center Breaker Box Flush Mount | eBay

No need to go that big... Typical hot tub disconnects will work:
Eaton 50 Amp BR Type Spa Panel-BR50SPA - The Home Depot
50A GFCI included.

I looked through my usual supply houses' catalogs and found absolutely nothing for inline 50A GFI's... I think the best you'll do is a small spa disconnect like the one I linked.
 
Last edited:

robby

Member
Aug 25, 2014
642
361
Andover, MA
Thanks guys, that 50A spa panel is perfect!

Is there any cheaper option you know of than camlock connectors? They seem perfect but at $17 per 15 connector I'll be at $459 to do the whole rig that way.
 

FlasherZ

Sig Model S + Sig Model X + Model 3 Resv
Jun 21, 2012
7,028
1,017
Thanks guys, that 50A spa panel is perfect!

Is there any cheaper option you know of than camlock connectors? They seem perfect but at $17 per 15 connector I'll be at $459 to do the whole rig that way.

Not for repeated use. If you didn't mind more set-up time, you might look at insulated Polaris connectors. Cap your wires with the giant wire nuts, then when you needed to use a new adapter, you'd uncap the wires, insert them into the connector, and torque them down with a tool you'd keep in the kit.

The CS (California) series of temp power connectors might work, there aren't too many of them around. They're kinda expensive as well.
 

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