GFCI Electrical Question

[Mike Goetzke]

My other hobby is homebrewed beer. Brewing systems called all-in-one are becoming popular - I have one on preorder. These are electric heated vessels. Some have the option to use 240V instead of 120V. Since one is mixing electricity with water a GFCI is required for this device. This is simple for 120V where GFCI outlets are common. For 240V I ordered a heavy gauge extension cord with an inline 240V GFCI.

On one of the brewing forums I visit there was a post where someone showed an extension cord with an inline GFCI. The plug ends were for 120V. A question was asked if they could just replace the 120V plug ends with 240V ones and a well known forum member said yes. I posted that this should be double checked because I'm not convinced a 120V GFCI will function with two hot leads and this same member said absolutely! I can save some $ if I went this route. Is this true (a 120V inline GFCI will protect a 220V circuit)?

Thanks

[Malcolm McLeod]

Don't know your costs for various options, so just food for thought... I might be tempted to install a GFCI circuit breaker on the 240V circuit feeding the 'brewery'. Probably more expensive, but seems safer.

[Mike Goetzke]

Don't know your costs for various options, so just food for thought... I might be tempted to install a GFCI circuit breaker on the 240V circuit feeding the 'brewery'. Probably more expensive, but seems safer.

Yeah - My main location for brewing I do have a 240V GFCI breaker but my secondary location at times feeds some machines that don't like GFCI so inline GFCI is my option.

More I think about it maybe voltage doesn't matter for these devices since they monitor current flow differential between two wires.

Mike

[Mike Henderson]

A GFCI works by comparing the current in the two wires providing power to the load. If the current between the two wires differs - because some of the current is shunted to ground, perhaps through your body - the GFCI trips. So from a simplistic view, the 120V GFCI could work on 240V. But there's more to the GFCI than just that simple view and if any part of the unit is voltage sensitive or not insulated for 240V you'll have a problem.

You'll be safer to use a GFCI designed for 240V.

Mike

[Frank Pratt]

Not safe. The electronics are designed, tested and approved for use with 120 V. Why try to save a little money on a safety device & then 'hope' it works?

[Jay Aubuchon]

Is this any help?

Southwire 25000016-6 120V/20A and 240V/20A, Dual Voltage In-Line User Attachable GFCI (https://www.amazon.com/TRC%C2%AE-GFCI-12-18-Line-Attachable/dp/B004SBV6BE?ref_=fsclp_pl_dp_5)

[Mike Goetzke]

Is this any help?

Southwire 25000016-6 120V/20A and 240V/20A, Dual Voltage In-Line User Attachable GFCI (https://www.amazon.com/TRC%C2%AE-GFCI-12-18-Line-Attachable/dp/B004SBV6BE?ref_=fsclp_pl_dp_5)

Yeah I saw that one but here is the one someone else is using but replacing the cord ends with #6-15:

https://www.amazon.com/gp/product/B073ZMLZGW/ref=ox_sc_saved_title_3?smid=A26OASPQYU1JXQ&psc=1

Here is the one I ordered but it is on backorder:

https://www.galco.com/buy/Arrow-Hart-Cooper-Wiring-Devices/GFI23A7NN

The one I ordered comes with 100' of 10/3 cord. I don't need this long of a cord but probably use it with my welder. I think this is a pretty good deal.

From all the good help I think I will just stick with what I ordered.

Thanks for the help.

Mike

[Bill Dufour]

A welder does not really need a GFCI unless something goes major wrong. It is an isolation transformer so the voltage has no reference to ground. This is why you can arc weld on a metal ship floating in salt water or even underwater.
This is the same reason a bird can sit on a 20kv uninsulated wire and not notice anything.
Are washing machines and refrigerators still NEC exempt from gfci requirements?
Bill D

[Mike Goetzke]

A welder does not really need a GFCI unless something goes major wrong. It is an isolation transformer so the voltage has no reference to ground. This is why you can arc weld on a metal ship floating in salt water or even underwater.
This is the same reason a bird can sit on a 20kv uninsulated wire and not notice anything.
Are washing machines and refrigerators still NEC exempt from gfci requirements?
Bill D

Thanks Bill - I wasn't clear. I will cut what I need with the GFCI, maybe 25', for the brewer and be left with a long length of 10/3 cord.

[Frank Pratt]

Here is the one I ordered but it is on backorder:

https://www.galco.com/buy/Arrow-Hart-Cooper-Wiring-Devices/GFI23A7NN

Mike

You chose wisely.