GFCI Protection for Welders

[FrancisJ]

Ok, I'm not a licensed electrician, don't keep a copy of the NEC on my bedside for reading.

Question: Have several welders I want to add to my "hurricane proof" garage and want to add GFCI protection (I know better than to "experiment" with AFCI breakers and welders since I've seen AFCI's "misbehave" in normal residence applications around electrical storms) .

My application is using a 60AMP GE subpanel with separate white and ground (tied to ground rods) per codes. The problem is many welders only use three wire on their input cords (two hot, one ground, no neutral) and GFCIs generally measure / monitor the imbalance of current between the ungrounded (hot) and grounded (neutral) conductor of a given circuit.

In this application (subpanel with SEPARATE white (neutral), ground) and the welder input cords only using the two hots and a ground, the neutral (deliberately separate per NEC on subpanels) used by the GFCI can't be connected to the NEMA 6-50P welder's plug to measure the imbalances. Again, I'm keeping the neutral and ground SEPARATE (per code), but curious if anyone has an idea on how to get GFCIs working in this application.

Any thoughts would be appreciated.

 

[Gerald O]

Sorry, why are you saying the neutral can't be connected? Two-pole 240V GFCI breakers measure the imbalance between the load conductors (L1,L2), not between load and neutral. However they still use a connection to the neutral in the panel for their operation.

 

[FrancisJ]

Sorry, why are you saying the neutral can't be connected? Two-pole 240V GFCI breakers measure the imbalance between the load conductors (L1,L2), not between load and neutral. However they still use a connection to the neutral in the panel for their operation.

(Beautiful car BTW).

The breakers can be installed and wired at the subpanel just fine, the problem I have is at the welder plugs --- two hots and a ground, no neutral. The welders frequently don't even use the neutral on NEMA 6-50s, but the GFCIs use it.

 

[Gerald O]

Please look up the data sheets on a few 240V 2-pole GFCI breakers. They do not rely on a neutral in the load for sensing. They do not need a neutral conductor at the outlet.
This is a quite common application. You are just not understanding how they work.

 

[FrancisJ]

Gerald O ---- Thank you. I just checked the data sheets and they don't require a neutral connection at the load to work, just on the line side at the subpanel.................take good care of that beautiful car !!

 

[wyliesdiesels]

Ok, I'm not a licensed electrician, don't keep a copy of the NEC on my bedside for reading.

Question: Have several welders I want to add to my "hurricane proof" garage and want to add GFCI protection (I know better than to "experiment" with AFCI breakers and welders since I've seen AFCI's "misbehave" in normal residence applications around electrical storms) .

My application is using a 60AMP GE subpanel with separate white and ground (tied to ground rods) per codes. The problem is many welders only use three wire on their input cords (two hot, one ground, no neutral) and GFCIs generally measure / monitor the imbalance of current between the ungrounded (hot) and grounded (neutral) conductor of a given circuit.

In this application (subpanel with SEPARATE white (neutral), ground) and the welder input cords only using the two hots and a ground, the neutral (deliberately separate per NEC on subpanels) used by the GFCI can't be connected to the NEMA 6-50P welder's plug to measure the imbalances. Again, I'm keeping the neutral and ground SEPARATE (per code), but curious if anyone has an idea on how to get GFCIs working in this application.

Any thoughts would be appreciated.

Why are u installing GFCI protection for a 240v outlet?

Its NOT necessary and NOT required by code.

 

[Gerald O]

Gerald O ---- Thank you. I just checked the data sheets and they don't require a neutral connection at the load to work, just on the line side at the subpanel.................take good care of that beautiful car !!

You're welcome!
The car is a 41K mile original survivor.

Why are u installing GFCI protection for a 240v outlet?

Its NOT necessary and NOT required by code.

To weld during a hurricane?

Not required for general purpose outlets, but they are required for things like pool or spa pumps.

 

[wyliesdiesels]

You're welcome!
The car is a 41K mile original survivor.

To weld during a hurricane?

Not required for general purpose outlets, but they are required for things like pool or spa pumps.

Ok so tell me just what the GFCI protection on a 240v outlet feeding a welder will do for the person using the welder.

Hint: nothing

A GFCI for personal protection on a 120v outlet prevents a person from getting shocked via a small tool that may have a wiring issue that bonds to the frame which is ungrounded(read: old 2wire tool or maybe even a newer grounded tool with missing ground pin on plug ).

Since the welder converts the 240v electrical and the person isnt using something in their hand that is energized with 120v, there is no point.

And pools and spas are a different animal. Thats comparing apples to oranges.

The OP is over thinking this one maybe perhaps because he doesnt understand the purpose of a GFCI and how it functions.

BTW- i dont know about u but if a hurricane was bearing down towards me, welding would be the last thing i was doing.

 

[sberry]

I got to agree with wylie here, this is a dedicated electrically grounded appliance, not 2 wire ungrounded. No real reason to put it on.

 

[sberry]

I am not sure about 240 anyway, the pool is 4 wire normally, has dual V.

 

[Gerald O]

Welding underwater in a pool?

 

[wyliesdiesels]

I got to agree with wylie here, this is a dedicated electrically grounded appliance, not 2 wire ungrounded. No real reason to put it on.

Its a case of "mental ************" (stealing your words ) and a misunderstanding of the purpose of GFCIs...

 

[Gerald O]

Let's say a guy runs his welder on a wet floor or even outside in the driveway and the driveway is wet...

There's a cord going to the welder from the 240v wall outlet. Could be damaged and has exposed conductor. Or maybe he's plugging in with an extension cord, plugs one end into the wall and carrying the other end out to the driveway to plug in. The cord is damp from being set on the wet lawn...

Could happen.

 

[Speedy Petey]

Sorry, why are you saying the neutral can't be connected? Two-pole 240V GFCI breakers measure the imbalance between the load conductors (L1,L2), not between load and neutral. However they still use a connection to the neutral in the panel for their operation.

This is wrong. A two-pole GFI breaker on the load side DOES monitor both line-line loads and line-neutral loads simultaneously.

 

[matt_i]

I don't know how a GFI could tell if there's a fault to ground...the energy is actively flowing thru the blue arc to "secondary side ground" the entire time with all nature of transients surges sags and spikes...pick AC or DC welder but if you make yourself part of the circuit with low enough resistance I don't think the GFI is going to help you as it cannot "see" what happens on the secondary side of the transformer. It might detect a flaw in the windings... I would hate to think what an IGBT welder would do as there seems to be lots of "leakage" with single phase VFDs.

 

[Gerald O]

This is wrong. A two-pole GFI breaker on the load side DOES monitor both line-line loads and line-neutral loads simultaneously.

Thanks. Yes you are correct, it does sense neutral currents, but I was also not wrong. I didn't say it doesn't "monitor" the neutral. I said it doesn't work on the imbalance between the load (interpreted as 240v line load in the context of the thread) and the neutral. The neutral current will always have an imbalance in a 240 only or mixed 240/120 load.

 

[sberry]

If they thought it was a good idea it would be code and every publication would endorse it, as it is none. No how to book for diy includes this.

 

[FrancisJ]

Why are u installing GFCI protection for a 240v outlet?

Its NOT necessary and NOT required by code.

Hi Wyliediesels, I live on the Atlantic Ocean and we get hurricanes frequently --- so I've built a (almost all) steel/concrete garage/shop/shelter to have a survivable building.

I see that code doesn't require GFCI for residential and for 208/220/230V, BUT the industry (GE, Square D, etc) has been making 2, 4 pole GFCIs for single and triple phase systems for some time to account for problems with multiple sources of power/asymmetric grounds (common in rural locations that have multiple sources of power like mine) and earth leakage (common ANY TIME you put electrical equipment in damp (high humidity locations like mine).

These single and triple phase 208V and above GFCIs are expensive but experts in this area all agree they work or these big electrical supply companies wouldn't be making them and their industrial, commercial customers wouldn't be buying them --- bottom line: GFCIs work on a whole range of systems not just 120V and can be found in hundreds of 208/220/230V single and triple phase applications. I'm just trying to get protection on the welders because I've heard about many cases of welders getting injured/killed because of earth leakage issues -- takes very little leakage (milliamps) to "do the job" --- about 1/10th of an amp for 1.5 seconds --- that's not much with welders.

 

[FrancisJ]

You're welcome!
The car is a 41K mile original survivor.

To weld during a hurricane?

Not required for general purpose outlets, but they are required for things like pool or spa pumps.

41K --- incredible beauty and low mileage. They just don't make stuff this classy anymore.

 

[Stuart in MN]

If they thought it was a good idea it would be code and every publication would endorse it, as it is none. No how to book for diy includes this.

In the 2017 NEC they are going to add GFCI protection for 240vac, 15 and 20 amp circuits in residential applications. 30 amp and higher won't be affected.

 

[ForceFed70]

Just another post to say "Why?" It's more work, it's expensive, and it'll provide little/no protection or benefit.

There's a reason code doesn't require it...

 

[wyliesdiesels]

Hi Wyliediesels, I live on the Atlantic Ocean and we get hurricanes frequently --- so I've built a (almost all) steel/concrete garage/shop/shelter to have a survivable building.

I see that code doesn't require GFCI for residential and for 208/220/230V, BUT the industry (GE, Square D, etc) has been making 2, 4 pole GFCIs for single and triple phase systems for some time to account for problems with multiple sources of power/asymmetric grounds (common in rural locations that have multiple sources of power like mine) and earth leakage (common ANY TIME you put electrical equipment in damp (high humidity locations like mine).

These single and triple phase 208V and above GFCIs are expensive but experts in this area all agree they work or these big electrical supply companies wouldn't be making them and their industrial, commercial customers wouldn't be buying them --- bottom line: GFCIs work on a whole range of systems not just 120V and can be found in hundreds of 208/220/230V single and triple phase applications. I'm just trying to get protection on the welders because I've heard about many cases of welders getting injured/killed because of earth leakage issues -- takes very little leakage (milliamps) to "do the job" --- about 1/10th of an amp for 1.5 seconds --- that's not much with welders.

What brand of panel do u have?

U cant just put any brand of breaker in your panel. It needs to be listed and labeled for that panel.

 

[sberry]

We have heard of many cases?. Where would this be? I am a career welder, never heard of one let alone many but havnt want looking for them either.

 

[sberry]

In the 2017 NEC they are going to add GFCI protection for 240vac, 15 and 20 amp circuits in residential applications. 30 amp and higher won't be affected.

I wonder what the deal may be? I don't have anything in residence that would cover and nothing in shop I can think of below 30.

 

[Stuart in MN]

I wonder what the deal may be? I don't have anything in residence that would cover and nothing in shop I can think of below 30.

Doesn't make sense to me either, but that's often been the case with updates to the NEC.

 

[Weird Tolkienish Figure]

At a certain point we need to stop with the safety obsession and we need to start weeding out the gene pool a little.

 

[CapinWinky]

I'm resurrecting this thread to say that most IGBT switching loads (including DC arc welders) will trip GFCI protection, so they should be actively avoided for such applications. Many newer/fancier shop pieces now use VFD control (lathes, drill presses, table saws, etc) which will also trip them. Servo control on various mills and CNC stuff will also do this.

IGBTs make common mode noise and the only reliable methods I know to insulate them from erroneously tripping the GFCI also make the GFCI unable to detect actual ground faults. Various filters that simply tamp down the noise still allow pretty regular tripping of GFCI breakers.

 

[sberry]

My Max runs from gfci 20/120. Its listed min circuit is 30 and will run on 50, both those going to be exempt? Or should I say will a legal welder circuit be gfci? I forgot, is this only recepts? I have a couple 30A items but dont recall having but 1 thing less. Dont think I have a single circuit 15 or 20A @ 240.
Got a few things I keep 120, table and chop saw. Just cause I can doesnt mean I do, be different if it didnt work. Paint fan too.

 

[pi_guy]

Welding underwater in a pool?

During a hurricane too.

 

[nadogail]

IMHO, GFCI for a welder is unwarranted.

 

[Norcal]

IMHO, GFCI for a welder is unwarranted.

There are 6 States that have adopted the 2020 NEC, in those States get used to GFCI’s for your dryer, A/C, and other 240 volt loads.

 

[sberry]

Did they rate it by circuit size and if its for AC must include hard wired?

 

[walrus]

There are 6 States that have adopted the 2020 NEC, in those States get used to GFCI’s for your dryer, A/C, and other 240 volt loads.

Already used to it in the deli's I service. If its cord and plug connected it will be gfci. No 2020 code in Maine until next year.

Sent from my SM-G950U using Tapatalk

 

[Norcal]

Already used to it in the deli's I service. If its cord and plug connected it will be gfci. No 2020 code in Maine until next year.

Sent from my SM-G950U using Tapatalk

Commercial kitchens have been required to have GFCI protection for a while.
Air conditioning condensers will have to have them.

 

[walrus]

Commercial kitchens have been required to have GFCI protection for a while.
Air conditioning condensers will have to have them.

I thought it was 17 where 208/240 recepts has to be gfci? Maybe it was earlier.

 

[reader2580]

I thought it was 17 where 208/240 recepts has to be gfci? Maybe it was earlier.

The 2020 NEC added the GFCI requirement for any receptacles up to 250 volts in locations that previously only needed GFCI protection up to 150 volts. A kitchen range and an electric dryer are two common receptacles that will require GFCI protection now. Garages require GFCI so technically a welder outlet would require GFCI now.

GFCI protection on outdoor outlets up to 250 volts is also required. An outlet in NEC parlance is any electrical connection, not just a receptacle. This means outdoor air conditioning condensers now require GFCI.

 

[78SC4X4]

I know this is an older thread but just got a comment from the inspector that all plug-in circuits 50amps and less require GFCI protection. I clearly have NEMA 6-50R receptacles installed. I can see the requirement in the code. So am I missing something? Will the breaker work without a neutral from the circuit and just compare the two hots?

 

[exranger06]

I know this is an older thread but just got a comment from the inspector that all plug-in circuits 50amps and less require GFCI protection. I clearly have NEMA 6-50R receptacles installed. I can see the requirement in the code. So am I missing something? Will the breaker work without a neutral from the circuit and just compare the two hots?

Yes, the breaker will compare the 2 hots. It doesn't need a neutral.

 

[wyliesdiesels]

I know this is an older thread but just got a comment from the inspector that all plug-in circuits 50amps and less require GFCI protection. I clearly have NEMA 6-50R receptacles installed. I can see the requirement in the code. So am I missing something? Will the breaker work without a neutral from the circuit and just compare the two hots?

yes it will work just fine since there is no 120v loads, the breaker doesnt need to compare the load on both hots & the neutral.