AFCI and a Welder?

[SlappyWhite]

Anyone have experience with AFCI and welders. Will the welder trip the AFCI breaker? Doing outdoor 20A 120V outlets, welder is a Lincoln 140A 120V unit. Panel is a SquareD QO... Pulled my permit before the Ontario code change so I have the option to either use them or not...

 

[Movover]

I have never had a problem with mine in the garage before on my Hobart 135. The arc is happening after some circuitry and not on the 120v side so I fathom that's why its not a problem.

 

[DpSyChO]

The table saw and miter saw that I have has tripped my AFCI breakers from day one (when the wiring in my shop was done a couple years ago). I think I may also have a Square D QO but would need to go out and double check. I searched online and saw several other threads about table saws tripping AFCI breakers and from what I saw the sudden surge of starting amps is the reason for the breaker tripping. I dont think a 120V welder will have the sudden surge and you should be fine.

 

[MagKarl]

I run my mig welder on GFI protected circuits in the garage and barn with no problems, GFI's are required here so no choice for me.

Edit - misread original post and was thinking GFI, not AFCI.

 

[SlappyWhite]

Yes a zombie thread but I am the OP.... just closing the loop as I forgot to back in the day.

All works fine, 20A Square D QO Dual Function (GFCI and CAFI) breaker and a Lincoln 140a 120 welder. Absolutely no trips or issues. Heavy duty 20A receptacles and of course no back stabbing!

 

[ycgoat]

Thanks for following up.

 

[mark-NJ]

There's a reason the AFCI doesn't trip: the AFCI doesn't "see" the welder's arcing. The AFCI doesn't see beyond the load it's feeding, which is (just) a DC power supply....diodes & capacitors. The IGBT board after the power supply controls the feed to the electrode, but the arc's "signature" is invisible to the AFCI because it's well beyond the power supply.

 

[bugman-74]

This is interesting. Is there a different level of sensing (algorithm) between AFCI breaker vs. an AFCI outlet? A year or so ago I tested an AFCI outlet (not breaker) with my Multimatic 200 on 120V, and it would trip the outlet every time I started the weld.

 

[SlappyWhite]

This is interesting. Is there a different level of sensing (algorithm) between AFCI breaker vs. an AFCI outlet? A year or so ago I tested an AFCI outlet (not breaker) with my Multimatic 200 on 120V, and it would trip the outlet every time I started the weld.

According the "expert" in this thread this is impossible, so it cannot be happening!

Having said that, there are other things you can check that may be tripping the AFCI:

-Is it a quality name brand AFCI outlet or no-name cheapo?
-Also check that the plug is not loose fitting in the outlet r otherwise damage on either side...
-If cheapo or loose try replacing the outlet.
-Are you plugging the welder directly into the AFCI outlet or one protected downstream?
-If it is one downstream is it backstabbed or is there a loose/poor connection between the two outlets?
-Loose or bad wiring in the 120v connection on the welder.

The above could be causing the trip...

 

[PressOn]

Um, or it could be that the AFCI is doing what is supposed to do, and detecting an arc fault.
ymmv
Press on, healthfully and prayerfully.

 

[bugman-74]

According the "expert" in this thread this is impossible, so it cannot be happening!

Having said that, there are other things you can check that may be tripping the AFCI...

I guess everyone's mileage may vary. I did this test about a year ago. At the time, I found a lot of different feedback about the combo outlets - so I decided to test it for myself to see if I was going to have issues with AFCI's (technically a combo AFCI/GFCI) in my new shop.

Did not have the space for AFCI breakers in the panel, so thought I would try to get some coverage via these combination outlets. I tried various things plugged into it like a hole hawg, angle grinder, small drill press, miter saw, shop vac. All worked just fine, but the welder tripped it consistently.

It was a brand new Leviton combo AFCI/GFCI from a big box store. Welder is a ~5 year old Miller Multimatic 200 with "low miles" plugged directly into the combo outlet. Long story short I wound up installing standard GFCI outlets in the shop. AFCI's were not required by code, but I thought they would be a nice-to-have.

I have not tried this welder on a circuit protected by an AFCI breaker. That would be another interesting test...