TIG Welders Tripping Breakers

[G-ManBart]

This is probably a dumb question, but I'll ask anyway

I've noticed that sometimes if I'm not deliberate with the power switch when turning on/off it will cause the circuit breaker to trip. I've seen this with two Miller Syncrowave 250, three Syncrowave 250DX, and two Hobart TIGWave 250 AC/DC machines. Imagine flipping the switch and your finger slips and the switch slows/pauses along it's path...snap, tripped breaker. If it's a smooth, positive throw it works fine. All of these are old style transformer machines with similar construction.

I don't recall it ever happening with my Miller Dialarc 250 or any of the various Millermatics I've run (35S, 35, 200, 250, 250X, 251 or 252). I know it never happened with my inverter TIG.

I'm running them on a new, dedicated circuit that's a bit under 50ft long, 8ga wire, and a 40amp breaker (going to bump that up to a 50 or 60 soon since it's a dedicated circuit). I've been able to turn any of those machines up to full power and max the pedal and not trip the breaker, so I don't think there's anything wrong from a wire/breaker standpoint.

It's not a problem....it rarely happens, but once I noticed it I realized I could make it happen, and that got me wondering. Anybody have an idea?

[Tbones]

My Syncrowave 250 does it also. Took it to the shop last month for a complete go through, nothing wrong. Some have said "inrush" current to charge the caps. I think my breaker may be getting weak.

[Pontiac Freak]

Syncrowave 250 needs 100amp circuit if I remember correctly.

[propanehotrod]

Are you using arc fault breakers?

[Louie1961]

Your circuit is completely undersized for those machines you mentioned. You need at least 6 gauge conductors and a 110 amp breaker is recommended. When I first installed mine I had the 6 gauge conductors and a 50 amp breaker and it never tripped with the inrush. If the machine has PFC caps, it will draw close to 50 amps at idle

[smithdoor]

Both stick and Tig need bigger breaker.
At less 50 amps for up to 200 amp.
You can use a time delay fuse. This type fuse is used for electric motors to take the high starting amperage. Which same as sticking a arc.

Dave

PS: My old shop for main used 200 amp time delay.

This is probably a dumb question, but I'll ask anyway

I've noticed that sometimes if I'm not deliberate with the power switch when turning on/off it will cause the circuit breaker to trip. I've seen this with two Miller Syncrowave 250, three Syncrowave 250DX, and two Hobart TIGWave 250 AC/DC machines. Imagine flipping the switch and your finger slips and the switch slows/pauses along it's path...snap, tripped breaker. If it's a smooth, positive throw it works fine. All of these are old style transformer machines with similar construction.

I don't recall it ever happening with my Miller Dialarc 250 or any of the various Millermatics I've run (35S, 35, 200, 250, 250X, 251 or 252). I know it never happened with my inverter TIG.

I'm running them on a new, dedicated circuit that's a bit under 50ft long, 8ga wire, and a 40amp breaker (going to bump that up to a 50 or 60 soon since it's a dedicated circuit). I've been able to turn any of those machines up to full power and max the pedal and not trip the breaker, so I don't think there's anything wrong from a wire/breaker standpoint.

It's not a problem....it rarely happens, but once I noticed it I realized I could make it happen, and that got me wondering. Anybody have an idea?

[vwguy3]

My Syncrowave is on a 60 amp breaker and has run flawlessly for 10 years.

[scsmith42]

My Syncrowave 250 DX used to trip a 50A breaker on 6 guage wire. No extension cord and only 12' or so of 6/3 SO cord on the welder and the machine receptacle was on a dedicated circuit less than 10' from the panel.

Increasing the breaker size solved the problem.

[G-ManBart]

My Syncrowave 250 does it also. Took it to the shop last month for a complete go through, nothing wrong. Some have said "inrush" current to charge the caps. I think my breaker may be getting weak.

Does it do it randomly when you turn it on/off or just if it's not done smoothly?

[G-ManBart]

Syncrowave 250 needs 100amp circuit if I remember correctly.

The manual and the welder data plate shows 96amps as max but it would only pull that if you're running the machine maxed out.

[danielplace]

The manual and the welder data plate shows 96amps as max but it would only pull that if you're running the machine maxed out.

That is why you can overprotect the wire on a welder. They know startup inrush can be higher as well as duty cycles limiting long term max amp draw.

The switch not switched quickly will have a harder hit because of the resistance of the contacts when switched slowly is like having a long thin cord and voltage drop because full contact has not yet been made and the amperage spikes even higher as low voltage makes it draw even more than a fast full contact startup. Be nice if the power switch was controlling a contactor for the power switch as that would be a fast make connection and would alleviate the possibility of a slow make connection when the switch may have if not been flipped quickly and solidly to ON

[G-ManBart]

Your circuit is completely undersized for those machines you mentioned. You need at least 6 gauge conductors and a 110 amp breaker is recommended. When I first installed mine I had the 6 gauge conductors and a 50 amp breaker and it never tripped with the inrush. If the machine has PFC caps, it will draw close to 50 amps at idle

The amp limitations vary with the wire type, so it's not that simple of an answer.

For example, the THHN 8ga that I used is listed as up to 55 amps, and you can double the amps on a dedicated circuit for a welder, so it would be within code. The breaker is undersized, and I'm going to swap it, but it's not going to cause a dangerous situation...quite the opposite.

I can flip the power switch on an off a hundred times in a row and not trip the breaker. If I pause somewhere in the movement is the only time the breaker will trip. That seems odd...

[G-ManBart]

That is why you can overprotect the wire on a welder. They know startup inrush can be higher as well as duty cycles limiting long term max amp draw.

The switch not switched quickly will have a harder hit because of the resistance of the contacts when switched slowly is like having a long thin cord and voltage drop because full contact has not yet been made and the amperage spikes even higher as low voltage makes it draw even more than a fast full contact startup. Be nice if the power switch was controlling a contactor for the power switch as that would be a fast make connection and would alleviate the possibility of a slow make connection when the switch may have if not been flipped quickly and solidly to ON

Thank you! That makes perfect sense...Ohm's law at work again

[danielplace]

The amp limitations vary with the wire type, so it's not that simple of an answer.

For example, the THHN 8ga that I used is listed as up to 55 amps, and you can double the amps on a dedicated circuit for a welder, so it would be within code. The breaker is undersized, and I'm going to swap it, but it's not going to cause a dangerous situation...quite the opposite.

I can flip the power switch on an off a hundred times in a row and not trip the breaker. If I pause somewhere in the movement is the only time the breaker will trip. That seems odd...

Makes perfect sense. The switch is arcing when switched slowly and that will draw more than a immediate full make switching will. The low voltage while it is arcing is actually drawing more than a fast switch action. If you were to put a amp probe on it you would be able to see the difference in the inrush spike.

It is like a line man remaking contact when refusing a transformer primary. If done slowly it will arc and maybe pop the new fuse because of inrush. A fast closure makes very little arc and things start back up fine.

[OPUS FERRO]

G-ManBart

All recommendation are weak - just, 'cut the Green wire' . . .

hth


Opus

[shovelon]

The good news is PFC capacitors was an option for the old SyncroWave line of tranny tigs. You can order the kit and put it in or have your service center put them in. Once charged the PFC capacitors will dampen the start surge and prevent tripping your breakers. How do I know? The one and only SyncroWave I bought did not have the caps and the cost was some $1100 to put in on a $2300 welder. So I sold it and bought and went to Lincolns with caps. At the time all high end tranny tigs came standard with PFC so I had no clue. Then the inverters came out and the Lincolns went bye-bye.

[Broccoli1]

[Tbones]

Any easy way to tell if it has PFC's?

[danielplace]

Any easy way to tell if it has PFC's?

https://forum.millerwelds.com/forum/...alled-proof-of

[Willie B]

Think of the main winding as a big wire, very long. If unwound, flip the switch, only resistance limits current.
Wind it back up, repeat, now at inrush there is not yet a strong magnetic field. Inrush current is big! Instantly, magnetic field builds, magnetic impedance limits current.
Turning it on, Inrush will always exceed breaker capacity. Usually it is brief enough it won't trip.

When you turn it off, a big powerful magnetic field collapses, inducing power into the line.

As Shovelon says Capacitors will spread that surge out.

[camfab]

This is so timely, my synchrowave 250 does this as well. Essentially at my old house I had a 50 amp but the the outlet was literally one foot away from the panel. In my newer house the panel is 100' away and it pops the breaker occasionally on start up and now anytime I weld aluminum over 175 amps. I'm so done with this BS. I had Edison out to the house to see what its going to take to increase my service cable size. Good news is that apparently Edison gives you up to $3,500 credit each year for stuff like this, something I was unaware of. So 400 amp panel here I come!! Calling Square D tomorrow to get the right panel that meets Euserc requirements.

[danielplace]

This is so timely, my synchrowave 250 does this as well. Essentially at my old house I had a 50 amp but the the outlet was literally one foot away from the panel. In my newer house the panel is 100' away and it pops the breaker occasionally on start up and now anytime I weld aluminum over 175 amps. I'm so done with this BS. I had Edison out to the house to see what its going to take to increase my service cable size. Good news is that apparently Edison gives you up to $3,500 credit each year for stuff like this, something I was unaware of. So 400 amp panel here I come!! Calling Square D tomorrow to get the right panel that meets Euserc requirements.

Save yourself the cost and aggravation and just increase the breaker size. Of course the 50 is tripping so put a 80 and see if that doesn't solve the issue. Even a new 60 may make it start doing all you need it to do I mean especially if your saying the 50 on it at the old place was enough for you. What is the actual wire size ? A new run you would need from the new service anyway. You could upgrade the run to what is there now and fix it if it is just a wire/breaker size issue also.

Before wasting a lot of money be sure of what they can actually supply to your service as they have a lot of rules they follow so you don't over load their equipment especially in a residential setting.

Have a real service planner out to go over the new feed it it it's entirely in writing before buying equipment is all I am saying because I have seen this same exact scenario play out a few times before.

Make sure the existing transformer can handle what your looking for. Are you sharing the same transformer with any other residential customers now ?

Make absolutely sure that they can deliver before spending.

You may not find a standard matter base that can deliver more than 320 amps continuous. Doubt they are going to set you up with a real 400 amp service. It would need to be done current transformer style most likely to make that happen.

Then they may come in and feed it all with 1/0 aluminum or something grossly undersized for the amperage of the service. Short run will still deliver pretty good amperage without too much voltage loss but not 400 amps. The wire size is their damper and fuse between your service and the transformer so it doesn't feel the hit as much when you throw a big load at it.

Probably looking at something like this for meter. Unless they supply the meters cans which hasn't been that way for 30 years here in Florida as prior to this they supplied most single phase residential meter cans.

https://www.homedepot.com/p/Milbank-...4MlA&gclsrc=ds

-or-

https://www.gordonelectricsupply.com...06546e0a848889

[WNY_TomB]

This is probably a dumb question, but I'll ask anyway

I've noticed that sometimes if I'm not deliberate with the power switch when turning on/off it will cause the circuit breaker to trip. I've seen this with two Miller Syncrowave 250, three Syncrowave 250DX, and two Hobart TIGWave 250 AC/DC machines. Imagine flipping the switch and your finger slips and the switch slows/pauses along it's path...snap, tripped breaker. If it's a smooth, positive throw it works fine. All of these are old style transformer machines with similar construction.

I don't recall it ever happening with my Miller Dialarc 250 or any of the various Millermatics I've run (35S, 35, 200, 250, 250X, 251 or 252). I know it never happened with my inverter TIG.

I'm running them on a new, dedicated circuit that's a bit under 50ft long, 8ga wire, and a 40amp breaker (going to bump that up to a 50 or 60 soon since it's a dedicated circuit). I've been able to turn any of those machines up to full power and max the pedal and not trip the breaker, so I don't think there's anything wrong from a wire/breaker standpoint.

It's not a problem....it rarely happens, but once I noticed it I realized I could make it happen, and that got me wondering. Anybody have an idea?

.
starting surge current on electric motors often 400% of normal load usually amps goes down in less than 1 second and time delayed circuit breaker usually ok with it. obviously if machine rated 100 amps and on 30 amp breaker that way too small. surge takes longer if wiring or extension cord way too small too.

[Willie B]

This is so timely, my synchrowave 250 does this as well. Essentially at my old house I had a 50 amp but the the outlet was literally one foot away from the panel. In my newer house the panel is 100' away and it pops the breaker occasionally on start up and now anytime I weld aluminum over 175 amps. I'm so done with this BS. I had Edison out to the house to see what its going to take to increase my service cable size. Good news is that apparently Edison gives you up to $3,500 credit each year for stuff like this, something I was unaware of. So 400 amp panel here I come!! Calling Square D tomorrow to get the right panel that meets Euserc requirements.

In my limited experience, (51 years electrician), I haven't yet seen a 400 amp breaker panel in a home. We do two 200 on a very few homes. Usually these are multi million dollar mansions. Truth is, no single family home needs 400 amps. NEC limited breaker panels to 42 circuit, I think that did change a few cycles ago. 80 circuits would make a breaker panel very cluttered.

Here, we have Green Mountain Power. They routinely power a 200 amp service with a 104 amp transformer. If there are neighbors near, they share that transformer. Overhead service drops are never bigger than 1/0, then only very short. On a very few applications GMP provides two overhead service drops.

[scsmith42]

In my limited experience, (51 years electrician), I haven't yet seen a 400 amp breaker panel in a home. We do two 200 on a very few homes. Usually these are multi million dollar mansions. Truth is, no single family home needs 400 amps. NEC limited breaker panels to 42 circuit, I think that did change a few cycles ago. 80 circuits would make a breaker panel very cluttered.

Here, we have Green Mountain Power. They routinely power a 200 amp service with a 104 amp transformer. If there are neighbors near, they share that transformer. Overhead service drops are never bigger than 1/0, then only very short. On a very few applications GMP provides two overhead service drops.

Bill, 400a services are actually not uncommon in the SE USA. We have heavy hvac related loads during the summer, and a 4K+ sq ft house with swimming pool pumps, shops/garages and other outbuildings can strain a 200a service.