Tripping Pro Power breaker with 120v welder

[alexose]

Now that I'm a Truck Guy™, I decided I needed to learn how to weld. So I went to harbor freight and got a small welder and convinced my diesel mechanic buddy to show me the ropes.

The unit I bought had a pretty short extension cord, so I figured I'd just plug it into the bed outlets and we could practice in the driveway. However, as we were going over the basics, the welder only work for a few seconds before Pro Power decided it was drawing too much current and turned off.

Based on his facial expression, I could tell that my teacher was unimpressed with my high-tech truck. He suggested I get an extension cord and plug it into the house. I assured him that this wouldn't work either, since we'd be plugging into a 15A breaker. Of course, it worked fine. The expression returned.

Dear readers, I'm not sure how to understand this. The welder pulled enough current to alert the Pro Power software, but somehow not enough current to trigger a 15A breaker.

Has anyone run into this before?

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[Azgunguy]

You need to look at the amp draw of the welder. I was using my titanium flux core welder yesterday (small green lunch box one). I was testing it to make sure it still worked for my cousin to use. It kept tripping the gfci, so I checked the amp draw and it’s 24 amps. On a 20 amp plug. So I had to turn down my power/ wire feed speed to make sure it didn’t trip.

 

[Runaway Tractor]

I have the same welder. I use it on the 15 amp circuit in my garage without issue. Haven't tried it on the truck yet. Was the message tripping on overload or ground fault? I'll try it this weekend as well.

 

[Azgunguy]

I have the same welder. I use it on the 15 amp circuit in my garage without issue. Haven't tried it on the truck yet. Was the message tripping on overload or ground fault? I'll try it this weekend as well.

For me it was overload. I used to use it on my 15a garage outlet and it would blow all the time. But I was always welding 1/8 on it which is on the upper end of that welder.

 

[alexose]

I have the same welder. I use it on the 15 amp circuit in my garage without issue. Haven't tried it on the truck yet. Was the message tripping on overload or ground fault? I'll try it this weekend as well.

It was overload. Odd considering it didn't trip the 15A breaker on the house, though. Maybe the software is throttling it somehow?

 

[Runaway Tractor]

The overload in the truck is much more sensitive than a home circuit breaker in my experience. If the welder has a high in-rush current, that will trip out the truck but not the house. No clue if these little welder have a higher in-rush current though.

 

[alexose]

The overload in the truck is much more sensitive than a home circuit breaker in my experience. If the welder has a high in-rush current, that will trip out the truck but not the house. No clue if these little welder have a higher in-rush current though.

I don't think it's inrush current, since it was able to run for a good 3-5 seconds before shutting off. I think it must be unusually peaky while it's running.

Maybe there's a way to smooth out the current draw?

 

[alexose]

You need to look at the amp draw of the welder. I was using my titanium flux core welder yesterday (small green lunch box one). I was testing it to make sure it still worked for my cousin to use. It kept tripping the gfci, so I checked the amp draw and it’s 24 amps. On a 20 amp plug. So I had to turn down my power/ wire feed speed to make sure it didn’t trip.

I was welding 3/16 so it was set pretty high. Awfully sketchy for it to draw that much current when it's only equipped with a regular 120v plug.

 

[Heliian]

I've run grinders and air compressors off my pro power and it performs better than my shop outlets.

I would test that welder to see how much it really draws. I'd guess that it's spiking beyond what it claims.
Also, as someone posted above, the trip threshold is different but its still pretty high.

 

[potato]

You could get an L14-30P to 6-20R adapter and use the 30 amp outlet. But yeah the welder is suspect. Household breakers take some time to heat up and trip so they might handle more of an overload.

 

[Runaway Tractor]

I agree. Nothing that plugs into a 15 amp outlet should be pulling 25 amps by design. The only time I tripped mine was when turned up really high, and also with other things in the garage on, so I didn't think much of it.

 

[hturnerfamily]

ALEXOSE, you don't mention whether you have the optional 9.6kw ProPower...

A) if you DON'T, the bed outlet is shared by the Cab and Frunk outlets, on a 2.4kw inverter, which is a Maximum amperage of 20 amps, shared by all of those outlets. Were you using any other outlets at the same time?

B) if you DO, the bed outlet circuits (A) and (B) originate from the REAR 7.2kw 240v inverter, which is a Maximum amperage of 30amps for the 240v twist-lock outlet, and 60 amps of 120v shared between the two 120v outlets(30 amps each)... yes, that's 30amp from each 120v OUTLET... I've tested this and pulled 30amps with several heaters and a toaster before the circuit tripped.
These outlets are shared from the 240v inverter, so while the outlets 'look' like typical household outlets, they are actually engineered to handle the load. Nothing in Ford's documents shows these as 'only' 20 amps of power, although many conversations and terms seem to label them that way.

I would suggest that it's not just the truck, or the truck's power, or even your 120v welding device, it's just the combination of the sensitivity of the truck's power monitoring while the device is in use.

Your home's breaker, wiring, and main panel are not nearly as 'sensitive' to this up and down of amperage while the welder is in operation - as most home breakers can handle a lot more moments of being 'close to' or even 'over' the actual breaker's limits before actually tripping. A breaker is not typically designed to 'immediately' trip just because a short time of amperage might otherwise take it too far, but it's more about the 'constant' power, or HEAT, that causes the tripping.

 

[Monkey]

I was welding 3/16 so it was set pretty high. Awfully sketchy for it to draw that much current when it's only equipped with a regular 120v plug.

Welcome to the world of cheap, Asian-made welders. Probably not UL listed and all that. It should be equipped with a 30A plug.

 

[Runaway Tractor]

B) if you DO, the bed outlet circuits (A) and (B) originate from the REAR 7.2kw 240v inverter, which is a Maximum amperage of 30amps for the 240v twist-lock outlet, and 60 amps of 120v shared between the two 120v outlets(30 amps each)... yes, that's 30amp from each 120v OUTLET... I've tested this and pulled 30amps with several heaters and a toaster before the circuit tripped.
These outlets are shared from the 240v inverter, so while the outlets 'look' like typical household outlets, they are actually engineered to handle the load. Nothing in Ford's documents shows these as 'only' 20 amps of power, although many conversations and terms seem to label them that way.

Wow that is great information. Strange of them to do that 30 amp thing on what anyone else would assume to be a 20 amp circuit. Guessing this is a combination of cost savings to not have additional 20 amp circuit protection. And also ends up being good for the user with less complaints and less nuisance tripping. Users tend to push it and overload things, and like you said it is more sensitive than a home breaker. Much less likely to nuisance trip if the users think it is 20 amps but it's really 30.

 

[Maquis]

A UL listed device that draws more than 15, but not more than 20A will have a NEMA 5-20 plug. With Harbor Fright, all bets are off.

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