50amp spider box tripping when welder plugs into other spider box??

[Stinger208DQE]

I have a construction site which has two spider boxes each fed from a 50 amp 2 pole breaker off 100 foot 64 s o cord. When the welding crew plug their welder into one of the spider boxes a lot of the time the other Spider Box will trip. This is the main breaker on the Spider Box that trips. I have not been able to figure this out as the two spider boxes are fed off of different Breakers and different cord drops but from the same panel. Does anyone have any idea on why this would do it?

 

[ptonsparky]

I have a construction site which has two spider boxes each fed from a 50 amp 2 pole breaker off 100 foot 64 s o cord. When the welding crew plug their welder into one of the spider boxes a lot of the time the other Spider Box will trip. This is the main breaker on the Spider Box that trips. I have not been able to figure this out as the two spider boxes are fed off of different Breakers and different cord drops but from the same panel. Does anyone have any idea on why this would do it?

Is the breaker tripping a GFCI?

 

[ramsy]

..Does anyone have any idea on why this would do it?

Saw the portable welder’s from China, at Harbor freight last night. My bet, they don’t comply with FCC noise requirements. Radio frequency line noise may be tripping nearby GFCI‘s