[Welding Mike]

Hello

I have a MAX200 that randomly trips a 56 amp d curve breaker when it goes to fire the arc. Have had a test meter on the cable and it trying to pull 577 amp from the mains(yep 10 X what the breaker is rated for !!! ), when it does fire it drops down to about 20 amps. Any ideas on what may be going wrong. It may do 28 starts then trips and then other time it has done 150 start before it trips again ...

Mike

[jimcolt]

Plasma systems have an extremely high inrush current....this occurs when the gas becomes ionized in the torch and a rush of current is needed from the power supply to maintain the arc.....the actual inrush current is probably closer to about 10,000 amps for a few line cycles. It is always recommended that you use either time delay fuses to accomodate this, or specify high inrush circuit breakers.

This is a common occurence with any piece of equipment with a large inductive load. The reason for the random occurence is simply timing....the inrush current can be higher if the arc happens to fire right at the right point of the AC sine wave.

Jim Colt Hypertherm

Hello

I have a MAX200 that randomly trips a 56 amp d curve breaker when it goes to fire the arc. Have had a test meter on the cable and it trying to pull 577 amp from the mains(yep 10 X what the breaker is rated for !!! ), when it does fire it drops down to about 20 amps. Any ideas on what may be going wrong. It may do 28 starts then trips and then other time it has done 150 start before it trips again ...

Mike