Plasma Cutter with Compressor - Too Much Current?

[SPIKER]

6 ga THHN is good for 63 amps, BUT not sure of the run/length you have so you may have had it de-rated for the voltage drop.

hope that helps.


I would suggest like someone already did, turn off compressor cut, stop for plasma cooling & on with compressor... much easier than running new wire if need be.

markM

 

[philbuilt]

Here is my though, You have a double pole 40 amp feed to the garage that = 80amps -20% for a total of 60amps use.
you should be ok. Please correct me if I'm wrong.
Phil

 

[Stimw]

Plasma cutters use a lot more air than you think because they use it during post cooling. If you hit the trigger it will run cooling air for 30 seconds or more after you stop cutting.

 

[RichT]

6 ga THHN is good for 63 amps, BUT not sure of the run/length you have so you may have had it de-rated for the voltage drop.markM

That is my concern. My 2002 NEC 2% voltage drop one way distance table shows 6awg with 50amps at 115ft which is in my ballpark. A 3% drop with 60amps puts me well within the run length. Any electricians on-board which can render an opinion?

 

[Highbeam]

I have run a plasma cutter and 5HP air compressor to cut metal in the field with, get this, my 5500 watt generator. Now granted the 220 plasma cutter wan't a high amp unit it still worked.

Both loads are 220 so the poster's setup should work fine. Nothing to lose by trying.

If you can use a 60 amp breaker on that 6 gauge circuit that is good news, I thin kyou can. Now is there a reason you need to use anything less than that same 60 amp main breaker at the sub panel? If the breaker protects the wire then it would seem that your 60 amp feed from the main panel could support a 60 amp main breaker at the sub.

 

[mudcat]

Here is my though, You have a double pole 40 amp feed to the garage that = 80amps -20% for a total of 60amps use.
you should be ok. Please correct me if I'm wrong.
Phil

 

[bucmeister]

Here is my though, You have a double pole 40 amp feed to the garage that = 80amps -20% for a total of 60amps use.
you should be ok. Please correct me if I'm wrong.
Phil

That would be 40 amps @ 120 in each of two legs for 80 amps total @ 120 volts, however only 40 amps when looking at it from the 240 volt configuration.

 

[philbuilt]

bucmeister,
You are right I checked with our company electrician. I do plan on putting my amp meter on my panel this weekend to check the running amperage. Now it's more of a curiousity than anything for me.

 

[390GT]

No problem replacing 40 amp breaker with a 50 amp in the subpanel.