Mig amps Vs Plasma amps?

[Shouting at cows.]

Morning all.

Probably a dim question to ask but why can my generator run my mig at 250amps happily but only run the plasma at 40-45amps.

What’s the difference in the way both machines consume the power?
Is a plasma cutting vastly less efficient in the way it uses the power compared to a welder?

Thanks.
Matt.

 

[Erie Fred]

What is the voltage of each process ?

 

[Brad93]

Morning all.

Probably a dim question to ask but why can my generator run my mig at 250amps happily but only run the plasma at 40-45amps.

What’s the difference in the way both machines consume the power?
Is a plasma cutting vastly less efficient in the way it uses the power compared to a welder?

Thanks.
Matt.

Voltage of plasma is often in the 100-160v range.

Mig/mag is 15-32v.

 

[Shouting at cows.]

Thanks for the reply’s
My old mig runs between 20-40v (at least I think it did before all the markings faded off!)

The generator is rated at 10kv 240v
And both machines are running off 32amp sockets.

How do the voltage and the amps correlate?
Sorry for the questions, just curious to understand it.

 

[Erie Fred]

Thanks for the reply’s
My old mig runs between 20-40v (at least I think it did before all the markings faded off!)

The generator is rated at 10kv 240v
And both machines are running off 32amp sockets.

How do the voltage and the amps correlate?
Sorry for the questions, just curious to understand it.

Volts X Amps = Watts

What is your genset wattage rating ?

 

[lynx85]

Generator is 3 phase or single phase? If your mig machine is 3ph and plasma is single, then plasma loads generator in worst way possible and can damage your generator. Read about balancing load between phases.
If that is not the case and generator is true 240V 10KVa, then it should power plasma just fine. For example, mig @40V 250A = 10000W or 10KW, plasma 150V 40A = 6000W or 6kw.
Provide datasheets from your machines, that would be helpful. Usually at the back, where input cable comes in.

 

[hotponyshoes]

Power is Watts

Volts and amps are how the power is moved around.

So, the generator delivers 230v × 32a = 7360 Watts

The mig and plasma adjust the incoming power to suit the process.

So if the wire coming out of the mig is at 30v you can get (W÷V) 245amps out.

If the plasma is using 130v to make the arc you can only get (W÷V again) 56amps

I don't expect either of these machines Draw the full 32a and both will use some power for operation which leaves you are about 200a for the mig and 40a for the plasma which is pretty standard for machines on a 32a plug

 

[hotponyshoes]

To answer the original question,
It's not how they consume the power, it's how they use it on the output side.

With mig you have the live mig wire getting pushed against the workpiece really close so you don't need much voltage to jump the gap (in short-circuit transfer).
Turn up the voltage a bit and you can jump a small gap and melt the wire before it contacts the workpiece (spray-transfer)

Turn the voltage up even more and you can jump an even bigger gap and you can stop the wire completely and just use the arc for cutting rather than melting in a filler wire.
As in a plasma cutter.

But see my last post as volts/amps/Watts all have to be linked together so if you use more voltage on the output side you'll have less amps available.

 

[Shouting at cows.]

Thank you to everyone.
It’s a single phase 10kv genset but realistically probably only 8.5kv.

And Hotponyshoes thank you. It makes sense what you said about the arc having to jump the gap, same as with to long/short stick out with mig affecting the voltage.

 

[E T]

When you run the plasma cutter do you run the compressor from the same generator?

 

[minimutly]

Generator is 3 phase or single phase? If your mig machine is 3ph and plasma is single, then plasma loads generator in worst way possible and can damage your generator. Read about balancing load between phases.
If that is not the case and generator is true 240V 10KVa, then it should power plasma just fine. For example, mig @40V 250A = 10000W or 10KW, plasma 150V 40A = 6000W or 6kw.
Provide datasheets from your machines, that would be helpful. Usually at the back, where input cable comes in.

It may be all on one, or two phases? And then you have compressor to run as well - is this on the same phase?
Or is it on three phase?