[big iron]

Question for Jim Colt,
We have 4 late model Hypertherm 1000 G3 Plasma generators that are set up on the same type CNC tables. Two are single phase 220 volt and two that are in a different part of the shop are set up for 3 phase, 240 volt input.
The small voltage differance aside everyone here thinks that the machines on 3 phase cut better, all output settings are the same and all are useing the same fine cut consumables.
I was told at the time I purchased these G3's that there was no output differance between single and 3 phase input.
What are your thoughts?

[jimcolt]

In most cases there is no difference in ouput With a Powermax1000 when comparing operation on single phase or 3 phase power input. The unit is designd to operate on a very wide voltage input range, between 190 volts and 600 volts input is acceptable for operation.

There of course could be exceptions to the above statement if you were comparing single phase operation with input voltage of say 208 volts to a three phase input of 480 volts.....but the difference in performance would only be noticed when cutting near (or exceeding) the maximum rated mechanized thickness capacity of the Powermax1000.

You cannot produce power in the plasma system.....so if there is less power available in killowatts at the input line than you are trying to cut with.....it just won't happen!

As an example I like to use our Powermax30 system which will operate on either 120 volts or 240 volts. This unit will sever 1/2" material on either input voltage level.....however I get calls from customers saying that it trips the breaker when they try this on 120 volt input.

When operating on 120 volts, while cutting the same thickness steel as you would if you were rnning on 240 volts, the Powermax30 will draw twice the input amperage. Most 120 volt circuits are wired with 12 gauge wire and have circuit breakers rated for 20 Amps.....and if you are running the PMX30 on one of these circuits for cutting 1/2" steel....it will easily draw as much as 30 Amps.....the 12 gauge wiring will over heat and will drop the input voltage, meaning you are tring to pul more power from the circuit than it can possibly deliver, and in a few seconds the breaker will trip. If you run a 30 Amp 120 volt circuit wired with 10 gauge (or better) input wiring, the Powermax30 will perform identically on 120 volt input power as it would on 240 volt power.

A similar scenario will affect performance of the larger units such as the Powermax1000 and Powermax1250.

Jim Colt