Upgrading garage circuit to 100A?

[Ignoramus8797]

Your buzzbox probably has lower open circuit voltage and lower welding voltage.

i

[John Grabowski]

What type of phase converter do you have? Is it motor driven? That may be contributing to your load and causing the breaker to trip.

[Ignoramus8797]

It is a rotary phase converter, with two idlers, 10 and 7.5 HP. It has a power factor correction capacitor, which mitigates power factor issues when it idles (no load).

i

[John Grabowski]

The phase converter is probably your problem. Those things consume power. I only suggest the use of them as an absolute last resort. Any chance that your welder will work off of single phase?

[Ignoramus16643]

It is a good question, but, unfortunately, there is no such chance. Everything inside it is 3 phase, the 3 phase transformer, 3 phase SCR rectifier, SCR firing controller that insists on having 3 phases, etc.

i

[John Grabowski]

Well I guess you can decide if it is cheaper to buy a single phase welder, or upgrade your subpanel, or install a separate circuit for the welder. If you decide to install a separate circuit for the welder you should take the load for the phase converter into consideration. One horsepower equals 746 watts. It sounds to me that if you didn't have the phase converter, you could probably use the welder on your existing subpanel. The more juice you need for the welder, the harder the phase converter works and draws more power. Your electric meter is also spinning more as that phase converter consumes power.

Another option is to contact the power company to find out if 3 phase power is available in your neighborhood and get quotes as to the cost to install a

3 phase service.

[Ignoramus5457]

This welder's main problem is bad power factor. It uses a lot more current than would a machine with better power factor. Looking at power, my 60A circuit can produce 14 kW, which ought to be enough for any welder or cutter. But this thing has a low power factor.

Yes, good point, I can check on that.

igor

[John Grabowski]

Why did you buy this monster? Are you planning to move to a commercial shop someday? It sounds like it is more trouble than you need for a home shop welder. My advice is to sell it and get something suitable for your situation.