power factor correction capacitors

[Carl W.]

I have a 11 year old 350 syncrowave that runs on 230 volt/single phase with power correction capacitors that runs on 230 volt/single phase. At idle draws 53 amps, removing the caps draws 5.2 amps. At what welding amperage will the caps "begin" to help at keeping primary amperage lower than without caps? As I recall there were two or three caps installed by the factory when I purchased the welder new. I'm thinking of adding switches to add and remove caps as the welding amperage demands increase and decrease. All this will be installed when I get the welding torch amperage range that the caps "begin" to help. When running five to seven hours a day on weekends with caps at low amps the meter really spins. Whats your thinking on this? Suggestions? Ideas? This Forum is the best!
Thanks,Carl W. ........=o&o>.............

[ASKANDY]

This is a good question that will be hard to explain but we will do this as simple as possible.

You power factor caps help get the voltage and current back in phase with each other. Because the machine has a large transformer, it appears to the primary power like an inductor which causes the current to become out of phase with the voltage applied to it. this causes the primary current draw to become higher and may cause some tripping of breakers or limit the number of other items you can run off that box. It DOESN'T change the KW or Kilowatts used by the machine which is what your meter measures for usage. This is why the power company likes people to have power factor and will sometimes surcharge companies that have a large power factor % because they are supplying more power that they are charging for. If you get your owners manual this is in the power draw specifications area and if you look under with or without powerfactor caps, the KW used is the same.

To answer your question, It doesn't matter. Where you gain is on the amperage used while welding. It frees up some amperage so you can run some more stuff from that line. It doesn't change what you pay for power while welding. I hope this made a little sense. This is a much confused subject because the general public puts a direct relationship with amperage and KW used and that is incorrect.

Hope this helps.

Andy