PF Capacitors for TIGWAVE 250?

[AWRIGHT]

Can anybody tell me the capacitance of the power factor correction capacitors in a TIGWAVE 250 AC/DC? I have the owner's manual from Thermal Arc but as far as I can see, it only shows two paralleled "460V" capacitors wired to terminals 1 and 20 on the main power transformer without indicating their values.

Thanks for any help.

awright

[canoecruiser]

Can you open the machine up? If you can read whatever markings you find on them, one of those numbers will be the capacitance. It will (most likely) be a number followed by MF or MFD or some variant of that. If there is a manufacturer name and part number, post it here and I'll try to decipher it for you.

While it goes without saying, I'll say it.....unplug it from the AC power line if you do this.

[dsdrewyor]

I went and looked at my TW 250 because I just happened to have the cover off and there are no capacitors in mine. The diagram shows them, but they also say they are optional. You might want to check to make sure your machine has them. My machine is the SP7114-001. The parts list shows (2) 460V 35mfd caps Part # 8TW-130 so I called and spoke with Jeff at Thermal Arc and he confirmed that they were the ones. Let me know if you have them. Jeff said they were to limit the current draw from the source. They acted as a reserve because some of these machines pull major current. Take care

Dave

[Blacksmith]

If they are PF; power factor [correction] capacitors, they don't really affect the welding, just the power bill. Power is generally metered simply as volts times amps (VA), in a purely resistive circuit you get some work out of every VA. Large transformers require power to magnetise the windings, this is often called volt-amps reactive (VAR). The VARs produce no useful work, other than making transformers work, but spin the meter up. A capacitor will produce VARs, thereby cancelling some of the VARs the power company provides. In a home setting it's not too bad, but line a few of these machines up, add a few motors (magnetic coils) and power factor correction can save big bucks (maybe 30%) on the bill. This is the idea behind the "green" plugs, etc. you see for your refridgerator, etc. except those are 1-12 hp motors and industry uses 500+ hp motors.