Miller 250DX power issue

[cruizer]

never drawing 60 amps at idle, thats just a ghost reading, whats happening is that the PF caps are charging. this eliminates any surge on the line once the machine is up and running. and yes industrial machines are being used constantly, unlike garage machines which are used erratically and often turned on and off, so the caps would charge then discharge when shut off, only to have to recharge when turned back on.

[ryanjones2150]

So it's pretty close to what I thought, minus the technical stuff. Not that long ago I passed on a decent deal on a dialarc 250 HF-P because of that. Wasn't sure if you could just unplug that stuff inside or not. Guess you can, depending on the machine of course.

[Meltedmetal]

Power factor is calculated by comparing the KVA to Kw. That is the apparent power to the real power. The power company wants it as close to kva=kw as possible which expressed as a fraction would be 1 if they are the same. The difference is lost in the transmission lines mostly as heat, I suppose. Transformer welders can be particularly bad as are large motors running unloaded(think continuous run compressors unloaded). I think IIRC that the specs on my Idealarc 250 without power factor correction is in the neighbourhood of 65%. Power Factor correction would reduce the loaded (welding) current by 30% and permit using smaller supply wire and smaller breakers, but it will change the idle current draw from 6.2 amps without power factor correction to 23 amps with it.IMO if you are in a situation where you will not be penalized for poor power factor(non-commercial) power I would not use power factor correction but if you are looking at monthly fines for poor power factor(commercial power) I would use power factor correction. I certainly don't weld continuously enough at home to justify power factor correction so the machine idling "on" but not welding while I re-position stuff, grind or whatever means I would use more total power if I had power factor correction than without it.
That said the new "smart meters",I'm told, are capable of delivering power factor information to the power supplier. The old single meters were not but they were designed when most domestic power consumption was resistive loads and power factor for houses was not a consideration as most were pretty good. The world has changed and we may see a time when the utilities may start to penalize homeowners for poor power factor usage.
It is my understanding that inverter machines are very efficient and as well as being able to perform various customizations of your arc, will keep your utility happier.---Meltedmetal

[griff01]

What's the purpose of the power factor doofloppy?

Not any benefit for a home or small shop. In a large shop (really large) the power companies penalize them on their electricity bill if their PowerFactor gets out of whack. If I remember correctly, they want the PF just below "1". If it gets to or over 1 they are penalized.
The PF (capacitor kit) helps to alleviate this.

Griff

[H80N]

What's the purpose of the power factor doofloppy?

It makes the power wattmeter think it is drawing less power under load

https://en.wikipedia.org/wiki/Power_factor

[ryanjones2150]

What's the purpose of the power factor doofloppy?

[griff01]

This was the issue. At idle it was drawing 60A. Unplugged them and it's drawing around a couple amps at idle.

Thanks for the feedback. Glad you got it figured out!
And just so you know, these aren't mentioned in the manual for the machine. The wiring diagram comes as a separate sheet with the capacitor kit.

Griff

[Zapperman]

Yep. That's the PF correction kit.
I see also that Cruizer has more info for you.

Griff

This was the issue. At idle it was drawing 60A. Unplugged them and it's drawing around a couple amps at idle.

[griff01]

Yes I believe it does have this. Looks like 4 beer can sized capacitors inside the unit.

Yep. That's the PF correction kit.
I see also that Cruizer has more info for you.

Griff

[cruizer]

parent board and IGBTS is likely smoked

[Zapperman]

TNX...

Built in the second half of 2003

Here is the link to download the correct manual version

https://www.millerwelds.com/files/owners-manuals/O359N_MIL.pdf

Thanks but I already have the manual and I didn't see my issue in the trouble shooting section

[H80N]

lc530538

TNX...

Built in the second half of 2003

Here is the link to download the correct manual version

https://www.millerwelds.com/files/owners-manuals/O359N_MIL.pdf

[Zapperman]

serial number..??? Pls....

lc530538

[Zapperman]

You may have a Power Factor correction kit (capacitors) installed. It actually pulls more amps at idle than in use.

Griff

Yes I believe it does have this. Looks like 4 beer can sized capacitors inside the unit.

[H80N]

Serial Number..??? PLS....