miller 320a/bp problems.....

[leeben85]

hi new to the forum and I hope you guys can help picked up a really nice 320a/bp from a trade school auction with remote pedal for next to nothing but here's where it goes bad when I try to strike an arc you have to scratch start and I can get it to arc but it refuses to melt metal the arc sounds like a fuzzy buzz and does little more than etch the surface of aluminum on high setting here's what I know....

I switched the voltage to 230v
I put a 25ft tig torch on it too long????
gapped the points to .008
adjusting the frequency knob changes the tone of the spark between the points
the mica capacitors appear to be leaking goo down the front panel
the pedal turns the current on but seems to have no a

[leeben85]

for some reason my post got cut off
the pedal turns current on but now has no affect on amperage
hopefully some of you guys can help me out thanks

[Aeronca41]

If you put the standard/remote switch in standard, can you control amps with the front panel knob? Please post serial number, and you may want to read through the "new to me Airco 3a" thread. Essentially the same machine as yours.

Will it stick weld?

[leeben85]

tried it in standard same problem haven't tried stick welding with it

[leeben85]

Serial number u512539

[Aeronca41]

Is this a Miller branded welder, not an Airco? S/N should start with two letters. No listings on the Miller web site that start with a single letter. Maybe it's really old? If so, you will need to call Miller and they will most likely be able to email you the correct manual. Not sure how to help without being able to look a manual that is at least close.

Btw, that thread I referred you to earlier is for a 330, not a 320. I am not sure of the differences.

[ryanjones2150]

The manual is probably the same. It has both machines in it. At least mine does. <br />
<br />
So I don't think that's a frequency knob you're turning. It's probably the HF intensity knob. It's on the front, under the lift up door, just about the gas solenoid I bet. <br />
<br />
Check the F1, that's the fuse on the body, top left by one of the remote plugs. <br />
<br />
I guess we really need to know which machine you actually have first. If it's an airco, Miller is going to want the stock number from the front of the machine to get you the right book.

[fcanaan]

Aeronca41 ive noticed that too. If you put in any of of the old numbers into the lookup it doesn't work sometimes. I usually look at this chart. We should have this link as a sticky: https://www.millerwelds.com/support/serial-number-chart

leeben85 That machine is from mid 1969, just like mine.. let me get to the garage.. set your switches to look like this:

[fcanaan]

Here is what's goin on under the apron


That big knife switch on the left side, when in the open position, sets the machine to TIG mode. Lower left is you water solenoid valve, in the middle is your post flow timer, and the right is your gas solenoid. The dial in the upper right is your HF intensity selector knob.

Are you seeing lightning between the spark gaps when you hit the pedal?

[leeben85]

thanks for all the responses! yes I was turning the frequency knob under the lid knife switch is up in the tig position fuse blew out once and has been replaced and hasn't had trouble since lightning starts when I push the pedal

[fcanaan]

i sent you a pm.. Do you have a decent digital multimeter? Id test your open circuit voltage next..

[leeben85]

thanks fcanann ill dig deeper

[ryanjones2150]

You're gonna end up taking the side off and inspecting your contactors. Right side, then there is a black box looking cover you'll have to remove to the right of the wire bridge. One screw on the top and another on the bottom. Will be four contactors under there. There is a fifth if your machine has a spot timer, but I'm not sure where it's located. <br />
<br />
There is one particular Miller tech that is pretty all over these old machines. If you end up going that route, I can PM you his name and number. Very helpful guy. <br />
<br />
A lot of the parts available for this old machine have updated part numbers that you'll probably have to get from Miller. I'd be sure to get those part numbers from the tech and not just the parts folks, there are some differences in what they recommend.

[Aeronca41]

Aeronca41 ive noticed that too. If you put in any of of the old numbers into the lookup it doesn't work sometimes. I usually look at this chart. We should have this link as a sticky: https://www.millerwelds.com/support/serial-number-chart

leeben85 That machine is from mid 1969, just like mine.. let me get to the garage.. set your switches to look like this: [ATTACH=CONFIG]n577747[/ATTACH]

Yes-most often with the older machines you have to put the model name in the other search box then choose among the ser no hits. In this case, the ser no is apparently so old the manuals aren't on line. I had the same problem with my ancient MM200. A phone call had a manual in my inbox in about an hour. Great service from Miller!

fantastic that you have the same machine; very helpful to be able to look at the parts when helping someone out.

[leeben85]

may be on to something pulled the side covers off and gave everything a once over the only thing that popped out was the amp range copper contacts are filthy and look pitted going to polish them up tomorrow just wondering if any one puts some kind of contact grease on them? or just clean and dry