I have an old miller AC welder, the model is M-180P. It
looks like de capacitor needs to be replace. The guys at Miller sent me a
part number and a pricy price ($150). Although I had asked for
As equivalent parts could be purchase at a better price,
does anybody now of a way to get specifications for the capacitor?
Soon a beginner.
here is what extra information I have (given by Miller tech.): The
part no for the capacitor on the M-180P is a 059417 and list price
is $149.53 US. Hopefully this will help you have a nice day.
There may have been a part number on the capacitor itself but no
info. on fharad, volts ... and it did say Miller.
"Tm" a écrit dans le message de news:
If you machine is an old AC buzz-box then it is likely that the capacitor is
a power-factor correction capacitor. If so, it is likely connected to from
one of the primary power leads to the transformer and the other end is
connected to a separate lead coming from the transformer. This is how my
Miller Thunderbolt 225 is shown but there are no values given and my welder
doesn't have this option.
If it is a power-factore correction capacitor, I would think that you should
be able to run the welder without this capacitor. Maybe somebody on this
forum can be more definite. It will draw a bit more current (but not cost
you anymore money since the extra current is reactive) but that shouldn't be
Can you let us know where the capacitor connects to in the welder?
Since you say the welder is an AC welder, it sounds as if it is a power
factor correction capacitor. Can you describe the capacitor? Oval
metal case? Size?
You might take the cap by a heating and air conditioning place and see
if they have an idea of what it is. $ 149.53 sounds like a very high
price. The airconditioning place is likely to have some similar caps
that they are throwing out. You might take some doughnuts 8-).
you are rigth the capacitor is power factor correcting model
(m-180p; p-->power correcting ...) And yes what you describe for the
wirering seems correct. The looks of the capacitor is metal all around and
top. With some oil sipping out, maybe bpc? The overall dimension is approx.
3x4x5. I will try to take pictures of it for you. But Easter time will make
me be away until wednesday.
Until then take care!
"Tm" a écrit dans le message de news:
I have not used this welder, the seller showed me that it work.
After getting the owners manual from Miller I opened it up for the annual
check up. This is when I saw the capacitor sipping, lightly, oil. When I put
the Ohmeter on the capacitor it has zero resistance. This makes me think
that it is not in functionning condition.
Is this a correct conclusion?
"Randy" a écrit dans le message de news:
You must disconnect at least one terminal on the capacitor before you
measure it. If you don't the ohmmeter will read the resistance of the
transformer coil in parallel with the capacitor.
When testing the capacitor you may see the ohmmeter needle move a little
when the capacitor first charges then settle back to a very high resistance
reading (ideally infinity).
The dripping oil is not a good sign but if it is very little it might not be
A very large cap, like I expect this one is, may require a lengthy
period before the it is charged up by the ohmmeter. Until that happens,
current flows through the cap, and the ohmmeter senses low resistance.
How long did you measure it?
Gilles Marchand wrote:
Well you got me wondering if I did this rigth. Actualy, I removed de
capacitor from the welder. It had no more wires to its connectors. Then I
mesured it with the ohmmeter. With no resistance...
How does the correcting capacitor help in the welding process? Or
what exactly is its purpose?
See you wednesday!
"Gerald Cooper" a écrit dans le
message de news: email@example.com...
If it had no connections to it other than the ohmmeter leads and it read 0
ohms (or a low value) the capacitor is shorted. If it is a power-factor
correcting capacitor it does not play a part in the welding process. To put
it very simply, the capacitor cancels out some of the effect of the big
transformer in the box and permits the welder to use smaller supply wires
and circuit breaker.
When you say no resistance, do you mean that there is no change is
indication on the meter when you connect it to the capacitor? I
suspect that is what you mean, because you said you saw the welder work
before you bought it. And if it had a really low resistance, it would
have drawn a lot of current, heated up, and exploded.
Assuming that the capacitor is not shorted or open, you ought to be
able to take it to a air conditioning shop and have them measure the
capacitance. The meter you have might work, digital multimeters in the
thirty dollar range now often have capacitange scales.
My dad had an old Forney welder that blew the capacitor and he took it
to a shop. They disconnected the capacitor and it has worked just fine
for the last 25 years.
If I were you I'd disconnect it, put the cover back on, and use it.
Gilles Marchand wrote:
Check the cap again. When you first touch the meter to it you should grt
some kind of reading in numbers. Eventually it should read as an open
circuit. Try this a few times momentarily shorting the cap with a jumper
wire after each test. A good oil cap should read infinite ohms eventually.
If it checks good see if there is a capacity checking postion on the meter
and see if you can measure it using this position. The cap maybe OK even if
it is leaking a little oil. Soon it will be bad though. If you can measure
the capacitance and tells the guys at the electrical supply place for what
you are using it they can probably give you a replacement. If you cant
measure it they can probably do this to as most decent meters have theis
capability these days. This all hinges on the premis that it is not shorted
or open ,just leaking a little oil. Baring this look at similarly rated
welders that have a cap. Value should be close.Once you find the value I
cant imagine it costing more than about $20.Also google checking a capacitor
Well I found a shop to test the capacitor, I live in a small
town..., it tested brooken. But he could not come up with a replacement
part. So maybe I will put to use the adage: If it works do not fixe it!
Thanks for help.
"Gilles Marchand" a écrit dans le message de news:
If you can determine the maximum voltage across the capacitor and give the
size or a picture with a reference item such as a coin,
it may be possible to estimate the ratings. Most of these oil filled AC caps
scale with the size.