View attachment 5B554972-5E68-4655-BBBC-7199FAADB6EC.jpg View attachment 5B554972-5E68-4655-BBBC-7199FAADB6EC.jpg

 

Disconnect the trigger connector, and see if it stops. If it stops, it might be a stuck trigger, or a shorted wire. In it doesn't stop, might possibly be the relay inside is stuck. Does the trigger move freely ? The gun usually gets most of the abuse, and dirt.


Good luck

 

The trigger is free and feeds very well as I can change feed settings and the gun responds but when I get close to my work piece or touch off with the wire at any length it will burn off back to the tip and or melt at the the tip. Gas flow is good also. The wire is staying powered up maybe? I’ll disconnect the trigger wire tomorrow and see what happens.

 

Do you have a manual? If not, download one from Miller, [Here] using the right search box, choosing the model name first and selecting the Serial Number range from the list of downloads it gives.

Then look at the wiring schematic and find the circuit with the relay for the weld current. Something there must be wrong. FWIW, once the trigger has been pulled and released but no welding done, the capacitors will have a charge that will cause a spark, but won't actually melt any wire.

Does that unit have the Spot Weld option (top right)? If so, are those controls set for continuous welding (vs spot or stitch)?

 

No spot weld option on this machine. I don’t think the wire being hot is from trigger pull, it’s trying to weld, very strong, not like a capacitor I don’t think? I have been studying a manual but I’m no expert either. My serial number and stock number is not showing in the database, only the year can be narrowed down by me alone. SN Jk600269 Stock Number 048290. I’m gonna pull off and check the CR1 relay and the main contactor W. Any ideas?

 

So the wire feeds when the trigger is pulled, but the gun is always hot (welding current on) and burns back to the tip when the trigger is released ? If so, there is the possibility that the "W" contactor is stuck in the closed position. Its an open contact, and junk can get in them or the can corrode, and wont move freely. With the machine unplugged, the contacts can be pushed together manually. They should move freely. All the welding current for the gun goes through this contactor , over time they can pit or weld together, as DC current is harder on contactors than AC.

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One or more sets of weld contactor contacts stuck. Shown as "W" on the wiring diagram and #18 on the parts breakdown illustration.

Easily serviced.

 

I’m going out to check contacts now. I ll get back to y’all shortly.

 

View attachment 6F3C7147-3AAD-417D-BE25-4F9AB3FC94C8.jpg

My contacts from item W..
They were stuck. I did clean them up and the machine welded pretty dang good. I’m currently using Argon. Testing was done on high setting and then I swapped to the low setting and it still welded surprisingly very well. I have heard a small pop a couple of times not knowingly seeing any odd affects? One thing I’ve noticed is that this machine is monster when it comes to running hot. I believe this thing has no limits for a garage or small fab or farm, it’s a hoss,!! Not so sure about thin stuff? Might just be my capabilities and set up so far? Gonna get some C25 and a new controller/contactor item W and go from there.

my contacts.

 

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Can someone recommend a replacement part and part # ? Millermatic 200 jk600269 sn.

 

Can someone recommend a replacement part and part # ? Millermatic 200 jk600269 sn.

From the printed-page #52 of This manual for your machine, Contactor W (part 18) is a 60 amp, 3-pole, 120v coil magnetic contactor, Miller part #114 780.

An equivalent Definite Purpose Contactor would be This Eaton one, sold on Amazon and found in a quick search. I'd do much further searching before ordering one.

For example, it looks like that same unit shows up as an "open box" unit on Ebay for a bit less:
https://www.ebay.com/itm/3949563897...EAf/GUBlh1GVVyVMY5lyvMrlz5pz788S0IptwyD7L6IPlJABGuAZSXZZCA==|tkp:Bk9SR-yR3qzuYg

 

I use Grainger occasionally, but something similar to this might do. You might find cheaper at a local electrical supplier. Make sure the coil voltage is correct, and that it has the same spacing for the buss bars. Should be 3 NO contacts

View attachment Eastoncontactor3pole.jpg


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best of luck

 

I use Grainger occasionally, but something similar to this might do. You might find cheaper at a local electrical supplier. Make sure the coil voltage is correct, and that it has the same spacing for the buss bars. Should be 3 NO contacts

View attachment 1770601


]

best of luck

Your first one, the Eaton, is the same one [C25FNF360A] I found and posted about above you, mine coming from both Amazon or for the second, from Ebay. But then he bought something else....:laugh:

FWIW, electrolytic capacitors that have been idle a long time can need "reforming", which is gradually turning up the voltage, allowing the internal layers to form without shorting. Besides running an idling machine off a large 220v Variac, (which I do have), is there any other easy way to do it on an old machine with installed capacitors? Wonder how long it takes a good capacitor to "refill" when recently working machine is turned on? Seconds, tens of seconds, or fractions of one?

 

Thanks guys for that info? Now I’m in search mode. Whew they can be pricey huh?

 

Just noticed that "W" is between the transformer, and the diodes. So its AC going through the contacts, not DC. Still there's an awful lot of energy in that circuit, and that why the contactors can be a little pricey, and Grainger isn't always(maybe even ever) the cheapest.


Stay safe, and watch out for juiced up capacitors.

 

OK so now I have ordered a 3 pole, 60 amp , 120v contactor and I believe the lugs will fit also. It’s a cheapo from Amazon and is returnable if the lugs won’t fit.
so now I’m looking at capacitors. 15000uf 50v Cornell Dubilier CGS153U050V4C. So any comments?? $35 each?
View attachment 2141B572-7313-41D4-AA32-8C94D0364C69.jpg

 

Thanks duaneb55. Good call and got me started on this old gimme machine. It’s alive! Needs minor tuning and clean up with some tlc and paint now. I’m starting to understand the basics of how this thing works and I mean like 4 step basic only.

 

I didn't search it out BUT you can get replacement contact kits for those and other contactors.

This is one of my go to's for replacement caps.
https://www.tedss.com/2020004768

Where ever you get them be sure they are of the "high post" terminal style so the buss bar clears the cap bodies.

 

Use the manual to learn out settings, techniques, and proper adjustments as well as maintenance. Its a pretty good manual.

http://www.millerwelds.com/files/owners-manuals/O1303L_MIL.pdf



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View attachment mm200maintpic.JPG

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Most parts on this machine are available from electrical supply houses, or some welding supply places. They were very popular back in the day, many shops have one that got pushed into the corner, or back of the shop somewhere. The wire feed motor and gearbox seems to be the hardest part to find on them

Good Luck with yours.

 

Search the Furnas PN 42EE108897R and several exact replacement reasonably priced sources will come up.

 

Can the capacitor bank be tested as a whole or is it irrelevant? I have pulled the bank back and visually inspected the caps and found no abnormal bulging or smut. I have not taken them out of the rack. You guys got any data related to testing that would signal replacement?
I checked out the the link that Duaneb55 sent and that was spot on but it is almost $300 to replace them all. The machine is running pretty good and will run better I think with a different gas and new contacts, and fine tuning setup.
Test capacitors??? Order a couple for spares?

 

Sorry guys I should’ve searched first. Just found the answer to cap test in another post.

[h=2]Re: Millermatic 200 not as hot as it used to be.[/h]

Testing cap bank is hard. most of us do not have access to the equipment needed.
The quick simple test I have found is done while welding.
set welder up and start a weld. slowly lift gun up and increase the stick out.
If the arc dies and you only have 1/4 inch of wire sticking out the tip. Cap bank is bad. A good cap bank will keep the arc going with up to 1 inch of wire sticking out the tip. One other thing you can do is look at the tops of the caps. Check the vent plug. If vent plug has a small bump sticking up cap is failing. is has over heated.
also check the mounting screws, black around them show they has started arcing.
If you want to replace it buy the cap bank from the Millermatic 252 and bolt it in.​