Miller syncrowave 250dx

[sdezego]

I know this is not a welder forum, but I know a few run this machine. Has anyone ever had the main power switch fail? Mine has been going bad since about a year after I started using the machine heavily.

I finally had a chance to take it apart. I was going to just buy a new switch, but that would go against my better judgement So, I figured I would investigate a bit more.

I drilled the rivets apart on the switch and separated it. Well, as I expected, the contacts were shot (melted, severely pitted, etc). Ironically, only one set of the 220 contacts (double throw switch), the other leg was perfect

So, I went to Home depot and bought some 8-32 solid brass screws. I drilled out the old contacts, cut the brass screws to leave about 2mm of threads and peened them onto the contactors. I ground the heads flat to match the stock contactor width and re-tensioned the springs below. Then used some long 6-32 screws to hold the switch back together.

Works wonderfully, but odd that it failed to begin with.

I guess some pics, might have helped, but I was in motion..

Shawn

[blind]

My uncle has had miller power switches burn up at work. He told me they started turning the breakers off instead of the machine and they no longer have issues with them.

[sdezego]

Interesting...

Yea, if I wasn't able to come up with a good fix, I was going to bypass the switch with industrial Cable lug connectors and just use the breaker/disconnect on the wall.

[nubVR]

interesting........ thanks for the post!

[sdezego]

I am pretty sure this welder hates me..

Welded some stuff today and the coolant pump started making some odd noise, so I checked the level and the rubber flapper valve in the coolant cap, just fell apart and some must have fell into the the tank Now I am getting a HLP 19 code. Not sure if the pump went bad or it ingested a piece of plastic/rubber from the cap or what.

I will pull it apart and report back. I have had this welder for a few years now, but only have 1-200 hrs on it and have had nothing but problems what the heck.

And I have used RO-DI water in it from the get go, so I know it is not that.