Miller XMT 304 low OCV display and welding higher than set amps

[mandylad]

Hi,
I picked up 3 304 xmt cc/cv welders the other day 1 is working the other 2 were sold to me as for parts.One of them won't turn on at all but the other would turn on but no display would show up so i opened it up and found that the display board was not connected up so i got it connected up and if fired up no problem. When i try to weld in stick mode it seems to be welding at a way higher amp than ive the machine set at for example if i set the amps at 120 with a 3.2mm rod it will weld at 260 amps give or take.when i strike the arc and weld then stop and look at the machine the amps will be up over 260. for few seconds after i've stopped. The amps will stay up over 260 then drop back down to were i had the set at 120.It doesnt matter where i set the amps it will weld at a higher amperage than i set the machine at.The only way i can get it close to the amps i want is if i turn the dig setting all the way down and if i do that it will weld alot closer to the amps ive set the machine at for example if i set it at 120 amps it will weld at like 130 or 132 amps. Another thing i noticed id the OCV dispaly is way lower than it shoud be. It reads .7 or .8 sometimes 4.4 or 3. something really low all the time.It did show 78.0 for a minute but it changed back to 4.4 before i got a chane to weld with it. Would any of you guys have any idea why it's welding at such high amps when i don't have it set that high?? and why the OCV reading is so low on it?
I have pics and a few short videos to put up but they won't load at the minute i'll try and get them later. I don't think there is anything major wrong and i'm hoping it can be a easy fix Any help or advice will be greatly appreciated.

[Munkul]

Hi mate, thought it would be easier to reply here than pm. Sorry I have no idea about those problems, it would indicate a bad part somewhere, but it'll take someone good with electronics to figure it out.

[mandylad]

Well Im on the case LOl!! I'm checking things out on it now and looking for bad or burnt wires .If i can't manage to fix it myself I'll get some who knows all about it to take a look.There isn't much up with it it's nearly going good . I only paid £5.50 for it on Ebay sp it's worth a go.. How is your XMT going for you ?is it still welding really well?

[ronsii]

Well Im on the case LOl!! I'm checking things out on it now and looking for bad or burnt wires .If i can't manage to fix it myself I'll get some who knows all about it to take a look.There isn't much up with it it's nearly going good . I only paid £5.50 for it on Ebay sp it's worth a go.. How is your XMT going for you ?is it still welding really well?

If you can... take some good clear pics of the boards and post em' up there are plenty of people on here that can spot obvious problems with components and give you ideas where/what/how to do things once we see exactly what you're up against.

[Munkul]

Well Im on the case LOl!! I'm checking things out on it now and looking for bad or burnt wires .If i can't manage to fix it myself I'll get some who knows all about it to take a look.There isn't much up with it it's nearly going good . I only paid £5.50 for it on Ebay sp it's worth a go.. How is your XMT going for you ?is it still welding really well?

haha, my XMT hasn't struck an arc in probably 6 weeks now. I've been TIG welding everything.

Have you tried out your pulser unit yet? Or are you still looking for a wire feeder? I'm sure I saw a cheap Lincoln LN25 the other day, I can't remember where though. The pro versions run on 24v and will hook up to an XMT.

[mandylad]

I haven't tried the pulser yet.Well i plugged it in to the welder to make sure it works and went through the programs it seems pretty easy to use.No word of a feeder yet been looking aabout online but aven't got one yet. I'd like to get a dual Miller feeder but i need to get it for the right price so may take a little time to get he right one. I fixed the welder yesterday it's going geat now. The OCV reading on the display is up over 90 now i'm so chuffed with myself. I took the positive and negative termanils apart and cleaned all the brass up with scotch brite and i changed a few wires that looked burnt. I also changed out the 14 pin reccaptable because i thought a few of the wires look burnt. I put it all back together and turned it on and it is welding like it should on stick mode. It was actually a easy fix just took time and patients to look and find the problem. I'm spraying up the covers of the welders now to give them a new lease of life.

[Munkul]

Spot on, that's a really nice save!

So you now have two working XMT units now? That's a nice feeling.

There's a guy on mig-welding.co.uk, name is HughF, he built his own suitcase feeder, and does a bit of that sort of thing. I'm sure he could build you a really nice feeder that would work for shop or site work. The pinout for contactor and 24v control on the XMT is widely available, so its very straightforward.
A voltage display/adjust on the feeder would be the icing on the cake.

https://www.mig-welding.co.uk/forum/...r-build.61646/

[mandylad]

I know Hugh spoke to him a few times i saw his wire feeders they look good.I now have 3 working xmt units and im going to get them set up in my shed for doing different things.im very happy with them.im currently doing them up i stripped them all down and im spraying them up and cleaning them as much as i can,im hoping they will be looking the part when im finished,yea id like a wire feeder that does wire and voltage display.your 60 series one can do it cant it?? i was looking at a 60 series feeder onlone it is 1300 euro
i think it has wire and voltage display and adjustment.is that the kind of money them feeders are making?

[Munkul]

My 64 feeder has voltage adjustment, and digital voltage and WFS displays. You can set it to display IPM or metres/min by setting jumpers. It doesn't display amps, but you get an average amp readout on the XMT unit for a few seconds after arc-out.

Also has a spot weld timer and burnback adjustment, but no run-in. Personally I'm not sure run-in is a great feature, since the arc starts perfectly without it.

It's a nice bit of kit,but I don't think I'd pay e1300 for one! But you could sell one of your power units and offset the cost...

3 XMTs is way overkill

[mandylad]

i know 3 of them is crazy lol.I was thinking of selling one i will see what happens lol. I didnt plan to have 3 of them but its the way it turned out and it turned out pretty good i must say .Yeah iagree 1300 euro is abit much for one i dont't think i'd pay that either.I'm in no gtera panic so i can take my time and try get one for the right money.I have the 3 welders nearly all done up now ill try post soem pics when im ready with them.

[mandylad]

[mandylad]

[mandylad]

[mandylad]

I posted some pictures of the welders i was working on.I have them all done just need to make some stickers for them.I'm going to try and make them myself with the printer and some sticker a4 paper.The welders turned out well and i'm really happy with how the paint came out.The 3 welders are running good and seem to be welding well on stick mode.
I don't have a wire feeder yet to try out the mig side but i did plug in the optima pulse box and it works fine with all 3 welders.I have 3 working 304 xmt welders now so i'm not stick for a welder LOL!!! and the one that is left i started working on it today thinking i might get it going to I will keep you all posted about it. One of the welders trips the breaker an odd time i was wondering if anyone had any ideas why iy does it?the others don't trip the breaker at all.

[Munkul]

My XMT 304 will trip a b16 breaker occasionally if I switch it on and it hasn't been used for a while. I assume its just the initial inrush of current to charge the capacitors up.... might be wrong though.

[mandylad]

that is the same thing my machine is doing.It's only when its cold or the first start of the day.After that i could start it 10 times just switching it on and off and no issues at all.Im not sure what size my breaker is its a 32 amp 3phase plug.