hot breaker/ miller 250 sync

[abstract]

Been using a Miller 350 sync for 14 years on this property off of a 100 amp breaker in the panel, to a 100 amp disconnect just for the welder. A week ago the 350 stopped throwing an arc, so I put in for repairs and bought a Miller 250 sync for back up. I'll run the 250 about 30 min. , welding 3/16" aluminum with machine set at 165 amps then the panel breaker trips and is very hot. I'll let it cool down for 30 min. , try it again, happens again.

Using a Miller Coolmate water cooler and CK 300 water cooled torch with a hand slide remote control.

I "NEVER" had this happen with the 350 sync. Appreciate your input to fix this .

[Mike W]

The first thing that comes to mind is to measure the current to see how many amps you are pulling from the breaker.

[Sberry]

there are 2 things I think of here, at 165A one of them might not apply, not sure. If this is a model without PFC it could be really greedy and need a larger breaker. The other is did you make sure the internal jumpers were set for 230? Chances they are but wouldnt hurt to check.

[hankj]

Assuming (bad word!) that you're running on 240V, the 100A service was actually undersized for the 350 at full output, which you probably already knew. The only two things that come to mind are a tired breaker (it do ahppen) or the 250 has a hickup in it. If the 250 has power factor correction, it should only be pulling about 50 amps where you're running it; about 70 amps if it doesn't have PF correction, so the breaker shouldn't be tripping.

Hank

[Thomas Harris]

Do you ever use the breakers as on/off switches. That is, turning them off on a regular basis. If so, check to see whether they are switch rated. If they are not the contacts can get bad and cause them to overheat when not even near the rating amperage. Hot breakers are not acceptable and should be corrected. Your wiring itself may be inadaquate. Remember, even if the wire itself is not hot enough to start a fire, it may lead to insulation break-down, which can cause sparks, and ultimately fire. Have someone qualified check this out.

[abstract]

Appreciate your quick respnses. I've been gathering what info I could to your questions.

1) Welder at 165 amp setting- drawing about 97 amps / lead while welding ; around 11 amps at idle. Voltage is 240 with 100 amp panel breaker run with # 3 wire to disconnect box- about 30' max.

2) Not sure about PFC; how do I determine that. There's nothing on the machine stating PFC or in the manual to to determine this option. I'm assuming I don't have it.??????????

3) Welder stock # 907194 and internal jumpers are at 200 volt setting; as is the 350.

4) Picked up a new 100 amp breaker this morning, but haven't installed it yet. Don't want to install till I check other options with you folks," Miller" and shop where I bought it.

5) I rarely switch the breaker off- maybe twice a year. Couldn't get an electrican this morning- have to wait till Mon. for many answers.

[Sberry]

Where do you have this machine installed at? Are there only 2 jumper settings? I thought they had for 200, 230 and 460? If you are on residential you should be on 230.

[Bigger Valves]

If you're on single phase power and just running two 120 or 110 hots into your breaker you need to be linked for 230V

If you're on a 3 phase like we have at work (not sure of the service) 2 hot leads will give you 208 volts so you should be linked to 200V. Depends on what 3 phase service you have.

I guess my main point is what voltage do you have to your machine. If it's 230 or 240V you need to relink. I don't know if this would cause the whole problem you're having, however.

I guess one obvious thing is to check the plate on the welder and be sure it's the phase machine that you should be using too.

[abstract]

The 250 has 3 jumper settings- 200, 230, and 460.

I'm residential with 200 amp single phase service to property

Both these welders were set-up by to different dealers. The 350 was done in 1991 when I bought it and the dealer linked for 200 volts. When the guy delivered the 250 and saw how the 350 was hooked up, he repeated it for the 250. Not being an electrican, I rely on what I assume to be the experts selling the welders.

[hankj]

Abstract,
You're gonna be happier if you swap the links to 230V. That's the optimum setting for your input juice. By running at 200V, you've sorta deprived yourself of a part of the machine's capability, and incurred some unnecessary cost because of it. While the $$ probaly aren't significant, I'll bet you notice a boost in performance!

Hank

[abstract]

It makes sense, but If it's common knowledge to set the machine at 230v, why would both dealers link it at 200v when I'm residential?

What should I be looking for to determine the machine "phase"- nothing is spelled out on the label whether it's single or 3-phase? A symbol?

Would the 200v link have caused: 1) the breaker to overheat and trip 2) any internal damage to the welders or just be less efficient 3) damage to the torches- I've had to replace 2 water power cables to the smaller "CK 200" torch over the years?

I REALLY appreciate all your help.

[Bigger Valves]

Yea sounds like you should definately be linked for 230V. Your 200 amp service doesn't matter for linking it's the single phase and (110,115, or 120V) voltage you have per hot lead that matters. Like I said I don't know that this could be causing your whole problem. We had a Miller mig linked for I think 230 when it should have been 200 but they ran it for years till I found the mistake. The performance increased a bit, but there was no huge difference. But in your case it could be different.

As for the phase of the machine. On all my Millers there is a tag on it stamped with the machine information. Sometimes on the front sometimes on the back but somewhere. It'll tell you what voltages it will run on, the hertz (60 or 50), the phase it's made for, and some other stuff. I would assume the information is on their newest welders.

All my trouble with welders not running right or causing problems has been wiring related. Basically with wires coming loose inside plugs and what not. I always keep a good eye on my plug contacts and tear them down every now and then. You'll learn to after you see a plug catch on fire in the wall or get a juice of current through a welder that's off that burns thru an aluminum lead out of the transformer of a syncrowave!! Hardwiring into a breaker is my favorite way to hook them up. Good Luck.

[hankj]

All the Synchrowave series are single-phase machines. You don't get to 3-pahse untill the Aerowave.

It'll be interesting to hear what you discover to be the cause. Finding out why the 350 quit may be a piece of the puzzle, but the 30-volt difference in transformer winding selection shouldn't have made that significant a difference. You may not even notice a change when you re-link for 230V, although you should notice that your old settings are running a little hotter, especially on thin stuff.

Hank

[Zrexxer]

What should I be looking for to determine the machine "phase"- nothing is spelled out on the label whether it's single or 3-phase? A symbol?

Yeah, for some reason Miller has decided that cryptic pictographs are universally understood the world over...

The single phase designation on my Syncrowave is a "1" followed by a sine wave symbol.

[wlbrown]

SIR,
my suggestion, check the simple things first.
if you can shut off the power to the breaker that
feeds the welder, check to see if the leads going
into the breaker are tight. if they are not, this will
cause the breaker to overheat, and later fail. what
kind of wire is feeding the machine, copper? if it is
aluminum, be sure the connection are tight. i have
seen breakers fail because the infeed was aluminum,
and the breaker did fail. the electric companies use
aluminum for the feed in, and this can get loose overtime,
because the wire extrudes. about a year after i move to
where i live now, my light started to flicker. i called the
electric company, and within 30 minutes they had a crew
out, and this is what they found. after they tightened the
wires that come into my main breaker, i have had no
problems.
wlbrown