I'm getting confused

So two different welders act up the same way. Why don't you hook a multmeter up to monitor the power line voltage so you can get some more info the next time it happens. You could have a bad connection in the power going to the welder. After some use it heats up and gets really bad. The problem could be in the receptacle that the welder plugs into. So connect the meter to the power cord of the welder. Not to the receptacle the welder plugs into.

=20 Dan

As you know, my Lincoln 175 +SP was acting up. I borrowed a Miller 175 wire feed.

Yesterday, I had the chance to weld 12 6" long pieces of channel on to a trailer frame on the outside for stake pockets. Worked fine, but as it heated up, it started acting up, somewhat like my Lincoln.

I would run a hot pass vertical travel down, then run a wide cover pass vertical travel up. .030", heat setting 8, wire speed 55-60.

My wife came home, and came over to inspect and make sure we were doing it right, so there was a chance for it to cool down. On restart, it was right back to the desirable level of hiss versus splut splut. Concentration was applied to keeping a clean tip, torch angle, stickout, small adjustments of wirespeed and heat, motion and hesitation on travel sequence, etc.

We got er done, just some looked a lot better than others. And when it would splut splut, I'd have to stop and restart and melt the ugly part.

Do these things act differently when they heat up, or do I just have some sort of vortex portal over my shop?

My electronics friend took the 175, and could find nothing obviously wrong with it. It started acting up at 40% of the load settings. Looks like time to go to the shop with it.

Steve

Don't know if it's relevant (I'm just a farm weldor), but if I can't get decent results in my shed, I move the welder to a supply from my house (and the source of the electric supply) or onto a mobile generator. The extra 100 yards doesn't seem to make much difference at low amps, but at higher amps it can be a different story.

Joskin

I'm runnin' my shed/shop on a 35 foot run of #8 fed by a 100 amp breaker . I haven't tried the big welder (tombstone) at more than 120 amps , but everything else runs well now . Except the mill , it still has problems starting at the highest 2 speeds . I think it's that cheap Chinese motor , and as soon as I can afford it I'm changin' it out to a 3ph and a VFD .

Before jumping to conclusions about the mill motor and long runs from the sub box, go look at the wiring coming from your transformer. Are you the only user? Is aluminum wire being used for the drop from the transformer to your meter? If either is "YES", then you need to have your power company come out and do a check on the transformer and wiring.

If you share a transformer, perhaps the other user is taking a big load of power, also. Had that problem at a rental house recently. Transformer was shared with three residences. I had to pay for a new, larger, transformer installation.

If the power drop from the transformer is aluminum wire, which is usual, the power company needs to check all the crimp connections. One was bad right at our transformer and had been bad since 1981. It just got worse over the years till the resistance got so high any load would drop the voltage to almost nothing. New crimped connectors solved the problem

Your experience makes me think you have a faulty crimp somewhere on your power line. when it gets hot, the resistance goes up and your 230 volts drops way down. When not used for a while, things go back to low resistance.

Paul

My line in is old , 3 copper wires from the pole . I just went out to look and there's only one other customer on that transformer . I'd think if there was a bad crimp or other high resistance problem it'd show up when my AC cuts on and I've never had any problems with that . BTW , my mill is a

110v RF45 clone . It's done this since shortly after I got it - the first year or two I was running on a 10ga extension cord . I guess I need to get the voltmeter out and watch what happens when I turn it on , but there has been no other sign of sagging voltage - no dimming of lights or anything even when I was on the cord . Perhaps one of the start winding connections inside the motor is a bit iffy ... as I rarely use those higher speeds I just haven't been all that concerned about it . Besides , I need an excuse to change it over to a 3ph motor and VFD .

I hope that was a typo and you have #2 or larger fed from your 100 amp breaker (or whatever your local codes require). #8 is totally inadequate for a 100 amp feed (the supply breaker governs, not your actual load) both according to any code I ever heard of and from a resistance (voltage drop) standpoint. If your shop burns down your insurance company might find the illegal wiring to have been the cause, and not pay.

The second troubleshooting step (after making sure your installation is up to code) is to trace back up the power feeds feeling every receptacle, junction box and breaker for excessive heat. Any component or splice with excessive resistance will get excessively hot. If that quick check fails to turn up a problem then move on to the more definitive voltmeter checks others have suggested.

It is always a good idea to check total voltage drop under maximum load when a feed is first installed or after any repair or modification, just to be sure there are no problems. I consider more than a 3% voltage drop a problem except in unusual situations (such as a distant and rarely used load with good low voltage tolerance, where it might not be worth the cost of the next larger wire size), and usually design for less than 2% voltage drop.

Resistance per 100 foot of wire is readily available, you can (and should) use ohms law to calculate your voltage drop before buying your wire. Minimum code size is usually not be adequate for a long run to a heavy load (although 35 feet is not a long run).

Glen

Unless it is a #8 extension cord - the code doesn't cover extension cords. Which it what I assumed, but re-reading his post it isn't clear. If it is an extension cord, it only needs to be sized for the actual load.

bob

Darn, I WAS using it with the 50' extension cord. I think I'll get a shorter extension cord and try that. I need a short one anyway.

Thanks.

Steve

TY. I believe all is copper, but will investigate to be sure. I am at the end of the power line, but no transformer on my pole. I shall call the power company and ask a couple of questions.

Steve

"Gunner Asch" wrote

Methinks we may be getting close. I have a 75' run from the house to the container, then 50' extension. Need to go look at the gauges of the wire. The work was done by my best friend, who is a union electrician, and looked at the max draw on the machine before we turned the first shovel of dirt. He, like me, tends to opt for overkill on most everything. IIRC, the max amp on that machine is 22 amp, not a lot. I could be wrong. I RARELY use anything over half power, and the lower settings were working beautifully. I use the SA200 for anything thick.

Steve

1.2 kW power loss in cable, 5v voltage drop. i

For a 100 amp, 120 VAC circuit 125 ft. long the wire size is 1/0; for

240 it is #3

I was calculating based on the 100 amp breaker that you mentioned. If actual amperage is lower then of course the wire size changes.

If the amperage is actually 22 amps then #6 for 120 VAC and #10 for the 240, but if the voltage decreases under load then either your service is not large enough or your amp meter is wrong :-)

-- John B.

It's set up as an "extension cord" with a plug , which meets code here as it's considered "temporary" . And the only reason it's fed with that bigass breaker is because I haven't taken time to swap the 60 in . I have a length of #2/0 3 conductor bigass aluminum wire I could have used , but every problem I've had with electricity in this house was related to aluminum wiring or bus bars in the old breaker box . I therefore will not use aluminum for anythin electrical .

That's a helluva lot of work for an isolated problem with one piece of equipment !

If I had problems with anything else out in the shed , I might take the time to do more investigating . But the welders , saws , lathe , grinders , and everything else out there work just fine . There's no sign of voltage drop (IE , incandescent light bulb don't dim , for example) and that leads me to believe the problem is in the mill itself rather than a power supply problem .

since ultimately you are interested in voltage to push amps through your machine this is undoubtedly the easiest method.

-- John B.

Before you get too carried away, is there any chance you're simply pushing the limits of the duty cycle on those welders......?

Pete

The thought had actually occurred to me, but the Lincoln definitely has problems. A friend of mine who knows electronics took it, and evaluated it, and said it does have internal problems. But now that they both are doing it, and one works better after cool down, I may go that way. I have a bunch of .065" tube to do, so will give it another test with less duty.

Steve

Steve

Got a Lincoln SP85. Recently wire feed motor quit. Had it in back of truck, ready for trip to junk yard.

Took off cover, disconnected wire feed wires. Connected to 12 volt battery, wire feed worked good. Put feed wires back together, motor now works good.

Guess there might have been some corrosion there in those connections.

The SP85 for me is a sort of easy, handy, mig to use, compared to some of my other mig beasts.

The SP85 has had several mods, to keep it going.

xman