Fan in 220V welder

Thanks, Stan

I have thought about adding a ground wire to the metal case of the welder, but haven't done it. Maybe that would make it safer.

Earlier this year I bought a Lincoln buzz box that had June 22, 1967 written in pencil on the margin of the application chart on top. The ground wire from the plug attaches directly to the inside of the case. I hadn't thought about it before, but what else is there for it to attach to?

This is a 185 amp AC unit which, at second glance, doesn't look exactly like the far more common 225 amp ones. The labeled amperage settings are different, and there is a saucer sized flattened dome on the lower back of the machine behind the transformer. Also, this unit doesn't have a fan. There is one unused wire coming out of the transformer but no empty mounting brackets or unused holes in the case where a fan would go. Besides, one wire is about one wire too few according to the information, admonitions, and sermonettes I've received on the subject.

All the best, Stan

P.S. You're over near the eastern side of the state, aren't you?

I hope we helped the poster with his great question and made things safer and educated others with this very important discussion.

Take care n God Bless yall n stay safe

John T Retired Electrical Engineer

Would it be safer to have a separate ground wire from the case to a known good ground rather than depending on just the neutral? I had a mobile home once and the electric dryer had a 4 conductor cord including a ground. I was told that the code required a separate ground for appliances in a mobile home. But when I built a new house, about 10 years ago, the dryer receptacle just had 3 openings.

And yes, I do live in Eastern Washington, SE of Spokane a ways. On the dry side, although the last couple of weeks have been super wet.

The safety equipment GROUND (often green or bare) should indeed be bonded to the welders metal case/frame so that if a hot phase wire got shorted to the steel case theres a low impedance return current path back to the PANEL SO THE BREAKER TRIPS AND CLEARS THE FAULT so you dont get electrocuted if you touch the case!!!!! !!!!!

Its true inside the service entrance main panel or the meter base or at the weatherhead the Neutral is bonded to a grounding electrode such as a metallic water pipe or a driven rod in the earth for a made ground BUT THATS NOT THE SAME AS THE SAFETY EQUIPMENT GROUND thats used to provide a low impedance return current path back to the panel to trip a breaker to clear a fault. The Neutral is kept tied to mother earth which serves as the common zero potential reference on BOTH the secondary and primary (if a grounded Y service) sides of the service transformer. The primary side Neutral is tied at every so many poles and the secondary Neutral is tied at the transformer and the meter base or main panel TO THE MOTHER EARTH ZERO POTENTIAL REFERENCE.

On Mobile Home services the main servie entrance is considered to be on the service pole and its there AND ONLY THERE that the Neutral and Ground busses are tied together plus the Neutral (as explained above) is tied to a grounding electrode for the mother earth zero potential reference. Then they require 4 wires (2 hots, Neutral, Equipment safety ground) to be ran to the mobile homes panel which is considered as a sub panel after the service entrance out on the pole. HOWEVER for a residential service, they only require 3 wires (2 hots and a Neutral) from the transformer to the maIn panel and at the main panel AND ONLY THERE the Neutral and Ground busses are bonded together. At any sub panels downstream after that, however, the Neutral and Ground busses are NEVER TIED AGAIN and it would take 4 wires to serve that downstream sub panel.

Neutral is NOT the same as the safety equipment ground. The Neutral is a current carrying grounded conductor while the equipment ground is normally (except for fault current) a non current carrying conductor. Its sole purpose is to carry fault current NOT the normal return current.

Its indeed true some ranges did not have a 4 wire cord and had both 120 and 240 volt loads but Im NOT aware of any welders that did that and except for these type exceptions ITS AN NEC VIOLATION AND A POTENTIAL SAFETY HAZARD to use the equipment ground as a Neutral

I hope this helps and clarifies the difference in a Neutral and an Equipment Ground and Earth Ground. Its been many moons since I graduated as an EE and am rusty on the NEC since I retired but made my living several years as a power distribution design engineer and contrary to some opinions expressed here, do have some grasp on this electrical stuff and have tried to help n explain it and keep others safe to the best of my abilty and olddddd ddd memory lol.

Best wishes n God Bless yall

John T

I come to this forum for information and advice. If I felt like I needed to be scolded or I wanted a sermon, I could give my ex-wife a call; all I'd have to do is identify myself, and she'd take it from there.

Stan

Take care n God Bless

John T

Great discussion

Yall take care now n be safe

John T

Why were you asking the question in the first place? If you were looking to replace a fan, then you need better info than somebody's uninformed opinion. But you can answer your own question in a few minutes with a screwdriver and a voltmeter. If your question was just academic, then my guess is that the fans are all 220.

Out of curiosity, I took a look at the schematic for my Lincoln MIG welder. The fan is marked "230V/60HZ FAN MOTOR". But there's more: The motor actually has four leads! The two extra leads are marked "24V WINDING AUXILIARY". It looks like Lincoln uses the fan motor as a step-down transformer to provide the control voltage for the gun trigger. Of course, that means you couldn't just use an off-the-shelf fan, you have to buy one from Lincoln.

Also, the schematic for my welder clearly shows the ground connector going to the case, with everything else isolated from case ground. The practical effect of this is that you shouldn't be able to get a shock from the welder output, since it's isolated from ground via the power transformer.

FWIW, I was an electrical engineer in an earlier life. And I didn't see anything wrong with your question.

I"m not a welder by any definition of the word.
And so far I haven"t exceeded the duty cycle.
Even welding at full current with 3/8 rods.

But I have been wondering, Could I add a small fan
to blow air thru the machine to help keep it cool.

Only welding I have attempted was during cold weather.
Don"t know what will happen this summer when it is hot.

Pooh Bear

It would be a good idea to add a fan. Heat buildup is the limiting factor in the duty cycle of a welder. I have no idea how much difference it will make, but I'd be interested to find out.

There's a typo in your question, I think. A 3/8 electrode would be about the size of a Louisville Slugger (okay, accuracy hawks, that's a joke; don't correct me.) I figure you meant 1/8, right? When you say you haven't exceeded the duty cycle so far, you must mean the true duty cycle of the welder---the one that shuts the welder down when you hit it. How did that amount of time compare to the stated duty cycle?

The reason I'm asking is because I recently had to do a small amount of welding at a location where everything about getting power was a problem. A capable 110 machine would have cut the time I spent by about 2/3. But not all house voltage welders are created equal. I bought a low end 110 stick welder at HF once (an Italian made one in a plastic case.) The main problem with it was that it was absolutely worthless, but it was a nice size. What you're describing sounds much better.

Stan

I was thinking of a small 110volt fan from Surplus
Supply and I could plug it into it's own outlet.

The welder is 110 or 220 but I only run 220.
It's been fun to play with but I'm no welder.
I did manage to get my two practice peices to stick
together and now I can't get them back apart.

Thanks.

Pooh Bear

Dusty

John T

John T