Electric Plug for Welder

[chemistbert]

I just got my hands on a old Marquette Model 32W RediArc stick welder and need some help with the plug it has. it looks like this

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That's not a NEMA plug that's for sure. Does anyone know what it is? Or at least what goes where. I assume it's a 240V of some kind so two hots and a gound?

Also if someone has a manual for this old beast that would be great too. I know I am fishing there, this welder is 50 years old and all but hey it was free!

Thanks as always!

Matt McCarrell

[Focus on Bees]

can you look inside and see what it's wired for ?
Then I'd just buy a new plug.

[randydrivesabus]

2 hots and a ground is correct.

[Barry]

More than likely a 50 amp 220.

http://www.lni.wa.gov/wisha/rules/corerules/images/28010-illustration.gif

[iddee]

It's 220, single phase. The two sides of the V are hot. The stand alone is ground. Just buy a male and female and wire the cord to the male.

[Troutsqueezer]

Probably ground but keep in mind standard household 240volt is two 120's and a neutral between them. Breakers in your house run from neutral to 120, not ground to 120 specifically, although the neutral may tie to ground within the service panel.

[tecumseh]

perhaps someone dropped something heavy on the plug to twist it up that way... extremely odd.

but yea follow basically what Barry and Iddee said.

[chemistbert]

You guys are great. Thanks Barry. My house is wired with the ground and neutral together. I'll open it up and make sure of the wiring. Now I just need a really big breaker...

Thanks all

[Barry]

Here's a basic reference for wiring a 220 receptacle. The same info applies to wiring the plug. You'll be grabbing current from each pole (2-120 amp) and using the third leg as the ground (either green or white to the neutral bar which, as you said, should be joined together in the panel).

http://www.lowes.com/lowes/lkn?action=howTo&p=Improve/220outlet.html

- Barry

[John F]

... and using the third leg as the ground (either green or white to the neutral bar which, as you said, should be joined together in the panel).
- Barry

No, not either/or...

Only bind neutral to ground at the service panel. Nowhere else. Do not bind at subpanels.

http://members.tripod.com/~masterslic/FAQ-2/18.html

The 3rd leg of the 220 is ground (safety ground, goes to green, green/yellow, or bare wire) Do not attach this to neutral (white). There is no neutral leg in a 220 single phase 3 pole plug/socket.

http://www.wikifaq.com/Electrical_Wiring_FAQ#What_is_.22grounding.22_vers us_.22grounded.22_versus_.22neutral.22.3F

In a 4 pole plug/socket neutral is used and generally means that the device has parts that run at 110.

If the neutral wire is bonded to safety ground anywhere (including miswiring) other than at the service panel (with assumed service ground) then errant voltages can find paths to ground other than through the service ground. This could be through any safety grounded chassis, like your washing machine, and could get someone hurt. Also, GFCIs could do strange things which can get someone hurt.

Don't mix ground and neutral.

[Barry]

No, not either/or...

Only bind neutral to ground at the service panel. Nowhere else. Do not bind at subpanels.

[snip]

Don't mix ground and neutral.

We're saying the same thing. The "either/or" was not referring to location of binding but to wire color and use. I specifically said "in the panel."

In reality, ground and neutral ARE "mixed" in the breaker panel. It's required by code here. But yes, one should never wire ground and neutral together anywhere else. In my location, steel conduit is required by code, so the whole electrical piping system is one big ground back to the panel, which is then bound to the neutral wire from the service and to the ground rod outside. Anytime greenfield (flexible conduit) is used, a ground wire is required to be attached to the junction box, through the greenfield, to the fixture. This, along with the neutral wire, but not tied together, as you said.

- barry

[Brent Bean]

chemistbert:

Not to rain on your parade, but before you hook it up to your house which will be 220V single phase. Open up the welder and check that it’s not wired up for industrial use, which could be 480V or 550V. You should be able to identify this where the wires are landed from the power cord. Most welders will accommodate various voltages most of the time it’s just a matter of landing the wires on the terminals marked for the voltage you have available. Also if you pull the cover off the welder you should find a wiring diagram pasted to the cover with hook up information.
If it came off a farm or private residence it will most likely be wired for 220V single phase but it’s better to look that just do a smoke test.

[skittlejr]

I just got my hands on a old Marquette Model 32W RediArc stick welder and need some help with the plug it has. it looks like this

|
\ /

That's not a NEMA plug that's for sure. Does anyone know what it is? Or at least what goes where. I assume it's a 240V of some kind so two hots and a gound?

Also if someone has a manual for this old beast that would be great too. I know I am fishing there, this welder is 50 years old and all but hey it was free!

Thanks as always!

Matt McCarrell

Is this one of those welders that has mulitple plug holes on the front that you use to get your desired amperage? I ask because I have an old Marquette welder like that and i cannot find the correct plugs to go on my welding cables.

[chemistbert]

It sure is. My leads are in pretty good shape and the welder as a whole runs excellent. I did a bunch of welding on my trailer and it'll really put down a nice bead.