Plug for welder

[Discoman]

trying to find the proper plug for my welder.
It needs one positive, one negative, and one ground prong. it will be running 230 volts and needs to handle 60 amps. power will be singe phase. what plug and receptacle do I need?
the power cable is rather thick, around maybe 1" diameter.
thanks.

[tkanzler]

For an arc welder, the plug only has to have the minimum ampacity of the branch circuit conductors (NEC Art. 210-21(b)(3), Exception), and the branch circuit conductor minimum ampacity depends on the duty cycle of the machine at max current.

You're probably fine with a 50A plug and receptacle, which would be a NEMA 6-50P for the plug, and 6-50R for the receptacle. It's a 250V, 2-pole, 3-wire arrangement, with two ungrounded (hot) blades, and a ground. There is no positive and negative, since with alternating current, they're switching polarity 120 times per second on 60Hz power. There is also no neutral, since it's 240V (only) power.

Here's a common 6-50 receptacle, which requires installation in a box. There are surface-mount types, also.



Post the nameplate current and lowest duty-cycle value for the welder, to help size the branch circuit conductors and receptacle/plug combo.

[Monica]

Originally Posted by Discoman

trying to find the proper plug for my welder.
It needs one positive, one negative, and one ground prong. it will be running 230 volts and needs to handle 60 amps. power will be singe phase. what plug and receptacle do I need?
the power cable is rather thick, around maybe 1" diameter.
thanks.

Here's a good guide: http://www.burrowselec.co.uk/SBplugs+connectors.pdf

Also check out the "extension cord" thread. There's a ton of questions and answers for various configs. That should get you started

[Discoman]

welder power plate specifies it needs a 230 volt 60 amp circuit or 460 volts 30 amps.
single phase power.

[tkanzler]

What's the duty-cycle at the highest current. Or, what's the lowest duty-cycle number on the dial/scales.

Or what's the make and model?

It matters as far as the minimum conductor size, and therefore the minimum receptacle and plug rating.