Why do welders have a 50a plug?

[2drx4]

Honest question. Why do they put a 50A plug on a welder that only draws 20-30A max?

I know there's some silly NEC exclusion for welder plugs, since surprise surprise, none of them actually draw 50A continuous... Or even intermittent, for that matter.

Seems pretty backwards.

 

[sberry]

It is so they can be used on common "welder" circuits that were around since they invented them.

An AC buzzer pulls over 40A with some 1/8 electrodes 250 feeders over 40

 

[sberry]

You are correct about the smaller machine draws but,,, say a 200A feeder, its actual minimum feed wire is 14 but you have to limit the breaker to 30 so to ikeep it usable on common circuits, which could be shared, they put a 12 cord on it and its own internal thermal protection after the switch, lets it be plugged in to a 50.

In this case the cord is a size heavier than the machine needs, will not overheat it and is rated for short circuit to 50, the breaker protects against fault and acts as a switch.

 

[jar944]

Standards.

The alternative would different plugs on multiple welders just based on draw.

Some shop sized tig welders (transformer) pull far more than 50 amps

 

[2drx4]

It is so they can be used on common "welder" circuits that were around since they invented them.

An AC buzzer pulls over 40A with some 1/8 electrodes 250 feeders over 40

I looked at the specs on my buzz box, and it looks like you're right.

My MIG has been bastardized with a 30A cord from usage with a generator, I was basing my thoughts on that.

I'll just buy 6awg and get it over with (romex). Never know what I might decide to plug into a 50A outlet down the road.

 

[sberry]

6 wont hurt a thing but 8 serves pretty much any welder that comes with a factory 50A plug. Yes, other machines may require bigger circuits but they do not come with factory plug.