Home electrical help (welder)
 

Calling all electricans, EE, people with 220 welders, or whoever wants to give their input. I just bought a lincoln 175 welder, It runs off of 220. Well here is my question the plug in the garage is 220/30amp, but the lincoln recommends that I have 40amp breaker. Is this just a "recommendation" from lincoln or is it manditory that I have a 40amp?

The worst thing that can happen with an undersized breaker is that it will Trip more often if you over load it. If you find that it trips too frequently then you will need to upgrade to the 40 amp, but you will also need to upgrade the wiring to handle the additional load. If you are just doing light fabrication work and not really taxing the system, the 30 amp breaker should be fine.

I thought the 30 and 40 amp plugs are differant....Will your welder even plug into the existing outlet?

Where's Mike?!

yes they are different, but I made a 10ft ext cord with a 10ga. wire with the correct female plug for the welder and the correct male plug for the wall.

The problem is the wire from the panel to the plug. I am sure if it was wired for a 30 amp, then the wire was sized accordingly. Be sure to check and see what wire was used before you just switch the breaker. If in fact, proper wire was used (and this will depend on distance from panel to plug as well), then just change the breaker. If not, I suggest you run proper wire and make a new circuit.

wire size
 

I'm a electrical contractor in louisiana. If you have a 30 amp plugin in your wall you should have a # 10 wire for it. If you need a 40 amp plugin on your welder you need a #8 wire to carry that.If you just change the end the welder could pull more amp's than the wire is rated for and either melt the end of the plug or melt the wire in the wall and cause a fire.If you are not going to use it alot you might be OK.But any new or remodel we do and they want a welder plug . We run #6. It 's good for 60 amps. We always over kill but we don't have fires. Hope this was helpful.

Great advice here. I tend to run upsize the wire for welders and certain machines due to the fact that they will run a bit hotter as well. Less voltage drop. 30 amp will more then likely have #10 wire which is too small for a 40 amp welder. #8 is fine, but you need at least #8.

??
 

Hi,
I'm curious because I have the same welder and can run it all day at full power out of my 220v/16A (I'm in Europe) outlet without ever triggering the breaker.
Could it be that there is some kind of conversion from 110/220 (like that the breakers are on the 110v side before converting to 220V or something like that)?
because if you are talking about 30/40A on 220volts that is allot
It is 6,6kw for 30A and 8,8kw for a 40A.