A few more questions about wire size.

[Ironhorse74]

Running the last few circuits in my shop. First is the welder outlets. The furthest is 25 feet from the panel. The current welder is 210 amps at 25% duty cycle. I really want this circuit to be fairly versatile, in other words handle expansion and a plasma cutter.

Second circuit is a compressor. 5 hp right now but may expand to 7 1/2 hp. 30 feet from the panel for this one.

Third circuit is a 240v lift about 25 feet. Haven't chosen the lift yet.

Final circuit is probably a strange one but I am trying to think ahead. I want to install a couple of boxes and run the wire for a future lathe, Mill and shaper. My thought is to run it into the panel but not hook it up. Just put notes in the boxes and panel. Wire nut everything? 51 feet.

So the bigame question is what Guage wire do I need? 2 conductor with ground?

Thanks in advance

Brad

 

[matt_i]

You need to study the welder and/or plasma cutter's manual or label and determine what the AC input requirement is going to be. The DC amperage doesn't really mean anything here. I'm purely guessing its going to be a 50A circuit on 240vac using #6 AWG.

Compressor, 5hp @ 240vac would use #10 AWG. #8 AWG for 7.5hp would be my choice.

Lift is probably 2-3hp (? guessing). Could easily commonize with the #10 AWG.

My personal preference is to run PVC surface conduit and pull THHN stranded conductors inside it. However getting pieces of NM wire #6-2 W Gnd or #10-2 w Gnd is entirely possible. It is nasty to bend and route though compared to the THHN but the tradeoff is the time to plan, fit, and hang the conduit. If a neutral wire is needed on any device then you will need a #6-3 w ground, or #6-4, etc.

On a welder circuit to be flexible you have to choose a style of plug and receptacle. The classic "50A oven plug" is a NEMA 14-50. Can have a neutral wire if needed but is typically not for a welder. But, every other device intended to be plugged into this outlet has to have the same style male plug. To truly be flexible the neutral is a good idea in my opinion.

 

[Ironhorse74]

Thanks for the reply Matt

 

[theoldwizard1]

I'm purely guessing its going to be a 50A circuit on 240vac using #6 AWG.

Compressor, 5hp @ 240vac would use #10 AWG. #8 AWG for 7.5hp would be my choice.

Lift is probably 2-3hp (? guessing). Could easily commonize with the #10 AWG.

That is a very good educated "guess" on the welding circuit. Also spot on with the comments about THHN in conduit.

On a welder circuit to be flexible you have to choose a style of plug and receptacle. The classic "50A oven plug" is a NEMA 14-50. Can have a neutral wire if needed but is typically not for a welder.

Most welders come with a 6-50 plug, but if you want "flexibility" Matt is right again. Pull 4 wires and change the cord end of the welder to a 14-50. Ignore the neutral for the welder.

 

[Norcal]

That is a very good educated "guess" on the welding circuit. Also spot on with the comments about THHN in conduit.


Most welders come with a 6-50 plug, but if you want "flexibility" Matt is right again. Pull 4 wires and change the cord end of the welder to a 14-50. Ignore the neutral for the welder.

What value is a neutral for a welder circuit?? You cannot just take a line & neutral for a 120V receptacle off a 30/50A circuit & a 240V welder does not require a neutral.

 

[wyliesdiesels]

What model welder?

Your best bet is a 6-50r with #8 THHN which is good for 50a. That should cover most larger welders.

If u get a smaller welder u will need either a 6-30r or 6-20r.

Wire for motor circuits is sized @ 125% of NEC FLC table.

A 5HP motor requires #10 THHN or #8/2 NM-b
A 7.5HP motor requires #8 THHN or #6/2 NM-b

A local disconnect is required if farther than 50' and not within sight of the panel.

 

[Jarnipman]

Flexibility is a nice thing in the future for unknown modification to the shop, so I always suggest pulling the neutral as well (really not much more money in the long run), the added benefit is if you want to change up the circuits in the shop, you can always remove the outlet and box and install a small sub-panel in its place if you ran 6 gauge. I have done this a few times, convert the 50 amp welder circuit to a small sub panel to reconfigure a bit.

 

[Ironhorse74]

Thanks for all the great replies you guys rock. The current welder is a Lincoln MP 210.

Thanks

Brad