Wiring up my 250ex

[dgarnier]

For 220-240V 2-phase operation, follow the instructions given previously:

Machine BLACK to wall BLACK
Machine WHITE to wall RED
Machine GREEN to wall BARE (GREEN)
Machine RED and wall WHITE are not used

The green machine wire is connected to the welders chassis, so it must be connected to the grounded conductor, normally bare. In a 2-phase system, one of the hot wires always acts as a return for the circuit, so there is not a common/return wire. The ground wire is for safety, and for chassis noise reduction, so while a 10AWG would work for the noise aspect, it may not be able to handle the current draw before the breaker tripped if a short to chassis were to occur. Plus I am pretty sure the NEC requires the same size wire - I can look it up if you want.

Ken

Ok so from the main pannel I could use 2 6awg wires(white and black) that are comming off 50amp 2 pole breaker for the 2 hots. Then hook up the green wire to ground which is hooked up to the to the box the outlet is wired to so the conduit will then carry the current is something goes wrong. Does this sound right?

[kenwhite]

Ok so from the main pannel I could use 2 6awg wires(white and black) that are comming off 50amp 2 pole breaker for the 2 hots. Then hook up the green wire to ground which is hooked up to the to the box the outlet is wired to so the conduit will then carry the current is something goes wrong. Does this sound right?

You can use the conduit if your local code allows its during retrofit. I believe all new installations require a seperate ground wire.

[PinkNinja]

Thank for all your replies!

She fired up beautifully! Couldn't be happier!

[A/C Guy]

Ok so from the main pannel I could use 2 6awg wires(white and black) that are comming off 50amp 2 pole breaker for the 2 hots. Then hook up the green wire to ground which is hooked up to the to the box the outlet is wired to so the conduit will then carry the current is something goes wrong. Does this sound right?

IF, and only if the machine requires a 50 amp circuit. If the machine requires, less than use the proper breaker. If you are doubling on a circuit such as the kitchen stove, then you must run the proper size wire for the breaker (same as the stove) to a fused box for the welder.

i.e. If the welder only needs 30 amps and you are tying into the stove circuit (50 amps), you run the #6 wire with ground to a $10 fused box that you mount on the wall for the welder. The fused box would be a 30 amp box since that is the size of fuse required by the welder. (60 amp boxes and fuses are larger, so they are not interchangeable.) From the new 30 amp FUSED box, run #10 wires with ground to the new receptacle for the welder.

If the welder requires 40 amp protection. Same scenario. Run #6 wire with ground from stove circuit to new $10 fused disconnect box. This time we use a 60 amp fused box, but with 40 amp fuses. (The 60 amp rating just means the box is rated for 35 to 60 amp fuses.) Now we run #8 wires plus ground from our new 60 amp box (with the 40 amp fuses) to our new receptacle that is mounted on the wall for the welder.

As a last option. With either above set up, we can substitute a long, heavy duty, black #10 (for 30 amp) or #8 (for 40 amp) power cord with a female plug instead of the wall mounted receptacle. That allows you to move the welder around instead of having to be tied to the wall mounted receptacle. That is what I did in my shop. This is legal in commercial and residential environments.

[dgarnier]

ok thanks for all the help guys, got some 10awg green wire that I am going to pull later tonight and get the new outlet for the welder all buttoned up tonight