Wiring up my 250ex

[A/C Guy]

so you only use 3 wires on the welder?? the 2 hots and ground? I was told I used to have to run 3 wires for 220, 2 hots and the netural, then ground to the box/conduit. The guy at the store said that a lot of places are making it 4 wires, 2 hots 1 neutral and 1 ground wire.

So my plan was to to use 2 hots and the neutral and then wire to green wire to the box. Sounds like there is no need for the white wire(neutral) on on the pt250ex as along as the neutral and ground are bonded at the box. If that is the case then couldnt I hook up the green wire to the withe neutral wire from the box?

First, NEVER, NEVER, connect ground to neutral at an appliance. Never use neutral for ground and never use ground for neutral. The only time you need a neutral is when you need 110. 110 is either leg connected to neutral. 220 is one 110 leg connected to the other. Driers and stoves use the neutral for clocks, timers, control pads, etc. The 220 is for the heating elements. The welder only uses 220 and ground.

Edit to add: Read the first post. The red wire on your welder is NOT for residential use. It is only for 3 phase power. The Black and White on your cord are for your 110 volt legs; green is always ground.

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

[kenwhite]

First, NEVER, NEVER, connect ground to neutral at an appliance. Never use neutral for ground and never use ground for neutral. The only time you need a neutral is when you need 110. 110 is either leg connected to neutral. 220 is one 110 leg connected to the other. Driers and stoves use the neutral for clocks, timers, control pads, etc. The 220 is for the heating elements. The welder only uses 220 and ground.

Edit to add: Read the first post. The red wire on your welder is NOT for residential use. It is only for 3 phase power. The Black and White on your cord are for your 110 volt legs; green is always ground.

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

Correct and good advice...

[dgarnier]

First, NEVER, NEVER, connect ground to neutral at an appliance. Never use neutral for ground and never use ground for neutral. The only time you need a neutral is when you need 110. 110 is either leg connected to neutral. 220 is one 110 leg connected to the other. Driers and stoves use the neutral for clocks, timers, control pads, etc. The 220 is for the heating elements. The welder only uses 220 and ground.

Edit to add: Read the first post. The red wire on your welder is NOT for residential use. It is only for 3 phase power. The Black and White on your cord are for your 110 volt legs; green is always ground.

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

ok now things are starting to add up in my head...so you could hook up a single phase 220 welder with just 2 hot wires and then tie the ground wire from the welder to the box/conduit? If this is the case, and I dont trust the box/conduit as a ground and I want to run a ground wire would it have the be the same gauge as the 2 hot wires(6awg)? or could I use a 10awg for the ground wire?

[kenwhite]

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

[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

[A/C Guy]

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

There is no such thing as 2 phase.
Single phase is 2 legs of 120 A/C in opposite phase of each other.
Next is 3 phase, where we have 3 legs of 120, 60˚ apart. Phase to phase voltage on each is 240 (or more commonly 208). Phase to ground is 120 volts. Phase to neutral is 120 volts.

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

See my previous post as to why this is a very bad thing to do.

Also, code requires the ground wire to be a continuous circuit and must be inside the conduit; not piggy backed on the outside. No daisy chaining allowed either.

[kenwhite]

There is no such thing as 2 phase.
Single phase is 2 legs of 120 A/C in opposite phase of each other.
Next is 3 phase, where we have 3 legs of 120, 60˚ apart. Phase to phase voltage on each is 240 (or more commonly 208). Phase to ground is 120 volts. Phase to neutral is 120 volts.

See my previous post as to why this is a very bad thing to do.

Also, code requires the ground wire to be a continuous circuit and must be inside the conduit; not piggy backed on the outside. No daisy chaining allowed either.

A 220/240 VAC center tapped transformer produces 2 voltages 180 degrees out of phase with each other, so technically this is a 2-phase system.

3-Phase systems have each voltage 120 degrees out of phase with each other, not 60 degrees.

While using conduit is not allowed for new installations, some locallities allow it for retrofit installations...

[Rivets]

A 220/240 VAC center tapped transformer produces 2 voltages 180 degrees out of phase with each other, so technically this is a 2-phase system.

[snip]

Ken, with all due respect,

1- If the voltages were 180 degrees out of phase, then the resulting voltage would be zero.

2 - Technically, it's called a Split Phase system.

Cheers,
Rivets

[kenwhite]

Ken, with all due respect,

1- If the voltages were 180 degrees out of phase, then the resulting voltage would be zero.

2 - Technically, it's called a Split Phase system.

Cheers,
Rivets

Rivets, with all due respect, if the voltages are in phase with each other, then the voltage would be zero...

Opposing phase or split phase phase is still a circuit with both voltages 180 degrees out of phase, or 2 different phases, or 2-phase..

[performance]

Rivets is right. Its single,split phase... There is 2 phase systems out there, albeit they are older and fading away in this country. I think the last two phase systems may be in NY state.

[A/C Guy]

ok now things are starting to add up in my head...so you could hook up a single phase 220 welder with just 2 hot wires and then tie the ground wire from the welder to the box/conduit? If this is the case, and I dont trust the box/conduit as a ground and I want to run a ground wire would it have the be the same gauge as the 2 hot wires(6awg)? or could I use a 10awg for the ground wire?

First part, Yes if they are opposite legs. You can verify by using a volt meter. If your meter shows < 100 volts, you probably are connected to the same leg of 110 on each line. I only mention this because I have see old boxes that wee mis-wired.

National Electric Code allows 10 gauge wire to be used for ground on circuits up to 60 amps. After 60 amps, the ground needs to be 8 gauge. Be sure to buy green wire or green electrical tape and mark the wire clearly with the green tape.

Although some locales allow using conduit for the ground, it is a very, very bad practice. I have seen the damage caused by that practice. Just last week, I was almost zapped when a machine went short to ground and the conduit was not properly bonded to the boxes at either end. The installer used #14 ground, it melted before the breaker tripped. The conduit was visibly vibrating and the arcs sounded just like a MIG running spray mode (240 volts at over 200 amps is some serious spray mode weld action).

[dgarnier]

First, NEVER, NEVER, connect ground to neutral at an appliance. Never use neutral for ground and never use ground for neutral. The only time you need a neutral is when you need 110. 110 is either leg connected to neutral. 220 is one 110 leg connected to the other. Driers and stoves use the neutral for clocks, timers, control pads, etc. The 220 is for the heating elements. The welder only uses 220 and ground.

Edit to add: Read the first post. The red wire on your welder is NOT for residential use. It is only for 3 phase power. The Black and White on your cord are for your 110 volt legs; green is always ground.

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

I really hate to bring this back up, but I am still not clear on something. On the 110 side the netural is the return side to complete the circuit. The ground comes into play if you loose the netural leg and the current needs to go somewhere. If that is true then for 220 wouldnt you want to use the 2 hot legs and then wire the ground from the welder to the netural wire. From the 110 the netural is always taking the return from the hot leg, why not use it to dump current in the case where you loose one of the hot legs for 220?

[kenwhite]

I really hate to bring this back up, but I am still not clear on something. On the 110 side the netural is the return side to complete the circuit. The ground comes into play if you loose the netural leg and the current needs to go somewhere. If that is true then for 220 wouldnt you want to use the 2 hot legs and then wire the ground from the welder to the netural wire. From the 110 the netural is always taking the return from the hot leg, why not use it to dump current in the case where you loose one of the hot legs for 220?

The neutral is only used as the return path back to the transformer for the 2-120 VAC phases.

For a 240 VAC connection, one of the hot phases acts as the return path back to the transformer, so no neutral is needed.

However, a safety ground is always needed. The safety ground is tied to the neutral back at the service entrance point, but it should never carry current unless there is a fault - it protects against the chassis/metal case from becoming hot and shocking you should you touch something that is grounded.

[dgarnier]

So what is the harm in using the neutral as ground for 220? Both the ground and neutral give the current a path to return rather then grounding through someone that might be touching the machine?

[performance]

One reason is high frequency issues.

[aaxiss]

The breaker in the panel is a 40 amp breaker going to the 220v compressor and I have been using it with the old Lincoln buzzbox for a number of years. I always unplug the compressor because I only have a one outlet. I have never popped the breaker, the sub panel the shop was installed to code by an electrician .

I suppose I should rephrase the question and provide more info . The house was built mid 60's and my question is ho do I tell how many amps are avail at the sub panel in the shop?, If I wanted to put in another dedicated welder circuit. The panel has room for the breaker and running the 6ga would not be a problem but I don't want to wast my time if the sub panel wont support a 50 or 60 amp line. Is there a way to tell how many total amps the service to the house is and the what the amperage to the sub panel is . Like markings on the panel or inside?

And Being That I will mostly be welding below the maximum output of the welder would it be ok to continue to use the 40 amp circuit. Iv'e never Popped the breaker Yet during normal welding with the lincoln ( usually in the 90 to 160 amp range ) except once when I had the welder and compressor On a Y adapter after the shop was built 5 years ago. now I make sure compressor is full then plug welder in . I would Like to be able to use both with a dedicated line for each if possible though I just want to be able to know ahead of time before I call out the electrician and get told no and charged for a service call .

thanks