220V 4 wire to 3 wire?

[plug ugly]

the new house we are moving into has a 4 wire 220 in the garage, but my welder and plasma is 3 wire, what do I need to do?

[ShaggyAnt]

You can just swap out the plug. the white wire should be neutral, just tape it off and leave it in the box. the reason for the 4 wire plug is so that appliances can use the neutral from the circuit box to tap off half the 220v and get 110v for internal motors or controls. That is not needed for a welder

[Wicked_S10]

All 220 runs to receptacles should be 4 wire. There are 2 hot wires, a neutral and a ground. 220 equiptment only requires that it have 2 hot wires and the neutral to function, but most of the stuff that you hook up to 220 will have provision for a ground, and should be wired up, but a lot of times it gets overlooked by the ameture electrician while they are hooking up their welder, dryer whatever.

Later,
Jason

[TNToy]

Like they said. You'll have two hots (usually black/black or black/red) that you'll use, and the ground. The neutral is left disconnected.

[Mechanos]

Originally Posted by Wicked_S10

All 220 runs to receptacles should be 4 wire. There are 2 hot wires, a neutral and a ground. 220 equiptment only requires that it have 2 hot wires and the neutral to function, but most of the stuff that you hook up to 220 will have provision for a ground, and should be wired up, but a lot of times it gets overlooked by the ameture electrician while they are hooking up their welder, dryer whatever.

Later,
Jason

Not necessarily. The neutral (4th wire) is only needed if the equipment powered by the outlet has 240V AND 120V components in it. If the equipment is purely 240V, the neutral will never be used and there won't even be a provision on the equipment to hook up a neutral. If the equipment has 120V components (clocks, lights, timers, etc..) then the neutral should be included as the return path for the 120V circuits. Without the neutral, the return path is forced to the grounding conductor and this not a good practice.

Since your circuit is already run, as stated above, just tape off and don't use the neutral if your welder and plasma are pure 240V machines.

[PAToyota]

Originally Posted by Wicked_S10

All 220 runs to receptacles should be 4 wire. There are 2 hot wires, a neutral and a ground. 220 equiptment only requires that it have 2 hot wires and the neutral to function, but most of the stuff that you hook up to 220 will have provision for a ground, and should be wired up, but a lot of times it gets overlooked by the ameture electrician while they are hooking up their welder, dryer whatever.

Should really learn what the deal is here before you really mess someone up. 220V is two hots and a GROUND - not a neutral (as others have also said). Four wire is ONLY for appliances that also have 110V in them - like the light in the dryer or the timer on a range/oven. Something like a compressor or welder only needs the three wires - there is absolutely no place to connect a neutral to in such a setup.

[Wicked_S10]

Originally Posted by PAToyota

Should really learn what the deal is here before you really mess someone up. 220V is two hots and a GROUND - not a neutral (as others have also said). Four wire is ONLY for appliances that also have 110V in them - like the light in the dryer or the timer on a range/oven. Something like a compressor or welder only needs the three wires - there is absolutely no place to connect a neutral to in such a setup.

How can what I said mess someone up? If you wire something for 220 that only has the provision for 2 hots and a ground, and you wire up 2 hots and a neutral to it, it makes absolutely no difference. The neutral and the ground are electrically the same damn thing. The point I was trying to make, is that if your equipment has provision for 2 hots, a neutral, and a ground that they should all be connected. If they are not, the neutral in the machine is isolated from the case/frame and any faults that occur may energize the case of the equipment rather than popping the fuse or breaker.

[PAToyota]

As you likely know, the neutral is the primary return path for any single phase circuit while the ground is a safety return path in the event of a fault - to help eliminate the potential for shock from any metal casing in the event of an internal short.

At the main panel the service neutral and the outside ground rod (and any internal water pipe or supplemental ground for that matter) are all technically one and the same wire and point - but that is where it ends.

Once you leave the main panel on any grounded system this extra added ground wire now serves a totally new purpose and because it is now isolated from the neutral from that point on - it adds the extra degree of protection that the neutral cannot - it is picking up any "bleed" to metal on all your appliances (the frame of your light fixtures or dryer or stove, etc) and taking that back to the panel and hopefully tripping the circuit breaker monitoring that circuit in the process.

The neutral, having an internal connection inside that device can NOT do this. So this is the main purpose (and why it's required) for this isolated ground (isolated only in reference to the neutral) to provide that extra safety path back to the panel. In the event of a fault or short electricity has a quick way back to main ground. Without this ground path the user might encounter a shock touching the device if it has an internal fault or in the case of electronics - internal circuitry damage may occur.

Technically it is more or less redundant - the two wires have no difference in potential - as say, the hot black and neutral would - but the 2 wires now serve completely different purposes once they leave the main panel.

[Pook]

just wait till the neutral bond back at the main becomes corruded, loose or faulty and you have something using the neutral as a ground path. You now having a floating neutral thats carrying current creating voltage potential and energizing the metal can of your equipment. Not good.

Neutral is a neutral not a ground bond.

[Pook]

And back to the original post...

I'd get a 4 wire range male plug and install it on my welder. Just don't connect anything to the neutral prong. This way there is no messing with the house wiring...and if you ever do need to plug a range or something in its easy.

[devinsixtyseven]

Originally Posted by Pook

I'd get a 4 wire range male plug and install it on my welder. Just don't connect anything to the neutral prong. This way there is no messing with the house wiring...and if you ever do need to plug a range or something in its easy.

Like he said but maybe even easier. No need to mess with existing connectors...

Pick up a pigtail that fits the receptacle, make sure it can take the load--the pigtails sold at your local hardware store should have the correct gauge/strands but always doublecheck--and a receptacle that takes the welder plug, then make an adapter cord. Just make sure the adapter wiring is rated the same or higher than the breaker. Should run you under 25 bucks out the door, and twenty minutes to wire and secure the adapter receptacle to the wall.

That way you can still install a range in the garage and have mac'n'cheese while you're welding .

O/T, but does anyone know when code changed to require 4-connection receptacles vs the 3-connections in older houses? When we move I'm gonna probably have to get another pigtail, which is another good reason to make an adapter vs changing the welder plug...pipgtails are only 10-15 bucks.

[tsm1mt]

Originally Posted by Pook

And back to the original post...

I'd get a 4 wire range male plug and install it on my welder. Just don't connect anything to the neutral prong. This way there is no messing with the house wiring...and if you ever do need to plug a range or something in its easy.

My $0.02, after running a 3-wire 50amp run in my shop for the welder and plasma..

I'd leave the 4-wire in place, and buy/build a 4-wire extension cord. Run it to a sub-panel on your welding cart (which holds your welder and plasma), then plug the welder and plasma into it (with 3-wire receptacles) AND put a pair of 110V outlets on the cart while you're at it.

Can't do that if you only run 3-wire.. d'oh.

[plug ugly]

Originally Posted by tsm1mt

My $0.02,.. d'oh.

not a bad idea, but the garage does have ample 110 in it. I may just rewire my extension cord I made to fit the 4 prong. I will ONLY run a welder and my plas off it. now my plas is a 110 or 220, but that is different than what I believe you guys to be talking about with the 110 and 220 stuff right?

[blahblahblah]

Originally Posted by plug ugly

the new house we are moving into has a 4 wire 220 in the garage, but my welder and plasma is 3 wire, what do I need to do?

Buy one of these

http://store.cyberweld.com/poadne6tone1.html

[plug ugly]

thats actually perfect, but a bit pricey. i think I can get a new end on myextension cord for like 15 or 20 bucks

[jasonmt]

Originally Posted by blahblahblah

Buy one of these

http://store.cyberweld.com/poadne6tone1.html

Chances are that plug ugly's dryer receptacle is a 30A 14-30R so the 14-50P plug on the adapter will do him little good.

[MT4Runner]

Originally Posted by tsm1mt

My $0.02, after running a 3-wire 50amp run in my shop for the welder and plasma..

I'd leave the 4-wire in place, and buy/build a 4-wire extension cord. Run it to a sub-panel on your welding cart (which holds your welder and plasma), then plug the welder and plasma into it (with 3-wire receptacles) AND put a pair of 110V outlets on the cart while you're at it.

Can't do that if you only run 3-wire.. d'oh.

Great idea!!!

[plug ugly]

my plug was never designed for a dryer (that connection is inside) however, thats not to say its not a dryer receptacle. I dont recall seeing the 90* slot tho, if that changes anything

[jasonmt]

Originally Posted by plug ugly

my plug was never designed for a dryer (that connection is inside) however, thats not to say its not a dryer receptacle. I dont recall seeing the 90* slot tho, if that changes anything

All the 4 wire 125/250V single phase plugs/receptacles should be a 14-xx series, the question is do you have a 15A, 20A, 30A, 50A or 60A receptacle?

[camo]

I haven't seen anybody bring it up but isn't 4 wire 220 also used for 3 phase ? how can you tell the diff between single phase and 3 phase 4 wire ?

[Mechanos]

You will not find 3-phase in a residence. At least around my part of the country, the power companies WILL NOT run 3-phase power to a residence.... commericial properties only. Nobody has 110V or 220V either... if that's all you measure at your outlets, you need to call the power company and tell them to fix your shit. Go and an stick a multimeter in one of your outlets see what it is. It should be 120V and 240V for single phase power. 3-phase power in commercial applications is either 208V, 240V or 480V and can be supplied in either a "delta" or "wye" configuration. It's about a gazillion times more complicated and harder to wrap your head around than that basic simple description.

[Stephenw]

Originally Posted by camo

I haven't seen anybody bring it up but isn't 4 wire 220 also used for 3 phase ? how can you tell the diff between single phase and 3 phase 4 wire ?

With three phase, each phase measures 120 volts to neutral. Phase to phase is 208 volts. This is because there is a 120 degree phase angle difference between each phase. There are actually 5 wires, L1, L2, L3, Neutral (usually called the grounded conductor), and Ground.

[camo]

oh great...sounds like we'll have all kinds of fun hooking up equipment in the new shop...

sounds like work for a professional

[Pook]

Originally Posted by camo

oh great...sounds like we'll have all kinds of fun hooking up equipment in the new shop...

sounds like work for a professional

could save you alot of headaches getting a pro.

Its really not that difficult to wire 3phase. If you have a pro around who can help quide you with what to do an dwhat to buy.

I personally usually get my friends who own the shops to do all the grunt work. I tell them what they need and let them run the cable, piping etc. I just make sure they do it nice and neat and to code. Then I'll come in do the connections and all the panel work.

[plug ugly]

Originally Posted by jasonmt

All the 4 wire 125/250V single phase plugs/receptacles should be a 14-xx series, the question is do you have a 15A, 20A, 30A, 50A or 60A receptacle?

its a 30 amp breaker