220 volt wiring.

[Phil Tibbetts]

I have a welder actually a couple of them that operate on 220 volts with a3 conductor cord. My generator and some other things use a 4 conductor cord. I've seen adapters for 3 to 4 conductor. How is the wiring on the 3 conductor set up? I know that 220 can be run with only 2 110 volt lines, so is the third lug connected to the ground or neutral or both. both go to the same buss in the main panel. I wired my whole garage when I built it and had it inspected. The inspector said I did a good job , no problems but I'm confused about thus aspect of wiring.

 

[old]

Old code was 2 hot 120 lines and a ground new code is 2 hots a ground and a neural

 

[Janicholson]

Old is correct. The new code does not allow the white wire (neutral) to be responsible for equipment/hardware ground. A generator may be setup or required to be setup with a chassis ground. Reading the directions (they might be on line.) Jim

 

[JustIn Case]

(quoted from post at 23:20:22 01/12/23) Old is correct. The new code does not allow the white wire (neutral) to be responsible for equipment/hardware ground. A generator may be setup or required to be setup with a chassis ground. Reading the directions (they might be on line.) Jim

Too late tonight to get into code book. BUT, if there is no place to connect a neutral and a neutral is not used/required I m pretty sure one can still use a wire/cable with two hots and a ground. YES the neutral cannot be used for a ground as it used to be on clothes dryers where the heat elements were 240 volt but the motor was 120 volt. I think any device that does not require a neutral can be fed by hot conductors and grounded by an equipment grounding conductor (Not Neutral)

 

[kencombs]

3 wire is 2 hots and a ground. Used when the welder or other thing uses no 120v current.

4 wire add a neutral and is required for any load that uses 240 and 120.

Either is OK when the load is as described above.

Recpts with 4 sockets will be marked 120/240v. 3 sockets, will be marked 240v only. Unless of course the 3 are Hot, Neutral and ground which would be 120v.

 

[Mike(NEOhio)]

With a 3 wire setup the chassis is grounded through the neutral wire. It's possible that a fault can energize the all the other circuits through the neutral bar in the panel. I converted out dryer from three to four because the duct would sometimes arc to a nearby water line. I added the four wire receptacle and removed the neutral bond.

 

[MarkB_MI]

Reading between the lines, it sounds like you're contemplating 'backfeeding' your generator through the welder outlet. The first concern I would have is whether your ground conductor is really up to the task of handling a lot of current for an extended duration. There is likely to be significant neutral current when running a generator, while the welder would normally have no ground current.

 

[Bob Bancroft]

Disclaimer: I shouldn't even be commenting! But I didn't see anyone mentioning- on sub panels ground and neutral are now separated. Therefore a four wire conductor is used to feed these subs. Three wires still come from the utility and feed the main panel. At least that's the way it is here. I have several sub panels. My system is old enough that I have no four wire, or four lug connectors, anywhere. Dryer outlet, welder outlet, all three lug, yet they all utilize both 240 and 120 volts. I think the change in the code is where the confusion is.

 

[wp6529]

Do not confuse welders which are nearly always 240V only devices with clothes dryers which typically use 240V for heating elements and motor and 120V for timers, they are completely different. Clothes dryers used to be allowed to put the small 120V load on the ground, but that exception was eliminated.

There is no code that requires a neutral to be run to a device that does not use a neutral. A welder will have two hots and a ground and that is all. The wiring is also not required to be sized for the welders peak input current, it is allowed to be a reduced size based on the welders duty cycle and newer welders will list I eff (effective current) on their rating plate.

 

[Bob Bancroft]

I have no idea, but you are sure the cooling fan in my welder is 240V?

 

[wp6529]

(quoted from post at 09:07:13 01/13/23) I have no idea, but you are sure the cooling fan in my welder is 240V?

If it has a 3 wire power input almost certainly. My Synchrowave 250 even has a 120V accessory outlet on it and is 240V (or 480V) only input. The 120V for the accessory outlet is derived in the welders transformer, not from the input power. Still 120V at the accessory outlet regardless of whether the input is on 240V or 480V.

 

[John T]

Good Morning Phil, great questions so I will answer and explain below:

1) I have a welder actually a couple of them that operate on 220 volts with a3 conductor cord.

Thats typical for welders that used 240 Volts .......There are Two Hot UNgrounded Conductors L1 & L2 which have 240 line to line, while the Green/Bare Equipment GroundING Conductor is attached to the Equipment Ground Buss in the panel and is there to carry fault current.

2) My generator and some other things use a 4 conductor cord.

Four Conductors being TWO Hot UNgrounded Conductors (L1 & L2 Black and Red),,,,,,,,ONE Grounded Conductor (White Neutral),,,,,,,,,ONE Equipment GroundING Conductor

A REASON WHY 4 CONDUCTORS MAY BE RAN TO A DEVICE IS IF IT REQUIRES BOTH 120 AND 240
Its NOT permissible to use the Equipment GroundINC Conductor for normal return current THE GROUND IS ONLYYYYYYYYYYYYY FOR FAULT CURRENT and doesn't carry any current otherwise, if alls well that is !!

Under the older NEC 3 wires were ran to some home appliances and the Ground may have been ???? used to carry Neutral current (NOW A NO NO)........ Under later code they use 4 wires so the Neutral carries return current and the Ground ONLY fault current. They may have BOTH 120 and 240 loads which is why 4 wires are now used.

NOTE A genset that has a FOUR Conductor Receptacle (IE Three Pole Four Wire Grounding) could be for one that has BOTH 120 and 240 (or perhaps two legs of 120 in phase) and requires the FOUR terminals, Two Hots,,,,,,One Neutral,,,,,One Ground. Those receptacles could be a NEMA 14-50 R or perhaps say a 120/240 Three Pole Four Wire Grounding Twist Lock


3) I've seen adapters for 3 to 4 conductor. How is the wiring on the 3 conductor set up? I know that 220 can be run with only 2 110 volt lines, so is the third lug connected to the ground or neutral or both

Three Conductor is as described above ...For 240 its 2 Hots one Ground...For 120 its One Hot One Neutral One Ground

NOTE Under the new code if you supply a 120/240 SUB Panel from a Main Panel YOU CARRY FOUR WIRES 2 Hots, 1 Neutral, 1 Ground and AT THE SUB (unlike Main) the Neutral and Ground Busses are separate insulated and isolated from each other..

HOW IS THE THIRD LUG CONNECTED ?????????

I dont know from here but above is how Three Pole Four Wire Grounding Receptacles are typically configured

NOTE Some gensets come from the factory with a FLOATING NEUTRAL while some come with a BONDED NEUTRAL for good reason and which way you use it depends on several things above and beyond this discussion

NOTE Some genset uses require a Grounding Electrode (driven rod) while other uses do not

Hope this helps Phil, post back any more questions

John T

 

[BarnyardEngineering]

(quoted from post at 06:07:13 01/13/23) I have no idea, but you are sure the cooling fan in my welder is 240V?

I can tell you for a fact that they are on the Lincoln AC225's.

 

[miangus]

I replaced a cooling fan in my wire welder and was 240 volts. Most of the replacement offering in the Granger Catalog were 240-volt.

 

[Stephen Newell]

Some equipment has something inside which runs on 110v. For that there should be a dedicated neutral and the fourth lead is the ground.

 

[wore out]

(quoted from post at 12:00:05 01/13/23) Some equipment has something inside which runs on 110v. For that there should be a dedicated neutral and the fourth lead is the ground.

''Some equipment has something inside which runs on 110v. For that there should be a dedicated neutral and the fourth lead''

The other option is to use a control transformer or ''machine tool transformer'' to power the internal lower voltage load WITHOUT the need for a neutral power supply wire to the equipment.

COMMONLY done.

 

[Phil Tibbetts]

That's one I have.

 

[Phil Tibbetts]

Okay so if I want to make up a 4 prong plug to plug into my generator with a 3 prong welder receptacle on the other end how do I wire the plug and most important the welder receptacle?

 

[old]

You can use either the neutral or ground as one leg and then the 2 hot 120 volts leads.

 

[Brian G. NY]

(quoted from post at 14:27:04 01/13/23)

(quoted from post at 06:07:13 01/13/23) I have no idea, but you are sure the cooling fan in my welder is 240V?

I can tell you for a fact that they are on the Lincoln AC225's.

Me too!