220v wiring question
RSS | Subscribe | Contact Us | Advertise | About Us
Results 1 to 24 of 24
  1. #1
    Join Date
    Mar 2004
    Posts
    12

    220v wiring question

    Looking at the 220v outlets I have they are all 2 hot wires and a neutral wire with the ground attached to the junction box. Looking at a schematic of a welder it shows the 3rd blade on the plug as a ground, can someone explain this to me and how would I change my outlet from a 10-50R to a 6-50R?

    I'm confused on how to wire the outlet to work with a welder. Just to clarify I have a red, black, white and copper uninsulated wire.

    Thank You

  2. #2
    Join Date
    Jan 2004
    Location
    Hilton, NY
    Posts
    1,985
    The configuration you have will work with a welder, since most machines don't use either the ground or neutral.
    If you were wiring the receptacle to serve only the welder, you would tape off the neutral in the box, and install a jumper from the bare ground in the box to the place you removed the neutral from on the receptacle.
    Appreciation Gains You Recognition-

  3. #3
    Join Date
    Mar 2004
    Posts
    12
    Thanks for the reply. So the neutral wire would not be attached to the receptacle or grounded is that correct?

  4. #4
    Join Date
    Mar 2004
    Location
    Browns Valley, CA
    Posts
    137
    The neutral (white) and ground (bare copper) are bonded together in the electrical service box. The neutral is the electrical center of your utility company's transformer. From the neutral wire to either leg of the phase conductors (red/blak wires) ther's 120VAC. Between the phase conductors, there's 240VAC, which is what your machine likes. That's why you don't need the neutral.

    Look at your welder wiring diagram. If it shows a ground bond to the welder's case, you should do as Franz suggests. If not, it's a moot point.

    Be well.

    hankj

  5. #5
    Join Date
    Apr 2004
    Location
    iowa
    Posts
    44
    I seem to be having a problem with my picture size. If this goes I will give the details later. It's what a 200 amp service panel looks like with the old cartridge type fuse pullouts.
    Attached Images Attached Images  

  6. #6
    Join Date
    Apr 2004
    Location
    iowa
    Posts
    44
    The pullout in the 200 amp panel for the lower left has been pulled. It has two 20 amp cartridges for fusing a 220 volt, 175 amp welder that has a maximum amperage requirement of 19.5 amps. The circuit is wired in #6 wire, the upper red wire to the terminal on the removed pullout block and the black wire to the terminal below the red wire. The neutral wire is the large white wire going to the center neutral bus. There is also a bare #10 ground wire in the cable which is also connected to the neutral bus. The box did not have a ground bus.
    Attached Images Attached Images  

  7. #7
    Join Date
    Apr 2004
    Location
    iowa
    Posts
    44
    This is to explain what is in the service panel. This is not a do-it-yourself how to do it. If you don't know what you can touch and what you can't, stay out of electrical service panels. Get an electrician.

    In the photograph of the electrical box, the two large, black wires dropping down from the hole are the hot wires from the power companies transformer. Electrical power to residential service panels, small farms, and businesses are from a 220 volt, center tapped secondary winding in the transformer.

    So the voltage between the two black wires is a nominal 220 volts. Actually, in this box it is more like 244 volts. The bare, twisted copper cable is the neutral wire from the center tap on the transfomer and goes to the neutral bus below the 4 pullout blocks. The neutral bus is also used as the ground bus in this box. The voltage between either black wire and the neutral wire will be one-half of the voltage between the two black wires. 240V/2=120V; 220V/2=110V.

    If you touch (DON"T!!!) either of the two black wires or the bus bars between the pullouts you most likely will be electrocuted, so don't. If you short them to ground with a tool, there will likely be an big explosion. There isn't anything between those wires in the box and the transformer to blow or open, so the full output from the transformer is present.

    The two black wires are bolted with connectors to two main buses that pass between the 4 pullout cartridge holders. Each bus divides and supplies power to the pullout terminals. The pullouts have a connection to both sides of the 220 volt supply which divides the 220 volts into 110 volt (or 117, 120, etc.-half of what the voltage between the two main bus voltage is) power.

    Each pullout has two fuse cartridges (or double circuit breakers in place of two fuses in a breaker box) has two 117 volt terminals which can supply two distribution buses. The two rows of Edison fuses shown are two distribution blocks.

    Or the two 117 (or 110, or 120) volt outputs can be cabled along with a neutral wire to supply 220 (240) volts to a welder. The lower left pullout has been pulled in the photo. The top red wire and the bottom black wire for that pullout and the large white wire connected to the neutral bus, along with a bare copper wire make up the cable for the welder circuit.

    The wires shown are #6 except the bare ground wire is #10. Yes, the welder may not need the neutral, but it should be run anyway. If the wiring is ever needed for a different machine, it will be there. Digging and running a service to a garage or running a service to the work shop shouldn't have to be done more than once.

    Yes, lower powered welders don't need #6 wires. Maybe #10. But, the wire is probably going to be cheaper than the labor or digging costs even if it's only your own time. Why not provide for any upgrade or more power requiring machine.

  8. #8
    Join Date
    Apr 2004
    Location
    iowa
    Posts
    44
    BTW. The two 20 amp fuses are mounted in adapters so that the pullouts will accept the smaller (smaller diameter and shorter) cartridges. The pullout was made to hold the largests cartridges which are from? 35 amp to 60 amp fuses.

    Pullouts built for small fuses can not be modified to hold larger ones, but the large fuses holders can use the adapters for smaller fuses.

  9. #9
    Join Date
    Jan 2004
    Location
    Hilton, NY
    Posts
    1,985
    In what will probably become an ill fated effort to simplify this, will your welder plug fit into the receptacle at the other end of the red/black wires attached to the fuseholder?
    If the plug fits, the welder will work.

    Both the Neutral and Ground are attached to the same buss, because they are bonded at the service entrance point. If you look at the pic of your pannel, there is a silver bar at the bottom of the neutral buss that bonds it to the metal housing for this purpose.
    Appreciation Gains You Recognition-

  10. #10
    thanks franz for your help!

  11. #11
    Join Date
    Mar 2004
    Posts
    12
    I need to convert the receptacle from a 10-50R to a 6-50R. When I took a look at the 10-50R (after pulling breaker) the neutral wire is connected to the receptacle and the ground is wrapped around the mounting plate.

    What had me concerned is the wiring diagram for the welder shows the plug having a ground. So as of right now if I left the wiring alone I would have the ground from the welding power cord connecting with the neutral from the receptacle.

  12. #12
    Join Date
    Apr 2004
    Location
    iowa
    Posts
    44
    Hi Franz;

    Yes, the red and black wire, and the neutral white wire are wired to the outlet connector the welder plugs into. Right, the silver thing is the bracket that screws the neutral and ground to the service enclosure box.

    The picture about says it all-it's the short version.

  13. #13
    Join Date
    Feb 2004
    Location
    La
    Posts
    5

    Wiring for welder

    When wiring for your welder don't forget that most welders require 120VAC as well as 240VAC. Cooling fans, wire feed motors, warning lights. etc.

    I say this because I have read every post on this subject and see contradictory comments on the ground and neutral. Please, if you are not an experienced electrician, save a life, probably your own and get the advice or help from a certified electrician.

    moe1942

  14. #14
    Join Date
    Jan 2004
    Location
    Las Vegas, NV
    Posts
    3,175
    Actually, I don't know of any 4-wire welders, ones that require a neutral for 120V in addition to the 240V.

    The ones I am familiar with (all the Millers, etc) from most eras either have 240V accessories (fans, lights, etc.) or they have a tap off the main transformer to feed 12 or 24 volts to these devices.

    I don't know if it was routine in the past, but modern equipment is not permitted to purposely use the equipment grounding conductor (green wire) to purposely carry current for 120V loads, and all the 240 welders I know of have only three wire plugs, two hots and one ground.

  15. #15
    Join Date
    Apr 2004
    Location
    iowa
    Posts
    44
    That 3rd wire in a 220 volt(or 240-take your pick) cable is the neutral! You can follow it back to the center tap on the power transformer. It is connected to ground at the entrance panel-so it is a ground in a sense, but a ground wire it isn't. A 4th wire is used as a ground. A cable is made up of a black, red, and white wire, and a bare copper wire. Black and red are 120 volts to the neutral and 240 between black and red. The ground wire, if used, is to tie the equipment case being powered to ground if for any reason the hot voltages in the equipment gets shorted to the case. That will blow the fuses.

    Some welders had a ground cable that had to be grounded to a ground rod where the welder was being used. The ground wire in the supply cable also had to ground to that ground.

    The smart and safe way to do it is to wire the outlet with all three service wires. If there is a ground wire, bare or green wire, connect it to the metal outlet box if it isn't plastic. Don't second guess the manufacturer about what or how he wired the equipment. Manufacturers may revise production units at any time. That's why they put serial numbers on equipment.

  16. #16
    Join Date
    Feb 2004
    Location
    La
    Posts
    5

    240 VAC wiring

    Stingers,

    Thank you. Again, you have described 240 VAC wiring dead on.

    We all must remember that, like me, there is a lot of old technology still making arcs and sparks.

    It is much better to err on the side of caution rather than being carried by six.


    moe1942


    PS: If I could edit my last post I would substitute the word "most" with "some." I have one of the "some."

  17. #17
    Join Date
    Jan 2004
    Location
    Brethren, Mi
    Posts
    513
    I dont think its any advantage to run a 4 wire cable in a welder circuit, and, if you are using a welder recept it has its ground pin bonded to the yoke of the recept so it grounds any box its connected to. Having 4 wires and grounding one to the box and another to the recept is a bad idea,, not so critical with welders, and it will work. There should be no neutral in a welder circuit and if there is a spare wire in the cable the white should be taped off and unused. It is a ground wire not a N wire.

  18. #18
    Join Date
    Feb 2004
    Location
    La
    Posts
    5

    240 VAC

    My last note on this thread is once again safety.

    Different parts of the country have different electrical requirements, all of which are designed to protect the user.

    Unless one is well versed in grounding and grounded conductors and/or the NEC, please consult an electrician.


    moe1942

  19. #19
    Join Date
    Mar 2004
    Posts
    12
    So if I understand correctly the only reason you would use the neutral wire is to split or use only one circuit of the 220v power to have 110v? If that is correct why do certain appliances use a neutral wire? Do they use 110v and 220v within the same appliance?

  20. #20
    Join Date
    Apr 2004
    Location
    iowa
    Posts
    44
    Hi Mason;

    Yes indeed, the neutral wire is for getting 120 volts on equipment that have 220-240 volt requirements. Electric stoves and ovens for example have 220-240 volt heaters and 125 volt light bulbs for lighting the oven when you want to take a peek at the cookies burning.

    I just looked at mine to make sure.

  21. #21
    Join Date
    Jan 2004
    Location
    Las Vegas, NV
    Posts
    3,175
    Originally posted by stingers
    That 3rd wire in a 220 volt(or 240-take your pick) cable is the neutral! You can follow it back to the center tap on the power transformer. It is connected to ground at the entrance panel-so it is a ground in a sense, but a ground wire it isn't. A 4th wire is used as a ground. A cable is made up of a black, red, and white wire, and a bare copper wire. Black and red are 120 volts to the neutral and 240 between black and red. The ground wire, if used, is to tie the equipment case being powered to ground if for any reason the hot voltages in the equipment gets shorted to the case. That will blow the fuses.

    Some welders had a ground cable that had to be grounded to a ground rod where the welder was being used. The ground wire in the supply cable also had to ground to that ground.

    The smart and safe way to do it is to wire the outlet with all three service wires. If there is a ground wire, bare or green wire, connect it to the metal outlet box if it isn't plastic. Don't second guess the manufacturer about what or how he wired the equipment. Manufacturers may revise production units at any time. That's why they put serial numbers on equipment.
    I don't think this is right. If it a three-wire plug, like on the MM175, 210, 251, etc., then it has two hots (with a 240V potential between the two) and a GROUNDING conductor. If you were to strip back the jacket, I am sure this wire will be either bare or green.

    Yes, at the main panel or transformer of the shop, the grounding conductor is connected to the neutral bus or center tap. This is how the grounding conductor does its job. But it is only at this point that it is allowed to be anything like a neutral. It is wrong to purposely use it as such anywhere else. If you require 120V in your 240V welder, there will be 4 wires, not 3, and one will be a dedicated neutral and white (called a groundED conductor in the NEC) and one will be a ground and bare or green (called an equipment groundING conductor in the NEC.) There is a big difference at a receptacle between these two, even though at the main panel or transformer they will be bonded to the center tap.

    The fan on your MM is probably a 24 or 12 V and probably runs off a tap from the welding transformer in the box. It is certainly not 120V unless it also gets that from a tap in the welding transformer.

    If you were to separate the conductors in your power plug and put an ammeter on the third wire, you should read zero current while the machine is in use. I say again, it is not a neutral, unless something is very much amiss.

  22. #22
    Join Date
    Jan 2004
    Location
    Brethren, Mi
    Posts
    513
    If you are at a main panel all this wont make much difference,, but if you are on a 4 wire sub it would.

  23. #23
    Join Date
    Feb 2004
    Location
    La
    Posts
    5

    240VAC

    I wasn't going to post on this thread again but I have one more question and a couple of comments.

    I wonder if anyone has bought or made an extension cord like I have. It's a 25' # 6-3 with a box on one end that has multiple outlets. 240 and 120 VAC.

    Whats unique about this cord is that when I use my portable range top to make gumbo, the third wire is white (grounded conductor) but when I plug up my MM175 the third wire is green (grounding conductor).

    Earlier in this thread someone said if your welder plug fits and it is the correct amperage receptacle, wired correctly, it will work. I agree.

    If you are an electrician, doing a job for pay, do it right according to the NEC and local code. If you are very familiar with electricity, doing your own wiring and short on bucks, do it safe. A pink and yaller wire can be just as safe as a green wire if it is wired correctly.

    And last but not least, in some circuits the white neutral is hot. A piece of black tape or black marker is used to identify this fact at the exposed ends. Guess I'll just get some green and white tape and put it on the third wire of my home made ext cord so I won't get confused.

    When in doubt, consult an expert.

    moe1942

  24. #24
    Join Date
    Jan 2004
    Location
    Brethren, Mi
    Posts
    513
    A pink or a yaller wire is not as safe as using the correct green or bare. Thats why they put it in the code. Moe, do you have a breaker box on the end of this cord?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
RSS | Home | Penton Media | Contact Us | Subscribe | For Advertisers | Terms of Use | Privacy Statement