220V plug question

[Will H]

I have two questions related to 220V service. I recently bought a house, and the detached garage is already wired for 220V. There is one plug on the wall, and another on the ceiling that the hoist uses. The plug on the wall has two problems - It is a 4 prong locking plug, and it is not wired to the sub-panel in the garage.

The hoist 220 is on the garage breaker, but the wall plug directly below the panel is not...it is wired directly to the main bus on the garage subpanel, so it's breaker is in the house, for the entire garage electrical supply. I doubt it would happen, but should that trip it could get real fun working my way out of a pitch black garage littered with tools and parts.

Question 1 - Can I piggy back the wall plug on the hoist breaker? The two would not be running at the same time, so I don't anticipate an overload problem.

Question 2 - the back of the wall plug has 4 wires for 4 locations...ground, white, black, and red. Black and Red each show 115V. I want to change this over to a welder-style 3 prong plug. How do I hook this up? The new plug came with no directions.

Here is a generic picture of the current 4-prong plug, in case it helps:

http://www.jackssmallengines.com/graphics/HondaGen/32310za0630.jpg

Thanks,
Will

 

[G1K]

I'll preface this by stating I'm not an electrician, but for the plug on your welder (3 prong), run the red wire to a prong, run the black wire to a prong, and the ground to the ground prong. Tape (with wire nut) off the neutral (white). That will get you the connection you need.

The other option is to buy a new male plug for the welder.

Ryan
* edit for spelling

 

[1320stang]

Do you have a space to add another breaker to the sub panel?

How many amp breaker is the hoist service?

Ryan has the correct answer for wiring the 4 wires up to the 3 wire outlet. I used a dryer outlet for my compressor. It's a 30 amp outlet and my compressor is 30 amp and didn't come with a cord. I used a dryer cord so I can unplug the compressor. I'm told it's code that there needs to be a disconnect, so rather than hard wire it...

While removing the panel cover to my panel (for the whole house in the attached garage) it slipped down and turned off the main. I know what you mean about being in a dark room with lots of trip over type stuff. I had to wait until my family came into the garage to see what happened. My son saved the day with his Lightning McQueen flashlight, I was afraid to reach up into the box in the dark to flip the main back on.

I'm planning on buying a emergency light, here's one from Lowe's that plugs into a normal outlet.

http://www.lowes.com/lowes/lkn?action=productDetail&productId=91540-290-HS1R&lpage=none

I'll probably mount it next to the garage door opener on the ceiling. There is a duplex outlet there and only the garage door is plugged in right now anyway.

 

[bmwpower]

Question 1 - Can I piggy back the wall plug on the hoist breaker? The two would not be running at the same time, so I don't anticipate an overload problem.

Thanks,
Will

I believe this is only permitted when you have one device that will be used on 2 plugs, ie a welder. Per code, you can have one 240v plug on one wall and another 240v plug on the opposite wall, both on the same circuit. This is permitted only if one device is being used on that circuit. Not sure if it pertains to hard wired things, like a hoist. My gut says no.

 

[Junkman]

You should install a few emergency lights in your home.... one in the basement shining on the stairs, and one on the electrical panel. You never know when you will need to evacuate the house due to a fire or some other emergency, and if there is no light available, the task of getting out is that much greater. I have picked up some emergency lighting on eBay for as little as $25 each, including the shipping. I just attach a short electrical cord to them and plug them into a wall receptacle. I have hard wired the one in the garage, since it acts as a cover for a junction box also.

 

[kbs2244]

For your existing set up the Plug in Emergency light may be the way to. I have always put shop lights on their own circuit for the very reason. It is all to easy to trip a breaker, or nowdays a GFI, when you are working in an awkward position. Doing it in the dark is not fun.

 

[Junkman]

For your existing set up the Plug in Emergency light may be the way to. I have always put shop lights on their own circuit for the very reason. It is all to easy to trip a breaker, or nowdays a GFI, when you are working in an awkward position. Doing it in the dark is not fun.

It was when I was 20!!!

 

[Special55]

You guys have me a little worried now. My electrician wired my 220 outlet with the neutral (white) wire on the third lug and grounded the metal outlet box with the bare copper ground wire.

How would I check to make sure it is wired properly for my welder?

Rich

 

[bmwpower]

You guys have me a little worried now. My electrician wired my 220 outlet with the neutral (white) wire on the third lug and grounded the metal outlet box with the bare copper ground wire.

How would I check to make sure it is wired properly for my welder?

Rich

Rich,
If you have a metal box, there should be a ground pigtail attached to box as well as a pigtail attached to the receptacle. Both should be there. If somehow the receptacle gets pulled out of the box (there is no physical connection between the receptacle and the metal box), you will still maintain proper grounding with the wire coming off of the receptacle.

Black - hot
White - hot
Bare - ground

That's all you need for 240v. I would personally cap and tie off the RED wire to avoid confusion. Technically you're also supposed to use electrical tape or a Sharpie marker to mark the white wire as hot - again, to avoid confusion.

 

[428]

Not sure you should ever make a white wire hot. We always used Red and Black as hot, either cut the white or tie it to the ground wire.
White is only used for 110.

With 4 prong plugs you have a black red white ground. You can tie the White and ground together on a three prong plug as the red and black are the hot wires.

 

[bmwpower]

Not sure you should ever make a white wire hot. We always used Red and Black as hot, either cut the white or tie it to the ground wire.
White is only used for 110.

With 4 prong plugs you have a black red white ground. You can tie the White and ground together on a three prong plug as the red and black are the hot wires.

You can, and will need to, on any 240v circuit using 14/2, 12/2, 10/2, etc. The white should be marked as hot by using tpae or marker, though.

The only 3 wires available in a piece of Romex is black, white and bare copper.

When using 14/3, 12/3, 10/3 on a 240v circuit, I would use the same method. The red will not be needed and should be tied off.

 

[Will H]

Thanks for the replies. Good idea on the emergency lights, I'll have to pick up a couple of those. Guess I've never noticed them for homes before...just commercial.

I opened up the panel and also pulled the plug out of the wall. Used a volt meter and visual inspection. With one lead grounded, the Red and Black read hot @ 115V each, leaving white as the return line. The hoist breaker has red coming out on one and black on the other. The wall plug is tapped to the same sources, but before the breakers. So do I stick with capping the white? For the polarity of the plug, does it make a difference which wire goes where?

I'm not sure the rating on the hoist breaker...I believe its 15 amps though. So that may not even be enough for the welder...perhaps why the plug is not on the breaker in the first place. The garage sub-panel only has 6 spaces, all are full. 220, compressor outlet, lights, attic, and all other outlets+door opener. The house has 200 amp service and plenty of room to expand, and I'm considering more garage power this spring. So a bigger sub-panel may be in the works as well.

Currently the lights are isolated and do stay on if a garage breaker trips, but if the 220 wall plug tripped the house breaker the entire garage would lose power. I understand the garage supply to be 30 amps @220V. If a welder is running and the compressor leaks down and kicks on, I would suspect it will trip.

 

[Charles (in GA)]

Most likely the twist lock 4 prong plug was intended for a generator to back feed into the house, or to connect to an RV. In any case, this is a bad plan, and should be connected to its own breaker in the garage panel.

Red is hot
Black is hot
white is neutral
green or bare is ground (earth)

For a three prong 240v receptacle, disconnect the white wire from both ends and screw a wirenut on each end to cap it off and tape it real good, and fold it back out of the way. NEVER, EVER connect the white wire and the green or bare wire together! The ground, or earth (green or bare) should never have the possibility of carrying any current thru it, except when there is a short and that is what it is there for, to provide a connection to earth so you won't! The white or neutral wire is a grounded conductor meaning that back at the service entrance, the neutral is tied to the ground rod system and the green/bare wire system, but only at this one point, making it grounded, but it is a current carrying wire just like a hot wire is. The two should not meet anywhere else.

Charles

 

[428]

You can use the white as a hot but definitely mark it as such. Found this on the web just now. Here's what I was referring to.

[Two-Wire or Three-Wire Cable?
Whether you need two- or three-wire cable depends on the appliance and plug that will be serviced by the new circuit. Some appliances only require two hot wires and a ground. In this case you can use two-wire cable, just be sure to color code the white wire as a hot wire. Other appliances require two hot wires, a ground wire and a neutral wire. In this case you need to use three-wire cable.]

I've used the white hot before but I'll tape it to be black so as to know. But I've also work on services where white was hot and not marked as such
I've even seen the green used. After all the current doesn't care what the color is as long as it's connected straight.
That's why I don't like it. People will do it thinking they'll remember later. NOT! Mark it good or go black red.

 

[Special55]

Thanx for the replies guys (sorry to hijack your thread Will).

I will disconnect the white wire from both ends and cap it off. Then add a pigtail to the ground wire to ground the receptacle and the box.

I'm using 8/3 cable and told the guy I was using the outlets for a welder. You would have thought he would know how it should be wired being licensed and all

 

[Junkman]

Most likely the twist lock 4 prong plug was intended for a generator to back feed into the house, or to connect to an RV. In any case, this is a bad plan, and should be connected to its own breaker in the garage panel.

Red is hot
Black is hot
white is neutral
green or bare is ground (earth)

For a three prong 240v receptacle, disconnect the white wire from both ends and screw a wirenut on each end to cap it off and tape it real good, and fold it back out of the way. NEVER, EVER connect the white wire and the green or bare wire together! The ground, or earth (green or bare) should never have the possibility of carrying any current thru it, except when there is a short and that is what it is there for, to provide a connection to earth so you won't! The white or neutral wire is a grounded conductor meaning that back at the service entrance, the neutral is tied to the ground rod system and the green/bare wire system, but only at this one point, making it grounded, but it is a current carrying wire just like a hot wire is. The two should not meet anywhere else.

Charles

There are exceptions to the code from what I have been told. My air condition condenser that is mounted outside is wired with 12/2 wire with a bare ground. I asked the local building inspector about this and the checked the code. It is allowed to use a 12/2 for a 220 air condition circuit, and the white wire is the hot wire. For some unknown reason, it doesn't have to be marked as a hot wire either. I don't understand this myself, but I did see it in black and white print! The code might have changed since then, because that was 10 years ago. I will never use white as a hot wire, and one of these days, I will probably change that wire to conform to modern day standards (assuming that the standard for air conditioning condensers has changed).

 

[bmwpower]

Most likely the twist lock 4 prong plug was intended for a generator to back feed into the house, or to connect to an RV. In any case, this is a bad plan, and should be connected to its own breaker in the garage panel.

Red is hot
Black is hot
white is neutral
green or bare is ground (earth)

For a three prong 240v receptacle, disconnect the white wire from both ends and screw a wirenut on each end to cap it off and tape it real good, and fold it back out of the way. NEVER, EVER connect the white wire and the green or bare wire together! The ground, or earth (green or bare) should never have the possibility of carrying any current thru it, except when there is a short and that is what it is there for, to provide a connection to earth so you won't! The white or neutral wire is a grounded conductor meaning that back at the service entrance, the neutral is tied to the ground rod system and the green/bare wire system, but only at this one point, making it grounded, but it is a current carrying wire just like a hot wire is. The two should not meet anywhere else.

Charles

Charles, why wouldn't you follow the "white/black=hot" rule for 3 wire connections as you would for common 2 wire 240v connections (as long as you mark the white as such)? Seems to make more sense to have one common method inside your panel/boxes.

 

[bmwpower]

Thanx for the replies guys (sorry to hijack your thread Will).

I will disconnect the white wire from both ends and cap it off. Then add a pigtail to the ground wire to ground the receptacle and the box.

I'm using 8/3 cable and told the guy I was using the outlets for a welder. You would have thought he would know how it should be wired being licensed and all

Not to mention he probably charged you more for the 8/3 wire compared to what you would have needed - 8/2.

 

[Akuhead]

You guys have me a little worried now. My electrician wired my 220 outlet with the neutral (white) wire on the third lug and grounded the metal outlet box with the bare copper ground wire.

How would I check to make sure it is wired properly for my welder?

Rich

Special 55
Your wiring is correct. Leave it alone

 

[1320stang]

My electrical engineer here at work (Mech/Elec/Struct Engineering firm) told me red & black are hot, white is neutral, green/bare is ground. When wiring up 3 wires in 4 wire romex, the white is unused. Something about the NEC (National Electric Code) stating it being done that way.

 

[W-Cummins]

I believe this is only permitted when you have one device that will be used on 2 plugs, ie a welder. Per code, you can have one 240v plug on one wall and another 240v plug on the opposite wall, both on the same circuit. This is permitted only if one device is being used on that circuit. Not sure if it pertains to hard wired things, like a hoist. My gut says no.

Just repeating this will not make it true. Multi outlet branch circuits _ARE_ allowed on 240V Single phase.

as for the color question, I would use the red as the other hot in a single phase 240V circuit as it's not ever suposed to be the grounded conductor. ( eg. the grounded conductor must be white/marked white only). They should just come out and say what colors should be used for the hots, maby in 2007 they will....

William...

 

[bmwpower]

Just repeating this will not make it true. Multi outlet branch circuits _ARE_ allowed on 240V Single phase.

as for the color question, I would use the red as the other hot in a single phase 240V circuit as it's not ever suposed to be the grounded conductor. ( eg. the grounded conductor must be white/marked white only). They should just come out and say what colors should be used for the hots, maby in 2007 they will....

William...

My mistake. Thought it was code that I read somewhere before.

 

[Will H]

Thanks for the answers, sounds like red and black for my application.

I didn't get a chance to look closer at the breakers last night, but I'll be sure to check the house panel and make sure all is normal in there. As well as double check the hoist breaker rating. But in the end it sounds like I just need an expanded sub-panel in the garage, and to add a stand-alone circuit for the wall plug 220.

 

[Charles (in GA)]

Charles, why wouldn't you follow the "white/black=hot" rule for 3 wire connections as you would for common 2 wire 240v connections (as long as you mark the white as such)? Seems to make more sense to have one common method inside your panel/boxes.

Sorry if I wasn't clear, it is quite OK to use the white and remark it as red or blue or whatever, generally red would be used, you find blue in three phase systems. If you have extra wires, use the proper colors and do not use the "extra" colors, thus if you have a black/red/white/green cable and do not need a neutral, then do not use the white wire. If you have this cable and only need one hot wire (a 120v circuit) then don't use the red wire. Don't go remarking wires if you don't need to.

For neutrals (actually known as "grounded conductors"), the NEC says that on 6 gauge and smaller, neutral is either white, or grey, or three continous white stripes on any color but green, over the entire length. Above 6 gauge, the neutral is either white or continous grey finish, three continous white stripes along its full length, or marked at its ends by distinctive white or grey markings, encircling the conductor or insulation. (ref NEC 200.6 and 200.7)

Green or green with yellow stripes is always ground/earth, and may not be remarked for other uses. In addition, the coloration or marking must be for the entire length of the wire, except that ground wires over than 6 gauge may be marked only on the ends and all other accessable points, such as where it passes thru boxes, elbows, etc. (NEC 250.119).

Beyond the above, any color is fair game for identifying hot wires. NEC 310.12(C) says that conductors (hots) and grounded conductors (neutrals) must be clearly identified from ground/earth wires.

Charles