220v 15a window A/C unit to 220v 50a outlet

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  #1  
Old 07-24-06, 06:47 PM
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220v 15a window A/C unit to 220v 50a outlet

In my garage I have 220v 50a outlet and I want to connect a window a/c unit to it that has a 220v 15a plug. One on my problems is that the outlet is about 30 ft from the a/c unit. I went to my not-so-local Lowes and talked to one of their "experts" and walked away with a 50a male plug, 40ft of 6-3 wire and a 15a female receptacle. My delima is now what color wires to connect to what connectors.

The Black & Decker complete guide to home wiring says that the 50a receptacle can be wired in one of 2 ways. The white neutral wire may or may not be connected. Connect the white wire IF 125v is necessary at the outlet. My receptacle is in my garage and is a 3 blade connector. I am assuming the white wire is not connected. The instructions that came with 50a plug says to connect the white wire to the middle flat neutral blade. Do I use the white wire making my extension cord?

The female 15a connector, I am guessing, needs the white wire connected to the middle terminal and then the black and red wires to the other terminals. Does it matter which terminals the red and black go to? Black on left or right or does it matter?

What about the ground (bare) wire?

Also, the 15a connector uses a max of 12g wire and I am using 6g. The 6g wire is a bit too big to fit through the holes on the receptacle but would it hurt any if I cut 2 (of the 12ish) strands and make the wire smaller?

This is why I never passed electricity class in high school. I cant see electrons so I dont know how this stuff works. Give me hydraulics any day.

Thanks!
 
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  #2  
Old 07-24-06, 07:38 PM
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This is all wrong. Please don't do it.
 
  #3  
Old 07-24-06, 07:39 PM
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Welcome.

The bad news : gas prices, Coz your going back to the store.

The good news:This can be done, But not with what you have, save the receipt.
Before the stock list goes out, explain the construction of the garage, Open,sheetrock,is it strapped off etc.This will determine the course.
Then we can help you to get the correct stuff. And get you "COOLED" off.
 
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Old 07-24-06, 07:46 PM
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Originally Posted by 594tough
This is all wrong. Please don't do it.
Hi 594,
There should be no problem down sizing this ckt.. Providing it is prominantly and properly labled, identfied and junctioned.
In my eye. Open to input if there is something I missed.
Thanx.
 
  #5  
Old 07-24-06, 08:09 PM
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NEVER get your advice from the hardware store. They may or may not know. They will say anything to make a sale.
 

Last edited by lexmarks567; 07-25-06 at 02:16 AM.
  #6  
Old 07-24-06, 08:54 PM
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Thanks guys. The garage is sheetrocked. I have 2 breaker panels in the garage. One breaker panel has the breakers for the 220v 50a circuit. There are 2 breakers ganged together but I dont know what amp ratings. 2x25? or 50a for each 125v? The panel also has open breaker slots. The receptacle is about 4ft from the panels.

I don not know what strapped off means so I cant help there. The house was built in 1997 and I had the builder put this circuit in the garage just in case I needed a high voltage large amp outlet. Arc welder, etc. I believe this outlet is the only outlet on this breaker.

Would I be better down sizing the circuit with a smaller breaker in the panel, a correct outlet (220v 15a), a 15-20 amp extension cord, cut the ends off and splice 220v 15a fittings on it?

Thanks for your help. I only like fried foods. Not fried a/c units or me.
 
  #7  
Old 07-25-06, 02:41 AM
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Well, that changes it all quite a bit.
The best idea.. is leave the 50A alone (if you weld,you may want it as intended) and install a new 220v/15A ckt.. Is the panel recessed in the wall or surface mount?
Either event I don't have time now, But maybe during the day someone will, to explain what you need to do.
Still save that receipt, It all goes back.
 
  #8  
Old 07-25-06, 06:14 AM
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The panel is recessed into the wall.
 
  #9  
Old 07-25-06, 06:55 AM
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Originally Posted by lexmarks567
NEVER get your advice from the hardware store. They may or may not know. They will say anything to make a sale.
Needs to be said......the advice was NOT given by a "hardware store"...Lowe's is NOT a hardware store it is a mass merchandising store.REAL hardware stores would never have created the situation in this thread.

Let this be yet another in a never ending series of lessons about going to big box stores for your purchases when the situation requires any sort of knowledge or advice.
 
  #10  
Old 07-25-06, 07:22 AM
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thank you, This information is noted.
 
  #11  
Old 07-25-06, 07:31 AM
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Only way to do this in my opinion is to run a new circuit.

Is their room for a double pole breaker?
 

Last edited by Roger; 07-25-06 at 08:45 AM.
  #12  
Old 07-25-06, 07:43 AM
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yes, both boxes have open slots. The left box has 7 open and the right box has 5 open. Each slot will hold (2) 15a breakers. So I assume I have room for 12 double breakers.
 
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Old 07-25-06, 08:45 AM
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If you were to run a cable to a receptacle location that would allow you to plug in your window a/c .... would you be able to stay on studded walls the entire route? Any corners you need to negotiate?

My thought is you could come out the bottom of the panel to the base plate and remove the base trim (if there is any). Then remove the bottom 4" of sheetrock, drill the studs with a 5/8 bit on center and route your cable to the wall cavity where the receptacle would be located. Install an old work box and your receptacle. If you take care in removing the sheetrock you can simply put it back and then trim over it or replace the old trim. No finishing of the rock that way. Only area of sheetrock that will need to be opened and repaired is the access you make to enter from the bottom of the panel. If by chance you already have a cable entering from the bottom you are allowed to double up 14/2 G or 12/2 G cables or mix the sizes in one clamp. If not then remove a knockout and install a romex (NM-B) clamp..snap in type or lock-nut type. Very limited repair to walls this way.

If the window a/c has a 15 amp 220 volt plug (6-15P) on it then all you need is 14/2 G or 12/2 G NM-B cable and a 6-15R receptacle to terminate the cable wires on. Then install the double pole breaker that is specified by the a/c nameplate or in the installation instructions this will probably be a 15 amp double pole.
 
  #14  
Old 07-25-06, 08:46 AM
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yes, both boxes have open slots. The left box has 7 open and the right box has 5 open. Each slot will hold (2) 15a breakers. So I assume I have room for 12 double breakers.
You’re confusing “skinny” or “piggyback” breakers with double pole breakers. (You still have room for double pole breakers, just not as many as you think.)

A regular single pole breaker takes up one slot in a breaker panel. The skinny is half the width of a regular single pole breaker, so you can fit two in a single slot. The piggyback is a one piece unit that takes up a whole slot but has two separate circuit breakers. In either case you get two breakers where one regular breaker would fit -- BUT -- both breakers are being fed by the same service leg, so each breaker is getting 120V.

A double pole breaker takes up two full slots in the panel and therefore gets 120V from each leg of the service, giving you 240V. The switches for the double pole are joined by a bar so they shut simultaneously.

Based on the what you said, seven open slots in one panel, five in the other, you only have room for a total of five double pole breakers.

Hope I’m being clear and not confusing you. Post back if you’re not sure.
 
  #15  
Old 07-25-06, 12:55 PM
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Thanks for the info DDR I completely understand. I appreciate your effort in my mess.

Here is a pic of the boxes before they sheetrocked that wall. There are (2) 200amp boxes and the 220v 50a outlet is at the far left of the picture. My a/c unit it at the far right end of this wall where I need the 220v 15a power. This is an exterior wall so there is insulation in it. It looks like there is only 1 220v drop out of the breaker box on the right which is where the 220v 50a outlet gets it power from. The box on the left has a 110v 20a RV outlet that goes to the ajoining exterior wall. Would teh big black wire coming up into the box on the left be the main power source from the utility company? The black pipe towards the left of the picture is the propane gas supply from outside. The house sits on a concrete foundation.

Picture:http://pg.photos.yahoo.com/ph/iflysh...cd.jpg&.src=ph
 
  #16  
Old 07-25-06, 03:10 PM
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Unless pristine appearance is a priority I would just run some 1/2 inch EMT (thinwall) conduit to an outlet box, all on the surface of the drywall. You would have to cut an access hole in the drywall under the panel and use some flexible conduit from the panel to a pull box and then patch the drywall. Pull #12 THHN conductors through the conduit and make the proper connections. All of this needs to be a minimum of eighteen inches above the floor in a garage.
 
  #17  
Old 07-25-06, 04:17 PM
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Originally Posted by furd
Unless pristine appearance is a priority I would just run some 1/2 inch EMT (thinwall) conduit to an outlet box, all on the surface of the drywall. You would have to cut an access hole in the drywall under the panel and use some flexible conduit from the panel to a pull box and then patch the drywall. Pull #12 THHN conductors through the conduit and make the proper connections. All of this needs to be a minimum of eighteen inches above the floor in a garage.

Furd is correct.
But it doesn't have to be the bottom.
You will have to cut out some rock.Run some 1/2" flex to a 4"square box (or an emt change over connector (i would go with the box). Then run the EMT from either the top or the bottem of the panel,to the A/C location. Mount a surface box there, pull in the wires, terminate the rec and breaker, turn on power and check. If all is OK, plug in A/C and ..... its majic your COOL!

It will take some time and material, But it will be worth it.
(what you return should cover all of it, if not most)

You will be in the panel... So how comfortable with that are you?
 
  #18  
Old 07-25-06, 07:11 PM
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I have never been inside of the breaker panel before and frankly it kind of scares me. I do not like electricity. I am willing to learn and enjoy learning out how things work though.

I also do not know what emt or change over box is but will look that stuff up and learn. #12 THHN I assume is a type of wire that can purchased at my not-so-local home improvement store.

Tripping the 4 breakers at the top of the breaker box will remove the power to the box correct?

I would then cut into the sheetrock to access the bottom or top of the box.

Would the EMT conduit be secured to the breaker box at the hole where the wire comes out of?

In my case, would the EMT just come out of the wall and run along the wall probably being secured with clamps every 16 inches or so?

Would it be better if there was a junction box that the wires came to, from the breaker box, and then run the EMT along the wall to the new receptacle box?

Would I run 3 different color #12 wire in the EMT (which I found out is electrical matallis tubing) and 1 copper wire? Can I maybe get some #12-4 already bundled and use that or should they be separate strands of wire?

Would you recommend running the EMT up to maybe the 8' height to prevent it from getting banged up by someone putting shelving along that wall? I do have shelving and would be concerned that the EMT might get damaged.

Can the EMT get painted with normal house paint to reduce the stark contrast of the tubing?

What breakers would I need? Would I need 1 double pole 15A?

My head hurts now from the questions. Any answers and suggestions are greately appreciated.

Thanks for your time guys!
 
  #19  
Old 07-25-06, 08:02 PM
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unless you have a pipe bender and/or wish to purchase a tool you will rarely use again in your home owner life. I would recommend running 1/2" flex to the top of the garage wall (out of the panel) (so as to vbe outta sight). Secondly, you can paint either emt or flex. (for resale and general asthetics I would go with the "behind the sheet rock approach") But other than those my opinions I would say your in good hands with the advise these guys are giving you.

SthrnAMP
 
  #20  
Old 07-25-06, 08:32 PM
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STHRNAMP, Thanks for the vote of confidance.

#I have never been inside of the breaker panel before and frankly it kind of scares me. I do not like electricity. I am willing to learn and enjoy learning out how things work though.#

IFLY, No need to FEAR, JUST RESPECT,and understand the potential.

You know hydraulics, Is there any one you know who may know electrical to help you with some of the terms and equipment?

If not we could walk you thru it, but only if your comfortable.
If the panel gives you trouble, We can also get you to a point were someone more comfortable can take over and save you some money.

CLARIFICATION: (so as not to be contradicting). Labor now is the 2nd biggest cost. Most pros, don't mind if you do the work (correctly) under guidence.That is how you save money.
 
  #21  
Old 07-25-06, 10:16 PM
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I suggested cutting the drywall below the main panel because from the picture taken before the drywall was installed it showed fewer wires in that area. You may cut the the drywall above the panel if you would rather. Use a drywall saw and do not allow the point to go any farther than the inside surface of the drywall, 1/2 or 5/8 inch strokes.

I have worked around electricity for several decades, everything from 24 volt instrumentation circuits up to 26,000 volt distribution circuits and I'm still not dead. I'm afraid of what electricity can do to me so I have a tremendous respect for it. If you are not sure then you must get someone more knowledgeable to help you.

In your case I would (after cutting the access hole in the drywall) select a knockout in the panel and run a short piece of flexible conduit to a 4 inch square steel box mounted to the stud next to the panel. Using a box with a flange will make it a little easier to mount the box. This is called a "junction and pull" box. Use the fittings that screw into the flexible conduit rather than clamp-type fittings. Mount the box so that the outer edge will be flush with the drywall patch.

At this point you may wish to patch the drywall or leave it until later.

Mount an "extension ring" (a 4 inch box with no back) to the box you just installed. Use an "offset box to EMT" connector to allow the conduit to lay flat on the wall. Use one-hole ("half") straps to secure the conduit to the wall studs, be sure to use screws long enough to pass through the drywall and securely into the stud. One strap every other stud will be quite sufficient.

When joining another piece of conduit you will use a "coupler" and I suggest that you use the type with setscrews in the side to hold the conduit so that the conduit is as close to the wall as possible. The ideal way is to bend an offset in the conduit to allow the coupler to set slightly above the wall surface but I doubt that you want to purchase a bender and it does take a little practice to make the proper offset bend.

When you get to where the outlet is to be mounted you will use another offset box to EMT connector. You may use either a 2 inch by 4 inch surface-mount box or (my preference) a 4 inch square surface mount box. Ideally you will be able to place this so that two mounting holes in the back will allow screws to enter the stud. If you must place the box away from the stud then you need to use a secure hollow-wall anchor. The box must be securely mounted.

For wire you will need black, red and green type THHN/THWN. You may use either #12 or #14 wire although I would prefer #12. Measure from the outlet box to the junction and pull box (J&P) and then from the J&P to the far end and back of the main panel. Add six inches for the outlet end. It is far better to have too much wire than not enough. Tape the three wires together (just an inch or so at the end) and push them through the conduit from the J&P box to the outlet box. Leave a minimum of six inches hanging out of the outlet box.

At the J&P box cut the green wire so that it has at least six inches hanging out of the box. Connect the two ends you just cut along with a "grounding jumper" (a short wire that has a machine screw through an eyelet on one end) with the proper size wire nut. The grounding jumper is pre-made and available at the home center. It may have a forked terminal end on the end opposite the terminal with the screw, in that case simply cut off the fork. The screw will be driven into the threaded hole in the back of the J&P box.

Take the three wires now hanging out of the J&P box and tape them together just like when you pushed the other end to the outlet box. Push these wires through the flexible conduit from the J&P box into the main panel.

At the outlet box screw a grounding jumper to the back of the outlet box, this will eventually be wire-nutted to the green wire you pushed from the main panel. If your outlet receptacle has a "back-wire" feature (NOT "back stabbed") you will need to take another grounding jumper and after loosening the green grounding screw, insert it into the hole for the grounding conductor and then tighten the screw which will tighten a pressure plate against the wire. If your receptacle does not have the back-wire option then you will use a grounding jumper that has the fork end and place it under the screw head of the grounding terminal and tighten. Then connect all three green wires with the proper wire nut.

Connect the black wire to the left side screw (or back-wire) when looking at the FACE of the receptacle and connect the red wire to the right side screw. If you used a 2x4 box for the outlet you will then carefully push all the wires into the box and fasten the receptacle to the ears of the box and install the cover plate.. If you used a 4x4 box then you will fasten the receptacle to the cover plate using the screws and nuts that came with the cover plate through the end straps of the receptacle. Then carefully push the wires and receptacle back into the box and secure the cover.

At the main panel you will connect the green wire to the ground bus. This may also be the neutral bus. It is the bus that has the bare copper wires connected.

You will need to install a 15 amp/240 volt circuit breaker. This will take two adjacent slots. The red and black leads will connect to the circuit breaker screw terminals. Ideally the black wire will connect to the circuit breaker that is powered from the left-hand vertical bus and the red wire will connect to the circuit breaker that is connected to the right-hand vertical bus.
 
  #22  
Old 07-26-06, 07:32 AM
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Thanks Furd and others for the great information. I truly appreciate it.

I did some more reading last night and completely understand the terms and type of equipment used in this project. From what I came up with last night is almost word for word what Furd said to do. Thanks for verifying my .

I now have a solid plan and a shopping list. I am headed to the Depot for my project. My local HD is a low volume store and usually has 90% of what I need. I hope they have everything today.

If I think I am getting in over my head, I will stop and call a professional before I cook something or someone.

I pledge to respect the electron.

Also, I am in the designing stage of building a 30'x60' shop and would like to wire it myself. This will give me a little more experience and understanding doing this type of thing. It will be a metal building and should be easier to run wires and such.

Thanks again guys! You rock!
 
  #23  
Old 07-26-06, 11:51 AM
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You're welcome. Keep us informed on the project.
 
  #24  
Old 07-27-06, 05:05 PM
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Hey Ferd, DONE! It worked as advertized with minor modifications. I put a 20a 220v breaker in the panel, ran the #12 wires out of the top on the panel through the sheetrock to a junction box. Then to EMT straight up the wall into the attic. Across the attic and back down the wall at the point of the receptcale. I wired that puppy up and that finished the easy stuff up. I also bought a new door, cut the henges, doorknob and bolt holes. Cut a hole in it for the a/c unit and installed it all. Plugged it in and out comes cold air!!! Just a little trim work and paint and it will be finished.

Ivan, Bob and Smokey really appreciate it. They (the outdoor cats) want to say thank you but I dont know your address to send you the hairballs they barf up.

Thanks again for your information and help. I too appreciate it!
 
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