Best wiring to run for a window A/C.

[Anonymous]

I had just relocated a window A/C unit to the dining room. And found out that I am six inches short of the outlet! So, I have decied to run wiring from the box to the A/C via the attic and down the wall to the A/C. What is the best rated wiring to use? And should it be all in one sleeve or single lines. The unit is 110, 12.0 amps, 1300 watts, 1200 BTU. Armored Romex is not possible due to the lack of space. Any ideas for the rookie do-it-yourselfer on a budget? Regards and thanks! monarch_usa@hotmail.com

[Wgoodrich]

I am not a big fan of extension cords. However they make an extension cord specifically for window air conditioners that are heavy enough wire size to be safe for use. When you buy and extension cord you must not look at thickness of cord it may be mostly rubber. Look on the side of the extension cord it should be written on the side what size wire '12 awg' copper should be fine. Buy a 6' air conditioner extension cord and plug in to your existing branch circuit if you had no problem with the old existing receptacle.

If you want to install a new branch circuit you may install 12/2wGrnd Romex cable with a black, white, bare wire in that Romex cable. Concerning the a/c loads you are providing you could get by with a 14/2wGrnd Romex cable if you like. I would advise the 12/2wGrnd Romex cable for safety and savings of electrical use in the long time run.

Make sure if you install the white on the neutral bar and the bare on the groundig bar and the black on the single pole 15 or 20 amp breaker matching your wire size.

You may use a nonmetallic remodel style single gang receptacle box with wings and recess it into the wall or you may come up from the crawl space and mount a surface box on the wood trim if you like.

The receptacle should be a single receptacle matched in amp rating fo the branch circuit ampacity rating you are intalling. Connect the black wire on the brass screw and the white wire on the silver screw and the bare wire on the green screw.

Hope this helps

Wg

[aphares]

Wg if a new cord was used in lue of the existing cord, and the existing cord did not provide protection, would the new cord (being bought just for the AC) have to meet the requirement of 440.65?

Extracted from NEC:
As indicated by the definition, power supply cords or cord sets with this type of protection automatically interrupt the circuit where leakage current between or from the conductors exceeds a predetermined level. Opening of the circuit is accomplished through the use of electronic switching or by “air-break” contacts. The circuit remains open until the cause of the leakage current is eliminated or the protection device is manually reset. Leakage current detection and interrupter protection is one of the protection methods for the power supply cord or cord set of a room air conditioner specified in 440.65.

440.65
Leakage Current Detection and Interruption (LCDI) and Arc Fault Circuit Interrupter (AFCI).

Single-phase cord-and-plug-connected room air conditioners shall be provided with factory-installed LCDI or AFCI protection. The LCDI or AFCI protection shall be an integral part of the attachment plug or be located in the power supply cord within 300 mm (12 in.) of the attachment plug.

[Anonymous]

Indeed very helpful, seems I should get into more reading on this stuff these days. Have one of those fixer upper homes. However on the note about extension cords. Perhaps the market is now providing for them now concerning window A/Cs. But on the cord is has a warning label advising against extension cords. The unit is about 3 or 4 years old. Perhaps then the industry standard for A/C extension cords were none exsistant. But will look into both options none the less. Much thanks once again.

[Wgoodrich]

Mick, the NEC requires you to follow manufacturer's recommendations. Recheck your instructions to make sure it is speaking of normal extension cords or if it mentions a/c extension cords. Many homes have caught afire due to extension cords installed on a/c units that were of the wrong wire gauge. Check to see if it points out the use of a/c extension cords.

Aphares.

The rule you mentioned is a new rule specific to 2002 and after. This is a new rule that applies to new a/c units built after that rule took into power of rule.

Replacing a cord is not what I was suggesting. What I was suggesting if he only needs to add a couple of feet is to buy an A/C extension cord about 3 or 6 feet long utilizing the existing a/c cord.

However if a repairman needed to replace a cord on an existing a/c unit manufactured before January of 2002 then he is performing minor repair and the new rule you mentioned would not apply to this minor repair.

Only new a/c units built after January of 2002 will be required to have this new AFCI protected cord for A/C units. You may still buy A/C units today that are in the stores yet manufactured before January 2002. Only those A/C units built after that date is controlled by this new rule.

I am glad you pointed that rule out though for people to be aware of it as new in the 2002 NEC rules.

Hope this helps

Wg

[Anonymous]

WG,

Re-cheecked the label. There is no mention of type of cord, just a straight forward warning about not using extension cords. Along with the one about not removing the ground prong of course. Have been considering giving it's own circut though. The plug does tend to get a little warm in the long run. And were it was last installed was a long distance from the box and did "borrow" power from the rest of the out lets in that area of the house. House was built in the early 60's. Have not found any aluminum wiring that I know of yet. Perhpas just to be safe I should install another circut just for it. An extension cord would work, but it's in the kichten dinning roon area. And I think that circut may be part of the load for the fridge and a few other outlets. Thanks.

[Wgoodrich]

Run a dedicated branch circuit from the panel using 12/2wGrnd protected by a 120 volt single pole breaker. Connect the black to the breaker and the white to the neutral bar and the bare to the grounding bar.

At the receptacle install a single outlet 20 amp rated 120 volt receptacle connecting the black to the brass screw and the white to the silver screw and the bare to the green screw.

You are allowed to install a 15 amp duplex receptacle on this dedicated branch circuit but if you do the receptacle again will get warm to the touch. Advise the single 20 amp receptacle.

Good luck

Wg

[Anonymous]

Ok, thanks!