electric outlet for window AC question

[ReadyToPuke]

What's the going rate in central NJ for a licensed electrical contractor to upgrade the wiring from an old breaker panel (1960) to a wall outlet that would be powering a new 110 volt window mount air conditioner?

I don't have the exact BTU capacity, but it's a standard 110v plug, and probably an existing 15 amp breaker.

When I try to run the unit off the existing outlet (controlled by a light switch), the breaker trips immediately.

I have not tried bypassing the light switch (since it's probably not rated for an AC compressor starting up).

My thinking however was it would be safer to run new wire w/double the amperage capacity (say 30 amps), and put in a new breaker and feed the outlet directly w/all upgraded wire and no switch (other than the breaker).

The home is a straightforward single level ranch structure, I was thinking of doing it myself, but it might be better to have a "pro" who's experienced, licensed, etc. do the job.

What's a fair price a typical contractor would charge ?

[Joseph Meehan]

Likely that circuit is protected by a 15 amp device. If your A/C is tripping it and there is nothing else on the circuit, then there is something really wrong with the A/C unit. The light switch would not cause it to trip.

Let's start by checking what the A/C says it needs. It should be indicated on the unit somewhere, don't go by the plug.

Don't try going to a 30 amp circuit breaker unless the A/C requires it. I suspect it indicates (if you have the manual) that it should be protected by a 15 amp device or maybe a 20 amp. More is NOT better. Larger wire gauge IS better however, but not needed.

[ReadyToPuke]

Hello,

Thanks for the post.

The unit does work though, when I plug it in at a friends house (newer wiring), it fires up and runs fine.

So that's why I was thinking just upgrade the wiring, put in a proper size breaker to match the AC unit, and bypass the light switch to feed the outlet directly.

What's a fair price for a "pro" to do that sort of job?

[scott_z500]

You most likely need a 20A circuit, not a 30A. That's what your friend probably has.

[Anthony]

"ReadyToPuke" wrote in news:d81ku8$eli$1 @news.monmouth.com:

You aren't going to get a price from here. Without looking at the house, how it is constructed, distance from the panel to the window in question, how many extra (if any) slots in the breaker panel, and many, many other factors, a price cannot be set. The methodology of the house contruction probably plays the biggest role in pricing. It may be as simple as using the existing wire to pull in a new feed, or it may be as complex as having to rip out the wall covering (drywall, paneling, etc) at both the outlet and the service panel to run the new wire.

[Chris Lewis]

According to :

What's most likely happening is that 15A is adequate, but the circuit is either unduly long (and is 14ga), or has lousy connections, so the high load of an AC pulls down the voltage too far, the AC works too hard starting up, and the breaker gives up on it because the startup surge takes so long.

Heck, the breaker may just be "tired".

Large window mount ACs should have their own circuit.

Usually, a 15A circuit will be fine, but if the circuit is longer than about 20-30', use 12ga for the circuit. If the breaker still trips, as long as you've used 12ga, switching to a 20A breaker is cheap.

There's no way to estimate how much it should cost to do without seeing it.

[w_tom]

Note what Chris posted. "... or has lousy connections ...". How well connected are wires inside wire nuts and wires attached to the switch and receptacle. Do they use the screws on side or do they just push in the back. Low voltage on startup (due to lousy connections or too long wire) results is excessive current draw during startup. Verify wires are fully twisted together inside wire nuts and that connections to switch and receptacle use side mount screws.

How l> What's most likely happening is that 15A is adequate, but the circuit

[Chris Lewis]

According to w_tom :

I thought I might add one person's experience:

_Many_ years ago, my parents finally got around to installing a window mount AC. Early 70's house, 15A circuits. Probably only a 6000BTU unit, whereas 10K (and even some 12K) BTU units can work fine on 15A circuits.

There's an outlet right underneath the window, on the end of a string of outlets in the dining room - only use of that circuit was for the dining room fixture. Simple.

Turn on the AC - _nothing_ else on that circuit turned on. The thing would make noises for a minute or so struggling to turn on. Lights dim. This isn't good.

Well, it's hot, we need the cool. We'll worry about another cirucit later.

Whoops!

Within an hour, all _three_ upstream outlets were smoking, blackened the outlet covers and stained the wall.

The wires were correctly sized for 15A. The circuit wasn't particularly long. But the idjit who wired it used the push in terminals. And it was aluminum wire...

[Push in terminals on Al has always been illegal. But 3 out of 3 catching fire at the same time is pretty spectacular confirmation that pushins are bad, Al or not.]

When installing an AC on non-dedicated circuits for the first time, DO NOT LEAVE IT UNATTENDED the first day. Check upstream outlets and switches for overheating.

It's so much more comfortable having an AC on a dedicated circuit with a spec-grade (or better) outlet.

[Stormin Mormon]

I'll highlight every where that needs more specific information. I think it makes more sense to run 12 or 14, and breaker it with the proper sized breaker for the wire size.

I also think that you need an electrician. We can't reasonably quote it over the internet.

[Stormin Mormon]

About $50 for the tripcharge and $60 an hour. Plus parts. Though, I might be way too cheep.

[John Gilmer]

The odds are that it will be about the same as what you paid for the air conditioner.

I note that Walmart sells 240 units when you get to the 10,000 BTU/hour size. If you have room for another two pole breaker in you box, it may be about the same charge from the electrician and you may be happier with a larger a/c.

If you run a new circuit, the electrician likely would want to connect it to a new breaker.

Likely, that's a 15 amp "lighting" circuit. Find an unswitched wall outlet. You CAN use a heavy duty extension cord. See if it still "trips." You can save some money.

As I said, if you are starting from "scratch" then consider going to a 240 unit.

[Al]

For all it's worth, in Massachusetts its about $5/amp. So a 200 amp service panel is one grand.

Al

[Stephen B.]

Remember to size the a/c, to small and the room wont cool off. to large of an a/c and the a/c will not remove the humidity from the air, causing you to keep the temperature lower to be comfortable. I think that the a/c will cycle faster and compressors do not like starting up.

Stephen B.

[John Gilmer]

Well, you can compensate for that by running the A/C on "LOW." Most machines will really pump out the moisture then.

I know the conventional "wisdom" is better slightly too small than too big. But when you have a HOT day and you A/C is too small, you might as well just open the windows.

[Edwin Pawlowski]

Additional residence time of the air over the cooling fins will take out a bit more moisture, but that is at the expense of poor air circulation and higher than needed operating costs.

Conventional wisdom is to have the RIGHT size and you get maximum efficiency and comfort.

[John Gilmer]

Well, the "right" size determination uses ASSUMPTIONS about the outside temperature and the heat load. Combine an extra hot and humid day with having a few folks over or just arriving back home after a day or two of your home being "heat soaked" and your conventional wisdom becomes nonsense.

The problem with running a room conditioner at low is that the outside coil doesn't get as much circulation but it sure does suck the water out of the air.

To each his own, but if you have the electrric power and the spare cash when you buy a window unit, go for a larger size. "Efficiency" just ain't all that important if all you are cooling is ONE room. >

>

[Edwin Pawlowski]

No, conventional wisdom still works. Why risk having an unsatisfactory situation 95% of the time when the exception is only 5% of the time?

And the inside of the room is not getting proper air circulation either.

One room may not cost much, but comfort is more important. Maybe you just have not experienced it properly. That does not mean it does not exist.

[John Gilmer]

Because its when it's hot as hell outside that you want an A/C that can keep you cool.

It's "nice" the have an A/C that "pumps" the exact amount of heat AND you can pay to get a variable capacity central unit. If you have a window unit, you can reduce capacity by lowering the fan speed, by putting a heater in the room (this used to be standard in "computer rooms" where it was essential to keep the RH within a certain range), or by permitting a little circulation to the remainder of the house. But during those HOT days, that "extra" capacity is a blessing.

Big deal. Turn on the ceiling fan. It will mix the air and even had a few watts of heat load. And it's fun to watch. Problem solved.

You are being silly. If you have a fixed capacity window unit you can size it to be "too big" all the time (and play games with fan speed to adjust capacity) or get a unit that's too small some of the time and be downright miserable. I will gladly sacrifice a few "perfect" days to avoid a single "miserable" day

[phil-news-nospam]

| To each his own, but if you have the electrric power and the spare cash when | you buy a window unit, go for a larger size. "Efficiency" just ain't all | that important if all you are cooling is ONE room. >

However, given the constant problems I see with central air conditioning, I will be going with individual room air conditioning instead in my new house (designing now, build in a few years). There will be air ducts for air flow, but they won't be the distribution of cooling or heat, they will be for the distribution of fresh air and filtering. However, I will not be using window air conditioners. My grandfather added a room onto his house back in the 1960's and heated and cooled it with a vertical wall unit that was about 6 feet high. The exterior portion for expelling heat was right behind it (e.g. it probably had to be installed only on an exterior wall). Today's market has quite a number of "mini-split" units, which are basically a split A/C system of varying sizes down to small rooms. Many including heating as an option. And there are still many wall-sleave units on the market with heat.

[Edwin Pawlowski]

No, not really.

Yes, also in printing plants.

No, not at all.

No, as yo already pointed out, it is a fixed capacity, not variable. You are deluding yourself to thing you can change the capacity. Sort of like people that keep pushing up the thermostate to get the house heated faster when the heat is already running. The copressor is either on, or off. There is no varialble capacity.

I said properly sized. If it is too small, it is not properly sized is it? You will still get reduced humidity in any case.