In-window A/C Unit and Current Draw

[Marilyn Manson]

Why would you welcome someone to your killfile 3 times?

[hubops]

A serious case of over-kill ?

As someone who has been on usenet since the stoned age - I have never been tempted to use any sort of kill-file. It is so very easy to _just ignore_ them. .. making the _big public pronouncement_ - of adding someone to your kill-file - seems to just be self-proclaiming " I know how to use kill-file .. so there .. take that ! " John T.

[hubops]

Yep.

[trader_4]

And I guess if they simply stated the right way to do it, eg you can use an extension of max length X, gauge X or heavier, route it properly, consumers couldn't follow that? But instead the dumb consumer is going to just follow the warning not to use an extension cord period and live in an 85F room or call in an electrician for a $500 job?

[gfretwell]

This AC is a <5a load, why wouldn't any garden variety 16ga 3 wire cord be plenty (the minimum wire size allowed). We let a lot of legends come up around refrigeration equipment when they were 12 amp loads with 500-600% LRA ratings but right now an inverter style window shaker has a lower ampacity requirement than your daddy's old 1/4" Black and Decker drill. I bet you wouldn't hesitate to plug that into an extension cord.

[Ed Pawlowski]

Usually the drill runs for a minute or so at a time. The AC can run for hours.

How long is that 16 ga cord too?

I'd sleep better with 14ga.

[danny burstein]

[snip]

well, sure, if the consumer buys an inverter window unit.

But

a: they're quite a bit more expensive than the commodity cheapos on the shelves at most stores

b: in the US at least, there are very few models of this type around. (Right now, of course, with the super heat waves, just about zilch).

I happen to have picked up the Kucky Goldstar 14,000 BTU ones and LURVE them. As far as I can tell the only others out there are some that Midea just started shipping.

[Ed Pawlowski]

Typical 6000 Btu is about 5A 8000 is about 6.5A Those sizes cover most bedrooms.

[gfretwell]

16ga wire is rated for a 13a (10.4a continuous load) If you want to use bigger wire you will never get in trouble but at a certain point matching the load to the wire does make sense. OK I will play your game and we will use a 50 foot orange cord. You will drop 2.4 volts with a 5a load. (2%) Again well within the recommendation in the NEC. There is no actual rule about voltage drop. If you want to go off in the weeds about the extra connections, you have the same issue whether it is a 16 ga cord or a 10 ga cord. That just gets down to the quality of the cord you buy. Short of cutting it open and looking you have no real way of knowing that. Don't count on U/L listings telling you that.

[trader_4]

I think we're in agreement. Using even a 16 gauge extension cord on a modern typical window AC would be fine, as long as you use a grounded one, it's not run where someone will trip over it, etc.

[Ralph Mowery]

That drop cord thing and air conditiioners has to just be a standard from years ago just to cover the company .

I remember back growing up where the refrigerator would start up and the TV picture would srink in from all sides a few inches. Sometimes start the picture rolling . Homes were not built with very much electricity usage. Now homes are designed with much more electric usage in mind. The appliances (not counting any of the ovens and heating devices) usually draw way less current now than they did years ago.

[gfretwell]

As these inverter designs start hitting the mainstream that refrigeration LRA problem is gone. It is really apparent when you are running off a generator. We don't even notice the mini splits starting.

[Ralph Mowery]

I have not checked it out and may be off base on what I am tryin to say.

Some of the newer compressors are going to a scrool system instead of the piston type. Do those compressors draw a lot of current when starting compaired to the piston type ?

I am thinking maybe the scrool compressors are sort of like a fan and there is very little resistance when they first start and more as they speed up.

Where I worked we had some large (100 to 300 HP) motors that had what I call a one shot inverter. The motor would ramp up slow and when it reached its maximum speed a relay would then put it directly across the line. Reduce the starting load a whole lot.

[Marilyn Manson]

No argument...serious question:

On a cheaper, commodity window AC that says "No Extension Cord" is it possible that that 2.4V drop is bad for the AC itself?

It may be within NEC specs/recommendations, but could it be causing the AC to work harder/breakdown faster/waste electricity/whatever?

[Ralph Mowery]

Probably not. As many things, you get into the depends situation.

Most homes have enough voltage at the receptical that an additional 3 volt drop will not make much if any difference. My home voltage runs around 125 volts most of the time. I have a volt meter that stays plugged in all the time in a room so all I have to do is glance at it.

Now if the power company cuts the voltage to a very low value (brown out) that 5 volt drop could cause a problem. Still not very likely.

One online calculator shows that for a drop cord of 16 gauge wire and a

10 amp circuit 20 feet long only 1.6 volts will be lost. Hardly enough to effect anything on a 120 volt circuit.

One other thing to keep in mind is how hot the wire will get. I have heard that some drop cords catching fire because they are coiled up and not streached out where air can circulate through or around them.

[bruce bowser]

What else is pluged into the circuit?

[bruce bowser]

On Wednesday, July 14, 2021 at 4:53:53 PM UTC-4, Boris wrote in alt.home.repair:

What else is plugged into the circuit?

[hubops]

Sometimes those 3 / 5 % voltage cuts for capacity problems do not even get to the residential consumer - the tap-changers at the rural distribution stations make-up-the-difference .. .. not sure about the big-city residential distribution. .. perhaps they are all computerized now .. John T.

[Marilyn Manson]

My daughter, living in a medium sized city, has had 3 recents storms accompanied with a serious brownout each time. Some lights worked, some flickered, some appeared to be fine.

She has at least 4 generations of wiring in her house (some black/black BX, some cloth covered "romex", some plastic covered "romex" and even a little bit of aluminum). I can't say if the difference in performance from light to light (and receptacle to receptacle) was based on wiring type but she said the neighbors were having the same issues.

All of the houses are of the same vintage (early 1900's) so I'm guessing they all have various types of wiring also. I'd like to be there when it happens so I can do some investigating, circuit by circuit, to see if that tells me anything interesting.

[gfretwell]

Any conventional motor is subject to locked rotor amps when it starts.The load might prolong that but the fix is the soft start inverter motors. Your place did a similar thing in a cruder manner with the soft start device they used. We did the same thing with big disk drives (3380s) but it also had to do with the heads ripping off since they landed on the disk. They could sequence up a bank faster tho.