Re: In-window A/C Unit and Current Draw

[bruce bowser]

On Wednesday, July 14, 2021 at 4:53:53 PM UTC-4, Boris wrote in alt.home.repair:
> My daughter wants to install a window type A/C in two different rooms in
> her home. She has no idea if the units she's looking at, which draw 4.9
> amps (115v), would overload any particular circuit. Without mapping the
> circuits, is there any way to know, other than plugging the unit in?

What else is plugged into the circuit?

[Michael Trew]

Yes, you'd have to know what else is plugged in, and it's not a good
idea to have them both on the same circuit.

[Rheilly Phoull]

Yup, and the ratings of the circuits etc.

[bruce bowser]

Including the distance covered by the wires? from the service's interface to the outlet?

[Peter W.]

No need to know what else may be plugged into the circuit, as there is much else to consider first:

a) Given a 4.9A steady-state current draw at 115 VAC, that comes to 563 watts. Less than a standard hair-dryer (~1,200 watts). No big deal, even for a 15A conventional circuit (1,725 watts). Even one that shares a few other small things.
b) Given that the typical surge for a conventional AC unit is very roughly eight (8) times the steady-state, the circuit must be able to withstand a very roughly 38 amp surge. This is well within the capacities of a standard 15A or 20A circuit breaker - AS LONG AS THERE ARE NO OTHER LOADS. *And as long as the breaker is functioning properly*.
c) Most recent (modern) window units come with a GFI device mounted on the plug. So there should be no intrinsic danger of fire or overheating.
d) Never, ever use an extension cord with a window AC unit. Ever.

With these in mind:

Plug them in, and let them rip. Should a circuit breaker blow, you will know what is shared. Remove those shared items and start over. If both units happen to be on the same circuit, use only one (1) at a time.

Ideally any AC line should be (at least) a dedicated 20A circuit using (at least) 12-gauge wire. Then there would be no discussion. If this is a rental, I feel her pain. If this is owned, install the dedicated circuits as-needed. They will not go to waste.

Peter Wieck
Melrose Park, PA

[Bennett]

It's easy enough to determine if the 2 sockets are on the same circuit.
Plug a lamp or radio into both, then flip circuit breakers. If both
devices stop, they are on the same circuit.

[Phil Allison]

Peter Wanker puked:
=================

>
> a) Given a 4.9A steady-state current draw at 115 VAC, that comes to 563 watts. Less than a standard hair-dryer (~1,200 watts). No big deal, even for a 15A conventional circuit (1,725 watts). Even one that shares a few other small things.
> b) Given that the typical surge for a conventional AC unit is very roughly eight (8) times the steady-state, the circuit must be able to withstand a very roughly 38 amp surge.

** But increase to 76A if both units come on together.
Current 16 times over nominal has a trip time of 0.1 seconds.

( C type breaker)

............ Phil

[Rheilly Phoull]

Not really, the cable should be rated for the distance which in domestic
situations is not great.

[Peter W.]

Result is exactly the same. If the breaker trips - reduce/eliminate the ancillary load(s).
Nor can you read for content "AS LONG AS THERE ARE NO OTHER LOADS".
In the USA, C-type breakers are used in specialty applications, generally not in a residential setting. Breakers here would be, typically, type A (plain), GFCI *breaker* (as compared to a GFI *device) and AFCI breakers. Within that group are many variants that describe how they are installed.
Domestic breakers are available with a "high" current setting that will allow up to 20X rating for up to one (1) full second. They are expensive. I have used them several times to support wood shops and machine shops for 'heavy' hobbyists and wood workers. Never for 'regular' stuff.

Point being that nothing changes. Plug in the units - see if the breaker trips. If it does, adjust the load accordingly. And NEVER run both at the same time.

Learn to read.

[Phil Allison]

Peter W. wrote:
============

> Result is exactly the same. If the breaker trips - reduce/eliminate the ancillary load(s).
> Nor can you read for content "AS LONG AS THERE ARE NO OTHER LOADS".

** Irrelevant, my point did not need them.

> In the USA, C-type breakers are used in specialty applications,

** Really? They the standard in every other place for GPOs.

> Domestic breakers are available with a "high" current setting that will allow up to 20X rating for up to one (1) full second.

** Yep - that is similar to a D type.

Used where large ( or multiple) motor loads are expected.

> Point being that nothing changes. Plug in the units - see if the breaker trips. If it does, adjust the load accordingly.
> And NEVER run both at the same time.

** Yawwnnnnnnn ....

A pair of window units in two separate rooms are ** GONNA** be run on the same hot day or night !!!

You tedious fucking wanker.



...... Phil

[Peter W.]

You always have a point. And, sadly, proper tonsorial attention is no longer an option for you.

[amdx]

  I had good luck with multiple freezers on one circuit breaker. I had
twelve-25cuft freezers on 5 circuit breakers, over 15 years

I never had a a circuit breaker trip. I was always waiting for two
freezers to start at the same time, but they never did.

I did have two freezers plugged into original house wiring, a bad
connection developed at one outlet (35 years old),

this bad connection got hot enough to create an odor.

The odor came and when over a couple days before I isolated it to an
outlet. When I took it apart the outlet crumble into pieces.

I was lucky to avoid a fire.

                                  Mikek

>
>


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[legg]

You can get an idea of what outlets are on the same branch circuit
by fiddling with the fuse box an a sunny day.

Plug something noisy into the intended outlets and pull fuses
till it stops.

RL

[Stephen Wolstenholme]

A long time ago I had a house rewired. The fuses were clearly labeled.
That has never happened since. If I was doing the job I would label
the trips but I have retired.

Steve

--
http://www.npsnn.com

[bruce bowser]

A 20A circuit max rather than a a 15A circuit max on a 240AC residential hook up.

[bruce bowser]

On Wednesday, July 21, 2021 at 2:10:33 PM UTC-4, bruce bowser wrote in alt.home.repair:
> On Wednesday, July 21, 2021 at 10:01:21 AM UTC-4, micky wrote:
> > In alt.home.repair, on Wed, 21 Jul 2021 06:29:13 -0700 (PDT), bruce
> > bowser <bruce2...@gmail.com> wrote:
> >
> > >On Tuesday, July 20, 2021 at 9:31:19 PM UTC-4, Alisha wrote:
> > >> I recently moved and my ac unit is a 220 and the only plug I have is a 110 how do I make this work
> > >>
> > >> --
> > >> For full context, visit https://www.homeownershub.com/maintenance/moving-from-a-220-plug-to-a-110-what-do-i-need-3145094-.htm
> > >>
> > >> Moving from a 220 plug to a 110 what do I need?
> > >
> > >The outlet should look like this upper most pictured outlet:
> > >
> > >-- https://www.zoro.com/leviton-receptacle-duplex-20a-5-20r-125v-white-cr20-w/i/G3837374/feature-product?utm_source=google&utm_medium=surfaces&utm_campaign=shopping%20feed&utm_content=free%20google%20shopping%20clicks&gclid=CjwKCAjwi9-HBhACEiwAPzUhHN1aeMWrf55qsUBQ3ZHvrWnhINUsWGnhs_7QFx7XMobaImvzxZflLRoCDSQQAvD_BwE
> > I don't think so. It's own url and label include 125V.
> At peak or non-peak? Here in the 21st century we are designed to go over and under you know.

Plus, The left prong port has a horizontal port for 220 VAC 15-20A or for 120 VAC 15-20A.