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

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?

Reply to
bruce bowser
Loading thread data ...

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.

Reply to
Michael Trew

Yup, and the ratings of the circuits etc.

Reply to
Rheilly Phoull

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

Reply to
bruce bowser

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 wat ts. 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 v ery 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 l ong 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 kno w what is shared. Remove those shared items and start over. If both units h appen 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 renta l, I feel her pain. If this is owned, install the dedicated circuits as-nee ded. They will not go to waste.

Peter Wieck Melrose Park, PA

Reply to
Peter W.

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.

Reply to
Bennett

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

** 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

Reply to
Phil Allison

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

Reply to
Rheilly Phoull

Result is exactly the same. If the breaker trips - reduce/eliminate the anc illary 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 n ot in a residential setting. Breakers here would be, typically, type A (pla in), GFCI *breaker* (as compared to a GFI *device) and AFCI breakers. Withi n that group are many variants that describe how they are installed. Domestic breakers are available with a "high" current setting that will all ow up to 20X rating for up to one (1) full second. They are expensive. I ha ve used them several times to support wood shops and machine shops for 'hea vy' hobbyists and wood workers. Never for 'regular' stuff.

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

Learn to read.

Peter Wieck Melrose Park, PA

Reply to
Peter W.

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

Reply to
legg

ch else to consider first:

atts. 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.

y 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 standar d 15A or 20A circuit breaker - AS LONG AS THERE ARE NO OTHER LOADS. *And as long as the breaker is functioning properly*.

e plug. So there should be no intrinsic danger of fire or overheating.

now 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.

t least) 12-gauge wire. Then there would be no discussion. If this is a ren tal, I feel her pain. If this is owned, install the dedicated circuits as-n eeded. They will not go to waste.

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

Reply to
bruce bowser

a 110 how do I make this work

and under you know.

Plus, The left prong port has a horizontal port for 220 VAC 15-20A or for 1

20 VAC 15-20A.
Reply to
bruce bowser

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.