How are these Air conditioning voltage numbers?

[Tacswa3]

My new TT has a 15K BTU A/C. I can reach my garage plug which is on a 15 amp breaker with the TT 30 amp cord and a 10'' pigtail 15 amp adapter. If nothing else in the garage is running, the camper A/C seems to run fine. I checked the voltage at the camper plugs and got 112.5 volts after a minute or so with the A/C on. 5 or more minutes later I checked voltage at the camper plugs I had 109.3 volts. I let the A/C run some more and did not check further voltage before I shut it off. My question is how do these numbers look? Will my A/C be fine if I ran it during the night if I wanted to? Should I check voltage more the longer the unit runs?

I am aware of the danger to A/C compressor debate, I just don't know where the danger zone is voltage wise. I do plan on installing a dedicated 30 amp plug in the future.

[Tacswa3]

Done. Got a dedicated 30 amp plug/breaker installed. Getting 119 volts in the camper with the AC rocking and rolling 🙂

[campigloo]

Good advice from Rhagfo

[rhagfo]

TechWriter wrote:

Tacswa3 wrote:
Should I check voltage more the longer the unit runs?

Get an autoformer instead.

Far better than this, just install a 30 amp circuit to the location of your trailer!! Do you really want to burn down your house to keep your trailer cool???:S

15 amp circuits run on 14 gauge wire 30 amp run on 10 gauge wire, for the cost of the Autoformer you could have the correct circuit installed for the trailer.

Something else to think about the greater the distance the cable is the greater the voltage drop, so if it 50' from your breaker box to the outlet a veavy draw on 14 gauge wire is very bad.

[therink]

I am set up as seasonal at a campground where I have experienced voltage drops as low as 105 during busy weekends. I was concerned so did some research. I ended up buying a Hughes Autoformer. Now my voltage never drops below 115. This solved my problem. The Autoformer was expensive but we'll worth it.
When plugging into a 120v 15amp circuit at a house the most common problem is the voltage drop you will experience if using a 12 or 14 gauge extension cord. A 10 gauge cord at minimum should be used.

[time2roll]

Motor is rated 115v +/- 10%
105-108 is within normal spec. Good part is home voltage should be steady vs a campground as it fills up on a hot day.

[Larryect]

Possibly I wasn't clear enough. Yes, it reduces the amperage at the AC. But the amperage at the breaker would have to increase.

Wattage is wattage. Lower volts doing the same work requires more amperage.

[TechWriter]

Larryect wrote:
An auto-former will increase the voltage to the unit by increasing the amperage draw on the input, overloading the breaker even more.

That would be decreasing, not increasing, amperage.

[Larryect]

He has a 15 amp breaker. An auto-former will increase the voltage to the unit by increasing the amperage draw on the input, overloading the breaker even more.

[Big_Katuna]

It could be a volt or two lower at the ac. I'd get a recep in sooner rather than later.

[TechWriter]

Tacswa3 wrote:
Should I check voltage more the longer the unit runs?

Get an autoformer instead.

[Tacswa3]

I just would like to use it on a as needed basis until I can get a dedicated plug installed. But I'm also nervous as I don't want to burn up the compressor. If I used it at night it would be cooler so maybe it wouldn't need to work so hard.

[Larryect]

On a hot day it may very well trip the breaker

[imgoin4it]

Should be ok down to 108 volts. Any lower shut it off. The best any electrical company will guarantee is 120 volts plus or minus 10%. That's the standard US wide.

[2oldman]

Those numbers aren't great, but they are acceptable.

I'd be feeling around the plugs to see if anything is getting hot. Voltage drops usually mean higher amp draws, and if your 30a plug wiring isn't tight and clean, it'll heat up.