Air Conditioner tripping breaker in my house while on shore power

[Wgbarrbevco]

Hi All,

I have an issue I can't figure out and I'm hoping someone on here with a bit more experience might know what's going on...

We recently had a brand new 15000 BTU A/C unit professionally installed on our 24' 1975 Argosy by a guy who specializes in Airstreams. When we plug the trailer into shore power (extension cord to our house), the air conditioner starts up with no problems and blows nice and cold for about 7-15 minutes, at which point a fuse blows IN OUR HOUSE and we lose all power to the trailer. I've tried multiple different outlets in the house that are on different breakers, and all of them do the same thing. None of the trailer fuses blow. The odd part is, there is no issue whatsoever when I turn the A/C unit on, which I would assume is when it draws the most power. It occurs 7-15 minutes into running the A/C. No other appliances or electronics were on while I was running the A/C. Anyone know why the A/C would be tripping the breakers in my house?

Thanks!

[Chuck]

because the house circuits are most likely only 15 amps, and that isn't enough. combine that with the rating and length of your extension cord, which is also probably not up to the task. The longer the cord, the higher the resistance, which causes the voltage to drop.
It may be that it starts out ok because the line is cold, but after a few minutes, the heat builds up, and then the circuit pops.

You should be plugged into a 30 amp circuit, optimally. I've run mine ok on a 20 amp circuit, with a 12 gauge extension cord (short as possible), or with just the trailer's cord (which is 10 gauge).
Most extension cords are 14...not heavy enough for high-draw situations.

[azflycaster]

Do you have a dedicated 30 amp RV circuit for the trailer? You should...

[rumrunner]

I think I hit a wrong button and lost my reply so her I go again.
If you are simply plugging an extension cord into random house circuits you will continue to blow breakers. Your TT is wired for a 30A circuit and you are connecting to 15 or 20 amp circuits and overloading the carrying capacity whick is probably heating the breaker and tripping it out as it is designed to do. Apparently the breakers in your panel have enough overload surge protection to handle the start up load initially but cant handle the continuous load. Without this protection you would probably have a house fire! Your 15K BTU A/C needs the 30A service to function properly.
Simple fix is to wire up a 30A outlet as close as possible to your parking pad and you are back in business.
tim

[Wgbarrbevco]

OK, thanks for the info guys. It seems like my best bet would be to upgrade to a 10-12 gauge extension cord (and limit its length) as well as plug into a 30amp circuit. The problem is, my situation is a bit unusual in that we plan to use our Airstream as a mobile office and are going to rent parking outside of a warehouse. The warehouse is providing power from their building, but I don't have the luxury of installing a 30 amp circuit on their property. If we are supremely lucky, they will have a 30 amp circuit already in place where we need it to be, but the odds of that are probably low, right? Is there any type of converter that can allow me to plug in the trailer to a 20 amp circuit and still run the A/C and other electrical stuff? Is there any other way to run it without installing a 30 amp circuit in their building?

Thanks again for the help!

[rumrunner]

If the warehouse has 220v circuits for equipment etc. it is easily adapted to a 30A 110v outlet. Worth checking.
If not, how far will you be parked from the nearest panel box?
tim

[Wgbarrbevco]

rumrunner - I'm not sure if the warehouse has 220v circuits...i'll have to find out, but thats a good thought.

Either way, i'd like to figure out a way to be able to run the A/C when plugged into a 20amp circuit. I picked up a 10 gauge 25ft extension cord, so hopefully that will help, since I was using a standard 14 gauge cord before. When people plug into campsites that only offer 20 amp circuits, do they just refrain from using the A/C?

I looked up the specs for our A/C unit and it says the compressor draw is 12.9 amps and the fan draw is 2.5 amps. That would put the A/C by itself at 15.4 amps, which theoretically should be ok on a 20 amp circuit if we don't run anything else at the same time, correct? Problem is, we will also have a fridge, printer, and telephone plugged in...

Lastly, is it possible to buy some sort of inline breaker/surge protector that would flip before the 20 amp building breaker would flip? That way, if we were drawing too much power and didn't have access to the building's breaker, our inline protector would flip before the building's breaker...we could then just reset our inline breaker without having to find the building's circuit box.

[Wazbro]

For an inline breaker to flip first dependably it would have to be a 15 amp circuit, not much help. You might be able to wire the ac separate from the rest of the trailer and use 2 circuits from the building.

[TBRich]

As long as you are plugged into a regular household outlet you will continue to have issues because you are not getting enough amps to the AC, and there will probably be long-term negative effects to your AC. The household hookup is good for everything except maybe a microwave (you'd have to test that). Another option is to use a generator for those times you need AC.... at least a 3000w or two 2000w generators run in parallel. With the latter you can run everything in your rig. There are many threads here dedicated to generator discussions...Hondas and Yamahas are the best and quietest (and they produce clean sine power for electronics, which will be important in your use)...

[ROBERTSUNRUS]

Hi, if you use your trailer's power cord with a dog bone adapter [no extension cords] you can run your air conditioner on a 20 Amp circuit, I do it all of the time at home, but you can't run anything else. Being that you are using your trailer for an office, your air conditioner won't be the only thing used on this 20 Amp circuit. You need to have an RV 30 Amp service installed or use a generator capable of making 30 Amps.

[garry]

Short drop cord of 25ft or less @ 10 gage and run the AC on low.

You need an AC meter to check the voltage if it falls below 108V you will damage the air-conditioner.