A/C Tripping Breaker Question

[merc1100sc]

All,

I have a FR Work and Play with a rooftop AC. Not sure of the model off the top of my head but I don't think it's relevant at this point as I just want to confirm a few things.

Here goes. Last night, being 80 something degrees, I turned on the AC unit for the first time since I purchased this camper used. Kicked on right away and cooled very quickly. I then adjusted the thermostat up to make sure that works and turns the unit off. It did. Then, when I slid the thermostat back down, I could hear something in the unit spinning slowly for a few seconds. I assume the compressor. Then the A/C breaker inside the camper trips. If I reset the breaker, the unit fires back up and runs like normal.

After doing some reading, I think my issue is that the camper, in my driveway, is plugged into a standard receptacle, with an adapter cord, connected to the 50amp cable. I am guessing my issue is not with the a/c unit but with the corded and adapter being the bottle neck and causing the breaker to trip. Does this make sense?

And if so, will the unit run ok using my two Yamaha 2000W genny's paralleled together?

Thanks

[dougrainer]

ROYB, That CHEAP plug in meter is worthless to tell you line voltage. They are only good for letting you know, you have 120 voltage, NOT the actual line voltage. I have had numerous customers come in and point to that meter and state the line voltage is LOW. I connect my Fluke meter and show they have 121 instead of the 111 or 113 the meter shows they have. They then spend a few dollars more and get the LCD 120 voltmeter. Doug

[road-runner]

As already suggested, after the compressor is shut down, you need to wait a few minutes before running it again. Many thermostats have a timer that enforces this, sounds like yours doesn't. As for the power connection being good enough or not, the only way you'll know for sure is to measure the voltage inside the rv when the air conditioner is running. Different people have a different opinion for the lower limit. The air conditioner spec lower limit is 103.5, at the air conditioner, so you have to add at least a couple volts when measuring to allow for losses in the wiring to the air conditioner.

[joebedford]

RoyB wrote:
Assuming your home 50AMP RV circuit was wired up

Pretty sure he was wired to a 15 or 20 amp circuit at the house end.

[RoyB]

Assuming your home 50AMP RV circuit was wired up according to code and you have a nice RV 50AMP Receptacle on the outside wall available to use... Sometimes your RV Unit may be too far away form the 50AMP Receptacle and you might use an RV adapter and a longer 120VAC standard extension cord. It could be this added extension cord is not a 10GAUGE heavy duty size cord and giving you some AC Voltage drop when being used. This will burn up your cable ends and could also do damage to your air conditioner unit... Just be sure what you are using is a good heavy duty 10GAUGE wiring... If you are doing something like this DO NOT use the small round type RV ADAPTERs and use what they call long DOG BONE type adapters which are available from WALMART...


Google Image

This then will allow you to use your standard RV SHORE POWER Cable to plug into the home 50A Receptacle... You should not have any too small cable sizes involved with this setup...

Like said above you really should have a small plug-in AC VOLTMETER like shown here that will tell you where the GREEN SAFE ZONE is with the incoming 120VAC power...

These are inexpensive and I got mine from AMAZON... I have mine plugged into a out of the way 120VAC Receptacle all the time. I just glance at it to tell me the the proper 120VAC level is present before I turn on the Air Conditioner.



Another thing one could do to verify your 120VAC 50 AMP setup is properly wired is to use a portable AC VOLTMETER and read the between the four 50AMP PLUG receptacle sockets like shown in this pictorial... I do this all the time at camp grounds for the 30A pedestal receptacle before I plug into it... If I don't see these readings then I will not plug into the pedestal...

50A


30A/20A/15A

NO SHOCK ZONE images

If you are going to stick meter probes into these AC SOCKETS please be very careful not to spark anything to ground.

Just for your info even my small footprint trailer with few 120VAC High Wattage being used I will sometimes trip my 30A trailer breaker if I have the Air Conditioner running and the Microwave ON at the same time... Just things you have to learn about for your particular trailer I guess haha...

Roy Ken

[merc1100sc]

The breaker in the camper. And yes, I get that now. Was just checking the thermostat.


Thanks

[MrWizard]

I don't think the cord is you bottle neck
Which breaker tripped, in the RV or in the house
You where playing with it
Once the compressor got Hit while running
The system head pressure was too great for the compressor to start
You restarted TOO SOON , should have let it rest aka cool down for a few minutes
Before restart
You play with it like that on the twin generators and you are going to get an overload fault

[pianotuna]

Add a microair easy start unit to the air conditioner.

Monitor voltage. If it is below 107 then turn off the air conditioner.

[merc1100sc]

Great. Thanks for the quick replies everyone. Appreciate it.

[LadyRVer]

IIRC start amp is 16 for a 13,500 ac. 20amp plug...? Possibility if the refrigerator was on auto, it kicked over to electric, too? Breaker kicking, not enough power...other things we don't even think about hit the electric supply.

Running load is about 13 or 14 amps, I have been through this. Above post very good.

[BobsYourUncle]

Wild Card said it. This is why any AC won't cycle back on right away. You must let the compressor pressure bleed off before restarting.
And a weak power feed will only magnify the problem, hence the tripped breaker.

And yes, it will run with the 2 gennys together.

[Wild_Card]

You also dont cycle it off then right back on. You must give the refrigerant time to equalize or else the compressor is trying to start against higher pressure...coupled with the sub par power supply. Let your unit sit for a few min before attempting to restart

[rrupert]

I believe you discovered the problem. You do not want to run the A/C from a circuit and cord that are too light for the job. The A/C was probably struggling for power. It was probably overheating and tripped the breaker. DO NOT run the A/C in this manner, it can do permanent damage to it. Your shore power cord plugged into a 30 amp outlet is the minimum supply you want to use.