30/20 Amp Breaker Worn???

As a rig vibrates and bounces down the road electrical connectors can become loose and checking them should be an annual maintenance item.

I just torqued my ATS and power protector terminals to 45 in lbs and 3 needed to be tightened. Next up will be the CB panel.

The recommended continuous load is 80% of the CB rating. And with the AC on all day your are in that ball park so this could be a factor.

ie For the 30A CB that's 24A maximum.

Good info above - switch HW and refer to propane.

I previously had another AC issue that I never resolved and seemed to have gone away (hasn't occurred in at least 6 weeks of heavy use). Maybe this is a part of the current issue.

What is was:
1) I would hear noises from the inside what I believe was some kind of relay trying to move. I suspect it was a device on the circuit board. Never did anything about it.
2) I changed out the starting capacitors, probably didn't need to.

Keep the advise coming.

Thanks,
John

I had a two pole 20/15 amp breaker get weak on the 20 amp side. The 20 amp side was for the AC. It would trip frequently particularly when first starting the AC after getting set up. 15 amp side never tripped. Replaced it and no more tripping.

Had to order it online as I could not find a two pole 20/15 at any box store, hardware store, or electrical supply house local.

I would look for a loose connection.
Before you start work, go to your local hardware store and get a small tube of electrical de-oxidation grease.
Disconnect all 120 volt power source, remove cover from the AC power panel, look in the back of the box for the neutrals(white wires), disconnect them one at a time. Apply a liberal amount of de-ox grease and reinstall.
Do the same for the black wires attached to the circuit breakers.
Yes, switching to another breaker away from the 30 amp can reduce the heat that causes tripping in some cases.

Thanks for the responses to to help me thru thought processes.

1) AC coils are clean.
2) Yesterday (when I had the AC breaker kick twice) it was 95 deg. F plus a heavy sun load. One of the instances I suspect the electric hot water was drawing and maybe the fridge too. Maybe the hot 30 amp and the 20 amp AC shared in the same casing is just getting to hot.
3) Currently RV voltage is 119V at an outlet.
4) I'll watch the voltage as it heats up to 95 deg. F again today.
5) I like the idea of swapping the 20 amp "pair" breaker with the 20 amp microwave solo breaker.

Thanks for the help so far as I try to get more information today as it gets hot.

John

Check your voltage. You mention that the A/C is running. If you have only 110 volts, the compressor motor will draw more amps. If less than 105 volts, then amps will really go way up, especially if over 100F outside.

Add to that, the breakers are in a warmer environment, and they trip based on the internal heater getting warm. So while a breaker might hold with a 30 amp load 10+ hours, at 100F it might also trip with 29.5 amps after a few hours.

The internals of the circuit breaker are a thermostat like device that will trip when the internal temperature reaches a certain temp. IT will also have a magnetic trip, so say you have a 200 amp overload, it will trip almost instantly. But a 31 amp load on a 30 amp breaker should take it more than a few minutes to trip. It sounds to me like you have very close to 30 amps going through the breaker, causing it to trip after a few hours being very close to overloading. . .

You can check it out properly for about $30. Buy a clamp on AC ampmeter at Home Depot. Yes they are that cheap these days. I bought one rated for both AC and DC clamp on meter, for $80. Back in 2000, that type of meter would cost $400. You just remove the circuit breaker cover, and clamp the amp meter over one of the wires, and you can read the amperage quickly.

You can buy a Kill-A-Watt at Amazon.com for about $20. You can leave that plugged in someplace in the RV and monitor the incoming voltage quickly, and know that running the A/C unit while under 105 volts can damage the compressor (the $600 to replace part). So turn it off, or buy a voltage booster to protect it!

Good luck,

Fred.

How long has it been since you cleaned the condenser coils on the A/C?

Check wire at breaker and at the A/C. Two RV's ago we had a loose wire at the A/C causing a hot and tripping breaker.

There should be another 20 amp breaker for the microwave. If there is, just swap the wires over.