Breaker Keeps Breaking

[Mootpoint]

My Carrier 15,000 air conditioner has worked great for the last month in So.Cal. but now starts blowing the 20 amp breaker in the trailer panel after 4 minutes of run time. Ground power hook up, 30 amp, fan runs, compressor comes on fine, roof unit clean and free of dust as well as vent systems and filters. It's a loss to us. Any suggestions? :h

[kellertx5er]

Ouch! Sorry to hear that.

[Mootpoint]

Yes! A new air conditioner!

[shooted]

Has there been a resolution to this or a cause identified?

[j-d]

As noted, breakers get old and soft. I believe there are thermal and magnetic ones, and household/RV ones are thermal. Ours are paired, two in one, and we have a 30+20 that's Main + A/C. When the A/C is struggling with low voltage, the two sides of that breaker heat up and it trips.

[csp_et2]

Do the easiest thing first. Check the wire going into the breaker. Make sure it's tight. Also, make sure you are disconnected from shore power before doing this. Safety first.

[shooted]

In an effort to cut costs, most manufacturers omit the optional starting circuit (start cap and PTC or relay). Your unit will however have one dual run cap, or two individual run capacitors. Please post a picture if additional clarification would be helpful.

[BB_TX]

The 20 amp breaker for my AC started tripping like that a few years ago. Replaced it and no problem since.

[CA_Traveler]

wolfe10 wrote:

wa8yxm wrote:
From personal experience there are some things I'd look at.

1: First: the voltage.. If the voltage is low (Say 104 volts though that is given as an example only) the compressor will need more time to start and will draw more current while starting (the blower will need more too) IN fact, there is danger of burning out the compressor at this or lower voltages.

2: CLEANING, go topside pull the covers (Outer and inner) clean the condenser coils, evaporator (if needed) blower and fan, IF there are lubrication ports.. USE THEM (usually there are none).

3: Breaker itself

4: Start capacitor (If you replace, get a "hard start" kit).

But start with the line voltage.

Good analysis.

Also measure the voltage with the AC running. If you can verify that your meter is accurate. I've found that the $5 and sometimes free HF digital meters to be good for RV work.

Plus are any wires/plugs warm? Could be a bad connection.

[JesLookin]

I would start with the breaker. The breaker uses heat, to detect too much current. Another thing that can cause heat is a loose connection. On an old 5er we had, the screw that connects the wiring to the circuit breaker was loose causing the circuit breaker to blow. While I was there I also checked the rest of the circuit breakers and tightened up those loose screws also.

[Chris_Bryant]

Did you look at the inside of the condenser (outside) coils? The full height Carrier throws the condensate against the coils, which tends to make them very dirty, but you have to disassemble the unit to even see this.

[RoyB]

I installed one of the RV 120VAC line meters that plugs into an out of the way 120VAC Receptacle. This is a great thing to have around to ocassionally glance at to confirm your line voltage is within the GREEN safe zone printed on the scale...

Available from AMAZON and most RV supply stores.



Roy Ken

[wolfe10]

wa8yxm wrote:
From personal experience there are some things I'd look at.

1: First: the voltage.. If the voltage is low (Say 104 volts though that is given as an example only) the compressor will need more time to start and will draw more current while starting (the blower will need more too) IN fact, there is danger of burning out the compressor at this or lower voltages.

2: CLEANING, go topside pull the covers (Outer and inner) clean the condenser coils, evaporator (if needed) blower and fan, IF there are lubrication ports.. USE THEM (usually there are none).

3: Breaker itself

4: Start capacitor (If you replace, get a "hard start" kit).

But start with the line voltage.

Good analysis.

[wa8yxm]

From personal experience there are some things I'd look at.

1: First: the voltage.. If the voltage is low (Say 104 volts though that is given as an example only) the compressor will need more time to start and will draw more current while starting (the blower will need more too) IN fact, there is danger of burning out the compressor at this or lower voltages.

2: CLEANING, go topside pull the covers (Outer and inner) clean the condenser coils, evaporator (if needed) blower and fan, IF there are lubrication ports.. USE THEM (usually there are none).

3: Breaker itself

4: Start capacitor (If you replace, get a "hard start" kit).

But start with the line voltage.

[Shadow_Catcher]

Use a VOM/multimeter and check the voltage and amps this will verify that your voltage is correct and that the problem is or is not with in the AC.
Diagnosis for electrical problems can in most cases be simplified with a VOM saving a lot of floundering around.