A/C breaker trips whenever ambient temp is high?

dougrainer wrote:

joshuajim wrote:
I live in the Mojave, so we see some spectacular temps. One day I decided to monitor my Dometic 13.5. When I started the test the OAT was 106 and interior temp was 101. The unit started easily on my Yammy 2400, but as head pressure built the wattage increases to 2040 watts or about 17 amps

The AC will increase 1 amp per 10 degrees above 95 degrees. Doug

Not to mention if running off a generator, the gen will simultaneously drop 1-1.5% hp for every 10 degrees.....lose/lose at higher temps.

joshuajim wrote:
I live in the Mojave, so we see some spectacular temps. One day I decided to monitor my Dometic 13.5. When I started the test the OAT was 106 and interior temp was 101. The unit started easily on my Yammy 2400, but as head pressure built the wattage increases to 2040 watts or about 17 amps

The AC will increase 1 amp per 10 degrees above 95 degrees. Doug

I live in the Mojave, so we see some spectacular temps. One day I decided to monitor my Dometic 13.5. When I started the test the OAT was 106 and interior temp was 101. The unit started easily on my Yammy 2400, but as head pressure built the wattage increases to 2040 watts or about 17 amps

wa8yxm wrote:

THere are two types of breakers, Magnetic and thermo. Not all are Thermo.

Virtually all household circuit breakers are thermal-magnetic breakers, combining both thermal trip (for moderate overloads, with some time delay so motors and such can momentarily use more than the rated current to start) and magnetic trip (for instantaneous response to hard, very high current short-circuits).

Thermal only residential circuit breakers (for service panels) do exist, but I think are mostly older/obsolete designs and in any case offer somewhat less protection to connected wiring. I think the little circuit breakers on power strips etc. are often thermal only, but I'm not positive about that.

Magnetic only circuit breakers are primarily used for specialized applications where short-term overloads are neither expected nor permissible. One example I'm aware of is some stage lighting dimmer systems where the individual dimmer output circuits have magnetic only breakers. They're designed to be able to output the full rated load continually, but to trip immediately at a (relatively small) overload. I'm sure there are plenty of other applications, especially in high voltage systems; but they're essentially non-existent for household electric panels.

dougrainer wrote:

j-d wrote:

Chris Bryant wrote:
...I would move to a single space breaker, if there is room in the panel...

Welcome, Pilgrim! I do NOT like those two-in-one Breakers. Even without being an electrical engineer, it doesn't make sense how (at least our) a Load Center is wired.

It has several 15/15 tandems, then a 30/20 where 30 feeds power INTO the whole breaker buss and feeds the A/C with its own 20 side. How can that NOT help overheat a thermal breaker?

I've replaced ours twice. Wonder how much it'd help to make the Main breaker a 30/15 and some other Branch a 15/20 to at least divide the load up.

I work in DFW, Texas and it is one of the HOTTEST areas of the country. I have never had a problem with a combo breaker set up. I have worked on thousands of AC units over the years and I rarely have to replace a breaker from being worn out or Heat related. I usually replace due to customer wanting it done, not because it is defective. Doug

Interesting- I've replaced far more breakers for tripping under the rating than I have air conditioners. And yeah- those 30/20 jobs get freaking hot when they are the main and a/c. When I find that, I move the A/C to a separate breaker and use the 20 for the microwave- intermittent use.

DownTheAvenue wrote:
There may not be anything wrong with your RV, circuit breaker, or the A/C. In fact, the circuit breaker may just be doing its job correctly. The RV park may be experiencing a ultra high electrical load during those high temperatures that causes a drop in voltage. The lower the voltage, the higher the amps. And the circuit breaker trips when the amps go up.

^^^ This! (If coil/filter in good shape.)

Get a voltmeter and monitor your voltage. A permanently moutned one is best. The voltage can be down in the CG due to many other AC units running at the same time plus at meal time can be even worse. Also check your shore power plug blades and make sure they are clean 'n shiny to ensure a good connection. However, a pedestal recept. in bad shape can also be a contributing factor but you can't see inside them. If they look crispy and blackened on the outside tho., it's probably not a good sign...

Reducing the loads inside your RV may or may not help a bit. An autoformer might be the best solution. If you have the choice and have a 30 amp RV, use a site with a 50 amp pedestal along with an adapter. Also, being closest to a pad-mounted transformer may help sometimes.

ON my units one breaker is a combo one is not. But as I said every time it trips it is the coils that need cleaning and I metered it with an ammeter and yes the breaker was holding at 20 amnps.

THere are two types of breakers, Magnetic and thermo. Not all are Thermo.

wa8yxm wrote:
...If your hands are as big as mine remove Fan...

Now you can clean the condenser by whatever method.
Also both a water wash or a Compressed air wash (After initial brush off) may help.

At least on ours, I can take a garden hose up to the roof and rinse the coils, using a deflector to send the water into the drain pain and not down into the cold air discharge area. Cutting board, license plate, etc.

About that Fan... My routine cleanings, and I've done it about annually, never included the outdoor fan or indoor blower wheel. I've actually found very little dirt or debris on the outdoor (Condenser) coil. Then we had Fan Motor Trouble and that called for pulling the Motor with Blower coming with it. A little hard to see, but that black plastic squirrel cage was FOULED! Probably with oily cooking vapor residue plus dust. So get in there and clean it if you can. At least if your A/C went years without that part of the cleaning being done. The blades are hard to get to so I copied what I've done with home HVAC blowers - Outdoors with Pressure Washer. Amazing amount of Black Goo came out.

I change Filters often. Simply cut a 20x20 home HVAC filter into four strips. Our non-ducted Mach 15 uses two filter strips and I leave my home made ones a little large. The edges show, but I know all the intake air is going through the filter. Not sure that was true before.

Recently, I found a new wrinkle in the A/C shutting down story. Since we camp in summer in FL and usually under full sun, A/C is a critical life support system. If it quits, we have to go home. So, I've got some tools and meters (amps and DVOM with capacitance) on board, along with a Spare Capacitors. We keep a DROK A/C voltmeter plugged in right where we can check it. Voltage was OK, Filters and Coils were Clean, and A/C compressor was shutting down on temperature.

I'd always thought a Capacitor was Good or Bad, Go or No Go, Capacitance in Spec on Meter or Not. The Compressor Run Capacitor tested Good on the Fluke Meter, but I decided to swap the spare in just because I had it. The compressor sounds better, like it used to, again, and has not cut out. Unexpected but true.

So I'd say, find out the values of the capacitors for Compressor Run, Fan Run, and Hard Start if equipped. Even if you don't plan on changing them yourself (which is easy, just turn Power off at Breaker then short across capacitor terminals with insulated tool in case it's still charged), you'll have spares on board for somebody who wants to help but doesn't happen to have the right parts. Available on Amazon for way less than appliance parts stores. I have maybe $40 tied up in spare capacitors.

j-d wrote:

Chris Bryant wrote:
...I would move to a single space breaker, if there is room in the panel...

Welcome, Pilgrim! I do NOT like those two-in-one Breakers. Even without being an electrical engineer, it doesn't make sense how (at least our) a Load Center is wired.

It has several 15/15 tandems, then a 30/20 where 30 feeds power INTO the whole breaker buss and feeds the A/C with its own 20 side. How can that NOT help overheat a thermal breaker?

I've replaced ours twice. Wonder how much it'd help to make the Main breaker a 30/15 and some other Branch a 15/20 to at least divide the load up.

I work in DFW, Texas and it is one of the HOTTEST areas of the country. I have never had a problem with a combo breaker set up. I have worked on thousands of AC units over the years and I rarely have to replace a breaker from being worn out or Heat related. I usually replace due to customer wanting it done, not because it is defective. Doug

Chris Bryant wrote:
...I would move to a single space breaker, if there is room in the panel...

Welcome, Pilgrim! I do NOT like those two-in-one Breakers. Even without being an electrical engineer, it doesn't make sense how (at least our) a Load Center is wired.

It has several 15/15 tandems, then a 30/20 where 30 feeds power INTO the whole breaker buss and feeds the A/C with its own 20 side. How can that NOT help overheat a thermal breaker?

I've replaced ours twice. Wonder how much it'd help to make the Main breaker a 30/15 and some other Branch a 15/20 to at least divide the load up.