Wimpy circuit breakers

[LHaven]

Family friends are staying here a few days with a small 30A trailer in one of our 30A slots.

They have been having problems with their 20A A/C breaker just popping. I lent him a Kill-A-Watt outlet meter to read his coach voltage while the compressor was running, and it doesn't drop below 113VAC, so it wasn't my service.

He figured he had a "soft" circuit breaker, so he took it out to buy a replacement. Apparently, it's not a popular model -- he had problems finding a match at the local stores, but found one more towards central Phoenix.

His power center is arranged vertically, with the converter vertical on one side, and the fuses and breakers grouped vertically on the other side. He notes that the converter, with its fan, is well cooled, but the breakers and fuses are on the other side of a partition and get no ventilation at all. Furthermore, his old breaker (in fact, all his factory breakers) is stamped 40°C, or 104°F, which is a "comfortable" summer day out here... and so is his new one. In fact, he was unable to find a replacement breaker with a higher temperature rating.

He said that just leaving his power center door open seemed to eliminate the breaker failure, helping to confirm the temperature problem. But it would be nice not to have the door hanging where he would rip it off on an unlit bathroom trip.

104° seems like a pretty lame temperature ceiling for any RV component.

My friend plans to port an interior partition when he gets back home, to provide some heat relief, but I was wondering if this was a common limitation for RV breakers, and if a source of more robust ones might be available.

[flybouy]

I think (not actually seeing the breaker) that the 40°C is the rise over ambient temperature and not a maximum operating temperature. He should check all connections and confirm that they are tight and that there's no discoloration of the wires. Also check fans on converter and blow everything out with compressed air.

[chuckster57]

I would put an amp clamp on the black wire at the AC breaker and see what it’s drawing when the compressor starts and when it’s running.

[wiredgeorge]

I ran into this issue a bit myself. I added an A/C computer fan to the outside venting on my power center door. I also removed my microwave from the power center and connect the micro wave cord to the breaker but the breaker to a separate Marinco outlet on the rear of my camper and plug into the 15/20A outlet on the pedestal. I swapped around breakers to the 30A main was ganged with a 15A circuit to reduce heat and moved the 20A microwave to share ganged breaker with some other circuit which doesn't have a big draw. Really helped a lot. Tell your friend an EMS is his camper's friend.

[LHaven]

Come to find out, my friend's power center is a standard WFCO 8955PEC horizontal...installed sideways, by Winnebago.

Fortunately, he has a blank cabinet right next to it (that Winnebago doesn't put a door on because there's a wheel well in it, but lots of other people do) and he's just going to port the dividing wall and install a little fan.

Didn't do the amp clamp stuff because he reported the breaker would pop after a significant runtime, not at startup.

[chuckster57]

If the wall is a wheel well, I don’t think I would be cutting it for a fan. When driving if he hits any water, the tire will fling it forward.

[rhagfo]

Originally Posted by chuckster57

I would put an amp clamp on the black wire at the AC breaker and see what it’s drawing when the compressor starts and when it’s running.

I agree with this, while at 113 volts that is fine, how many amps is the AC drawing?
If the motor is starting to fail it may be drawing too many amps causing the breaker to trip. We have been in some very hot weather and our AC has run continuously for hours on end and never tripped.

[LHaven]

Originally Posted by chuckster57

If the wall is a wheel well, I don’t think I would be cutting it for a fan. When driving if he hits any water, the tire will fling it forward.

No, he's not cutting a wheel well.

There's a space under the counter that would otherwise have been a great kitchen cabinet, except that a wheel well intrudes into much of it, so Winnebago put a blank partition on it instead of a cabinet door. One of the more popular mods for this model is to buy an extra matching cabinet door and make a cabinet out of it anyway, wheel well or not.

He'd be porting an interior sidewall of this compartment between it and the fridge, where the WFCO is.

[chuckster57]

Originally Posted by LHaven

No, he's not cutting a wheel well.

There's a space under the counter that would otherwise have been a great kitchen cabinet, except that a wheel well intrudes into much of it, so Winnebago put a blank partition on it instead of a cabinet door. One of the more popular mods for this model is to buy an extra matching cabinet door and make a cabinet out of it anyway, wheel well or not.

He'd be porting an interior sidewall of this compartment between it and the fridge, where the WFCO is.

That’s good.