Help needed - A/C keeps throwing pedestal circuit breaker

[Bluepill]

Also: Check the temperature of the 2 plugs and 2 sockets (includes the entry socket) by carefully touching after running the A/C for 10 minutes. They can be warm but shouldn't be hot to the touch.

If one is much hotter than the others, you have a poor connection there.

[tomrob1161]

It looks like to me you have 2 issues, extension cord and running too many electrical appliances. On a 30 amp circuit, don't run any heavy amp appliances when using your A/C, especially the water heater. The extension cord is also a problem, you have a 25' cord from your coach then you've added another 50' of extension cord so you are running 75' of extension cord, with the amp drop over this length you don't have 30 amps at your coach. Another potential problem could be the circuit breaker at the post. It may be weak from popping so many times. When 50 amp is available, I always use a 50/30 adapter.

[CedarCreekWoody]

Originally Posted by MNtraveler

Line in has been 117-124V. Pretty steady around 118-120. No line errors.


Land of 10,000 Lakes
2016 Forester MBS 2401R

These are good voltage numbers, but are they taken under load? The meaningful number is the voltage under load. A long, or under sized extension cord will provide good readings with no load but the added resistance under load will pull the voltage down, and the amps up.

[tomrob1161]

In follow-up to my earlier post, here is a list showing typical AMP draws for an RV.

Microwave 12.8 amps
Air Conditioner - 15,000 BTU 12.5 amps
Electric Water Heater – 6 gallon 12.5 amps
Toaster 10 amps
Hair Dryer 10 amps
Electric Frying Pan 10 amps
Electric Coffee Pot 10 amps
TV 2 amps
Crock Pot 1.5 amps
Heating Pad .5 amps

[philobeddoe]

Just to add to this....my 5'er is 30 amp service. I've fought power issues during the heat of summer as well. With 30 amp service, you certainly have to manage your power usage. I bought a 30ft open ended 50 amp power cord and put a 30 amp female plug w/weather boot on it to mate to the trailer. Since then, I've also started running both the frig and water htr on propane. At this point, I think I've conquered the 30 amp blues.

[Mrpsyko]

Could still be breaker on pedestal being week. Even second pedestal could be weak. See if cg will replace breaker.

[MNtraveler]

Originally Posted by CedarCreekWoody

These are good voltage numbers, but are they taken under load? The meaningful number is the voltage under load. A long, or under sized extension cord will provide good readings with no load but the added resistance under load will pull the voltage down, and the amps up.

Yes, those were under load.


Land of 10,000 Lakes
2016 Forester MBS 2401R

[MNtraveler]

Originally Posted by tomrob1161

In follow-up to my earlier post, here is a list showing typical AMP draws for an RV.

Microwave 12.8 amps
Air Conditioner - 15,000 BTU 12.5 amps
Electric Water Heater – 6 gallon 12.5 amps
Toaster 10 amps
Hair Dryer 10 amps
Electric Frying Pan 10 amps
Electric Coffee Pot 10 amps
TV 2 amps
Crock Pot 1.5 amps
Heating Pad .5 amps

Thanks. This does not include the refrigerator which is a big draw (but in and off so you might miss it when taking readings) or the converter (charger) which is usually a small but continuous draw.




Land of 10,000 Lakes
2016 Forester MBS 2401R

[MNtraveler]

Thanks all for the help and suggestions. I'm pretty sure it was the extension cord plus the combination of things that were on together.

Later in the trip we needed the heat pump at night and even with extension cords either 50' or 100' in total line (yup) I had no problem with it as long as I turned off the hot water heater. Refrig on but not working too hard in cold nights (down to 45) and converter on.


Land of 10,000 Lakes
2016 Forester MBS 2401R

[itat]

Would a hard start capacitor on the AC help reduce the amp draw from the AC on start up and therefore the voltage drop? I've had the low voltage problem at a local Provincial Park. The pedestal only had about 110 to 111 volts.

[Mark S.]

A total length of 50 feet is all you can do for 30 amps on a #10 wire at 120 volts. Get the free app from Southwire and that will help answer a lot of questions the next time you think it's your cords. southwire voltage drop calculator

[MNtraveler]

Have run that calculator and with 100' of wire, the voltage drop is about 5%. It's not the voltage from what I can tell, it's that the amps go up to compensate to achieve the needed wattage. The voltage was not tripping the breakers, the amps were. Comments/feedback?




Land of 10,000 Lakes
2016 Forester MBS 2401R

[Herk7769]

Originally Posted by MNtraveler

Have run that calculator and with 100' of wire, the voltage drop is about 5%. It's not the voltage from what I can tell, it's that the amps go up to compensate to achieve the needed wattage. The voltage was not tripping the breakers, the amps were. Comments/feedback?

Attachment 113215


Land of 10,000 Lakes
2016 Forester MBS 2401R

You are 100% correct; low voltage caused high amp draw in inductive loads. There is also a thermal circuit breaker in the compressor motor that will shut down the compressor (but not the fan) when the excessive amps causes the compressor to overheat. The result is poor cooling as the compressor only runs intermittently as it overheats; shuts down; cools off; and restarts.

This can happen with or without breaker issues depending on the tenacity of the breakers and the sensitivity of the thermal overload switch in the compressor.

This can happen

[MNtraveler]

Thanks!


Land of 10,000 Lakes
2016 Forester MBS 2401R