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mlts22's avatar
mlts22
Explorer II
Nov 21, 2013

AC Barely starting to starting on econ mode?

I have a Yamaha 3000 iSE which was dicey to get it to start the 15K BTU Dometic A/C on my rig. I'd make sure the eco throttle (on Yamahas it is called the econ switch... same thing.) I'd toss something in the microwave for 30 seconds, then as soon as the magnetron clicked off, flip the A/C on, and it would catch 90% of the time, and 10%, I'd have to wait 5 minutes, repeat.

I paid a friend of mine to pop the outer housing off, hose it down and take a fin comb to the cooling area, then clean out the inside part. After he did that, I started my generator with econ mode on... forgot that I had the thermostat set to fire up the A/C, and it pops right on without causing the generator to bog down. Just for kicks, I let it sit for a week, and the same thing. No bogging down whatsoever. To make sure, I verified the compressor was on and running, and the inside fan was on auto as normal.

Is this just something weird, or did cleaning out the coils cause the compressor to not need as many locked rotor amps, especially at a full head pressure after a stop and restart?

2 Replies

  • j-d's avatar
    j-d
    Explorer II
    Chris Bryant's A/C Tuneup is good for all of us to do. It's made huge performance improvements on the two RV A/C's we've had.
    That said, I can see where having the unit clean would reduce its operating temperature and make starting easier once the system was warmed up and cycling. I don't understand how it would help with the first startup of the day, unless the blower motor was balky and started easier after oiling. Other than cleaning, oiling the blower motor's about all the maintenance there is on those.
    Some of the OPs here have added a compressor start delay to their rooftop A/C units. The idea is to let the blower get going and stabilize on Run Amps vs. Start Amps THEN let the compressor go for Start Amps. That would reduce total Amp demand on startup.