ongoing generator issue

[Glenn_And_Kitty]

I had some problems with my generator but just had a new control panel and interface installed by a certified dealer. It is now running fine but it trips when my RV A/C compressor kicks on. Gen shop is closed for a few days so maybe I can get some advice here. Please allow me to explain:
I have a Yamaha EF6300ISDE gen. Specs say it is rated for 5500 watts and I think the 6300 watts is for surge or start up. Amp rating is 45.8/52.6 amps when running on 120 volts.
RV A/C is a 13,500 BTU that should be drawing about 14.5 amps on start up and about 2700 to 2900 watts on start up.
Here is the problem:
I turn off everything in RV. Start up gen and run full throttle (about 3450 RPM), I go in and turn on A/C. Fan comes on and gen barley does anything. The A/C compressor kicks on, there is a big surge on gen, and I note a large drop in voltage on a meter I have inside RV. Generator continues to run but power trips and no power is being generated. There is zero voltage on RV meter and no lights on Gen. It does not show overload on gen but no power is being generated and motor runs back at 3450 RPMs.
I turn off A/C control so there is once again nothing on in RV. I shut down gen for maybe 30 seconds, start it back up and power is restored and available. I repeat turning on A/C, fan comes on (no problem), then compressor comes on, gen surges, and then power trips/fails again.
I tried turning gen to Eco mode and same result. I also tried not turning on A/C and turning on microwave and some other electronics. gen surges a bit but power stays on. Gen power only fails when RV A/C compressor comes on.
Gen should have more than enough capacity to start/run A/C. I don't have any load testing meters but with gen just coming out of dealer repair shop it should be in top notch condition.
Could my single A/C unit, which is on a 2019 Coleman TT, be drawing more than what is considered normal? Even at that it seems that my gen is rated well above what is needed for a 13,500 BTU A/C and probably should be able to run a 15,000 BTU unit.
Anyone have any idea what is going on. I'm in Louisiana so altitude is not an issue. It was 90 degrees plus degrees today with high humidity. Could that be an issue?
Does anyone think I have an A/C issue for an RV dealer to look at or do I have a gen issue and I should take it back to gen repair shop?
Glenn

[cptqueeg]

I enjoyed the helpfulness and collegiality in the thread and the clear responses and persistence of the OP. Glad you found the cause and I learned something as well. Well done mikestock!

[jjrbus]

Thanks for telling us what happened. The issue I run into is when I learn something like this, by the time I need the info again I have forgotten it. LOL
\

[jjrbus]

Ron3rd wrote:

jjrbus wrote:
5500 watts should start a 13.5k AC with ease and 6300 surge is waaaaay overkill. The info I have from Duotherm specs a 3500 watt generator for a 13.5. I would suspect another problem.

Any inexpensive watt meter will not do you any good as they are not fast enough to measure LRA, locked rotar amps. Which is starting amps when the compressor first kicks on, lasts only a micro second. Is there another RV around you could hook up to and try and start their AC or can use their gen to try and run your AC, that might isolate the issue or hook up to shore power to test AC.

My best guess is the start capacitor on the AC is going bad, my way of dealing with it, not having the proper tools to test is to replace the start capacitor. Does not take an electrical degree and should be $20 or less, if it is not the issue, you have a spare capacitor. Google or you tube replace RV AC start capacitor.

Disclaimer, I am not an electronics guy, just another RV'er trying to get by.

Fwiw my daughter's 3400 watt Champion genny runs her 13.5 AC with ease

I can run a 13.5 roof air with my Honda 2000. Only under certain conditions and not dependably! I suspect doing it regularly would damage one or the other.

[Ron3rd]

jjrbus wrote:
5500 watts should start a 13.5k AC with ease and 6300 surge is waaaaay overkill. The info I have from Duotherm specs a 3500 watt generator for a 13.5. I would suspect another problem.

Any inexpensive watt meter will not do you any good as they are not fast enough to measure LRA, locked rotar amps. Which is starting amps when the compressor first kicks on, lasts only a micro second. Is there another RV around you could hook up to and try and start their AC or can use their gen to try and run your AC, that might isolate the issue or hook up to shore power to test AC.

My best guess is the start capacitor on the AC is going bad, my way of dealing with it, not having the proper tools to test is to replace the start capacitor. Does not take an electrical degree and should be $20 or less, if it is not the issue, you have a spare capacitor. Google or you tube replace RV AC start capacitor.

Disclaimer, I am not an electronics guy, just another RV'er trying to get by.

Fwiw my daughter's 3400 watt Champion genny runs her 13.5 AC with ease

[enblethen]

Thanks for the update

[MEXICOWANDERER]

NEVER EVER SWITCH UNDER LOAD
It reconfigures the 6 wire hookup from delta to ZZ.

[Glenn_And_Kitty]

Found the problem and gen is fixed. Here is an F.Y.I. - for anyone's future reference:
The Yamaha EF6300isde has a switch that either supplies full current/amps to the 110, twenty amp outlets and the 110 thirty amp outlet when in 120 only mode. It "splits" power, when it is moved to the 120/240 mode, between those outlets and the 240 volt outlet. The switch was in 120 mode only however some internal corrosion did not allow it to actually switch over. The 110 volt outlets and the 30 amp outlet were only producing about 22 amps. Not enough to start A/C thus the gen went into default. Another switch was not readily available so I took out the one in the gen, cleaned and refurbished the switch, tested it, and got constant continuity on either pole. I then re-installed the switch and A/C started up with no problem. In addition, with A/C compressor on, I was able to run microwave and a coffee pot at the same time and still had a little room to spare. With switch operating correctly in the 120 only mode the 20 and 30 amp outlets are capable of producing about 45.8 continuous amps and 52.5 start up amps.
What a learning experience for me. I hope this explanation will assist someone else in the future.
Rock N Roll

[dougrainer]

What you really need, is, to have a AMP draw readout AT the Compressor when the compressor tries to start. THAT will tell you if you have a compressor that is starting/is failing. The fact you stated that on CG 30 amp it would trip on rare occasions-----Remember, the AC unit is ON a 20 amp CB in the RV. So, IF the AC is pulling in excess of 20 amps, THAT 20 amp breaker should trip first, not the 30 amp CG breaker. NOW, IF you trip a 30 amp CG breaker, that points to YOUR RV pulling in excess of 30 amps, which is usually the case when you have the WH on 120(11 amps)and the refer on 120(2.5 amps), then the start load of the compressor(14 to 16 amps) and then the Fan motor (1.6 to 2.0 amps). Have you tried using your Genset on a fellow RV'ers unit to see what happens? Doug

[K_and_I]

I know you said the water heater is off, but I would check it again. It really sounds like too great of a load on the generator.

[mikestock]

If you have a 240 volt generator it is only sending half the power to a single 30 amp receptacle, unless it has a switch to allow all power to go to one side. Even with that, it should start the ac.

Since you have installed the hard start capacitor I would think the problem is with the ac unit. I think you said the ac trips on shore power occasionally.

I ran into a similar problem with a fellow tailgater. I can't remember the ac brand but it was a 13,500 BTU on a brand new trailer and tripped his EU3000IS generator. We tried my EU3000IS and same thing. My generator easily ran my 15,000 unit with lights and tv running.

He ended up having the air conditioner replaced and all was solved.

[jjrbus]

In my bumbling electrical diagnostics, I would have done about what you are doing. At this point with the AC working well on shore power there is a remote possibility of a fluke in the wiring, BTDT but rare.

It should be the generator, a micro air may mask the issue but it not the cure. There is no re4ason your generator should not start your AC, it waaaaay more generator than needed.


A weak or defective breaker on the genny was mentioned, that would be my next guess. Or the generator has to go back to the shop. I would want to hook up the genny to a heavy load to test, preferably another 13.5 AC. A long shot would be a intermittent short or some other defect in the AC, that is absolute worse case scenario and a nightmare. Good luck

[byronlj]

The 30amp breaker on the generator could be weak causing it to trip before the compressor winds up. Try the 2 1500w heaters as stated and turn them on simultaneously with a switch, like a good power strip. See if that breaker pops on the generator.

[Lynnmor]

Gather up a couple of 1500 watt electric heaters and see if the generator will power them.

[Glenn_And_Kitty]

Another update:
I purchased a replacement capacitor and installed it. No help. Ran gen at full throttle, plug in RV, nothing else on in RV (hot water heater does run on electric or gas but it is off completely). Turn on A/C, fan comes on, no change in gen or very slight, compressor kicks on, gen revs up and loses all power, gen motor then slow down to normal full throttle mode but is not generating any power. I unplug RV from gen, shut gen down for about 30 seconds, start gen back up, and it is generating power again.
I plugged my RV back into 30 amp shore power and A/C works fine. I left the new capacitor on A/C and will keep the old one as a spare. Obviously it is not the A/C capacitor and I'm back to square one.
I guess my two options are one: wait for Micro Air Easy Start 364 to come in and try that or two: take gen back to repair shop and have it tested some more.
Any other suggestions would be greatly appreciated