Generator issue

[blizzardplowman]

OK, so due to lack of funds I ordered our toy hauler without a generator, but did pay for the gen prep package. Last year the toy fund was a little flush so I could spring for a 3600 watt, gas powered generac quite pac unit, only used it about 6 hours last season but did run it 15/20 minutes a month until storage time.

I got it out this Spring, checked the oil and added fresh gas to the tank and it fired on the second try, used it about 1/2 hour or so to top off the battery's on my spring trip (April) and just ran it once in Mid May. Went to run it tonight and thought, hey its hot lets give it a good run and use the AC in the trailer for 1/2 hour or so.

That's when my issue showed up, unit runs fine, powers up and gives me 124/125 volts, ran just the TV,lights, and fan for 10 minutes then turned on the air, worked great for 10 minutes, the bam no AC, and white ish smoke out of the exhaust along with a lugging sound from the motor....WTF? Shut everything down, re hooked up to shore power, ran the AC for 1/2 hour with no issue, humm. So I unhooked, restarted the genny and went all over again, TV/dish,all the lights (charger was on also) and the fan, 15 minutes, 123.8 volts nothing abnormal, on with the AC (123.2V), 15 minutes and all is well, ha must have been a fluke, good I'm ready for the 4Th. Went outside for one more walk around and bam, heard the AC cut out, motor lug, white smoke and the burnt rubber smell. Shut the genny off, plugged into shore power and the AC came right back on.
I am puzzled to say the least, any ideas? Unit has 7.8 hours, gas is from April 10Th, has seafoam in the tank and my quads and lawn mower run just fine on it, got most of it used out of the tank so I can put fresh in for the trip. The tank is my fuel station and has a pickup for the genny.

TIA
Bliz

 

[Cowracer]

Possibly, just thinking...

Maybe you A/C compressor cycled off, and started back up under pressure and the genny didnt have enought oomph to start it. Is that 3600 watt peak power or continous?

Tim

 

[Acesneights1]

What size a/c are you trying to run. Generac is not exactly top of the line compared to Onan. That said I'm not knocking it but a comparable Onan will usually take more abuse so if you are specing a genset I would go a size bigger than you need. A 3600 Generac would probably barely power a 9000 btu coleman powersaver . Most Rv's have the 13,000 btu units which your generac will not run. You need to find out which A/C unit you have then compare peak power demand to what the genset can put out. I can tell you this, in my Travco I had a 9000 Polar cub and a 4,000 watt Onan CK series(which were damn good) and it struggled when the a/c unit tried to kick back on. Another possiblty would be a fried startup cap on the a/c compressor but if it's running fine on shore power I doubt it. I think you undersized your genset and you are tripping the tthermal breaker.

 

[blizzardplowman]

30 amp cont, 33 surge is spec, my total draw is well under that.

 

[cwq21]

Was the white smoke coming out of the exhaust?

If it's out of the exhaust, you blowing pressure into the crankcase under a load.

What type engine on the generator? Briggs?

If so, it could possibly be a head gasket (most likely) or maybe valve cover (unlikely). I know this may sound off the wall but I had a small engine business for years and have seen issues like this before on these engines. Even new ones. If you can get to the head bolts, you can try to just re-torque them and it may help.

Edit: re-read your post, try re-tourquing the head or replacing the head gasket.

 

[Acesneights1]

OK It's been awhile and I had to call the big Kahuna(My 76 yr old father)
I forgot that that was with 220 volts.
The formula is watts/Volts=amps.
My Bad
If it were a 220 genset then amps would be too low.
120 you should be fine. I just remember our 4000 watt struggling with the a/c

 

[blizzardplowman]

Ok, like I said, unit runs fine under load for about 20 minutes, then you can hear it load up, and see it produce white smoke, it will contine until I shut it off too. I got a call into the store I bought it from, hope they have an answer.....

 

[Cowracer]

30 amp cont, 33 surge is spec, my total draw is well under that.

Perhaps not. Most A/C induction motors draw their max amps at zero speed, that is called Lock-rotor amps, and it can be 400% of normal full load amps (FLA) An RV roof AC can draw 100-150 amps (breifly) on start up till the motor comes up to speed.

Most A/C compressor motors do not have enough oomph to start a compresor that is pressurized. Thats why they put a time delay in the compressor start circuit, so that the pressure has time to bleed off before a restart.

If you have a failure in your A/C unit, and its trying to restart on a pressurized compressor, it will not be to, and will draw an ungodly amount of current because the compressor motor is at locked-rotor condition.

watch your a/c unit closely and run the genset. if it starts acting up, immediatly shut down the A/C. If the genset straightens out, you may want to look at the A/C further...

Chances are, thats not the problem, but at least you can eliminate it very easily.

Tim

 

[GMCYA]

That must be the qp40g that you have. We have those on our emergency response trailers. It should have no problems running one AC and other small accessories. It is a heck of a unit for the price, we put them through the paces regularly. If it were a problem with the load it would trip the breaker fairly quickly. If it were an AC issue the breaker in the TH would trip also. That genset will hold 30 amps all day long. I don't think you have a load issue being the AC runs fine on shore power because either way it still uses the same breaker. Sounds like an issue with motor itself, Charlie is on the right track. They come with a 3 year warranty that covers everything. Just look up your local service provider and make sure you have the receipt, they will fix you up. Let us know what you find.

 

[blizzardplowman]

Well, its looking like it might be fuel related, I added 5 gal to the tank tonight and while it burped a few times it never quit and ran almost 2 hours. I plan on changing the oil and draining the fuel tank this weekend, hope that what it is. Simple is good. Thanks for the help and I will post back how it works out.

 

[blizzardplowman]

Well, so far so good, fresh fuel, new filiter and a oil change and all seems fine. Will use the shit out of this coming trip and I guess time will tell. If not The service DPt will be getting a large package dropprd off for them to fix LOL.

 

[Joey D]

You should be using stabil fuel treatment in the tank all the time on anything that sits. I use the blue marine version.

 

[blizzardplowman]

But it really don't sit, I fuel the Atv's and the lawn mower out of the tank just to avoid issues. It will sit over winter, but nothing I can do about that. As far a stabil products, I have never had any luck with them, that why I switched to seafoam.

 

[Acesneights1]

Hey never forgot about this thread but FWIW I rented a Honda EU3000 and it can barely run my a/c in my camper. I my father about it. He was an Authorized installer and service center for Coleman and Duotherm. If anybody has an old owner's manual he is listed as the dealer in NY. anyway he has had a stroke, heart attack diabietes etc so he has good days where he actually remembers alot and bad days where I might as well ask my 3 yr old. Today was a good day. He went into a big thing about elec theory which went over my head but basically he said in the 70's basically a 9000 btu a/c needed a 4000 watt genset to run comfortably and a 6k for 13,500 and above .That was the spec when he did the installs.Granted the older units used more juice on start up. It sounds like your problem was engine related but he said also the capacitor on the compressor could cause startup issues.Of course in those days Onan CCK series was pretty much it. Saw some Kohlers here and there but Onan was it. I still have a 4k cck.40 yrs old original and starts and works great.IFWIW I never had any luck with stabil either. We use it at work on the trash pumps and snow blowers and the gas still goes rotten. Gas nowadays sucks.

 

[blizzardplowman]

Knock wood, been working great. I changed the fuel filter and have swapped out the gas 2x now. Must of had water in the fuel. Thanks for all the help guys!

 

[Ozzie]

Hey never forgot about this thread but FWIW I rented a Honda EU3000 and it can barely run my a/c in my camper. I my father about it. He was an Authorized installer and service center for Coleman and Duotherm. If anybody has an old owner's manual he is listed as the dealer in NY. anyway he has had a stroke, heart attack diabietes etc so he has good days where he actually remembers alot and bad days where I might as well ask my 3 yr old. Today was a good day. He went into a big thing about elec theory which went over my head but basically he said in the 70's basically a 9000 btu a/c needed a 4000 watt genset to run comfortably and a 6k for 13,500 and above .That was the spec when he did the installs.Granted the older units used more juice on start up. It sounds like your problem was engine related but he said also the capacitor on the compressor could cause startup issues.Of course in those days Onan CCK series was pretty much it. Saw some Kohlers here and there but Onan was it. I still have a 4k cck.40 yrs old original and starts and works great.IFWIW I never had any luck with stabil either. We use it at work on the trash pumps and snow blowers and the gas still goes rotten. Gas nowadays sucks.

This hard start issue is related to the unit storing heat and producing a high compressor surge when it kicks in again. I was just going through this with my buddie last weekend and found an interesting read about it:

http://www.modmyrv.com/2009/05/27/rv-air-conditioner-hard-start-capacitor

 

[Acesneights1]

wow. That is a good site. Thanks.