A/C or generator issue??

[tvantuyl]

John,
It might be good to measure the actual load on your genset before beginning to replace parts. I have added a hard wired TRC surge protector that provides real time load measurements to help manage my AC loads. In my configuration, I like to stay at 80% or below of my genset (3kw) rating. When using our air conditioner on generator power, we normally switch to LP on the hwt and fridge. Hope my musings help you some. Ted
PS. Even have my bride watching the readout to avoid overloads, too. LOL.

 

[K5IP]

John, Harbor Freight sells a clamp on ac ammeter for $17.00. It also a voltmeter.
You might consider getting one of these and get some answers. Item #95683. Not of high quality but good enough for what you need.

 

[Tuesdak]

FWIW,
I have had a similar issue, but i don't get any breakers popped.
My trailer has a built in Generator, and when i start the AC it runs fine for the first cool down. Then when the pump cycles off, then back on it puts a heck of a load on the generator, it bogs down and almost stalls. and does not do this hooked to shore power unless using a 50' extension cord.
mine only does it when it's cycling the compressor back on. might look into it.

Can you add any more load to the generator with the AC on? Thinking the genset is starving for fuel like mine was. (It would randomly go full throttle and not recover with a steady load of AC and hot water heater.) Gummed carb, fuel filter, or bad main propane regulator depending on your fuel. Also check the genset propane regulator vent tube for mud dabbers plugging it up. I use a washer hose screen held on with silicone self adhering tape on the end of my vent tube to keep them out. I replaced the failure prone China main LP regulator with a Made in USA Rego regulator. http://www.propaneproducts.com/prop...tomatic-changeover-regulator-7525b34-737.html

 

[TCollier]

The quick heavy load could be causing the system to lose synchronization for a second and shedding the load. It could be an issue with one generator or the paralleling system itself. Does just one generator have the synchronization module on it? I'm not familiar with those units but I have a lot of time with the bigger stuff with a centralized switchboard. The fast hard loads put the system tuning and finicky engine to the test even when either runs fine under rated load by themselves. If you could get your hands on another generator and swap one out at a time to see if you can duplicate the issue.

 

[AH64ID]

Yeah that's crossed my mind. I will hopefully be ruling that out tonight.

 

[AH64ID]

I did some testing tonight.

With either pair of EU2000i's with ECO mode off then A/C barely makes them change tone when it starts.

With ECO mode off I am not able to get the gen's into overload mode where I was last weekend.

With ECO mode on I am able to get both pair of gen's into either overload mode or the A/C thermal temp switch trips.

The borrowed pair of gen's actually responds to the demand of an air compressor worse than my pair. With the borrowed pair I could hear the small air compressor cause a voltage drop and sputter with ECO mode off but with my pair it doesn't waiver at all.

The ambient temp is cooler today by about 3-4° AND I have the camper parked in its storage spot so it's not heat soaked. In fact it's only 84° in the camper and the windows were open in it all day. So I think the compressor is having an easier time with the lower temp and lack of heat soaking so the LRA aren't being drawn. That being said it still doesn't seem right.

I am still thinking the run capacitor is starting to fail.

 

[B.G. Smith]

Might consider checking all the wiring/connections/breakers you can get to with a non contact Pyrometer. Could be a bad connection somewhere causing high resistance when it runs a while? bg

 

[tvantuyl]

I have one of those temp sensors. Real handy to spot failing circuit breakers and high resistance connections. ah64id has mentioned the problem occurs when on genset and not on commercial power. My bet still goes on genset capacity, though.

 

[AH64ID]

After 6 years, and well over 300 hours, of using this exact combo I am pretty well versed in the capacity of the gens, the gens are not at capacity.

 

[tvantuyl]

I have been following your thread with interest. Do I remember you saying that the problem only happened with the economy mode turned on? I have the eu3000 inverter genset that also has the economy mode. Have not seen the problem happen on it though. Ted

 

[AH64ID]

I was only able to get the issue to reccur yesterday in ECO mode; however, on the previous few days where the trailer was sun soaked it would happen with ECO mode off.

 

[MichaelOverfield]

John,
Consider installing this meter, it tracks your amps/watts/AC volts, and even KWh. It has a loop for current, just goes around the input wire from your shore power to breaker box, then connect to the AC side volts.. This will let you see what is going on with voltage, and current. My A/C has been having some similar issues, and it's inconsistent. I have a Yamaha ES 2400i, it normally will start A/C no problems.. but not always. I've had mine not start on shorepower a couple of times.. I also had it trip the 20A breaker a couple of times, it is not consistent. I may also look at that hard start capacitor, my unit is 2004 vintage, so it has a few years on it at this point. https://smile.amazon.com/gp/product/B014W3D1OC/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

 

[MichaelOverfield]

For $14 I think I'll give this a try, the $299 unit in the video looks nice, but that is pricey for my budget.. from what I read the start capacitor can make a huge difference. https://smile.amazon.com/gp/product..._title_dp_1?ie=UTF8&psc=1&smid=A3QDWM5U2X49ZP

 

[K5IP]

John,
way to go. I have taught engineering classes and always wanted my students to measure, not guess. Also, I teach some very basic electronics to some mid school kid's
as a part of our local ham radio group. As a group we all try to go down to harbor freight and use their free coupons to get the $10 multimeters. We give them away to everyone who completes the class.
I have checked the accuracy of these very inexpensive meters and they are unusually good.

 

[GCroyle]

Can anyone chime in on the function and failure modes of start and or run cap's on these units?

 

[K5IP]

GCroyle,
Not sure about these units, but I just had a failure on my home AC run cap. It was 10 years old.

 

[GCroyle]

My wiring diagram shows it has them, not sure about diagnostics.

 

[AH64ID]

A failed, or not present, start cap will be noticable during start Without a properly operating one the compressor will be slow to start and could cause light dimming even on shore power. A generator may labor quite hard to start a compressor without an operational start cap.

The run cap can cause a hot running motor or a high amp draw, or keep it from running at all.


I am only getting intermittent high amp draw with voltage fluctuations but I do feel my compressor is running hotter than it should be.

John,
Consider installing this meter, it tracks your amps/watts/AC volts, and even KWh. It has a loop for current, just goes around the input wire from your shore power to breaker box, then connect to the AC side volts.. This will let you see what is going on with voltage, and current. My A/C has been having some similar issues, and it's inconsistent. I have a Yamaha ES 2400i, it normally will start A/C no problems.. but not always. I've had mine not start on shorepower a couple of times.. I also had it trip the 20A breaker a couple of times, it is not consistent. I may also look at that hard start capacitor, my unit is 2004 vintage, so it has a few years on it at this point. https://smile.amazon.com/gp/product/B014W3D1OC/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

I ordered one

If you don't have a hard start cap then I would really look into one. They make a world of difference.

I'd even consider just replacing the caps you have. They are cheap and rather important.

I'm headed out not to pull mine and go get replacements tomorrow.

 

[AH64ID]

I picked up the capacitors this morning. $18 for 3 new caps. Even thou I don't suspect an issue with the fan run or the Supco hard start it's too cheap to replace everything.

I am also swapping my Supco SPP6E out for a SPP6. The E works well but I believe that the SPP6 might work better.

I'll get them installed this evening and see what happens.

 

[Tuesdak]

Can anyone chime in on the function and failure modes of start and or run cap's on these units?

I have seen a home unit with a loud buzzing noise from the compressor, compressor not starting, and then tripping the internal thermal protection from a bad cap. Strange noise and not working means turn it off now to prevent further expensive damage and then repair or call tech to repair. Bulging or leaking of the capacitor itself is a visual sign that isn't always present. A voltmeter that has a capacitance checker would indicate if the cap has drifted off it's rated value. HVAC techs do this as part of a system checkup and will replace caps that are way off the rated value with the 20% or so tolerance of the rated value they have new. Shorted or open are also failure modes. More info starts here including a small failure mode section. I find it interesting that a bulging HVAC cap can open itself up electrically as a safety feature to prevent it from exploding. https://en.wikipedia.org/wiki/Motor_capacitor