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AirCondition Issue...Help!


rbertalotto

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Here is my sey up:

(2) Honda 2000 Generators with parrell kit

Progressive Industries EMS-HW30C with Remote display

Dometic 457915.701 AC unit / 13,500 btu / 1/5HP, 20amp min cir

Supco Hard Start Capacitor SPP6 in AC unit.

 

I installed the hard start capacitor at home in 80 degree temperature last week. Tested the AC with one generator and it started with Honda NOT in eco boost mode....running full tilt. AC started fine. Would not start with generator in eco boost mode.

 

This weekend I'm camping in 90 degree, extreme high humidity weather. Both generators hooked up.

 

AC will not start if both generators are on eco boost. If I run them both full tilt, the AC starts fine. Then I can return the generators to eco boost and it will run fine until they cycle the compressor off, Once it tries to start again, the PI-EMS unit trips and the compressor never comes back on until I go outside and shut off eco boost.

 

If I deactivate the EMS, then the AC will function with both generators on eco boost.

 

Does humidity have any effect on the starting requirements of an AC unit?

 

Anyone have a similar setup they can report on?

 

Thanks in advance!

 

 

 

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Altitude is also a factor in generator performance. Having a recent bad A/C experience another factor is compressor age/wear. Our current unit was bought used it was stored under cover in FL the last 2 years. They ran the A/C, fridge, & furnace 24/7/365. As a result the A/C started drawing excessive current (tripping the breaker) a month into our current trip. There may be a combination of reasons.

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Probably what is going on is that when in eco mode the generators are not able to keep up with demand when the A/C unit starts. Motors pull up to about three times their running amps to start. When the power drops due to the unit starting the EMS senses a low voltage situation and shuts things down. In other words it is doing what ti is supposed to do.

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In Eco mode, the generators do not respond to the load fast enough and the voltage will sag or drop to the point that the compressor will not start and/or the EMS will will drop you off. The A/C starting can draw up to SIX time the running amps, not just three times.

 

The only real solution is to run the generators with the Eco n=mode off. The other solution is to get a larger generator(s). If the weather is not too warm, I can sometimes get the A/C to start in Eco mode if I put the fan on continuous run.

 

I have the same set up as you and I have to run the generator "full-tilt" to have A/C.

 

Ken

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In Eco mode, the generators do not respond to the load fast enough and the voltage will sag or drop to the point that the compressor will not start and/or the EMS will will drop you off. The A/C starting can draw up to SIX time the running amps, not just three times.

Exactly what I would have responded. The Honda folks know that this can happen an that is the reason Eco mode is optional.

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It's mostly just physics & electronics I believe. As the temperature increases so does the system pressure in the cooling circuit, therefore you need a little more power to start the compressor while at the same time, the motor is a little less efficient as temperature increases and also needs more power. If you are on the cusp for starting power that would explain it. First thing I'd try is a shorter and heavier gauge extension cord from the generators to the coach.

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At home, connected to a 50 foot 12g extension cord on a 20amp circuit, with a metered 117v, the AC starts fine.



Right now, 88.9 degrees outside in the sun and 92% humidity, the PI is showing 125V / 15A / 60hZ....... With the two generators on non ECO or ECO mode and the AC running at "coldest" setting.


Back when I owned a chain of stores, I was always told by my HVAC contractor that heat and humidity had an effect on the operation of my dozens of roof top AC units. That is why I asked is it had an effect on these RV units.


Thanks for all the feedback. Guess in these conditions "ECO OFF" and I'm "GOOD TO GO"...

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Elevation has an effect, for sure. When I ran my 100 amp charge section (of the inverter) off my single Honda 2000 it would work at elevations below 2000', but above that.....nada. Of course, it also had to do with the state of the battery bank, but mostly it started maxed out....

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Exactly! Altitude will play a small part, but you really don't want to be running eco-mode while running in parallel. They aren't built for that. While the Honda's "allow" it.. the Yamaha's and others disable eco when in parallel. Let them dial up/down as needed.The sync technology limits output and response times (ie., 16.7amps full on per single only equals 29amps in parallel) so that you will actually get a brown out on a heavy load startup if you do. Your EMS is going to read that as a low voltage situation and shut you down. If your 13.5k is your only heavy load then you are better off (power output and fuel consumption wise) to just run a single. You already have your SPP6 in so you you're good to go on that front.

 

I have a near identical setup. 13.5k, SPP6, PI-EMS, 2x2000 Yamaha's. The only time I run in parallel is for fast charging or running A/C while planning on additional heavy loads (charging, WH, etc.)

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When the A/C starts, the pressure in the system is equalized across the compressor. The RV systems use a capillary tube feed for the evaporator and not an expansion valve and solenoid, thus the pressure will equalize when the compressor is off. With the pressure equalized, the motor is not starting against any additional load. This is why the units are held off line for about 3 minutes before they are allowed to restart. If you tried to start before the pressures equalize, the motor will have a hard time starting and may trip the breaker or trip the thermal limit on the compressor motor.

 

In higher ambients, the biggest difference will be the running amps as the compressor discharge pressure will be higher and the motor has to work harder to pump to the higher pressures.

 

Hopefully this will give some insight to the issues.

 

Ken

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I agree with Iceman. Even though the compressor is starting with little load due to the mentioned refrigerant equalizing , it still draws too much current far too fast on start up for the Honda gen to react to in eco mode. You will need to run the hondas in regular mode for air conditioning.

 

I never use ems on a gen.... just shore power.

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Thanks for all the feedback. Guess in these conditions "ECO OFF" and I'm "GOOD TO GO"...

I'd be willing to bet that if you could talk to the Honda design folks, that is exactly what they would tell you. It is the very reason that "ECO OFF" was put in the controls. Basically, the ECO mode is to allow you better fuel efficiency but with it off you still have the same generator, just with fewer limitations and slightly less efficiency.

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rb " Guess in these conditions "ECO OFF" and I'm "GOOD TO GO"...

 

I also guess the same. In the softer gentler lol ECO mode in lower current conditions she runs quieter and consumes less fuel BY ENGINEERED DESIGN but when a motor starts it can, subject to load, design and start methods, momentarily draw as much as six times the normal run current which simply isn't available (again by design) in ECO. The problem is if there's insufficient available energy at start up, the voltage can drop and current demand increase WHICH IS A DOUBLE WHAMMY as far as what the genset can provide. If ECO OFF don't cure your problem take two aspirins and call me Monday at the office lol

 

John T

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So now I'm at a "real" RV park and connected to a 30A service. No issues with AC working through PI. Obviously the little Hondas can't carry the load in ECO mode.

 

But under the "Always Something" title......now my WeBOOST stopped working. I traced it down to a bad 12V to 6V power supply that is included with the WeBOOST. Took it apart to see if it was something I could fix in the field. Nope...Blown up capacitor!

 

WeBoostPowerSupply1-vi.jpg

 

I work out of this trailer and need internet access. Thankfully I have my ALFA WiFi booster and there is lots of free Xfinity, high speed WiFi available. Super fast up and down. I tried the RV Park's as advertised "Fast WiFi"........I guess "fast" is a relative thing! :wacko:

 

I sent an email to WeBOOST to see if I can simply buy a generic 6V / 2.5a adapter to use. Waiting to hear back.

 

Thanks for all the help on the AC issue. Greatly appreciated!

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I had 2 Honda Eu2000i's & a GenTran connection kit with a 30A breaker & outlet. Coleman 13500 AC.

Had no problem using the "eco" on both- they would self-adjust as the compressor kicked in and then slow down after startup. Could get up to 10 or 11 hours before reflueling.

I assumed this was normal operation but maybe not.

Ron

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Ron, congrats on how your system functions satisfactorily. The thing is (for rb) when you are operating near the limits of a genset, little simple things such as how long any extension cords may be and their ampacity (10, 12, 14 Gauge??), line voltage drop, the integrity/tightness and conductivity of plugs and receptacles, carbon build up on contacts etc. etc. I'm one of those guys who regularly clean and shine the blades on all my plugs and use 20 amp receptacles versus only 15 and adequate sized cords, but we aren't in charge of maintaining the parks distribution hardware which is often worn, loose, carboned and maybe inadequate in the first place for todays energy hungry mega RV's.

 

John T A "low energy use" kinda guy

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