AC won't work with Generator

[rubicon327]

Originally Posted by Jubal

Rv Surge Protection | United States | Progressive Industries, Inc. | Disclaimer

Originally Posted by davescape

The EMS was not designed to function with generators and while it plays nice with Honda, it does not play nice with Yamaha. Not sure why, its just that way. Its not an issue of quality.

Originally Posted by wetzk

Edit, went back and looked at the first post again. The Yamaha EF2000iS if that is what you have will not run your air conditioner without the expensive soft start kit and may not even then. Check around and you will find post after post complaining about that on other forums. The Honda will, it has surge capacity, mine does too. The older small Yamaha does not. The newer version the EF2000iSv2 may but I know the first version did not work. We had one and traded in for the larger unit due to the same issue.

I think a few people may have missed the link in Jubal’s post. Progressive Industries explains the problem specific to the generator in question which agrees with what davescape and wetzk have said.

[rubicon327]

Originally Posted by yardsale

That's interesting. Nothing for me to do then? I suppose the soft start capacitor wouldn;t help either.

It’s only a 9200 BTU A/C. Can you try putting the EMS in bypass? This disables all functions except the surge protection. This way the EMS won’t freak out with the few seconds of non-true sine wave power and the A/C will then settle in with lower running amps. A soft start capacitor certainly can’t hurt either.

There are debates about needing the EMS or not with a generator anyway. A generator is much more reliable than campground power regarding high/low voltage, etc. Many trailers don’t even have an EMS.

[davescape]

Originally Posted by rubicon327

It’s only a 9200 BTU A/C. Can you try putting the EMS in bypass? This disables all functions except the surge protection. This way the EMS won’t freak out with the few seconds of non-true sine wave power and the A/C will then settle in with lower running amps. A soft start capacitor certainly can’t hurt either.

There are debates about needing the EMS or not with a generator anyway. A generator is much more reliable than campground power regarding high/low voltage, etc. Many trailers don’t even have an EMS.

The problem with bypass mode is that it disables low voltage protection but does not disable high voltage protection. The EMS interprets that particular Yamaha power as too high and locks it out. That's my carpenter brain talking. While I can wire a lamp, I'll leave the sine wave talk to others. I suppose you could bypass the EMS entirely with some sort of transfer switch at the panel or trade your Yamaha in for a Honda. That's what I did. I think a larger Yamaha would be fine too. 2000 watts is pushing the limits. Propane probably doesn't help either.

[padlin]

Don't know how much you know about it but the part of the EMS that has the display is just that, a display panel, the real unit is a black box inline with the incoming power wires. See if that is what is clicking, which is what it's internal relay can do if it's dirty or there is a power problem. Like Rubicon suggests, you can try it with the EMS turned off, then you'l know if that's the source of the chatter.

[mpupeza]

This subject has been beaten up pretty well in the Fiberglass RV forum over the last several years and the consensus, and my personal experience, is to install the Micro-Air EasyStart 364 for $300 or just the board EasyStart 366 for $158 (provide your own Start Capacitor and mount inside along one wall - which I did). Also, request the discount which 'was' available for the FiberglassRV and Casita Crowd.
My 13.5K BTU Dometic Briskaire now starts and runs fine with myHonda EU2000i which is well over 10 years old. The board also dampens the bang, or heavy thump, when starting up on shore power too, making it more pleasant while snoozing or relaxing. I've never regretted it and was disappointed to wait so long until this magic box came along. You won't be sorry.
Mike .....>

[wetzk]

Originally Posted by rubicon327

I think a few people may have missed the link in Jubal’s post. Progressive Industries explains the problem specific to the generator in question which agrees with what davescape and wetzk have said.

The tent camper I had back in 2012 did not have EMS but it did have a small Coleman air conditioner. We were concerned about the noise the generator was making at start up when we tried it. So I checked startup and run amps and volts. The voltage was dropping below 100 volts, amps drawn was to quick to check as I did not have a working hold button on the ammeter but went over 20 amps per the needle swing. Amps during run were over 12 amps and voltage was around 106 if I remember correctly. The overload light was flickering and the unit was loud. Since the run voltage was barely above the allowed voltage in cool weather and start was below it a hard start kit or a soft start kit would not have worked. I traded the just purchased unit in on the larger one that was advertised as being able to start a 13.5K BTU as I did not want the two generator kit. I did not look at the small Honda at that time as I felt it would be barely better than the Yamaha.

I would consider the new Honda 2200 watt if I were buying a generator as it is significantly lighter, cost less and has a fuel pump so it would be easier to add an auxiliary fuel tank. And like the Yamaha is a reliable unit But I would need to verify it does not draw voltage down to low during startup. The one I have now just makes a momentary increase in engine noise as the air conditioner starts and voltage never drops below 114 volts.


Edit, back then I did not know about soft start kits or EMS, I just knew that generator was not enough to run the air conditioner without possible damage.

[steve dunham]

The general trade rule for sizing generators is take the FLA of the largest load x 2 and the other loads at 100%
A/C = 10 FLA
10 amps x 2 = 20 amps
20 amps x 120 VAC = 2400 Watts
A 2400 or 2500 watt generator will start the A/C without creating a low voltage condition
A 2000 watt generator’s voltage will normally drop below 110 VAC when starting a 10 amp A/C
Just my experience from Y2K

[yardsale]

Thank you everyone for many helpful responses. Collectively you have offered several options for me to consider.

[yardsale]

Originally Posted by steve dunham

The general trade rule for sizing generators is take the FLA of the largest load x 2 and the other loads at 100%
A/C = 10 FLA
10 amps x 2 = 20 amps
20 amps x 120 VAC = 2400 Watts
A 2400 or 2500 watt generator will start the A/C without creating a low voltage condition
A 2000 watt generator’s voltage will normally drop below 110 VAC when starting a 10 amp A/C
Just my experience from Y2K

Steve, do you think the unit (https://www.microair.net/products/ea...nt=30176048267) Rbryan4 is suggesting can overcome the voltage drop you describe? How about a soft start capacitor?

[DenverRTC]

I believe if you check the power requirements you'll find that the compressor needs about 3,000 real watts to start. That means a generator of at least 3,500 watts.

[rbryan4]

Originally Posted by DenverRTC

I believe if you check the power requirements you'll find that the compressor needs about 3,000 real watts to start. That means a generator of at least 3,500 watts.

If that is so, then the thousands of people who run their AC with a 2000 watt generator will be a bit surprised. Altitude also plays a big part in that. We can run our AC easily with a Honda eu2000i at sea level. Not so in Cortez CO at my uncle's place.

[Moaboy]

“I’ll say” on the weight issue. I just sold my Honda Handi 3000, which I really liked, but as I got older it got heavier. Gonna buy the new Honda 2200.

Does anybody know the amp draw on the “low” setting compared to the “high” setting on the 11.5 BTU AC ?

[rubicon327]

Originally Posted by davescape

The problem with bypass mode is that it disables low voltage protection but does not disable high voltage protection. The EMS interprets that particular Yamaha power as too high and locks it out.

I'm not sure I understand this. When the EMS is in bypass mode all of the protections are disabled, except for surge protection.

[wetzk]

Originally Posted by Moaboy

“I’ll say” on the weight issue. I just sold my Honda Handi 3000, which I really liked, but as I got older it got heavier. Gonna buy the new Honda 2200.

Does anybody know the amp draw on the “low” setting compared to the “high” setting on the 11.5 BTU AC ?

Since you look to be over 4000 feet could you give a review on how it works during the hot summer months. I'd love to replace my Yamaha as it is a chore to move around. Also, did they need to rejet it for where you live?

[Iowan]

Have you tried plugging the A/C directly into the generator to rule out any other draw. If you use an extension cord be sure it is heavy and as short as possible. Just a thought.

[JohnFromABQ]

Originally Posted by wetzk

Since you look to be over 4000 feet could you give a review on how it works during the hot summer months. I'd love to replace my Yamaha as it is a chore to move around. Also, did they need to rejet it for where you live?

I just bought a Honda 2200i a couple of months ago. I live at about 5800 feet and have no problems with it on our 18' with AC. To make the EMS happy, I did have to do the ground/neutral bonding workaround, but that was it. I have even run it on ECO mode, but not for long periods of time or with a significant other load.

[TAfraser]

I own the Yamaha 2400 and have always used it to power the air-conditioner in our 21'. I have the EMS installed, but have to put it in bypass for generstor operation. Mine will not work unless it's in bypass, so I labeled the bypass switch as GEN. One less thing to re-learn every year.