Mermaid 12,000 btu vs Honda Generator

[Dulcesuenos]

My boat has a Mermaid 12000btu unit, the spec ssheet say it requires 9.4 amps to run, and for start up amperage multiply this by 1.8 equalling 16.92 amps. Our Honda unit puts out 2kw and 16.7 amps. Can attempting to run the ac off our Honda Gen possibly damage the AC or will the breakers protect it? Is there a chance that the honda will run it?

I really wish we had bought the Companion unit with the 23 and 30 amp breaker set up.

[djmarchand]

Try it and see what happens. The instantaneous starting current will be much more than 1.8 times running. I measured my Cruisair which takes 11 amps to run at 38 maximum to start. A Honda EU2000i would not start it.

Dometic makes a Smart Start kit which I think can be adapted to non Dometic A/Cs like the Mermaid. It will cut the peak startup current in half.

David

[S/V Illusion]

Our 16K BTU Mermaid starts and runs fine on our H2000e. If, so any reason, yours will not, all you need do is install a hard start capacitor kit on the A/C and it will definitely work. Easily found with a simple internet search.

[osirissail]

Originally Posted by Dulcesuenos

. . . Our Honda unit puts out 2kw and 16.7 amps. Can attempting to run the ac off our Honda Gen possibly damage the AC or will the breakers protect it? Is there a chance that the honda will run it?. . .

That is the Honda advertised Maximum short time output. The actual output is 13.3 amps continuous and from experience the Honda EU2000i will overload and trip. Also the fuel consumption goes through the roof at that level of load.
- - You can, of course, hook two Honda Eu2000i's together with the parallel cable option and double your available power.

[S/V Alchemy]

I also have the same MMA unit at 12K BTU and while I haven't been able to try this, I have tripped my Honda 2000 with a vigourous attempt to use a circular saw on a particularly knotty log.

Remember that in some installations, you are just kicking off the A/C, but the March pump (115 AC volts) that circulates the sea water.

Therefore, I am going to pop for the companion kit, not just because I want A/C at anchor, but because it's its own backup and I find the things bloody useful around the boat when I don't want to use the inverter (like 10 minutes of power tool).

[Jeff P]

I have a dometic Cruisair 12,000 BTU unit with the Dometic Smart Start installed to spread out the starting load. I was planning on using a Yamaha EF2000i generator to run it at anchor, but ran into a problem. The Yamaha cause the smart start to kick out even though it worked fine under shore power. Further diagnosing revealed that if I bypassed the smart start, the generator would start the AC unit fine under regular power, but not under economy mode (which wasn't surprising). After more testing, I rented a Honda EU2000i and it was able to start, both the AC unit and my battery charger on Economy mode and well as full power mode with what seemed like relative ease.
So even though it may appear the the Yamaha and Honda models would be identical, there are obviously differences in how they invert their power and in this case, the Yamaha will not work with the dometic Smart Start.
Hope that saves someone else the time I put into all this investigation.

[Astral Blue]

If I may make a recommendation... Taking into consideration the total number of watts the AC unit consumes versus the BTU rating is more helpful. If you view 2 AC units with the same BTU rating side by side...and one unit is more efficient than the one next two it, the efficient one will consume a lower number of watts. Efficiency varies a lot between marine units, so this is something to take into consideration.

The Honda EU2000 is capable of handling 1600 watts continuously. Pushing it beyond that will trip the circuit. Your AC should have the consumption in watts stated on it. If not, multiply volts by amps to get watts. Take into consideration the unit will use the most power on startup, so make sure the generator has the capacity to handle considerably higher surges than the continuous watt output. Most marine AC units will not be able to start using the capacity of the EU2000.

[GordMay]

Greetings and welcome aboard the CF, Jeff P.

[Dulcesuenos]

A follow up is our eu2000 will indeed start and run the ac. I am pleased with its performance. upon startup the amp load needle almost hits 20 then comes down to 9 or 10 amps it seems the ac water pump draws over an amp alone.

[Jeff P]

I did choose the 12,000 btu on purpose to make sure I had a cushion to run some other light loads at the same time. The Dometic smart start does reduce the start load to somewhere in the 14 to 16 amp range for less than a second, then about 10 amps.
I just wanted to make sure people knew that the Yamaha will not work with the smart start because of an incompatibility between how Yamaha designed their inverter and how the dometic smart start is designed.
I did spend some time talking to the higher-ups at dometic and maybe they can get together with Yamaha to solve that compatibility issue, but in the mean time, stick with Honda.

[US1Fountain]

A buddy has a 12k CruiserAir and his single Honda 2000 runs his AC fine when 1st turned on, but after a while it trips the gen. He has resigned to just using both of his gen parralled. My Honda 2000 runs my 10K AC, as well as the micro at same time.

Is there a device that would start the AC 1st, long enough for the compressor to start and run, then the water pump come on afterwards?
Seems like that would make all possible power available to start the AC, vs having the water pump come on 1st, drawing a small amount of the power before the AC starts up.

[osirissail]

Originally Posted by US1Fountain

. . . Is there a device that would start the AC 1st, long enough for the compressor to start and run, then the water pump come on afterwards?

I don't think you will find one in retail type suppliers - but - it would not be difficult to put one together. Simple "time delay" relays are available. They can be set to wait a specific amount of time after power is applied before the main relay closes and allows power to flow to your AC unit's water pump.

See: Relay, Time Delay - Time Delay Relays - Relays - 6A855 : Grainger Industrial Supply

[Free Agent]

Sometimes it takes a few re-starts but I've run our RV 13.5 BTU on our 2K Honda.
Make sure all other accessories like the battery charger and water heater are off.

The initial high starting amperage can be overcome once the gas charge pressure in High side of the A/C reduces somewhat after a few starting trys.

Make sure the generator isn't on econo setting during the initial first start of the A/C.

Should be OK running as the compressor cycles on and off there after but keep it off the econo because it's too big of a drink of water to rev back up when the compressor is on the low RPM/econo mode.
It states that in the owners manual BTW.

[Astral Blue]

Originally Posted by US1Fountain

Is there a device that would start the AC 1st, long enough for the compressor to start and run, then the water pump come on afterwards?

Yes. But it wouldn't help you. The water pump is using a negligible amount of current compared to the start up current of the compressor. You need a start capacitor (or several of them) wired into your compressor. Start capacitors hold enough current to start the compressor and release it once it is engaged.

Wiring this is not for novices. You will void your warrantly. If not properly done, you will destroy your compressor motor. If not properly handled, you might shock the bejeezus out of you. Just some fair warning here.

Seek the advice of an experienced HVAC electrician, explain your dilemma, and suggest wiring a start capacitor into your system. Most will be afraid to do it because you are modifying your system against manufacturer specs, but it is a harmless modification if done properly.

[Dulcesuenos]

Our ac unit comes stock with both start, and hard start capacitors. Mermaid said it wouldnt make any difference wiring in a diff hard start capacitor. The Dometic smart start may help but at the price I can live without it.