Here' some specs (BTU/Compressor Amps/Fan Amps/Inrush-LRA):Dometic (standard unit) 13,500/12.4/2.5/63Total amps: 14.9Colman Mach (standard unit) 13,500/11.9/3.4/63Total amps: 15.3Dometic High Efficiency 13,500/8.6/2.5/50Total amps: 11.1Coleman Mach 3 PS 13,500/8.3/2.9/58.4Total amps: 11.2Once started these high efficiency units use about 3-4 amps less current than the standard units. The Dometic has a respectable 13 amp (63 to 50) reduction in inrush/LRA/startup current. A very good thing for smaller generators.Did notice the Coleman Mach 3 PS had much less reduction in inrush/LRA/startup current vs. their standard unit. Wonder why? Quite a few small generators will never have the opportunity to see the reduced steady current demands because they'll never get the past the higher inrush/LRA/startup current.Typically these high efficiency units can be purchased for $650-$750. Purchasing one of these might be a better investment vs. buying a larger generator--say, one EU2000 vs. two EU2000i's--$1000 vs. $2100 :)

Do they use a hard start cap? That significantly reduced the initial amperage load on my Coleman MachIII.

BillyW wrote:Do they use a hard start cap? That significantly reduced the initial amperage load on my Coleman MachIII.That's a good question. These specs were pulled from aftermarket literature. I'm assuming these specs reflect use of a starter caps; however, I can't be certain.

Carrier Air V (no longer made) 13.500 BTU 13.5 ampsAdvent Air (Replaces top (Roof) unit on the Carrier when the Carrier fails due to poor construction) 15000 BTU, 13.5 amps. (My Front and Bedroom air conditioners,,respectively)(Construction fault corrected on front unit...By me).

Dometic does not offer a Hard Start Cap on regular units. I am not aware of Dometic offering a Hard Start Cap as a optional part.RVP DOES allow you to option a Hard Start Cap. BUT, that may be OEM only and you have to purchase the Hard Start Cap kit from RVP. When you talk to whoever you are buying from, ask for the Hard Start CAP system. That will usually be a Special order, so it is quicker to just buy the RVP model you want and buy the RVP Hard Start Cap as an extra part.If you read the archives, you will find a lot of RV'ers using a non RV Genset having good luck with adding a Hard Start kit. You do NOT have to use the RVP Hard Start kit. You can get one locally from your regular HVAC supply company. Doug

dougrainer wrote:Dometic does not offer a Hard Start Cap on regular units. I am not aware of Dometic offering a Hard Start Cap as a optional part . . . When you say "regular" do you mean OEM or aftermarket?Dometic #3310727.015 Hard-Start KitDometic #3102903.006 Hard-Start Kit

High Efficiency 13.5k BTU a/c = Smaller Generator?

otrfun
Explorer II
Apr 12, 2014
NinerBikes wrote:
Do you have a part number from Dometic for the high efficiency model? Are you sure it's a 13.5k or an 11.5k A/C unit?
The part number for the Dometic high-efficiency a/c unit is 459530. As for whether I'm sure it's a 13.5k or not, well, I've seen it advertised as a 13.5k a/c, but ya never know . . . it could very well be a 11.5k in disguise :)
westend
Explorer
Apr 12, 2014
otrfun wrote:
NinerBikes wrote:
Do you have a part number from Dometic for the high efficiency model? Are you sure it's a 13.5k or an 11.5k A/C unit?
The part number for the Dometic high-efficiency a/c unit is 459530. As for whether I'm sure it's a 13.5k or not, well, I've seen it advertised as a 13.5k a/c, but ya never know . . . it could very well be a 11.5k in disguise :)

Dometic brochure with specs
NinerBikes
Explorer
Apr 12, 2014
Brochure still recommends 2.5KW to start this 13.5 High Efficiency Unit. An Eu2000i puts out 1600, 2000kw tops.
NinerBikes
Explorer
Apr 12, 2014
otrfun wrote:
smkettner wrote:
Yes and unfortunately the fan starts before or the same time as the compressor.
When will they figure out it is ok to run the compressor ten seconds before the fan kicks on.

Or has this changed? I installed a new Dometic control box/digital thermostat a year ago and it starts the blower fan first by design.
Can this Dometic digital thermostat be used on the garden-variety, Dometic 13,500 BTU, non-ducted, rooftop units? Got a part number? All the units I've seen, the fan runs constantly, 24/7. It would be awesome to have the fan turn off with the compressor.

I've a standard 2 speed Dometic with the square box. There are 3 settings for the fan. AUtomatic, High, and Low. Automatic will run in the low fan setting it the thermostat setting is within 5* of the actual air temp inside, and if over 5*, it will start in the High setting.

Since I mostly run my 13.5 on the generators, I almost always use the low setting, it especially seems to help during the first AC start up of the day, which draws unusually hard on the pair of Eu2000i's, unless nothing else is running at all on the travel trailer. By all means, use propane, not electricity to heat your water, and perhaps turn the AC off when running the microwave, if you are heating something up for lunch or dinner.
otrfun
Explorer II
Apr 15, 2014
NinerBikes wrote:
Brochure still recommends 2.5KW to start this 13.5 High Efficiency Unit. An Eu2000i puts out 1600, 2000kw tops.
True. But, on the other hand, Dometic recommends a 3.5kw for their standard 13.5k units. A number of folks have reported running their standard units with their 2.0kw Honda/Yamaha generators. Agreed, it's probably not recommended, but nonetheless they were successful. Given the 13.5k high-efficiency units use 25-30% less current (~11 vs. ~15 amps), I think it's a reasonable to assume a much higher percentage of folks could successfully power these units with their 2.0kw Honda/Yamaha generator.

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High Efficiency 13.5k BTU a/c = Smaller Generator?

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