15K Dometic Heat Pump

[zuckerburg]

Originally Posted by Oscarvan

Why wouldn't you be able to wire a second unit into the coach system? Aren't we talking a 50A electrical supply here?

Edit.... just saw that this is not a Berkshire on the Berkshire page.

No, you can't run 2 ac's on a 30A system. So yes, getting a second supply from the pedestal is a good answer.

Gee thanks.

[mikey]

Originally Posted by chief5631

I've been in Texas and Arkansas in the 100-108 degree real feel range the past couple weeks and if you can get in the shade, a/c will make cool happen but if you're in the direct sun, no matter what you do...a/c will not be able to keep up.

Thanks Chief

[mikey]

Originally Posted by zuckerburg

Your problem is nor the A/C as long as it functions as it is supposed to.
Do you have a front OUTSIDE windshield shader? Awnings on the side windows help. I have sunscreen material on the slide windows that stay on all the time. I have two 13500 A/C's and can cool it nicely in 95degree Florida humidity.

On our Berk it has both an MCD daylight & night shade & we will add an external Magnashade this fall. Both shades were in use last trip, still unbearable, as in HOT! Probably will add it to the FR cut list after this upcoming trip.

[mikey]

Originally Posted by Oscarvan

This. The "Delta T" should be at least 10ºF, preferably more.

Sounds as if it's time to break out the digital with its temp probe and do some real in depth trouble shooting. Oscar, question for you: can I shut off rear air and achieve reliable readings being that both fwd and aft air use the same duct?

[Oscarvan]

Originally Posted by mikey

Sounds as if it's time to break out the digital with its temp probe and do some real in depth trouble shooting. Oscar, question for you: can I shut off rear air and achieve reliable readings being that both fwd and aft air use the same duct?

I would open the register into direct blast mode on the unit your are evaluating. But in theory, yes as long as only one unit is feeding the duct that's the one you're checking.

That said, you may get different readings at different outlets, as some of the duct work will be passing through hot spots..... Again, I would run it right out of the unit and not into the ducting.

[gordonsick]

Originally Posted by chief5631

I take it if I have a 15k dometic on a 2018 coachmen concord with 30 amp service I cannot install another ac?

My 2015 Berk 34QS has two Dometic AC units and the front it is a heat pump. Both are 15,000 BTU. On my most recent trip, I attempted to run both AC units while on 30 Amp power. The first time it didn't work, and the second time it did.

Moreover, for the time it did run both AC units, we were also able to also run the residential fridge and an ANOVA Sous Vide cooking unit that can draw up to 800 amps. Went out for the afternoon and never blew any of the fuses. And we didn't draw any fault codes on the thermostat.

I had the ME-RC unit set to expect 30 Amp power when on shore power. Note that the two Dometic units are connected to each other for control purposes: the front unit controls the rear unit. Presumably, this prevents them from trying to start at the same time. I'm sure that they can't both start at the same time on 30A.

I'm not sure what the difference was between the two situations, but it is likely that the voltage couldn't keep up when I attempted to run them together the first time. The Fault Code E7 on the Dometic CCC control may just come on to indicate that the voltage was too low to start the unit.

When I did get both units working the second time, I checked the voltage in the coach when all was running and noticed that it was a steady 110 volts.

–Gordon