Originally Posted by Sky_Boss
I'm not sure of what you are speaking of except that some EMS (energy management system) systems shed devices if they will exceed the coach's power rating. So, as an example, I have an EMS that will shed the block heater, then something else and then AC 2. This gets problematic when I am on 30 amp service because AC 1 runs around 12 amps (not counting the start up surge) and a few other items that peg me right at 15-17 amps. When AC 2 kicks in it generally exceeds 30 amps and shuts it back down. OTOH, if AC 2 is running and then AC 1 kicks in, it shuts down AC 2.
So...in my experience with my 15,500 BTU Penguins, it is not reasonable to consistently run them both at the same time when on 30 amp service. Even AC units with smaller, stable amp needs will cause some EMS systems to go freaky on you.
I think a good answer would be to run the extra 20 amp circuit on AC 2. That would give you consistent electrical output to that unit and free up your coach to run AC 1 and not have nearly the chance of exceeding 30 amps running other things at the same time. BTW, I don't think alternating AC units makes for even AC coverage unless you have a ducted vent system and even then, that is marginally so.
The only thing that has me scratching my head is that I wouldn't think a 30 amp RV would have 2 AC units. Am I missing something or just uninformed?
My 30 amp coach came from the factory with 2 AC units, with the Intellitec (Shed) EMS, keeps both compressors from cycling at the same time, which are the big amp hogs on the A/C units.
They are wired so the EMS runs the fans/compressor units independently on each A/C.
However; with generator running, the front A/C has a direct link from the 20 amp on the genny. The genny has 30 amp and a 20 amp breakers, it is a Cummins Onan 5500
I had real issues the first summer with my coach and low voltage at a state park. Being 30 amp with 2 A/C pushes it to the limit and then when you have voltage issues in the middle of the heat of summer in an older wired park/CG, the combo can be very bad if you don't have some sort of protection, like I installed the Progressive EMS-HW30C to keep my coach safe from under/over voltage issues.
Also, I request/use the 50 amp service and use an adapter from 50 to 30, which I have had no issues with since I've been plugging in that way in the heat of the summer.
Kent - '03 Fleetwood Storm Ford F-53 V-10
With Susie (Lhasa); Angie (Shorkie) Ferbie (ShihTzu)
In Memoriam: Katie, Spencer and Zoey