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Hisham Amaral · 03-06-2013, 09:36

(03-05-2013 12:52)davidmbrady Wrote: Thanks everyone, glad to serve!

That's right Ms. Bee (and thanks for the rep! I appreciate it! ), as best you can, control the AC's via the Duo Therm CCC thermostat.

Now, those switches up front were put there for a reason, and I think the best use of them is to turn off the AC's to prevent overload of the inverters.

My bus has two AC's wired to one inverter. I have to actively manage that cause the inverter can only handle one. So, if you find yourself pulling into a dusty area and you want to turn off the generator (and fan to keep things clean), use the switches up front to conveniently and quickly turn off the AC's. Another scenario is plugged in at a campground. Before I remove the shore power I often reach inside and flip the AC switches off. Using them as a means of temperature control; i.e., turning them on when hot and off when cold is probably a no-no. Use the CCC for this.

It also occurs to me that this may be why BB poo-pooed the idea of running an AC on an inverter. They wired them that way, but in time BB came to recommend to not run AC's via an inverter. I never quite got this cause the inverter and engine mounted 50DN alternator can easily run an AC and I've done it many times. One time my genny broke down in Texas and the only AC we had for the house was an AC running on an inverter. But, you'll hear it time and time again, "don't run AC's on the inverters". Well I'm thinking that the AC switches up front might be the cause of this folklore. Imagine a lowly 3600W inverter (modified sinewave) attempting to deal with the kinds of compressor starts and amperage draw that Darrell has seen. That'll definitely bring the inverter and the AC's to their knees, and probably shorten their lives.

The other benefit of letting the CCC brains do it's job is that by inserting a 2 minute delay, the high side and low side pressures equalize a bit allowing for an easier compressor start.

David
The M450 does run two A/C's on the inverters and the alternators. Both the living room and the badroom A/C's run off the invertor while on the road. The smart energy management control the overload and shots down components as needed to keep the use in line with available power i.e 30 amp on each leg on the smart controller. The alternator load does show about 100 to 150 amps when running the these A/C's.
I know that the 97 was wired to run the bedroom A/C on the inverter while on the road with engine running, that did put big load on the alternator. I tried running the BR A/C with engine running on the 97 the alternator out was will in the 250 Amps, I quite doing it.