Inverters and air conditioners

Lee Bradley · August 03, 2017, 11:42:03 AM

With the Trace inverters, you add a sync cable and you can have 5KW of 110 or 2.5KW of 220.

windtrader · August 03, 2017, 01:39:46 PM

Quote from: buswarrior on August 02, 2017, 03:09:05 PM
Talk around the water cooler?

uninformed B.S. said out loud by idiot techs to a customer to shut them up?

typing on internet boards?

windtrader, you are set up to run that inverter fed AC going down the road, powered by the coach big alternator.
Simply a choice by the previous owner.

I can, if I choose, run a pair of mid 80's roof airs going down the road with a Trace 4024. Load on big alternator is somewhat less than running the coach HVAC, if it still worked.

Cooling the inverter while it is working hard to run big loads like AC is a VERY significant issue. It needs a lot of cool air, the inside of an unvented baggage bay is completely insufficient.

As to the choice of how to run, it all depends on what bits and pieces the busnut has available at the time.
Many of us piece the coach together over the years, as funds, opportunities and inclination come along.

Some don't have a generator that is readily installed for mobile use, YET, but have bought that excellent inverter as part of the final equation.

Some change direction mid course.

Prices of various things have changed over the years.

happy coaching!
buswarrior

BW - Thanks. There are so many variations on how to configure and power A/C, it gets a bit confusing. The inverter/charger in my bus is a Vanner 24-3600C. The specs state continuous output is 3600 watts, 2 minutes is 7200, 10 minutes is 5400 watts, 30 minutes is 4500 watts and surge is 10800 watts. If the specs are accurate the inverter should easily handle one rooftop Duo-Therm (Dometic) Quick Cool High Efficiency A/C.

After thinking it through, the configuration works nicely for us. Having the front A/C running off the inverter that is powered by battery bank that is charging from the alternator while running down the road seems quite smart.

The inverter is in a big open bay and I hear the fan running. I'll keep an eye on the temperature. I suspect it has a overheat shutdown mechanism in it but never hurts to watch it.

belfert · August 03, 2017, 06:57:39 PM

I had an air conditioner running through my Prosine 3.0 inverter. The Prosine 3.0 has 30 amp AC passthrough. I had problems with my rooftop air conditioner occasionally causing the inverter to cut power due to the inverter thinking there was a problem with the AC power. No problems after moving the air conditioner off the inverter.

buswarrior · August 03, 2017, 08:12:31 PM

windtrader, does that bay open to the outside? vented? And I mean VENTED, not a couple little squares in a door, hoping ambient air will magically flow.

There must be air exchange in and out, equal to what the inverter needs to keep cool, otherwise the inverter sits in there and heats the space up.

Some of the best installs, the busnut ducted outside air straight into the inverter air intake, and force fed it with another strong fan. (put a critter screen on the intake, of course!) Not waiting for the inverter's own fans, this aux fan would be run whenever the inverter did. (this strategy would reduce the run time of the inverter's own internal fans, keeping it cooler longer without its own fans coming on.)

There is no such thing as "too cool electronics" in this case. Too many bus bucks tied up in a good inverter, it must be supported in its mission.

Squirrel cage fans are your best friend, move lots of air, make little noise.

happy coaching!
buswarrior

windtrader · August 03, 2017, 08:42:58 PM

BW - The bay is a full width bay for general stuff. The Vanner sits in one part of it and has no external venting. Your point is well taken and I've added an inverter project to the bus projects list. Running the A/C off the inverter is nearly always when the ambient temperature is warm so having an external fan connected to the inverter on circuit seems fine. If it was running electric heat in the winter, I'm not so sure I'd want zero degree air blasting the inverter.

buswarrior · August 03, 2017, 08:47:12 PM

please do not run electric heat in the winter with an inverter.

do some BTU calculations vs power consumption...

You have an engine full of hot water back there.

happy coaching!
buswarrior

Jon · August 04, 2017, 01:00:58 PM

Quote from: Lee Bradley on August 03, 2017, 11:42:03 AM
With the Trace inverters, you add a sync cable and you can have 5KW of 110 or 2.5KW of 220.

That depends on the particular model. Some older inverters cannot be synced, and some newer ones automatically sync.

windtrader · August 04, 2017, 08:55:44 PM

BW - no plans on running electric heat when I have a bay full of Webasto plumbing for central heating.
https://www.dropbox.com/s/ytrw130ybqiou2k/Webasto.JPG?dl=0

TomC · August 05, 2017, 08:44:40 AM

Yes my Trace 2500 could be stacked to create 5,000 watts at 120vac. But, then you'd have to have a giant battery bank since 5,000 watts would pull 417 amps at 12v.
I don't like hydronic heat. Too complicated, maintenance intensive, too much space taken up. The simplicity of propane air furnace and electric water heater is astounding. Good Luck, TomC

belfert · August 05, 2017, 04:32:10 PM

Quote from: TomC on August 05, 2017, 08:44:40 AM
Yes my Trace 2500 could be stacked to create 5,000 watts at 120vac. But, then you'd have to have a giant battery bank since 5,000 watts would pull 417 amps at 12v.
I don't like hydronic heat. Too complicated, maintenance intensive, too much space taken up. The simplicity of propane air furnace and electric water heater is astounding. Good Luck, TomC

Propane heat takes up a lot of space too for the furnace and duct work. My interior design is pretty open so I don't have room for ducts. The propane tanks also take up a lot of space.

I had originally purchased a propane furnace and propane tank, but I eventually realized it wouldn't work for me.