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Author Topic: two roof top AC start coordinator/inhibitor current load minimizer SEAN?  (Read 3999 times)
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« Reply #15 on: July 12, 2010, 05:20:35 AM »

I agree with you Barn Owl.  I am on my third rv with 6.5kw generator and have never had trouble running two air conditioners (13,500 and 12,000 btu). 

gary t'berry
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'85 Neoplan Spaceliner "Odyssey"


« Reply #16 on: July 12, 2010, 07:47:34 AM »

...  Each of those draw 9 amps as I recall.  So to keep two running I would need 18 amps and that is a 2.2KW.  To run one and start the other I would need 18 amps start-up plus 9 amps to run or 27 amps from the inverter.  That translates to 3240KW for the inverter capacity. ...  What am I missing?

I think your numbers are off.

My 13,500 BTU/hr units draw about 13 amps each steady-state in average temperatures (more in sweltering heat, and a bit less in more temperate conditions).  They call for 20-amp HACR breakers and draw at least that much at start-up.  To run two of these would require a minimum 3.3 kW inverter -- 3.0 is too small.  Practically speaking, the next size up from 3 kW is 4 kW.

BTW, as I wrote in the other thread, I ran two of these A/Cs just fine on a 5 kW generator.  At 20 amps each for startup, even if they start together that's 4,800 watts.  It was a little Onan Marquis on a Fleetwood gasser.  I didn't call you on the 6.5 genny because you told us not to... for all I know, you have a 3,600-watt battery charger that runs every time the generator does (not an uncommon configuration), which would leave you just 2,900 watts for your air -- not enough, as I just described.  Now, if you want to discuss that problem, we can, although perhaps a new thread would be appropriate.


Full-timing in a 1985 Neoplan Spaceliner since 2004.
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« Reply #17 on: July 12, 2010, 08:28:06 AM »

I agree with you both.  I think 6.5KW would be ideal for two rooftops and everything else with just a smidgen of management on occasion.  Its the 2.5KW inverter doing it that sticks.


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