HOW MUCH CURRENT SHOULD BASEMENT AIR PULL ?

As I understand it, there are two compressors in the basement air on our '05 Winnie Adventurer. I am pulling 21 amps with a big difference between set and actual temp. If one draws that much -- then wouldn't I expect around 38 amps ?  Please explain if you know.

Max - with both compressors running you should be pulling 21-22 amps.  Search in the Winnebago board for "basement air" - this has been much discussed.

It sounds like both of your compressors are running, but the 21a seems a bit low to me. Normally, the first compressor will pull apx 17 amps. After the second kicks in, together they will pull up to 23-24a, depending on what else is running.  Here are three things you can do to help verify both are operating:
1) Watch the amp meter when on 30a shore power OR on generator. Set the thermostat for 5+ degrees colder than the thermometer display. Watch the amp meter as it kicks on comressor #1. It should settle around 17a. Keep watching the amp meter, and after apx 2 min the second compressor should kick in and you will se the amps jump up to 23 or so. (depending on other loads you are running).
2) Turn the system on and it will start the first compressor. Then go outside and stand where you can hear the unit running. If the second compressor is called for (3+ temp diff between ambient and requested temp), after apx 2 min you will very clearly hear the outside blower shut down, then very quiickly start up again. That is when the second compressor kicks in. 
- One caveat ...if the second compressor start capacitor is bad it can try to kick in and fail, but the amp usage should then settle back down to the same as it was.
3) You can also check output temp with an infrared thermometer.  Set the thermostat for one compressor (1-2 degrees colder than display) and after a minute or so check the air temp in one of the ceiling vents. It should be in the ballpark 20 degrees colder than at the return air vent.  Then set the termostat for both compressors by lowering the temp 5+ degrees.  After a few minutes check the air temp in one of the ceiling vents. With both compressors running the output air temp should be 30+ degrees colder than the return air temp ...my output air will be at least 30 and often up to 40 degrees colder than the return air with both compressors running.

...you could always turn off the breaker for ac circuit #2 and check output temp and amps knowing that only #1 could be operating. Then turn the #2 breaker back on and check output temp and amps again with both presumably running.

On my '06 Meridian, when I turn on the generator, then the basement air, it reads that I am pulling 13 amps to start with and then when the 2nd compressork kicks in, it goes to 18-19 amps total. (after the initial start up) That seems low in comparison with what John is quoting.

On my 2004 33V I draw about 23 amps with both compressors running. There will be a small surge at start up. The thermostat seems to have a mind of it's own. Be sure that your ducted air is not blowing directly on the thermostat. 

I recently went on a 5 day trip to Winnemucca, NV where the temps were in the 103+ degree range during the day. We only had 20A hook-ups and I was able to comfortably run my AC all day long. It never got above 19A, which still is a lot on a 20A circuit, but we never blew a fuse or tripped a breaker.

Yesterday was another 100+ degree day here in Indy. I was getting new tires put on and watched the current draw again. Started the gen. , but with the AC off until the transfer switch put it online. Then I turned it on and after the instantaneous spike, it settled on 22 amps. Then I added TV and sat. rcvr. . It stayed around 23/24 amps.  So I guess all is well.  Running on 20 amp with AC, was there a voltage sag?  Makes me wonder if the breaker is good. The startup should have tripped it.

Are all Basement A/Cs the same size, I read concern when amp draws weren't the same between different MHs????

Director said:

Running on 20 amp with AC, was there a voltage sag?

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So you only had 20 amp shore power available?  Was 20 amp selected on the EMS panel?

weewun said:

Are all Basement A/Cs the same size, I read concern when amp draws weren't the same between different MHs????

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Seems like they are all two ton units and should draw about the same current.  You can have a look around RVP's website and see.

RVP shows a max of 24.7 amps for the two ton, two stage, high efficiency heat pump, which I think is what Winnie was installing. 2 x 9A for each compressor, 3.3A for the outside fan and 3.4A for the inside (air circulation) fan. Since the fans may not need to run at absolute max capability, a total of around 22A seems reasonable.

Spec sheet here:  http://www.rvcomfort.com/rvp/pdf_documents/6535data.pdf

Thanks for the home work Gary.  Those numbers look right on..Next question. Are these like home units, so you can add coolant? Yesterdat it was 103. I turned unit on about 2:30 p fully exposed to sun. It was a lot cooler than outside, but never cool enough for me.

Max

I doubt if there are service fittings, but you could call RVP and ask them.

We just had another thread here discussing the cooling (or lack thereof) of the Winnie basement air systems. I doubt if your a/c needs freon, and if it does its because there is a leak. It doesn't just disappear.

http://www.rvforum.net/SMF_forum/index.php?topic=55668.0

John, to answer your question: Yes, I selected 20A on the panel. Never had a problem. The only thing that I had was a portable 30A power booster between the power pedestal and the coach.

My basement air is identical to what Afchap describes. Set your tstat delta at 1 degree and look at amps for first stage, over 2 degrees and the second stage kicks in, make sure fan speed is on high. I have used mine on 20a circuit, just make sure the EMS sets to 20a so it knows not to let the 2nd comp start. Biggest worry here is the voltage dropping too low unless you have a booster like Ramzfan. My surge protector has shut me off more for low volts that anything else I think. Might just have to look into a booster.

Director, I have a 2005 Adventurer 38, my basement air with 2 running pulls 24amps and sounds like it's groaning.

That's about the same as mine. Depending on the heat, your paint job and the temp you're looking for, the basement air may just not cut it. You may need more BTUs to cool. Open an overhead cabinet and feel the temperature inside.

You may just need more cold. Look for the threads about adding a roof air conditioner.

I was just reading a post on the iRV2 forum that dealt with the same problem that you're having. It was titled "Who can service basement AC?" and the last post on there stated that he had his basement air serviced and when they removed the heat pump, the serviceman found that his interior cooling fins were filthy and caked with mold. They cleaned them and everything works as it's supposed to. Hope this helps.
Steve