[Richard]

And to give you more to noodle while driving back to the mothership. There are a lot of devices used in home applications to keep the compressor from short cycling. The problem is that all of them are based upon 24VAC circuits used in houses. I could not get them to work on the 12VDC control systems used in RVs. I also could not find at the time a 12VDC tstat with built in short cycling protection.

Since I have two compressors per basement unit, and the tstat controls the internal fan and compressor on separate circuits, I used 4 of the above relays. I programmed them so that once the compressor gets a start signal, the relay will not close until five minutes after the compressor has stopped. I did the same for the internal fans. The programming has a little quirk in that it delays the compressor five additional minutes from the initial turn on.

Here is a pic of a spare board. The board is inserted between the tstat and the AC units. It is small enough that it was easy to hide close to the tstats.