RV AC 521 compressor saver

Chris Bryant wrote:
I hav emailed the 521 folks and they do not have a model for 120 volt operation- I haven't measured the back emf voltage on a running unit though. The Supco SPP6E is a relay based unit, and while Supco used to spec it for 90-270 vac, now they spec it at higher- and don't recommend it for 120 volt units. I'm not sure what changed.
Dometic does make a potential relay based start kit- I'll look up the number. It is specifically meant to run a Penguin low profile unit on an Onan 2800 microlight.

Here's the Dometic instruction sheet for the relay based kit-
http://bryantrv.com/docs2/docs/quickstart.pdf

The 120 VAC problem may be why I haven't seen a 521 on an RV AC. And, I did not see at what voltage the 521 1 - 3 ton kit was rated. I'm interested in seeing what Dometic has to offer. If someone can tell me how to post an image from my computer, I'll attach a photo of a 13,500 btu(1.125 ton) Airxcel (Coleman Mach?) wiring diagram showing the 521. The Dometic wiring looks somewhat unconventional to me.