Who has a Supco Hard Start on their A/C unit?

The voltage rating of a capacitor is not important as long as it's higher than what your using it for. So you could use one that's rated at 277volts (or more) for a 120 application and it would perform exactly the same.

Thanks everyone. I'll take some pictures and post them along with the wiring diagram.

My generator loves the SPP6E on my Coleman Mach III 13.5 K BTU unit, which by the way had the caps neatly arranged in one corner and a nice wiring diagram on the inside of the cover. Simple install. Just piggy backed onto the existing caps.

I put one in my Coleman 13.5 a few years ago --- took a picture of the exiting capacitors and emailed it to Supco asking for how to install the Supco 6 - they walked me through the install same day. Great service.

I have the SPP6E on my current 13.5K BTU A/C, and had one on my previous 9K BTU A/C. They work very well.

I will post some photo's I took later today.

We installed the SPP-6 in my Sons 15,000 BTU Dometic on his 2006 Cedar Creek last month.
Before install my 2- 20000 Honda's would not start the AC. Now it's not a problem.


C.B.

I bought an SPP6 capacitor for my A/C, opened it up, discovered that Coleman had already installed a hard-start capacitor, put mine back in the box, closed up the air conditioner, and was done.

If you find a capacitor in there that already has a relay mounted on top, that's a hard-start capacitor. You can still install the new one, but it will have little additional benefit.

Confusing, Huh?
SPP6 is the right size and SUPCO will agree with that. There's debate whether it should be SPP6 or SPP6e. One of our resident RV tech gurus, Chris Bryant, prefers the "e" version but allows that SPPCO will recommend the SPP6.
Do you know that your Dometic A/C does NOT already have a Start Assist? I'm not an engineer either but here's what I know:
- your A/C needs two "run" capacitors - one for the FAN motor and one for the Compressor
- the two run caps may be individual - two connecting points on each
- if there are two individual caps there will probably be a jumper connecting one side of each of them
- or could be a dual capacitor - both in one - terminals would be marked something like COM for a Common Wire, FAN for Fan, HERM for Compressor (the hermetically sealed refrigeration portion of the A/C)

All this means you need to know that there is presently only a Run cap wired to the compressor. Those capacitors are usually silvery metal. If there are other components, then it already has some form of start assist. There can be only one start assist. The wiring diagram may show that there was one as an option that wasn't actually installed. That's why you must look and figure out if one's already there. If there's a third cap, probably hard plastic with a metal retaining ring holding it together at the top, it's part of a start assist device.

If you can see the sides of the caps, you can see the capacitance rating numbers. They're in MicroFarads, probably shortened to "MFD."
FAN will be less than 10MFD, HERM around 45MFD and Start (if present) around 100MFD.

See how this compares with what you see up there. Be sure the power is OFF at the source. Don't touch the cap terminals till you have shorted across them with an insulated metal tool. They're meant to store a charge so you want to be sure it's bled off.

Take pictures of the capacitor area and wiring diagram if you can and post them.

And be encouraged - IF you find NO start assist already in place, the two wires on the SPP6 go to HERM and COM, and it doesn't matter which is which.