Addition of HSC to AC unit

[KathyandDave]

Following Mike and Kat (snfexpress)'s lead and PM help, we installed a Hard Start Capacitor in the stock 15KBTU AC unit so we could run it off a generator. The pictures are here:
http://photobucket.com/HSC_upgrade

[jsmitfl]

Do you have a part # Thanks

[snfexpress]

Supco SPP6E E

[seahunter]

Generators and AC's are new to me. Is this something everyone requires using a generator for AC? Also, since we ended up with two 15k AC units rather than a 15 and a 13.5, I asked the tech and he said we COULD run both AC's with the generator - does this sound right to everyone? I thought the 15/13.5 was pushing it, but two 15's as long as nothing else is on?

[snfexpress]

seahunter,

With your Onan, you can run both air conditioners because you have a 5500 watt generator. A hard start capacitor would still benefit you since the amperage spike would not be as high & long and so would lessen the strain on your generator.

Remember though that while you have a 5500 watt generator, it only provides a little over 45 amps for your whole trailer so you should still monitor your 120 volt usage. When connected to 50 amp shore power you effectively have 100 amps because each leg has 50 amps.

[Art-n-Marge]

What a great idea! If I understand this correctly, what this does is lessens the surge of the start up spike when the A/C first turns on. Is this correct?

If so, this would help any power supply situation even when connected to a pedestal so that other things that are running when the A/C starts up, the chances of brownout or circuit breaker resetting are lessened. With my dual EU2000s I wasn't concerned but I have not run the gennys, the A/C and the rest of the rig for no more than a day (and a half). It wasn't very hot so the A/C wasn't running very long. What generators do you have where this was a concern?

Now that I know what these are, I clicked on the link and wonder why that one was selected. I see there are others at the bottom that have better reviews (but don't know the quality of the reviewer) and several other capacitors that are higher priced. Is there an advantage to the others?

[snfexpress]

We chose the Supco based on the advice of a fellow Rver who also custom modifies chillers. Otherwise I don't know which one we would have chosen.

[Ozz]

If the unit is working correctly, you shouldn't need the hard start. I install them if the compressor is tight, or if there are service problems.
It won't hurt to have them, and I like them, but I do not have any evidence that one is needed for generator usage. The spike in amp draw is a fraction of a second. If the system has been off for a few minutes, is has equalized and the start is soft anyway. That is what the time delay in the thermostat is designed for.

[KathyandDave]

The way I look at is: If I have a 15A circuit, like a Honda 2000 provides, then the short 20A draw to get the AC moving is too much. If I'm on a 30A post, no worries and, since the vast majority of campers will be using the AC in that situation, then I think that's how they decide how expensive a capacitor to supply on these AC units. But, if you want to boondock, as we sometimes do, then some ability to reduce the start-up draw is desirable. I went ahead with the mod and posted the pix to take away the mystery.

[Ozz]

The units are designed to run on factory start and run components, The compressors are engineered for the RV industry, park power, generators. It won't hurt to install the capacitors, but if the system has no problems, you just don't need the extra cap.
I install them all the time, but only as a rule for problem compressors; (tight bearings, worn unit parts.)
Many residential and commercial unit will have an expansion valve in the coil, this does not equalize like the capillary tube used in RV units, these units need an assist at times, although they do not come with them in many cases, there is no starting against unequal (High) pressures, as the cap tube equalizes after 2 or 3 minutes. The new Scroll compressors used now also are easier starting.

[Art-n-Marge]

I guess this is one of those things like upgrading the tires on the rig even though the older, lesser rated ones were supposed to work, or upgrading the autoresetting breakers for the slideouts because the ones from the factory seem underrated. Now we can add installation of a startup capacitor to the A/C to lessen the impact to a power supply (in this case a generator).

If everything in this world worked the way it was supposed to and never had difficulties, we'd die of boredom. We can only wish we have the sense and the money to make whatever adjustments we need to do and hope we made things better.

[Ozz]

OK, but you probably won't need it.

[jimcol]

Old marketing saying: "Tell them what they need. Sell them what they want!" Jim

[Ozz]

quote:Originally posted by jimcol

Old marketing saying: "Tell them what they need. Sell them what they want!" Jim