hard-start kit for A/C (helps smaller generators work)

[rickst29]

CORRECTED IN AUGUST, 2020

In other Threads, some people have looked at the 58-amp power requirement for the Polar Mach 9203 A/C start-up and said, "that's impossible, I don't believe it". But the figure is correct for the motor with fan and compressor attached -- you didn't remember that they've got a fairly big "run" capacitor in there to help it along, for higher efficiency, and that capacitor also provides substantial help during start-up. (It's either 40 or 45 Mfd@370v, depending on whether your model year has the Sanyo or Tecumseh compressor). There is a separate 7.5Mfd capacitor for fan start assistance, but most of the improvement is provided by the bigger "compressor run capacitor". Polar Mach 9203 is not built with a compressor start capacitor, because they cost money and plugged-in people all have 30 amps available, don't need 'em.

That's what these "hard start kits" add back in. When needed, the "run" and "start" capacitors only assists for small fraction of a second, but the power draw of the motor and compressor also go down rapidly as they begin to move. And so, the maximum draw from the 30A plugin (to shore power or Generator) is quite a bit less than the 58A figure. Exactly how much less, I don't know (and I'm not going to move and open up the Trailer just to measure it). But from what I've been reading, I'll SWAG that's right around 26 amps.

This can be improved, enormously, by adding on a hard-start kit. I've just poked around the Internet a bit, and finding a few posts like this one, raving about this particular product in use with Coleman-Mach 9203 3500-BTU units, so it seems to be the right one to get. (NOTE: he typo-ed the model name, it's actually "Supco SPP6".) BTW, efficiency would go down, a lot if you merely replaced the current run capacitors with bigger ones. The monitor and timing circuits within the "head" of this hard start kit prevent it from creating mismatched capacity during regular "run" time. That's why you buy the kit, instead of just a wrongly-sized "run capacitor". BTW: For the standard Coleman-Mach A/C on most TM (roof air conditioner), the slightly more expensive Supco SPP6E"e" would be a mistake, the discharge timings end up wrong.

After removing the A/C shroud, it's a 10-second job: just clamp the leads right in parallel with the existing "run" capacitor.
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Now, some of you might want to ask if this would let you run our A/C units with a mere "2000 watt" generator after installing this. Well, in Desert temps, and late July in the Central valley, the continuous draw from the 9203 gets up to about 14 amps. The "2000 watt" Honda and Yamaha models offer 16.7 amps peak, but only 13.3 amps continuous rated power. So, although the hard-start kit probably WOULD allow you to start, it's a really bad idea: it's just too much load for one of those little guys. Those "2000 watt" generators are really "1600 watt" generators with 200-watt peak output. I'm recommend against this kind of generator overload abuse even at sea level, in lower temps.

I won't need one if I proceed to buy dual, interconnected "2000 watt" Yamaha or Honda generators for running A/C -- even in Desert heat at high altitude, A/C start should be a piece of cake for the "4000 watt" combination. But for owners of the Yamaha 2400is and units of similar size, this is the ticket to assuring safe A/C start in high altitude/high heat conditions. (Which reduce your generator's output at the exact same time they're increasing the A/C electrical requirements). I'm pretty sure that this $30 add-on will help get you "over the bar" in all such circumstances.

typical pricing on the web is about $20, plus $8-10 shipping. (Directly from Supco, it is available about $35.)
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NOTE ON CORRECTION: Corrections were provided to me by our member RejoiceWay who emailed to Suppco (to verify the correct model for TM Air Conditioners). (Thanks !!!) From Technical Support representative Michael DelMauro, he received the following:

The current Trailmanor air conditioner is 120 volt 9000 BTU. RVP is the manufacturer with model #9203c876. I went to the web and looked at the specifications for the Supco SP66E units and saw it was for units above 170 volts. I followed up with an email to Supco to check on using this unit on our air conditioner. MIke DelMauro responded with the following " The SPP6 would be the proper match. The SPP6E is designed for higher voltage applications.

https://www.supco.com/web/supco_live/products/SPP6.html

Michael DelMauro
Technical Support
T 732-223-6644 x 261
[email protected] | www.supco.com