jjrbus Posted March 7, 2015 Share Posted March 7, 2015 My AC would barely start with my Honda EU2000i. I did some web searching (not enough) and decided I needed a hard start capacitor. Some more quick searching and decided on a SUPPCO SPP4E. After ordering I found the schematics for my 11K BTU Duo therm brisk air 57912.602 according to the schematics has a hard start capacitor. Then decided it must be weak, so decided to replace anyway. On removing the cover I discovered it does not have a start capacitor! I am glad I decided on the SPP4E as it barely fit On testing the little Honda struggles a bit but starts the AC on eco mode. As long as I am at it I will clean the condenser I take off the cover and OMG I knew it was dirty but look at this! Amazing any air went through it at all. . I don't have time to deal with this now, it is not a vacuum and brush job and will take some prep work and coil cleaner. Another post another time. Any and all thoughts, input, suggestions, ideas, criticism or wise cracks greatly appreciated. JIm SW FL Quote Link to comment Share on other sites More sharing options...
Totem Posted March 9, 2015 Share Posted March 9, 2015 I bought the same starting cap, then found out it was designed for 240. There is quite the argument about whether the spp6e is damaging to an RV AC or not. In my case it would not start my AC out of the box. My Spp6e had when i opened it a bridged resistor at the capacitor and was much larger than the stock starting cap in my unit. I swapped it out and it didnt help at all. I then read up about the spp6e and found the spp6 not the spp6e was recommened for RV generator cold start. I decided to put the controller relay of my stock starting cap and connect it to the larger capacitor and cut the resistor making a hybrid cap. hooked it up crossed fingers and it easily started my AC. Ive been using it ever since. I am considering buying an SPP6 anyway though because I don't trust the situation I have created even though it works. Quote Link to comment Share on other sites More sharing options...
Totem Posted March 9, 2015 Share Posted March 9, 2015 an interesting read: https://www.rv.net/FORUM/index.cfm/fuseaction/thread/tid/24152633/print/true.cfm Quote Link to comment Share on other sites More sharing options...
jjrbus Posted March 9, 2015 Author Share Posted March 9, 2015 Thanks for the response. It is difficult for the untrained to sort through a 1000 posts of info and misinformation and make a decision. As near as I could tell the 6E can possibly burn out a compressor if the internal switch fails. Where the 4E should not? Who would not trust an internal switch made by an unknown manufacturer who is the lowest bidder in China? It is working for now, if I burn out a 20 year old AC unit it will be no big deal. I will then use a scrap of plywood some duct tape and bailing wire and install a window unit until I can do something else. I am looking at a converted window unit, my 2000i eaisely starts a 10K BTU window unit. http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/21943313/print/true.cfm There is another article on this complete with pictures but I cannot find it at the moment. JIm SW FL Quote Link to comment Share on other sites More sharing options...
jjrbus Posted March 9, 2015 Author Share Posted March 9, 2015 Here it is! http://forums.woodalls.com/Index.cfm/fuseaction/thread/tid/21943313/print/true.cfm Years ago I tried converting a window AC to a mini split, it was a dismal failure. Quote Link to comment Share on other sites More sharing options...
zero Posted March 10, 2015 Share Posted March 10, 2015 My AC would barely start with my Honda EU2000i. I did some web searching (not enough) and decided I needed a hard start capacitor. You DO realize that Honda is only rated to make a sustained 1600 watts, and not 2000 watts, right? Most small AC units surge at 2400-2800 watts when starting. Quote Link to comment Share on other sites More sharing options...
Totem Posted March 10, 2015 Share Posted March 10, 2015 My cousins honda 2000 started my rooftop unit but only with eco mode turned off and was successful in starting only 1/3 tries on average. My HF inverter gen unit starts it in eco mode (which the eco mode on my hf inverter gen is permanent) although I plan on adding an eco kill switch thanks to the schematic you found me, jde. Quote Link to comment Share on other sites More sharing options...
shibs Posted March 10, 2015 Share Posted March 10, 2015 You DO realize that Honda is only rated to make a sustained 1600 watts, and not 2000 watts, right? Most small AC units surge at 2400-2800 watts when starting. what is the consumption when running? So, the a/c consumes less power while on eco mode? Quote Link to comment Share on other sites More sharing options...
Totem Posted March 11, 2015 Share Posted March 11, 2015 the eco mode is on the generator not the AC. eco mode throttles the gas on the generator gas motor spinning the generator faster... eco mode doesnt like taking a huge hit of current as its effectively idling the motor and has to actuate the fuel revving the motor up. If the draw is higher than the threshold of the circuitry overload setting the generator faults and quits. The AC compressor takes a huge amount of current to get going especially on units with no starting capacitor. If there is a capacitor that capacitor takes the hit and gives the generator time to take the load (this is all in a fraction of a second.). the capacitors we speak of are "beefier" than the stock ones or better than none at all also. Older stock caps might even have dried up electrolyte and so it helps to replace them with one of the supco spp6 or spp4 series in that case. finally, on the honda, when you turn off eco mode the motor essentially guns it and revs up higher rpms, this increases the instantaneously available current and can (but not will) start the AC. Once the AC compressor starts and is running its consumption drops exponentially and the nominal running mode of the generator can keep it going. Now if anything i just said is wrong jde will bark at me but I believe i just got that explanation correctomundo as fonz would say. Quote Link to comment Share on other sites More sharing options...
zero Posted March 11, 2015 Share Posted March 11, 2015 Now if anything i just said is wrong jde will bark at me but I believe i just got that explanation correctomundo as fonz would say. I don't bark at people unless they intentionally step on my tail Two additional comments (comments . .NOT disagreements). #1. I doubt there has ever been an RV sized alternating-current motor-driven AC unit built without starting caps. But as you already indicated they go dead over time. With some, even when good they are inadequate unless power is perfect. #2 When it comes to "eco-mode", how well it works in the real world is going to depend on the individual unit. In theory, starting power should be the same with eco "on" or "off", but it all depends on the lag-time. A conventional AC generator MUST run at one preset speed all the time in order to make the proper 60 Hertz sinewave. With an inverter-generator, DC current is being fed into an DC to AC inverter and the correct 60 Hertz sine-wave can be made at any engine speed. Thus the idea of eco-mode. It is supposed to sense load-demand and only run fast enough to satisfy the amps called for. Again, in theory - when the AC calls for 2400 watts, the inverter generator in eco-mode, is supposed to rise to the challenge and rev up almost instantly. I know some are slower to do it then others. I'm getting off track a little here - but with conventional AC generators - you can turn up the governed speed, make them run faster, and get more power. When you do that, the 60 Hertz sinewave is wrong - but many appliances don't care what the wave-cycle it. Clocks certainly do. When your clocks run fast or slow on an AC generator, it's usually because the engine speed is off and the sine-wave is wrong. With an inverter generator - that should be virtually impossible. Quote Link to comment Share on other sites More sharing options...
Totem Posted March 11, 2015 Share Posted March 11, 2015 OP mentioned his was missing a starting cap (on an old unit) Quote Link to comment Share on other sites More sharing options...
zero Posted March 11, 2015 Share Posted March 11, 2015 Some AC units came with one capacitor instead of two. The AC unit in this thread came either way. The so-called "running capacitor" is also what starts the motor when there is no extra starting cap wired in parallel with the running-cap. My point being that the AC unit being discussed here does have a starting cap. It's just a small one and serves dual purposes. I have no idea if his had one and it was removed, or it came new with just one cap (many did). if it had no cap at all it would likely just sit there and humm - instead of trying to start. As I recall, there are only three types of motors used in conventional 120 volt AC wiring. Split-Phase, Capacitive-start, and Induction-Repulsion. Split-phase is the cheapest but also has lousy starting power so is rarely if ever used on compressor or AC units. Cap-starts are the cheapest when it comes to hard-starting appliances and pretty much rule the consumer market. I haven't seen an induction-repulsion motor on a home-appliance in a long time. This Duo-Therm AC unit can draw around 34 amps at first start. That's 3700 watts. That is an awful lot to ask of a 1600 watt Honda generator with a 2000 watt surge rating. A well built 2500 watt generator can surge to 3700 watts for the split second needed to get the motor started. And yes, I know you won't find a 2500 watt generator saying it can surge to 3700 watts. That is because surge-ratings are based on X amount of seconds, not a fraction of a second. His Duo-Therm when working right - probably draws 3700 watts for a small fraction of a second, then 2300 watts for a few more fractions of a second, then it tapers down fast if all is right. A 20 amp circuit breaker in a normal 120 volt AC circuit has a time-delay and will run it. A "fast trip" circuit breaker will not. How low that surge can be made with extra caps, I don't know. Low enought for a Honda 1600 watt generator? I doubt it, but maybe. I also don't know how high that Honda can surge for the first fraction-of-a-second at motor-start. Honda publishes a surge rating of 2000 watts - but Honda is know to be conservative in their surge ratings and often out-do other makes with higher surge-ratings. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted March 15, 2015 Author Share Posted March 15, 2015 Without the cap it would not start, with the cap it starts. Will it be dependable, will it start on a 90 degree day? I do not know, time will tell. I will not be able to try it out for a couple months. JIm SW FL Quote Link to comment Share on other sites More sharing options...
zero Posted March 15, 2015 Share Posted March 15, 2015 Depends on the AC unit. Some start harder the longer they run and hotter they get. Only way I can think of to make a test now, is to plug the air conditioner into grid power and let it run half a day. Then without letting it cool off, try hooking it to your Honda generator and let it cycle a few times. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted March 15, 2015 Author Share Posted March 15, 2015 Thanks JD, but I will not be home for a couple months. JIm SW FL Quote Link to comment Share on other sites More sharing options...
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