Supco Hard start capacitor on Coleman A/C
I have a 1996 camper with a Coleman A/C. I bought the Supco SPP6E. My A/C has 2 round capacitors, one small and one large. The small one has 2 wires and the large has 3 wires. Which one do I replace?...
Forum Discussion
While the SPP6E has a electronic circuit to take the start capacitor out of the circuit after a time delay, it is NOT the correct capacitor for the task at hand. The "Drop out voltage" for a 120 volt compressor is about 130 volts, then the start capacitor stops being in the circuit with the run capacitor. In your case, you are installing the 190 - 277 volt SPP6E with a drop out voltage well above 180 volts, so it will only drop out on the timeout relay.
If you disconnected the run capacitor that has the red and yellow wires going to it (in the picture above) then the compressor probably will not run at all. The SPP6E and SPP4E are designed to add to the run capacitor, not replace it.
IF you are still having difficulty starting the compressor with the generator, my suggestion is to measure the capacitance of the factory capacitor, or replace it with one that is 5 mfd higher rating, and about the same voltage rating.
IF you have a volt meter, you will be surprised what voltage is read across the red and yellow wires. You normally will find about 135 to 155 volts. Yes even the two brown wires going to the outside fan should read about 135 - 155 volts when only 110 - 120 volts is applied to your RV power cord. This is normal. Even measuring your home 220 volt A/C unit capacitor will read about 250 - 300 volts, perhaps more.
So the SPP6E will work, but it is not the product designed for 120 volt compressors. It is designed to drop out at 180 volts, for compressors using more than 190 volts input power. It is only the electronic time delay that keeps the capacitor from staying in the circuit all the time, and burning up the compressor with high amperage that it is not rated to use. The SPP4E will drop out at 120 - 130 volts across the capacitor, something that will happen in your system, even with only 108 volts applied to the compressor run winding.
Fred.
If you disconnected the run capacitor that has the red and yellow wires going to it (in the picture above) then the compressor probably will not run at all. The SPP6E and SPP4E are designed to add to the run capacitor, not replace it.
IF you are still having difficulty starting the compressor with the generator, my suggestion is to measure the capacitance of the factory capacitor, or replace it with one that is 5 mfd higher rating, and about the same voltage rating.
IF you have a volt meter, you will be surprised what voltage is read across the red and yellow wires. You normally will find about 135 to 155 volts. Yes even the two brown wires going to the outside fan should read about 135 - 155 volts when only 110 - 120 volts is applied to your RV power cord. This is normal. Even measuring your home 220 volt A/C unit capacitor will read about 250 - 300 volts, perhaps more.
So the SPP6E will work, but it is not the product designed for 120 volt compressors. It is designed to drop out at 180 volts, for compressors using more than 190 volts input power. It is only the electronic time delay that keeps the capacitor from staying in the circuit all the time, and burning up the compressor with high amperage that it is not rated to use. The SPP4E will drop out at 120 - 130 volts across the capacitor, something that will happen in your system, even with only 108 volts applied to the compressor run winding.
Fred.
