Split Capacitors on Resi AC

[crisrs]

I was wondering if there is any damage to be caused by leaving an oversized capacitor on a fan or compressor after an emergency repair. Like a 45 /7.5 when the original was a 35/5. .

[wambat]

I was wondering if there is any damage to be caused by leaving an oversized capacitor on a fan or compressor after an emergency repair. Like a 45 /7.5 when the original was a 35/5. .

All PSC motors will have run capacitors on them and as such this means that the start winding is always in the circuit but in order to keep the start winding in the circuit you need a way to control the amp draw, thats where the amount of capacitance comes in so for your edification I will tell you that the lower the capacitance the higher the impedence this in effect controls the amount of amperage so the start windings don't over heat. Now if your concerned about the bigger one then take an amp reading on both moters and make sure that the amps are within the motors specs

[Larry2]

I can say from my experience with my system shutting down during hot outdoor temperatures, that the larger sized capacitor will cause the fan motor to run hotter and consume more power. You can expect the compressor to do likewise. Just as you're describing, I made an "emergency repair" and forgot about the excess sized capacitor. It took a long time to figure out the cause of intermittent shutting down.

My recommendation is to locate the correct part that has been engineered for your application.