Start Capacitor Query

[wayne]

Hi all
I’m recently replaced a motor start capacitor for a refrigerant compressor on a ground source heating system. The previous item failed, I have since replaced it and the system is working fine. But it wasn’t like for like. The original capacitor was 145-174uF but the item I replaced it with was 150uF. Essentially I needed to get the system running and reinstate the heating to the property. Could anyone tell me if the capacitor I’ve used is sufficient, or should I order a like for like part? I’m unsure what significance the 145-174uF range of the old capacitor holds? The start package consists of a start relay, start capacitor, run capacitor and soft start module.
Any help would be greatly appreciated
Cheers
Wayne

 

[Andy™]

should be fine. close enough to original. unless the one you replaced was way out of spec after being replaced previously...

 

[Geoff1946]

That sort of capacitor has a wide manufacturing tolerance. The one quoting a range is declaring that, the other is stating its nominal value. The important thing is that the voltage rating is high enough.

 

[stuboy]

Yep as long as you got an ac mains capacitor of the correct rating u r good to go. If a cap shows only one value without a plus and minus percentage then the value stated should be a minimum value. Capacitors can have really quite wide tolerance values compared to say resistors. The Starter cap is basically to get the motor running in the first place by causing a phase shift in the AC waveform causing magnetic flux to build up in one direction in the stator thus getting the rotor to start spinning.
Cheers
Stuart

 

[wayne]

Thanks for the help all I checked that the failed capacitor was original spec, I would have ordered the same again but was only available from the U.S. on a long lead time. New capacitor is rated to the correct voltage, so should be all good Thanks again