Wiring a Capacitor in Series vs. Parallel

A good skill to be able to master is combining capacitors in the field.  Have you ever been on a service call and needed a specific capacitor, only to find that your truck stock is out of that particular size?  The local supply house is closed, it is late in the day, and the customer would like the house to cool down before bedtime.  

Increasing the size of the capacitor, wiring in parallel, is the easier of the skills to master.  The capacitance is simply added together.  For example, you need a 40MFD capacitor.  Simply wire a 10MFD with a 30MFD, in parallel, and you have your 40MFD capacitor.

Wiring a capacitor in series can be a little tricky.  The formula for capacitance in series is : 1÷ (1÷C + 1÷C) = total capacitance wired in series.  The total capacitance will always be less than the smallest capacitor.  Imagine you need to change the capacitor of a condenser fan motor.  Most of the Rheem 13 SEER condensers use a 5MFD capacitor for the fan motor.  Say you only have two 10MFD capacitors on your work truck.

 

Capacitor = 1÷((1÷10)+(1÷10)

1÷((.10)+(.10))

1÷20

Total = 5MFD

 

Alternatively, ABR Wholesaslers stocks Turbo 200 Capacitor and Turbo 200 Mini Capacitors.  The Turbo200 ranges from 2.5MFD to 67.5MFD, and voltages from 370V to 440V.  The Turbo200 Mini ranges from 2.5MFD to 5MFD, and voltages from 370V to 440V.