Hvac School - For Techs, By Techs

In this short podcast episode, Bryan goes through the process of testing and replacing a run capacitor.  Run capacitors provide continuous phase-shifted current to the start winding, allowing the motor to run in the right direction and with the appropriate amount of torque. These capacitors are needed in most of the single-phase PSC motors we work with. Run capacitors are in the circuit all the time and are connected in series with the start winding (compared to start capacitors, which need to be taken out of the circuit after startup). They don't actually "boost" voltage. The bigger the capacitor, the more current can move in and out of the start winding. Run capacitors are made of foil and oil (and the manufacturing quality usually correlates to the capacitor's lifespan), and they usually fail due to overvoltage or overheating. Capacitors may also be replaced with one of a higher voltage rating but not a lower one. Before you test a capacitor, perform a visual inspection. Bloated tops and oil leakage are si