Checking Run Capacitors Underneath Load

Tip: Checking Run Capacitors Underneath Load

By Gary McCreadie

Checking run capacitors beneath load is an alternate technique to shutting down energy to a system and checking within the conventional method through the use of the uF (microfarad) setting in your meter.  I’d at all times suggest checking capacitors with the facility off, from a security stand level, reaching right into a reside electrical cupboard in contrast reaching into a cupboard with no energy is at all times the safer possibility.  However, there are some circumstances the place the system might have to proceed operating throughout testing, if maybe the system is serving a crucial surroundings or you are attempting to carry out a arrange of system controls and are unable to kill the facility.  

Observe the process beneath.

1. Set your clamp meter to amps and take an amp draw studying of the motor begin winding wire related to the capacitor, notice the studying.

2. Now, set your meter to volts and take a studying throughout the capacitor, that offers you the again electromotive power (EMF) of the motor, notice the studying. 

3. Plug your readings into the next formulation beneath…

4. Begin winding amps x 2650 (fixed) / Again EMF

The above process will spit out the microfarad studying beneath load.  Run caps are stamped with a +/- proportion, in case your calculation falls inside that +/- vary, you need to be good to go.  

Take a look at the video beneath for a demo of the above rationalization

Take a look at the hyperlink to my YouTube channel for extra suggestions, methods, and troubleshooting movies and take a look at the The HVAC Know It All podcast right here or in your favorite podcast app.  Glad HVACing…

Gary McCreadie