HOW TO CHECK BLOWN FUSES & CAPACITOR CELLS
In Fixed Power Factor Correction Capacitors
Trouble: Fuse light is illuminated.
- This indicates that a fuse is blown. Power surges or harmonics are two common causes of fuse failure.
- Disconnect power from the capacitor unit and wait one minute after the power has been disconnected to allow capacitors to discharge.
- Check affected capacitor following steps below: How to Test a Capacitor Cell
- Replace affected fuse.
Trouble: Amber light is illuminated in KIM model PFCC
- This may indicate that a fuse is blown or the capacitor has lost capacitance.
- Check amperage draw of capacitor unit while it is connected to power based on following table. If the amperage is low complete the next three steps.
| Applied Voltage | 208V | 240V | 480V | 600V |
| Amps / kVAr | 2.78 | 2.41 | 1.20 | 0.96 |
- Disconnect power from the capacitor unit and wait one minute after the power has been disconnected to allow the capacitors to discharge.
- Check the fuses using an ohmmeter. Replace any blown fuses.
- Check the capacitors following steps found in steps below: How to Test a Capacitor Cell
- Replace bad capacitor cells.
How to Test a Capacitor Cell:
With a Capacitance Meter
Capacitor cells are rated in microfarad and voltage. The easiest way to test a cell is to measure the microfarads with a capacitance meter.
- Disconnect power from the capacitor unit and wait one minute after the power has been disconnected to allow the capacitors to discharge.
- Measure microfarads using capacitance meter. The microfarads should be equal to the microfarad rating or up to 5% over the rating. This microfarad table may be used as a reference.
- If microfarads are below the minimum, the cell is going bad.
- Replace bad capacitor cells.
Visual Inspection of Cell
If a capacitor meter is not readily available, the status of a cell can sometimes be determined visually.
- If the cell can is “bulged out” or “pouched up” on the top, it is definitely bad.
- Disconnect power from the capacitor unit and wait one minute after the power has been disconnected to allow the capacitors to discharge.
- Replace bad capacitor cells.
