Schneider Electric Low Voltage Capacitor Bank VLVAF5N03519AB

- Check the controller display to confirm it is active and there are no alarm conditions (refer to the VarPlus Logic user manual for alarm details)

- Check alarms such as: - Alarm A9: Indicates internal temperature exceeded the thermal limit of 122°F (50°C)

- Alarm A10: Indicates the maximum THD (7%) has been exceeded

- Check that the cubicle ventilation fans are active. If not, verify by adjusting the thermostat (ST1) after powering down the main breaker and wait for 5 minutes before re-engaging

- Check that all ventilation openings are clear

- Listen for any loud noise (>50 dB) with the unit in full operation. Investigate identified noise sources or contact Schneider Electric if unresolved

- De-energize the capacitor bank by opening the disconnect and ensure the external upstream main breaker is open. Follow lock-out, tag-out procedures and wait five minutes before opening the door

- Open the front door and test for line voltage at the bottom of F1, F2, and F3 (control fuses), which should be 0 V

- Manually trip all stage breakers, then reset to ON

- Repeat all steps outlined in the first scheduled PM

- Use the procedure in "STEP.TST" (page 58) to manually turn the first stage on. Measure and record line-to-line voltage

- Use the procedure in "STEP.TST" to manually turn on each stage one at a time, measuring the stage’s 3-phase line currents and recording results. Turn off the stage before moving to the next

- De-energize the capacitor bank by opening the main disconnect device and wait five minutes

- Test for line AC voltage at the bottom of F1, F2, and F3, which should be 0 V, then repeat the test at the top of F1, F2, and F3

- Use a DC voltage meter to test each capacitor stage for residual DC voltage. Isolate the capacitor if any reading is higher than 1V

- Inspect the capacitor bank for signs of overheating, such as discoloration or flaking

- Check all field-installed bus bar connections and torque values listed on page 55

- Inspect terminal lugs for damage and replace if necessary