Capacitor (For Ac Operators) - Chamberlain LA500U Troubleshooting Manual

To protect against fire and electrocution:
• DISCONNECT power (AC or solar and battery) BEFORE installing or servicing operator.

CAPACITOR (FOR AC OPERATORS)

SYMPTOM:
A bad capacitor will cause a motor to hum when trying to run, or stall while it is running.
CHECK THE CAPACITOR:
1
Disconnect ALL power from operator.
SOLUTION:
If the capacitor measures less than 90% of the rating, it should be replaced.
BASIC TROUBLESHOOTING
2
IMPORTANT: Discharge the capacitor BEFORE
touching it!
Discharge the capacitor by touching a
screwdriver across the capacitor terminals
(make sure to hold the insulated end of the
screwdriver when doing this). You may see a
small spark when discharging the capacitor,
this is normal.
Visually inspect the capacitor for any burn
marks, bubbling or oil leakage. This is a good
indication of a bad capacitor.
6
3
Using a multi-meter, measure the capacitance
between the capacitor contacts. The
measurement on the meter should be within
10% of the uF rating on the label.