Troubleshooting - Chamberlain LiftMaster Professional SW470 Installation And Maintenance Instructions Manual

24

Troubleshooting

Troubleshooting
A properly installed SW470 or SW490 operator will operate for many years with a minimum or service
maintenance. It is important to note, however, that a binding or defective gate can severely reduce the
life of the operator. The gate operation should be checked frequently as recommended by the
manufacturer. All operator bearings are of the lifetime sealed anti-friction or impregnated type. The
motor is factory lubricated and requires no additional lubrication.
Should electrical malfunction occur, consult the troubleshooting chart below.
Symptom
Motor does not run when
OPEN or CLOSE button is
pressed.
Gate closes when OPEN
button is pressed and limit
switches do not function.
Operator does not shout off
at fully opened or closed
position.
Doc 01-G0665
Rev C
Possible Cause
Building fuse blown or
circuit breaker tripped
Overload protector tripped.
Control circuit not
functioning.
Three phase power supply
is connected out of phase.
R.H./L.H. program.
Limit nuts not properly
adjusted.
Limit switch damaged.
Table 10
Remedy
Replace fuses or reset
breaker and check for
cause.
Reset and check for cause.
Check transformer
secondary voltage. Check
contactor coils for possible
burnout. Check limit
switches. Inspect control
station and all field wiring.
Interchange any two
incoming power supply
leads.
Review page 13 for
R.H./L.H. programming.
See: Limit Switch
Adjustment.
Check limit switch
operation and replace if
necessary.