Troubleshooting - Chamberlain LiftMaster Professional SL540 Manual

Operator fails to run
" No stop control
➤ Check the green LED (D17) on GL board. If the green LED is off, check to make sure a stop control has been installed across terminals J1-3 and J1-5 of
the GL board.
" Fault in the operator – check the yellow diagnostic LED at the top right of the GL board next to the programming dip switches
➤ If the yellow LED blinks six times, there is a master/second unit communication failure. If operator is a single unit, make sure there is a jumper across
terminals J4-1 and J4-2. If operator is in a dual gate configuration, make sure that the communication wiring between the two units is undamaged and
complete.
➤ If the yellow light is solid, the board needs to learn the motor. Follow the directions on page 21.
" An accessory is active or malfunctioning – check the red input status LEDs, D11-D31
➤ If any red LEDs are on, check the corresponding input. An installed accessory may be wired incorrectly or malfunctioning. Remove the accessory and test
the operator.
➤ If the soft open or interrupt loop LED is on, make sure factory plug-in loop detectors are working properly and appropriate loops are installed on the loop
input terminals P1-P4.
" Improper J4 connector wiring (master/second)
➤ Stand-Alone Operators: Make sure there is a jumper installed across the J4 connector.
➤ Master/Second Operation: Make sure that the master/second wiring is installed correctly and is intact (not damaged).
" Low or no high voltage power
➤ Measure the incoming voltage at the unit's on/off switch. It should be within 5% of the operator's rating when running. Make sure that the proper wire
gauge was used for the distance between breaker and operator by consulting the wiring specifications section on page 14 of this manual.
" Low or no low voltage power
➤ Measure the voltage at terminals R1 and R2 in the operator. This voltage should be within 5% of 24Vac. If the high voltage power is good and the low
voltage power is bad, check to make sure the circuit fuse is not tripped and that the correct primary tap is used on the transformer. If fuse and tap are
correct, replace the transformer.
" No LEDs illuminated on GL board
➤ If both primary and secondary power is good, check to make sure that the J2 connector is making good contact with the pins on the GL board. If all is
good, replace GL board.
Contactor chatters when operator begins to move
" Transformer's secondary is overloaded
➤ Remove all accessory devices and test the operator. If the contactor stops chattering, find an alternate power source for some of the devices.
" Low primary (high voltage) power
➤ Measure the incoming line voltage at the unit's on/off switch. It should be within 5% of the operator's rating when running. Make sure that the proper wire
gauge was used for the distance between breaker and operator by consulting the wiring specifications section on page 14 of this manual.
Operator runs slow and/or trips the internal overload
" Low primary (high voltage) power
➤ Measure the incoming line voltage at the unit's on/off switch as well as the meter base or sub panel. Make sure there is not a major change in voltage. The
voltage at the operator should be within 5% of the operator's rating when running.
➤ Check the number of amps currently being drawn from the panel. Make sure that the total power being drawn does not exceed the panel's rating.
➤ Make sure that the proper wire gauge was used for the distance between breaker and operator by consulting the wiring specifications section on page 14
of this manual.
" Problem in the motor
➤ Perform a visual inspection of the motor. Examine the motor's labels for any distortion or signs of overheating. Replace the motor if it is humming,
grinding or making excessive noise. NOTE: Repeated motor problems indicate poor primary power.
" Problem in the contactor
➤ Examine the contactor for sparking, smoke or burn marks. Remove the wires from one side of the contactor, then measure the contact points for high
resistance (above 1 ohm). Replace the contactor.
" Problem in the brake system
➤ Make sure that the brake is disengaging when the contactor pulls in and engaging when the contactor releases. Replace solenoid.
Master or second operator is not functioning properly
" Failure to cycle power after setup
➤ The power to each unit must be cycled in order to initiate proper master/second communication if the operators were previously in stand-alone mode.
" Communication wiring may be damaged or improperly wired for dual gate operation
➤ Make sure that the communication wire that is used is a twisted pair and not run in the same conduit with any power wiring. Failure to do so will result in
interference across the master/second communication line.
" Master or second unit is not programmed correctly
➤ Review program settings pages 22-23 and check both the master and second for proper programming.
T R O U B L E S H O O T I N G
SYMPTOMS
25
"
POSSIBLE CAUSES
➤
SOLUTIONS