Chamberlain LIFTMASTER PROFESSIONAL MSLDCBB, Installation And Service Manual

14

WARNING: Disconnect batteries and AC power before servicing
any mechanical or moving components.

BATTERY CHECKOUT

When the batteries become weak the gate will begin to run
noticeably slower. 

(

NOTE:

Batteries should only be checked when

you are sure they have had adequate time to fully charge.)

Turn

off the AC power and run gate for 5 to 10 cycles while observing
low battery indicator LED D12. If LED 12 comes ON, batteries are
too weak to function properly. If LED 12 does not light, then
voltage should be checked as they still maybe near failure.
Correct voltage is approximately 25.5VDC. 

(

NOTE:

If LED D12

does light, gate will open to conserve batteries in this test or in a
real power loss, even if mode switch 8 on S2 is off.)

Return of AC

power will clear low battery indicator. Correct charge voltage is
27.5 VDC with batteries not connected (adjustment is at R63).

GATE NOT OPERATING

GATE WILL NOT CLOSE

1)

Check for any active inputs, AC power loss, AC power switch
is off or weak batteries.

2)

Check that batteries are connected properly.

3)

Is switch S-3 in on position (this is manual open switch).

4)

Check for S-2 switch number 8 is in on position and if AC
power is lost, see LED D14.

5)

Check LED D12, if lit and AC power is off, then batteries
needs to be charged or replaced.

GATE WILL NOT OPEN

1)

Check for AC power loss at D14 (check AC power switch)
and that batteries are fully charged.

2)

Check fuses and if inputs are wired correctly, test S-3
manual open switch.

O P E R AT I O N

MANUAL OPERATION

To operate gate manually, turn off the MOTOR BREAKER switch
located on the right side of the gate operator frame.

Once turned off, motor will not run and gate can be pushed by
hand.

T R O U B L E S H O O T I N G

Flip switch up for
normal operation.

Flip switch down to
disengage power to
motor and for manual
operation.

M A I N T E N A N C E

GENERAL SERVICE

1)

Belt loose or needs replacement, adjust with 4 bolts that
support motor to allow 1/4" play.

2)

Charge voltage for batteries should be 27.5 VDC with
batteries disconnected (set at R63).

3)

Replace batteries with 

LiftMaster MBAT or 29-NP712

, 7 or

10 amp hour 12 VDC sealed lead/acid type.

GATE DEAD, NO OPERATION

1)

Check LED D14 for AC power indication and check AC power
switch is on.

2)

Check LED D11 for Heart Beat pulses, if none and D14 (AC) &
D5 (Brake) are  on, then gate has repeatedly sensed
obstructions. Clear obstruction then clear with next new input.

3)

IRD (D2) LED is flashing, Maximum Run Timer (MRT) has
expired. Gate was unable to reach the closed limit
switch.Check that fast run timer is set to run as long as
possible.

4)

Motor breaker switch is OFF or TRIPPED. Be sure gate is
unobstructed before resetting!

FUSE(S) ARE BLOWN, F-3 (10 AMP AC) AND/OR F-4 (15 AMP DC)

1)

Check for shorts in wiring. If F-3 AC fuse is blown then
batteries may also be dead.

Warning: For continued protection against fire, replace ONLY
with the same type and rating of fuse.

GATE CLOSES THEN REVERSES

1)

See IRD adjustments, also check for obstacles in gate travel,
trees, sticks, rocks, etc.

2)

Charge voltage to batteries too low, adjust at R63. With
batteries disconnected set to 27.5.

IRD OBSTRUCTION SIGNAL TO OTHER GATE NOT WORKING
CORRECTLY

1)

Remove connector at J3, obstruct gate, LED D13 should go
off for a few seconds. This indicates signal was transmitted.
Be sure gates share a common ground (see master/second,
page 10).