Adjustments; Instant Reverse Device (Ird); Adjust The Barrier Arm - Chamberlain MADCBB Owner's Manual

ADJUSTMENTS »
To reduce the risk of SERIOUS INJURY or DEATH:
• Disconnect power BEFORE performing ANY adjustments near drive shaft.

INSTANT REVERSE DEVICE (IRD)

Adjustments to be done by qualified service persons only.
The instant reverse device is an internal circuit that continuously monitors the
motor's current for increased draw in order to detect obstructions. If the arm
is obstructed while closing the arm will reverse to the open position, time out
(using the time delay set at S-2 switches 1-5) and then close. If arm is
obstructed while opening, the arm will stop, time out (using the time delay set
at S-2 switches 1-5) and then close.
Turning the IRD1 right (clockwise more sensitive), or left (counter clockwise
less sensitive) in small increments will allow sensitivity adjustments (IF ARM
DOES NOT REVERSE, DO NOT CONTINUE TO FORCE).
1 Place an obstruction in the path of the arm. Adjust sensitivity so that
consistent reversal occurs when the arm hits the obstruction. If the gate
stops while opening then the IRD is TOO sensitive.
NOTE: Instant reverse device (IRD) should be tested monthly to ensure proper
operation.

ADJUST THE BARRIER ARM

The arm should be level in the HORIZONTAL POSITION. If the arm is not level it can
be adjusted by sliding the control board and/or adjusting the limit cam. The control
board has two sensors on the back of the control board that sense when the limit
cam has reached the open and close limit.
• If the arm is closing too far: Loosen the control board screws and slide the
control board UP to increase the time it takes for the limit cam to travel between
each sensor.
• If the arm is not closing far enough: Loosen the control board screws and
slide the control board DOWN to decrease the time it takes for the limit cam to
travel between each sensor.
• If the arm is not stopping at the limits: Move the limit cam closer to the
control board by loosening the set screw on the limit cam.
After any adjustment open and close the arm to test if the arm is level. Ensure the
limit cam set screw and control board screws are tight when adjustments are done.
OPERATION AND MAINTENANCE »
1. READ AND FOLLOW ALL INSTRUCTIONS.
2. NEVER let children operate or play with gate controls. Keep the remote
control away from children.
3. ALWAYS keep people and objects away from the gate. NO ONE SHOULD
CROSS THE PATH OF THE MOVING GATE.
4. Test the gate operator monthly. The gate MUST reverse on contact with a
rigid object or stop when an object activates the non-contact sensors. After
adjusting the force or the limit of travel, retest the gate operator. Failure to
adjust and retest the gate operator properly can increase the risk of INJURY
or DEATH.
INSTANT REVERSE DEVICE (IRD) + INSTALL THE BARRIER ARM
IMPORTANT SAFETY INSTRUCTIONS
To reduce the risk of SEVERE INJURY or DEATH:
1
J2
AUX LIMITS
U1
OLS
D7
OPEN
D6
BRAKE
D5
CLOSE
D4
CLS
D3
Location of limit sensor
NOTES:
• In some cases, additional adjustments may be required after the belt wears in.
• To prevent entrapment, allow for two (2) feet minimum clearance past end of
arm when in down position.
IMPORTANT SAFETY INSTRUCTIONS
WARNING
5. Use the emergency release ONLY when the gate is not moving.
6. KEEP GATES PROPERLY MAINTAINED. Read the owner's manual. Have a
qualified service person make repairs to gate hardware.
7. The entrance is for vehicles ONLY. Pedestrians MUST use separate entrance.
8. Disconnect ALL power BEFORE performing ANY maintenance.
9. ALL maintenance MUST be performed by a LiftMaster professional.
SAVE THESE INSTRUCTIONS.
10.
15
MANUAL
1
J3
OPEN
Q2
M/S R14
S3
OPEN 1
C3
X1
U6
IRD1
U7
Location of limit sensor
Limit Cam
(Control Board)
1 2 3 4 5 6 7
J5
T2 T4 T6
T1 T3 T5
OPEN 2 OPEN 3 AUX 4 SAFET
R24 R35 R41 R46 6
(Operator Chassis)
Control Board
Screws