Entrapment Protection Accessories (Optional); Limit Switch Adjustment - Chamberlain H Owner's Manual

ENTRAPMENT PROTECTION ACCESSORIES (OPTIONAL)

SENSING EDGES & PHOTO EYES
Sensing devices supplied for door industry type operators
with an isolated normally open (N.O.) output are compati-
ble with your operator. This includes pneumatic and elec-
tric edges, and through beam and retro reflective photo
eyes. If your door does not have a bottom sensing edge or
safety photo eyes and you wish to add a safety device to
your application, please contact your local LiftMaster
Authorized Dealer.
If not pre-installed by the door manufacturer, mount the
sensing edge on the door according to the instructions pro-
vided with the edge. The sensing edge may be electrical-
ly connected by either coiled cord or take-up reel. Refer to
the steps below.
Important Notes:
a) Proceed with Limit Switch Adjustments before making
any sensing edge wiring connections to operator as
described below.
b) Electrician must hardwire the junction box to the oper-
ator electrical box in accordance with local codes.
MAKE SURE THE LIMIT NUTS ARE POSITIONED BETWEEN THE LIMIT SWITCH ACTUATORS BEFORE
PROCEEDING WITH ADJUSTMENTS.
1. To adjust limit nuts depress retaining plate to allow
nut to spin freely. After adjustment, release plate
and ensure it seats fully in slots of both nuts.
2. To increase door travel, spin nut away from actu-
ator. To decrease door travel, spin limit nut
toward actuator.
3. Adjust open limit nut so that door will stop in open
position with the bottom of the door even with top
of door opening.
4. Repeat Steps 1 and 2 for close cycle. Adjust close
limit nut so that actuator is engaged as door fully
seats at the floor.
OPEN Limit Switch
Retaining Plate
AUXILIARY OPEN
Limit Switch

LIMIT SWITCH ADJUSTMENT

6
NOTICE
IT IS STRONGLY RECOMMENDED THAT A
SAFETY PHOTO EYE OR SENSING EDGE BE
USED IN CONJUNCTION WITH THE OPERATOR.
WIRING:
For wiring of your sensing device to the operator,
refer to the wiring diagram supplied with your opera-
tor. See field connection terminals identified as
Sensing Device or Safety Edge.
TAKE-UP REEL: Take-up reel should be installed
12" above the top of the door.
COIL CORD: Connect operator end of coil cord to
junction box (not supplied) fastened to the wall
approximately halfway up the door opening.
WARNING
TO AVOID SERIOUS PERSONAL INJURY OR DEATH
FROM ELECTROCUTION, DISCONNECT ELECTRIC
POWER BEFORE MANUALLY MOVING LIMIT NUTS.
If other problems persist, call our toll-free number for
assistance - 1-800-528-2806. CAUTION
CLOSE Limit Switch
Actuator
SAFETY
(Aux. Close) Limit Switch
W