Chamberlain Power Drive Security+ HD400DM Owner's Manual page 5

Planning (Continued)
ONE-PIECE DOOR INSTALLATIONS
• Generally, a one-piece door does not require
reinforcement. If your door is lightweight, refer to the
information relating to sectional doors in Installation
Step 11.
• Depending on your door's construction, you may need
additional mounting hardware for the door bracket
(Step 11).
ONE-PIECE DOOR WITHOUT TRACK
Header Wall
Gap between fl oor and
bottom of door must not
Safety Reversing
exceed 1/4" (6 mm).
Sensor
ONE-PIECE DOOR WITH TRACK
Gap between fl oor and
Safety
bottom of door must
Reversing
not exceed 1/4" (6 mm).
Sensor
Without a properly working safety reversal system,
persons (particularly small children) could be
SERIOUSLY INJURED or KILLED by a closing garage
door.
• The gap between the bottom of the garage door and
• The fl oor or the garage door MUST be repaired to
FINISHED CEILING
Support bracket
& fastening hardware
is required. See page 15.
Rail
Slack in chain
tension is normal
when garage
door is closed.
Wall-Mounted
Door Control
Access
Door
Safety Reversing
Sensor
Header
Wall
Access
Header
Door
Wall
Safety
Reversing
Sensor
5
the fl oor MUST NOT exceed 1/4" (6 mm). Otherwise,
the safety reversal system may NOT work properly.
eliminate the gap.
Motor Unit
CLOSED POSITION
Trolley Stop Bolt
Header
Rail
Bracket
Door Bracket
Straight
Door Arm
Garage
Door
CLOSED POSITION
Trolley Stop Bolt
Cable
Curved
Header
Door Arm
Bracket
Door
Straight
Bracket
Door
Arm
Garage
Door
Cable Trolley
Emergency
Curved
Release Rope
Door Arm
& Handle
Chain
Rail
Emergency
Release
Rope &
Handle