Chamberlain Power Drive PD420D 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 12.
• Depending on your door's construction, you may
need additional mounting hardware for the door
bracket (Step 12).
ONE-PIECE DOOR WITHOUT TRACK
Header Wall
Gap between floor
and bottom of door must not exceed 1/4" (6 mm).
Safety Reversing Sensor
ONE-PIECE DOOR WITH TRACK
Gap between floor
and bottom of door
Safety
must not exceed 1/4" (6 mm).
Reversing Sensor
Rail
Wall-mounted
Door Control
Access
Door
Safety Reversing
Sensor
Header
Wall
Access
Door
Garage
Door
Safety
Reversing
Sensor
5
WARNING
Without a properly working safety reversal system,
persons (particularly small children) could be
CAUTION
SERIOUSLY INJURED or KILLED by a closing garage
door.
• The gap between the bottom of the garage door and
the floor MUST NOT exceed 1/4" (6 mm). Otherwise,
the safety reversal system may not work properly.
• The floor or the garage door MUST be repaired to
eliminate the gap.
Motor unit
CLOSED POSITION
Rail
Bracket
Header
Trolley
Bracket
Door
Bracket
Straight
Garage
Door
Door
Arm
Header
Wall
CLOSED POSITION
Rail
Trolley
Bracket
Header
Curved
Bracket
Door Arm
Door
Straight
Bracket
Door
Arm
Emergency Release
Rope & Handle
Rail Assembly
Emergency
Release
Rope & Handle
Curved
Door
Arm
Rail Assembly