Chamberlain 7220 1/2HP - Manual (Page 5)

Access
Door
Gap between floor
and bottom of door
must not exceed 1/4"
Safety
Reversing Sensor
Safety
Reversing
Sensor
CLOSED POSITION
Header
Bracket
Cable
Pulley Bracket
Door
Bracket
Straight
Door
Arm
Curved
Door Arm
Trolley
Emergency Release
Rope & Handle
T-rail
Garage
Door
Cable
Header
Wall
Chain
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).
FINISHED CEILING
Support bracket
& fastening
hardware is required.
See page 17.
Slack in chain tension
is normal when
garage door is closed.
Safety Reversing
Sensor
Header
Wall
Safety
Reversing Sensor
Gap between floor
and bottom of door
must not exceed 1/4"
Motor Unit
Access
Door
Wall-
mounted
Door
Control
Cable
Pulley Bracket
Header
Bracket
Trolley
Straight
Door
Arm
Emergency
Release
Rope
& Handle
Door
Bracket
Curved
Door
Arm
Header
Wall
T-rail
Garage
Door
Cable
Chain
CLOSED POSITION
ONE-PIECE DOOR WITHOUT TRACK
ONE-PIECE DOOR WITH TRACK
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 floor MUST NOT exceed 1/4". Otherwise, the safety
reversal system may not work properly.
• The floor or the garage door MUST be repaired to
eliminate the gap.
WARNING