M-Series Technical Manual
71
Cambridge Engineering, Inc.
9. Remove the wire from the “G” terminal of the termi-
nal block. (This is to avoid a “Call-for-Fan” signal
from the Remote Control Station during the next two
steps).
10. Let the damper assembly hang down (suspended
by the damper motor support bracket) and turn
the heater disconnect on and momentarily turn the
blower service switch to the “LOCAL” position (for
approximately 5 seconds). Do not restrain the drive
tube from turning freely. Then, turn the blower
service switch to the “REMOTE” position until the
damper motor drive tube stops turning. (Drive tube is
now fully retracted).
11. Turn the heater disconnect switch off and manually
trip the motor starter overload. The manual trip lever
is located on the overload between the overload and
the motor starter.
12. Connect the damper linkage to the drive tube by
manually rotating the drive tube in 1/2 turn incre-
ments until the 3/8" diameter bolt can seat into the
nut on the damper linkage. Maintain the damper
blades in the tightly-held, fully closed position dur-
ing this adjustment.
13. Turn the heater disconnect switch on and place the
blower service switch to the “LOCAL” position.
Damper will open to the point the upper cam engag-
es the upper limit switch.
14. Using the deep-well, 1/2" hex socket or nut driver,
turn the upper cam hex nut in a clockwise
direction in one click increments until the damper
blades fully open.
CAUTION:
Do not over-drive the damper motor as damage to the
PC board or tripping of the onboard fuse may result.
If the fuse trips, place the blower service switch in the
“OFF” position for 15 seconds to allow fuse to reset.
15. Turn the blower service switch to the “REMOTE”
position and, after the damper motor closes, turn the
heater disconnect off.
16. Re-install the weather cover push-in plug.
17. Re-connect the wire removed in step 9 to terminal
“G” and reset the motor starter overload.
18. Verify both service switches are in the “REMOTE”
position, close the electrical enclosure door and turn
the heater disconnect switch on.
