Mixing Box/Filter Mixing Box Damper Linkage; Damper Linkage Adjustment; Linkage Adjustment - Carrier Aero 39MN Series Installation, Start-Up And Service Instructions Manual

Mixing Box/Filter Mixing Box Damper Linkage

CAUTION
It is important to properly link the outdoor-air and return-
air dampers. Failure to do so may cause mixing problems,
stratification, or coil freezing under some conditions, espe-
cially in combination type filter mixing boxes.
Refer to Fig. 39 for typical damper arrangement and con-
necting rod position.
CONTROL DAMPERS — Control dampers may be operat-
ed with pneumatic or electric actuators. These items should be
set up in accordance with the control manufacturer's installa-
tion instructions.
DAMPER LINKAGE ADJUSTMENT — After the air-han-
dling unit has been powered, the dampers should be checked to
ensure they move freely and close tightly. Adjustment of the
linkage may be required.
Fig. 37 — Zone Damper Assembly Details (Horizontal Discharge Shown)

LINKAGE ADJUSTMENT

1. With the damper actuator unpowered and the damper
linkage disconnected, rotate the outdoor-air damper so
that it is fully closed. Make sure the spring return actu-
ator has completed its stroke (with power disconnected
this will be achieved). The return-air damper should be
fully open at this point.
2. Tighten the actuator on the damper jackshaft, ensure
all linkage is connected, secure and moves freely.
3. With power applied to the actuator, check for a com-
plete stroke and free movement in the dampers and
damper linkage.
.
Dampers and linkage must be checked prior to applying
power. Make certain that there are no obstructions that
could interfere with the operation of the dampers, or equip-
ment damage could result.
98
CAUTION
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