Friedrich OES Series, Installation & Operation Manual

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920-138-02 (3-04) 920-138-02 (3-04)
Motorized Fresh Air Damper (XM)
General Descrption
The MFAD has two positions. It can be closed or fully open
allowing up to 30% of the total airflow rating of the unit to
be introduced from the outside. A 24-Volt actuated motor
from an external input controls the damper. Pressure relief is
not provided. The damper is wired from the factory to open
whenever the indoor fan is on.
Extension Flange
Damper Frame
Damper Motor
3/16" Rivet for
Mist Eliminator
Stop Rest
Damper Blade
Damper Motor
Linkage
Damper Frame
Extension
Flange
No Vent Option (XN)
General Description
To be used in applications where the outside air is not required
to be mixed with conditioned air. Units with vent packages
have louvered front panels to allow for air intake. Units without
ventilation packages have a BOP (blank off plate) instead of
a louvered panel. The BOP completely restricts the intake of
any outside air.
Figure 16
Motorized Fresh Air Damper Components
Outdoor Temperature (°F)
80 75 70 65 60 55 50
Enthalpy Setting
A
15% 40% 65% 85% >90% >90% >90%
B <10% 25% 45% 70% 90% >90% >90%
C <10% 15% 35% 55% 75% >90% >90%
D <10% <10% 20% 40% 60% 80% >90%
* The economizer control makes the decision to economize at outdoor temperatures and enthalpy settings shown above. At %RH above the setting, the econo-
mizer will not open. At %RH below the setting, the economizer will open to maintain space temp.
Table 7 - Enthaply Set Points
Adjustment
No adjustment necessary. The damper will open when the
indoor fan turns on.