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73
YORK INTERNATIONAL
FORM 100.50-NOM1 (604)
5
This operation is not available when an OA Flow Sta-
tion is installed.
The Exhaust Fan will be controlled by the OAD posi-
tion as follows:
• Fan ON when the position = OAD Position for the
Exhaust Fan to Turn ON. The damper position to
turn on is programmed through the parameter “
OA
DMPR Pos For ON”
• Fan OFF when the position = OAD Position for the
Exhaust Fan to Turn OFF. The damper position to
turn off is programmed through the parameter “
OA
DMPR Pos For OFF”
• Exhaust fan OFF when Supply Fan is OFF
On/Off control Based on OAD Position is illustrated
in Figure 40.
On/Off Exhaust Fan Control Based on Building
Pressure
This power exhaust option uses the building pressure to
turn a constant volume exhaust fan on or off.
This option requires the following:
• “
Economizer Enable”
ON
• Supply Fan – ON
• Constant volume exhaust fan
• Building Pressure Transducer
Sequence of Operation
When the Building Pressure reaches or exceeds the
“
Building Pressure”
setting plus the “
Exhaust Cntrl
Offset”,
the Primary Unit Controller will energize the
constant volume Exhaust Fan. The Exhaust Fan will
remain energized until the Building Pressure drops to
or below the “
Building Pressure”
setting minus the
“
Exhaust Cntrl Offset”
. Figure 41xxx illustrates this
operation.
FIG. 40 –
OAD POSITION CONTROL
LD06577
Exhaust Fan
Turns Off
OAD Position
for EF to Turn
OFF
ON
OFF
OAD Position
Exhaust Fan
Turns On
OAD Position
for EF to Turn
ON
N
FIG. 41 –
BUILDING PRESSURE CONTROL
ON
OFF
Building Pressure
Setpoint
minus Exhaust
Control Offset
plus Exhaust
Control Offset
Exhaust Fan
Turns Off
Exhaust Fan
Turns On
LD06578
On/Off Exhaust Fan Control Based on Building
Pressure and Exhaust Damper Position
This power exhaust option uses the building pressure
to modulate an exhaust damper. The position of the
exhaust damper is used to turn a constant volume ex-
haust fan on and off.
This option requires the following:
• “
Economizer Enable”
ON
• Supply Fan – ON
• Constant volume exhaust fan
• Building Pressure Transducer
• Modulating Exhaust air damper