Model IGX Make-Up Air
35
®
Potentiometer Recirculation Control
• Power passes to inlet damper which opens.
• When damper is fully opened, normally open
damper limit switch (DL1) closes.
• Power passes to and energizes supply starter relay
(RF).
• Power passes to normally open fan contact (RF),
which is energized and closed. Power reaches and
energizes supply fan.
• The potentiometer will output a 2-10 VDC signal
to the recirculation damper actuator to control
recirculation damper position.
External Signal Recirculation
• Power passes to inlet damper which opens.
• When damper is fully opened, normally open
damper limit switch (DL1) closes.
• Power passes to and energizes supply starter relay
(RF).
• Power passes to normally open fan contact (RF),
which is energized and closed. Power reaches and
energizes supply fan.
• An external source will provide a 2-10 VDC or
4-20 mA signal to the recirculation damper
actuator to control recirculation damper position.
Building Pressure Recirculation Control
• Power passes to inlet damper which opens.
• When damper is fully opened, normally open
damper limit switch (DL1) closes.
• Power passes to and energizes supply starter relay
(RF).
• Power passes to normally open fan contact (RF),
which is energized and closed. Power reaches and
energizes supply fan.
• The photohelic building pressure controller will
monitor the pressure differential between the
pressure in the controlled space and the pressure
outside the controlled space.
• If the pressure differential is below the set point
range established on the photohelic controller,
the recirculation damper will be modulated further
closed.
• If the pressure differential is above the set point
range established on the photohelic controller,
the recirculation damper will be modulated further
open.
• If the pressure differential is within the set point
range established on the photohelic controller,
the recirculation damper will remain in its current
position.
OPTIONAL NIGHT SETBACK
Night Setback Schedule
• The night setback schedule is established within
the programmable thermostat on the remote
panel. The schedule must be set for the occupied
and unoccupied hours of the controlled space.
Night Setback Fan Control
• During occupied hours, the fan sequence of
operation is the same as that described in the
“Supply Fan” section.
• During unoccupied hours the fan is turned off.
• If there is a call for heating from the space
thermostat, the fan will be turned on to allow for
tempering operation.
• When the call for heating from the space
thermostat ends, the fan will be turned off.
Night Setback Heat Control
• During occupied hours, the heating sequence of
operation is the same as that described in the
“Heat” sections.
• During unoccupied hours, the unit is off until there
is a call for heating from the space thermostat.
When the unit is enabled by a call for heat from
the space thermostat, the heat is also enabled
and the discharge temperature overridden to a
maximum value to provide the maximum amount
of heat to the space.
• When the call for heating from the space
thermostat ends, the unit will be turned off.
Night Setback Variable Volume Control
• During occupied hours, the variable volume
sequence of operation is the same as that
described in the “Optional Variable Volume”
section.
• During unoccupied hours, the unit is off until
there is a call for heating from the space
thermostat. When the unit is enabled by a call for
heat from the space thermostat, the supply fan
will run at minimum speed.
• When the call for heating from the space
thermostat ends, the unit will be turned off.
Night Setback Recirculation Control
• During occupied hours, the recirculation sequence
of operation is the same as that described in the
“Optional Recirculation” section.
• During unoccupied hours, the unit is off until there
is a call for heating from the space thermostat.
When the unit is enabled by a call for heat from
the space thermostat, the recirculation damper
will be opened to provide a maximum amount of
recirculated air to the unit.
• When the call for heating from the space
thermostat ends, the unit will be turned off.
Sequence of Operation
