Nortek YDHA - Optional Dampers and Damper Actuator

Form O-Y P/N 273647R5, Page 9
3.3 Optional
Dampers
and Damper
Actuator
Inlet Air Dampers
Location: Dampers and damper motors are located in the inlet air opening.
Function: Dampers operate in response to a variety of controls (GF Options).
Service: Clean dampers and controls of dust and dirt.
2-Position Damper Actuator (Options AR7, AR8, AR2D, AR2L, AR2Y)
Function: The 2-position damper motor opens and closes the dampers in response
to unit operation or a eld-supplied time clock. The motor closes the dampers on
heater shutdown.
Modulating Damper Actuator (Options AR25, AR2G, AR2H, AR2M)
Function: The modulating damper motor actuates the dampers in response to the
selected control with actuation from input switch settings.
The motor closes the inlet dampers on heater shutdown.
Service: Other than external cleaning, there is no service required on the dampers or
the damper motor. If the damper, control, or motor need to be replaced, replace with
a factory-authorized replacement.
For additional information on damper controls (Options GF 1-9), see the system
installation manual Form I-Y.
FIGURE 6 - Damper
Actuator is mounted
on the damper frame
and is accessible
through the Damper
Access Door (See
FIGURE 1, page 4).
Outside Air Humidity
and Temperature
Sensor
Function: All systems have an outside air humidity and temperature sensor in the
outside air inlet. The sensor is wired to the system controller in the electrical compart-
ment.
Service: Check the wiring. If the sensor needs replaced, use a factory-authorized
replacement designed for the application.
FIGURE 5 - Outdoor
Air Sensor, P/N
222754, is mounted
in the outside air
inlet (behind the
hood)
Air Proving Switch
P/N 234712
Set Point 0.10 I.W.C.
Function: The airow proving switch is a pressure switch that veries to the main
controller that the supply fan is operating. If equipped with power exhaust or an
energy recovery wheel, there is a second air proving switch that veries the exhaust
fan is operating. See location in FIGURE 1, page 4.
Service: If a switch needs to be replaced, use a factory-authorized replacement
designed for the application.
3.0 Maintenance and Service Procedures - Unit & Cooling (cont'd)
3.2 Supply Fan and Variable Frequency Drive (cont'd)