Carrier 69NT40-541-306, Operation And Service

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7–37 T-354
Figure 7.30 Return Sensor Positioning
Sensor STS/SRS
Reinstall the supply sensor as shown in Figure 7.31 . For proper placement of the supply sensor, be sure to position
the seal section of the sensor against the side of the mounting clamp.
Figure 7.31 Supply Sensor Positioning
Sensor DTS
The DTS sensor must have insulating material placed completely over the sensor to insure the coil metal tempera-
ture is sensed.
7.24 VENT POSITION SENSOR (VPS)
The vent position sensor (VPS) determines the position of the fresh air vent in near real-time via the function code 55.
The fresh air VPS alarm (AL50) will occur if the sensor reading is not stable for five minutes or if the sensor is out-
side of its valid range (shorted or open). This can occur if the vent is loose or the panel is defective. To confirm a
defective panel, assure that the wing nut is secure and then power cycle the unit.
The alarm should immediately go inactive. Check the four-minute stability requirement. If the alarm reoccurs after
the four minutes and the panel was known to have been stable, then the panel should be replaced.
If the alarm immediately reappears as active, the panel should be replaced.
Cap and Grommet
Assembly
Probe
Holder
Return Sensor
Sensor
Wires
Return
Air
Stream
Evaporator
Back Panel
6mm
(1/4--inch)
Evaporator Grille
Combination
Sensor (Mount in
Either Clamp)
Mounting
Clamp
Seal