Wireless Zone Sensors (Wzs) - Trane UniTrane Installation, Operation And Maintenance Manual

Table 62. Fan coil and cabinet heater troubleshooting recommendations
Symptom Probable Cause
Missing filters
Excess dirt in unit
Filter bypass
Microbial growth
(mold) inside air Standing water in drain pan
handler
Incorrect airflow
Expansion valve is not operating properly or is sized
incorrectly
Incorrect refrigerant charge
Condensing unit failure
Low refrigerant coil Coil is piped incorrectly
capacity Clogged refrigerant line filter
Failure of suction/liquid line components
Dirty fin surface
Fin frosting

Wireless Zone Sensors (WZS)

The receiver for all models has four LEDs: LED1, LED2,
LED3, and LED5. Figure below shows their locations.
Note: To view LEDs on a flush mount receiver on a fan coil
unit, the front panel of the unit must be removed.
Figure 108. Receiver for all fan coil models showing LED
locations
1
Pb-FREE
J2
LED1
LED1
LED2
LED2
LED3
LED3
S1 S2 S3
SIGNAL
ADDRESS
LED5
LED5
POWER
C34 J1
HEATING SET
FAN/SYSTEM
S5 SETPOINT
ZONE
GND-SIGNAL
24VAC/DC
GND-POWER
COMM +
COMM -
The sensor for a wireless zone sensor (WZS) has four
LEDs: LED1, LED2, LED3, and LED5 and a test button.
Figure below shows their locations.
UNT-SVX07J-EN
WIRELESS
INSTALL
LED4
S4
C35
R77
Diagnostics and Troubleshooting
Recommended Action
Replace filters
Reduce filter bypass by ensuring all blockoffs are in place.
See "Standing water in drain pan" above
Check fan operating condition.
Check sensing bulb temperature.
Verify valve operation.
Verify proper valve size.
Verify refrigerant charge and adjust if necessary.
Verify condensing unit operation.
Verify coil piping (see "Coil Piping and Connections," p.
Change filter core.
Verify component operation
Clean the fin surface.
Do not use steam to clean refrigerant coils.
Verify defrost cycle operation.
Verify frostat operation.
Verify refrigerant charge.
Figure 109. WZS showing LED locations and test button
1
J2
LED1
LED1
LED2
LED2
LED3
LED3
S1 S2
SIGNAL
ADDRESS
LED5
LED5
POWER
C34
HEATING SET
FAN/SYSTEM
S5
SETPOINT
ZONE
GND-SIGNAL
24VAC/DC
GND-POWER
COMM +
COMM -
The sensor for a wireless display sensor (WDS) has test
symbols and error codes that appear on the display, and a
test button. See the figure below.
53.)
WIRELESS
Pb-FREE
INSTALL
LED4
S4
S3
J1
C35
R77
131