Trane Voyager CV Installation And Maintenance Manual page 114

Diagnostics
Table 83. Troubleshooting
SYMPTOM
T. Economizer modulates, but
system does not seem to
operate as efficiently as in the
past.
U. Power Exhaust will not
operate.
V. VFD will not operate
properly
W. Power Exhaust Fan cycles
ON/OFF
Table 84. Component failure mode
COMPONENT
(OAS) Outdoor Air Sensor
(RAS) Return Air Sensor
(MAS) Supply Air Sensor
(OHS) Outdoor Humidity Sensor
(RHS) Return Humidity Sensor
Remote Minimum position
Potentiometer
Cooling Setpoint (CSP) for CV or
SZ VAV ZSM slide potentiometer
Heating Setpoint (HSP) for CV or
SZ VAV ZSM slide potentiometer
TDL1, TDL2 or TDL3
(Temperature Discharge Limit)
114
PROBABLE CAUSE
1. Comparative enthalpy setup, RAS or
RHS failed. System is operating using
Reference enthalpy.
2. Reference enthalpy setup, OHS has
failed. System is operating using dry bulb
control.
3. Comparative enthalpy setup, OHS has
failed. System is operating using dry bulb
control.
1. Exhaust motor has failed.
2. XFR has failed.
3. ECA has failed.
4. XFSP has Failed
1. RTAM has Failed
2. VFD has Failure
3. Setpoint Failure
4. RTOM has Failed
1. Space Pressure Deadband is too
narrow
2. Space Pressure Setpoint is too high/
low
FAILURE RESPONSE
1. Economizer in minimum
position. Will not modulate.
2. ODM3 will not cycle off (runs
continuously).
Economizer operates using
Reference Enthalpy
Economizer in minimum
position, will not modulate.
Uses Dry Bulb operation and
economizes if below 60 F DB.
Economizer operates using
Reference Enthalpy.
1. Economizer modulates but
minimum position stays at
zero.
1. Uses HSP and CSP CSP=
HSP + 4 F or use RTRM Default
Mode.
1. Uses CSP and HSP HSP=
CSP - 4 F.
1. Comp1, Comp2 or Comp3
will not operate.
RECOMMENDED ACTION
1. Check the return air sensor (RAS) at connector P10 by disconnecting
P10 from RAT on the ECA. Check for resistance between P10-1 and P10-
2, refer to the Resistance versus Temperature Chart. Replace the sensor
if necessary. Check the return air humidity sensor (RHS) by measuring
the operating current at terminals RAH-1 and RAH-2 on the ECA. Normal
operating current is 4 to 20 milliamps mA. Note: The humidity sensors
are polarity sensitive, and will not operate if connected backwards.
2. Check the outside humidity sensor (OHS) by measuring the operating
current at terminals OAH-1, and OAH-2 on the ECA. Normal operating
current is 4 to 20 milliamps mA.
3. Perform #2 above.
1. Check the exhaust fan motor, and replace if necessary.
2. Check the exhaust fan contactor (XFR). Replace if necessary
3. Perform the ECA Test Procedures discussed previously.
4. Perform the Exhaust Fan Setpoint Test Procedures discussed
previously.
1. Perform the RTAM Test Procedures discussed previously.
2. Check the VFD
3. Perform the VFD Setpoint Test Procedures discussed previously.
4. Perform the RTOM Test Procedures discussed previously.
1. Increase the Space Pressure Deadband.
2. Verify Building Pressure with maximum building exhaust enabled.
Adjust Space Pressure Setpoint accordingly.
NORMAL RANGE
-55 to 175 F 
680K to 1.2K
-55 to 175 F
680K to 1.2K
0 to 209 F
90K to 7.1K
0 to 209 F
90K to 7.1K
4 to 20 mA
10 to 90% RH Honeywell
C7600A.
4 to 20 mA
10 to 90% RH Honeywell
C7600A.
Potentiometer range 50 to 200
Ohms.
100 to 900 Ohms Use ZSM Test
Procedures.
100 to 900 Ohms Use ZSM Test
Procedures.
Open 230 F +/- 6.5 F
Close 180 F +/- 12.5 F
Normally closed
DIAGNOSTIC
Heat and cool failure output at RTRM J6-7 to J6-
6 and RTRM J6-8 to J6-6. Heat and cool LED's
blink at ZSM. Check at RTRM connector P8,
between P8-1 & P8-2.
Check at RTRM connector P8.
ECA LED 4 Flashes. Check at ECA connector P1
between P10-1 & P10-2.
ECA 8 flashes.
ECA 6 flashes.
Check at ECA OAH-1 and OAH-2 by measuring
current draw.
Check at ECA ECA 3 flashes. RAH-1 and RAH-2 by
measuring current draw.
*NONE* Check resistance at ECA P and P1 50 to
200 Ohms.
*NONE* Check at terminals 2 and 3 on ZSM
*NONE* Check at terminals 2 and 5 on ZSM.
Cool Failure Output at RTRM J6-8 to J6-6 LED
blinks at ZSM.
RT-SVX34F-EN