Trane Voyager Commercial Installation, Operation And Maintenance Manual page 140

D D i i a a g g n n o o s s t t i i c c s s
Table 79. Troubleshooting (continued)
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 80. 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)
140
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.
1Economizer modulates but
minimum position stays at
zero.
Uses HSP and CSP CSP= HSP
+ 4 F or use RTRM Default
Mode.
Uses CSP and HSP HSP= CSP -
4 F.
Comp1, Comp2 or Comp3 will
not operate.
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 175F / 680K to 1.2K
-55 to 175F / 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
RECOMMENDED ACTION
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-SVX34R-EN