Trane S*HF*20-75 Troubleshooting Manual page 142

DIAGNOSTICS Menu
Table 11: Diagnostics Troubleshooting Chart (continued)
Unoccupied Zone Cool
Setpoint Failure
Module: RTM
Unoccupied Zone Heat
Setpoint Failure
Module: RTM
VCM Aux Temp. Sensor
Failure.
Module: VCM
VCM Communications
Failure.
Module: VCM
142
Problem: The source
assigned to Unoccupied
Zone Cool Setpoint is out of
range (Temperature < 45 F
or Temperature > 94 F).
Check: Wiring and
external devices on the
associated RTM input.
Problem: The source
assigned to Unoccupied
Zone Heat Setpoint is out of
range (Temperature < 45 F
or Temperature > 94 F).
Check: Wiring and
external devices on the
associated RTM input.
Problem: At least one
enabled unit function has
the VCM Aux Temperature
Sensor input designated as
its sensor, and the signal is
out of range (Temp < -40 F
or Temp > 200 F).
Check: The HI value and
wiring between the VCM
module and the sensor.
Removing the plug from the
VCM module there should
be no shorts, opens and
sensor resistance should be
between 830 ohms and
345.7Kohms.
Problem: The RTM has lost
communications with the
VCM module.
Check: Check unit wiring
between RTM and VCM
module.
The Active Unoccupied
Zone Cooling Setpoint
reverts to the default
Unoccupied Zone Cooling
Setpoint of the Human
Interface.
The Active Unoccupied
Zone Heating Setpoint
reverts to the default
Unoccupied Zone Heating
Setpoint of the Human
Interface.
The functions with the VCM
Aux Temperature Sensor
input designated as their
sensor are disabled.
Airflow measurement will
be disabled and the unit will
revert to the default OA
Damper Minimum Position.
CO
sensor value will be
2
disabled, DCV functionality
will be disabled.
(PAR) An automatic reset
occurs after the source
input assigned to the
Unoccupied Zone Cooling
Setpoint input returns to
within range for 10
continuous seconds, or
after a different, valid
Unoccupied Zone Cooling
Setpoint source is applied
(BAS/Network).
(PAR) An automatic reset
occurs after the source
input assigned to the
Unoccupied Zone Heating
Setpoint input returns to
within range for 10
continuous seconds, or
after a different, valid
Unoccupied Zone Heating
Setpoint source is applied
(BAS/Network).
(PAR) An automatic reset
occurs after the designated
temperature input returns
to its allowable range. In
order to prevent rapid
cycling of the Diagnostic,
there is a 10 seconds delay
before the automatic reset.
PAR) An automatic reset
occurs after
communication has been
restored.
RT-SVP07B-EN