Trane S*HF*20-75 Troubleshooting Manual page 126

DIAGNOSTICS Menu
Table 11: Diagnostics Troubleshooting Chart (continued)
GBAS 0-5VDC Module
Communications Failure
Module: GBAS(5VDC)
GBAS 0-10 VDC Module
Communications Failure
Module: GBAS(10VDC)
Heat AUX Temp Sensor
Fail (formerly: MWU
Zone Sensor Fail)
Used With: Heat options.
Module: HEAT
126
Problem: The RTM has lost
communications with the
GBAS(5VDC) Module.
Check: Check unit wiring
between RTM and GBAS.
Problem: The RTM has lost
communications with the
GBAS(10VDC) Module.
Check: Check unit wiring
between RTM and GBAS.
Problem: The Heat
Module's Auxiliary
Temperature Sensor has
been assigned to at least
one function, and this
sensor signal is out of range
(Temp < -55 F or Temp >
209 F).
Check: The HI value and
wiring between the HEAT
module and the sensor.
Removing the plug from the
HEAT module there should
be no shorts, opens and
sensor resistance should be
between 830 ohms and
345.7Kohms.
The UCM will initiate the
following actions:
a. Any Demand Limit
request issued by this
GBAS will be canceled. The
Demand Limit request may
continue if the BAS/
Network is requesting it.
b. All active Setpoints that
source this GBAS will revert
to their Human Interface
default values.
c. A fail safe function in the
GBAS module will cause all
GBAS outputs to be zeroed
and de-energized.
The UCM will initiate the
following actions:
a. Any Demand Limit
request issued by this
GBAS will be canceled. The
Demand Limit request may
continue if the BAS/
Network is requesting it.
b. All active Setpoints that
source this GBAS will revert
to their Human Interface
default values.
c. A fail safe function in the
GBAS module will cause all
GBAS outputs to be zeroed
and de-energized.
The functions that
designated the Heat
Module Auxiliary
Temperature Input as their
input are disabled.
(PAR) An automatic reset
occurs after
communication has been
restored.
(PAR) An automatic reset
occurs after one complete
set of the required IPC
packets has been received.
(PAR) An automatic reset
occurs after the Heat
Module Auxiliary
Temperature input returns
to its allowable range for 10
seconds.
RT-SVP07B-EN