Trane IntelliPak I Programming, Troubleshooting Manual page 132

System Testing & Troubleshooting
DIAGNOSTIC DISPLAYED
HEAT Mod Aux Temp
Sensor Fail (formerly: MWU
Zone Sensor Fail)
Problem: The HEAT Mod Aux
Temp Sensor Input is out of
range.
Check: Sensor resistance
should be between 830 ohms
(200 F) and 345.7Kohms (-40
F). If so, check field/unit
wiring between Sensor and
HEAT Module.
Heat Module
Communication Failure
Problem: The RTM has lost
communications with the Heat
Module.
Check: Check field/unit wiring
between RTM and Heat
Module.
High Superheat (Ckt1 and/
or Ckt2)
Problem: Evaporator
Temperature Differential is
greater then the Evaporator
Temperature Differential
SETPOINT minus 5 F.
132
REASON FOR DIAGNOSTIC
At least one enabled unit
function has the HEAT Module
Auxiliary Temperature input
designated as its sensor, and
the unit is reading a signal
that is out of range for this
input (Temp < -55 F or Temp
> 209 F).
The RTM has lost
communications with the Heat
Module.
High Superheat (Ckt1 and/or
Ckt2) The cooling circuit has
been active for 10 minutes
and the difference in the
entering and leaving
evaporator temperatures is
greater than the Evaporator
Temperature Differential
SETPOINT minus 5 F but less
than the Evaporator
Temperature Differential
SETPOINT for a period of ten
minutes.
UCM'S REACTION
The functions that designated
the Heat Module Auxiliary
Temperature Input as their
input are disabled.
An "All Heat Off" request is
sent to the Heat Operation
function.
If the unit has staged gas or
electric heat, all Heat Module
outputs will be zeroed and de
energized.
If the unit has Hydronic Heat
or Chilled Water installed, the
unit will turn off the Supply
fan and close the Outside Air
Damper upon the occurrence
of a HEAT Module comm
failure. A fail-safe function in
the Heat Module will cause all
water valves to be set to
100% to provide full water
flow. Unless used for switching
purposes (Air Handlers with
Chilled Water and Mod Gas, or
Chilled Water and Hydronic
Heat) all binary outputs will be
de energized.
High Superheat (Ckt1 and/or
Ckt2) An Information Only
diagnostic is set.
RESET REQUIRED
(PAR) An automatic reset
occurs after the Heat Module
Auxiliary Temperature input
returns to its allowable range
for 10 seconds.
(PAR) An automatic reset
occurs after communication
has been restored.
(PAR) An automatic reset
occurs after the difference in
the entering and leaving
evaporator temperature is less
than the Evaporator
Temperature Differential
SETPOINT minus 5 F
RT-SVP04F-EN