Trane IntelliPak I - Page 138

138 RT-SVP04F-EN
System Testing & Troubleshooting
RA Humidity Sensor Failure
Problem: On units with both
Air Economizer and
Comparative Enthalpy
Installed: The Return Air
Humidity sensor input is out of
range.
Check: Check field/unit wiring
between Sensor and ECEM.
The unit is reading a signal
that is out of range for the
Return Air humidity sensor
(Humidity < 5% or Humidity >
100%).
The Economizer Enable r.e.
Enthalpy function reverts to
Reference Enthalpy
changeover (“Level 2”)
control.
(PMR) An automatic reset
occurs after the RA Humidity
input returns to its allowable
range continuously for 10
seconds.
Return Air Temperature
Sensor Failure
Problem: On units with the
Comparative Enthalpy option,
the Return Air Temperature
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
ECEM.
The unit is reading a signal
that is out of range for the
Return Air humidity sensor
(Temperature < -55 F or
Temperature > 209 F).
The Economizer Enable r.e.
Enthalpy function reverts to
Reference Enthalpy
changeover (“Level 2”)
control.
(PAR) An automatic reset
occurs after the RA
Temperature input returns to
its allowable range
continuously for 10 seconds.
Return Fan failure
Problem: There is no return air
flow indication after the return
fan has been requested on.
Check: Check belts, linkages,
etc. on the Return Fan
assembly. If these are ok,
check field/unit wiring
between RTM and Return Fan.
Also check wiring on MPM.
(
Note: A communications error
from the MPM can also cause a
return fan failure lockout.)
If
Return Fan will run in service
mode, then verify airflow
proving.
Return Fan Proving input is
detected OPEN for 40
continuous seconds during any
period of time in which the
Return Fan binary output is
ON.
A fan off request is sent to the
return fan control functions.
(PMR) A manual reset is
required anytime after the
Diagnostic is set. The
Diagnostic can be reset by the
Human Interface or Tracer, or
by cycling power to the RTM.
Return Plenum Pressure
Sensor Failure
Problem: The Return Plenum
Pressure input voltage is out
of range.
Check wiring between Return
Plenum Pressure sensor and
MPM. If correct verify correct
voltage on sensor input on
MPM.
Return Plenum Pressure
Sensor Failure. Input voltage
is out of range: Input < 0.625
V or Input > 4.80 V.
Return Plenum Pressure
Sensor Failure. The supply fan
and return fan are requested
OFF. The outside air damper is
requested to close. The
exhaust damper is requested
to close.
(PAR) An automatic reset
occurs after the Return
Plenum Pressure input returns
to within range for 10
continuous seconds.
DIAGNOSTIC DISPLAYED REASON FOR DIAGNOSTIC UCM’S REACTION RESET REQUIRED