Trane S*HF*20-75 Troubleshooting Manual page 124

DIAGNOSTICS Menu
Table 11: Diagnostics Troubleshooting Chart (continued)
ECEM Communications
Failure
Module: ECEM
Economizer DryBulb
Setpoint Failure
Module: GBAS(5VDC/
10VDC)
Emergency Stop
Module: RTM
Energy Recovery Wheel
Proof Failure
Module: MPM
124
Problem: The RTM has lost
communications with the
ECEM.
Check: Wiring between the
communications terminal
block and the ECEM. Check
for polarity, crimp and wire
integrity of the pins.
Problem: The GBAS input
assigned to Economizer
DryBulb Setpoint is out of
range. (Temperature <50 F
or Temperature > 140 F)
Check: Wiring and
external devices on the
associated GBAS input.
Problem: The circuit wired
to the Emergency Stop
Input has opened. This can
occur by design or un-
intentionally.
Check: An open circuit has
occurred on the Emergency
Stop input caused either by
a High Duct Temp T-stat
trip, the opening of field-
provided contacts, etc., or
due to a fault of the wiring
or external devices.
Problem: Comparison of
the Leaving Recovery
Exhaust Temp and Return
Air Temp indicates
inadequate temperature
differential exists which
could be caused by
improper energy recovery
wheel operation.
Check: Wheel operation,
dirty wheel material,
temperature sensor
integrity.
On units w/ Comparative
Enthalpy option, the
Economizer Enable
Enthalpy function will
revert to Reference
Enthalpy or Drybulb
comparison.
On units w/ Statitrac
option, the space pressure
control is deactivated, the
exhaust fan is turned off,
the exhaust damper is
closed and the outside
damper is limited to
minimum position.
The Active Economizer
DryBulb Setpoint reverts to
the HI default Economizer
DryBulb Enable Setpoint
value.
The unit will trip all outputs,
de-energize dx cooling,
staged heating, fans, etc.,
and will drive all analog
ouputs closed/stop, fan
speed, dampers,
modulating heat, etc.
Energy Wheel output is de-
energized and associated
dampers closed while in
heat mode. In cooling
mode the dampers will still
open during economizing
operation.
(PAR) An automatic reset
occurs after
communication has been
restored.
(PAR) An automatic reset
occurs after the GBAS input
returns to within range for
10 continuous seconds, or
after a different valid
Economizer DryBulb
Enable Setpoint source
selection is user-defined.
(PMR) A manual reset is
required after the
Emergency Stop input
recloses. The Diagnostic
can be reset by the Human
Interface or Tracer or by
cycling power to the RTM.
(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.
RT-SVP07B-EN