Trane S*HF*20-75 Troubleshooting Manual page 120

DIAGNOSTICS Menu
Table 11: Diagnostics Troubleshooting Chart (continued)
BAS/Network Comm
Failure
Used With: BAS system
control is expected.
Module: BAS
Blocked Air Return
Failure
Used With: Option
available w/Fresh Air
Measurement (VCM), OA
Damper w/DCV or CO
2
Reset installed.
Module: VCM
CO2 Sensor Failure
Used With: DCV option or
CO reset function
2
installed.
Module: VCM
Compressor Contactor
Fail (Ckt-1 or Ckt-2)
Used With: See
compressor protection
devices on MCM control
wiring schematic.
Module: MCM
120
Problem: The LCI or BCI
has lost communications
with the Network for > 15
minutes.
Check: That the Network
(Tracer or 3rd party
building control panel) is
powered up and running
properly. If so, check unit
wiring between LCI or BCI
and network (Tracer or 3rd
party building control
panel).
Problem: The low
pressure limit on the VCM
module is detected closed
for 1 second.
Check: Mixed air section
damper linkages and
actuators for proper travel
and operation and return
duct for impediments to
airflow. Check wiring
between mixed air
pressure sensor and VCM
module. Check wiring
between all damper
actuators and control box.
Problem: The CO Sensor
2
input is out of range.
Check: Wiring between the
VCM and customer terminal
block, and between the
terminal block and sensor.
Problem: The compressor
contactor for the given
circuit has malfunctioned.
The circuit's compressor
proving input is detected
closed continuously for
more than 3 seconds while
neither compressor is on.
Check: The circuits
contactor, side contacts,
wiring, etc.
All active commands and
control setpoints provided
by the network, through
the LCI or BCI, will be
cancelled and/ or ignored.
Setpoints will fall-back to
the default designated
sources, otherwise Human
Interface setpoints will be
used.
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.
All DCV (Demand Control
Ventilation) functions, or
CO reset functions, will
2
cease and the unit will fall-
back to the default outside
air damper minimum
position arbitration logic.
All compressors on the
associated circuit will be
locked out and prevented
from operation.
(PAR) An automatic reset
occurs after
communication between
the network and LCI or BCI
has been restored.
(PMR) A manual reset is
required after the
diagnostic is set. It can be
reset by the HI or Tracer, or
by cycling power to the
RTM.
(PAR) An automatic reset
occurs after the CO Sensor
2
transducer input receives a
signal that is within range
for 10 continuous seconds.
(PMR) A manual reset is
required after the
diagnostic is set. It can be
reset by the HI or Tracer, or
by cycling power to the
RTM.
RT-SVP07B-EN