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SCXF-SVX01B-EN
Diagnostic
Troubleshooting
RTM Aux. Temp. Sensor Failure
Problem: The RTM auxillary temperature
sensor data is out of range.
Check: Sensor resistance should be
between 830 ohms (200 F)and 345.7
Kohms (-40 F). If so, check field/unit wiring
between sensor and RTM.
Reason for Diagnostic: At least one
enabled unit function has the RTM
auxillary 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).
UCM’s Reaction: The functions with the
RTM auxillliary temperataure input
deignated as their sensor are disabled.
Reset Required: (PAR) an automatic reset
occurs after the designated zone
temperature signal returns to its
allowable range. To prevent rapid cycling
of the diagnostic, there is a 10 second
delay before the automatic reset.
RTM Data Storage Error
Problem: There was a data transmission
error.
Check: This can be caused by an
intermittant power loss. Turn the unit off
for 1-2 minutes, then back on again. If
diagnostic persists, then the RTM may
need to be replaced.
Reason for Diagnostic: An error occurred
while the RTM was writing data to its
internal non-volitile memory (EEPROM).
UCM’s Reaction: An information only
diagnostic will be displayed at the Human
Interface.
Reset Required: (INFO) A manual reset
may be made at the Human Interface, at
Tracer Summit
®
, or by cycling power to
the RTM.
RTM Zone Sensor Failure
Problem: The RTM zone temperature
sensor input is out of range.
Check: Sensor resistance should be
between 830 ohms (200 F)and 345.7
Kohms (-40 F). If so, check field/unit wiring
between sensor and RTM.
Reason for Diagnostic: At least one
enabled unit function has the RTM zone
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 > 150 F).
UCM’s Reaction: The functions with the
RTM zone temperataure input deignated
as their sensor are disabled.
Reset Required: (PAR) an automatic reset
occurs after the designated zone
temperature signal returns to its
allowable range. To prevent rapid cycling
of the diagnostic, there is a 10 second
delay before the automatic reset.
S
SCM Communication Failure
Problem: The RTM has lost
communication with the SCM.
Check: Check field/unit wiring between
the RTM and SCM.
Reason for Diagnostic: The RTM has lost
communication with the SCM.
UCM’s Reaction: A “Lockout” request is
sent to the compressor staging control
function. A failsafe function in the SCM
will cause all SCM outputs to be zeroed
and deenergized.
Reset Required: (PAR) An automatic reset
occurs after communication has been
restored.
Space Static Press Setpt Failure
Problem: The active space static pressure
setpoint is out of range.
Check: Check setpoint value. Also, if
space pressure setpoint source is GBAS,
but this setpoint has not been assigned to
any of the 4 analog inputs on GBAS, this
message will occur.
Reason for Diagnostic: The unit is reading
a signal that is out of range for the space
static pressure setpoint (input < 0.03 IWC
or input > 0.20 IWC).
UCM’s Reaction: The default space
pressure setpoint will become the active
space pressure setpoint.
Reset Required: (PAR) An automatic reset
occurs after the designated space
pressure setpoint source sends a signal
within range for 10 continuous seconds,
or after a different space pressure
setpoint source is user-defined.
Supply Air Pressure Sensor Failure
Problem: The supply air pressure sensor
voltage input is out of range.
Check: Check field/unit wiring between
the sensor and RTM.
Reason for Diagnostic: The unit is reading
a signal that is out of range for the supply
air pressure sensor voltage input (Input <
40mV or Input > 4.75V)
UCM’s Reaction: The IGV’s will drive
closed, and the following functions are
disabled;
a. SA pressure control
b. SA static pressure limit
Reset Required: (PAR) An automatic reset
occurs after the SA temp heating setpoint
input returns to within range for 10
continuous seconds, or after a different
SA temp heating setopint selection
source is user-defined.
Supply Air Pressure Setpoint Failure
Problem: The SA pressure input signal is
out of range.
Reason for Diagnostic: The SA pressure
setpoint input is sending a signal that is
out of range (Input < 1.0 IWC or Input > 4.3
IWC)
UCM’s Reaction: The default SA pressure
setpoint will become the active SA
pressure setpoint.
Reset Required: (PAR) An automatic reset
occurs after the designated SA pressure
setpoint source sends a signal within
range for 10 continuous seconds, or after
a different SA pressure setpoint source is
user-defined.
Diagnostics
