Trane 4WCC4036E1000B Installation And Operation Manual page 23

Table 14. LED Fault Codes
LED
FAULT
FAULT
DESCRIPTION
CODES
Ambient Temp Sensor is
out of range (open/
1 FLASH
shorted)
Coil Temp Sensor is out
2 FLASH
of range (open/shorted)
Low Pressure Switch is
3 FLASH
open
Hard Lock Out (can only
be cleared with power
4 FLASH
cycle)
5 FLASH Soft Lock Out
Defrost cycles too close
6 FLASH
together
In Timed Defrost mode.
Check Ambient sensor
placement and verify
7 FLASH
SOV is operating
properly.
In Timed Defrost mode.
Check Coil sensor
placement and verify
8 FLASH
SOV is operating
properly.
Low Ambient Soft Lock-
out Outdoor
temperature dropped
9 FLASH
below 3°F. (OFF at -7° F/
ON at 3°F)
1. Initiate Adaptive/Timed Defrost so long as Coil
Temp Sensor is functional. Monitor actual time in
defrost and add or reduce run time until next forced
defrost based on achieving a 4 minute (+/- 1) defrost
period.
2. This Defrost control utilizes a safety method called
"Inferred LPCO". If both Coil Temp Sensor and
Ambient Temp Sensor have failed, initiate a 15
minute forced defrost after every 60 minutes of run
time. This is in conjunction with the normal Low
Pressure trip definitions. An "Inferred LPCO" trip is
defined as: A heating cycle that enters defrost in 15
minutes or less and then enters another defrost in
the same heating call within 15 minutes of the last
defrost call -does not complete a learning
algorithm. This could be caused by a condenser fan
motor failure or other reasons. The first soft lockout
occurs on the 4th defrost that was entered before
18-BB41D1-1C-EN
DEFROST CONTROL
BEHAVIOR
Initiate a 15 minute forced
Defrost after every 60
minutes of runtime. See
Note 1 & 2
Initiate a 15 minute forced
Defrost after every 60
minutes of runtime. See
Note 2
3 flash goes away when/if
LPCO closes
Occurs after 9th trip of
LPCO. Note 6
5 flash goes away after soft
lockout periods expires. See
Note 2
Heating Short Cycle Fault
triggers 6 flash & 5 flash
codes. Follow Soft Lock-out
sequence until Hard Lock-
out (4 flash) or can clear if
conditions no longer exist
Implied sensor fault
(calibration/range) set after
defrost and reset after 15
minutes run time after
defrost. See Note 4
Outdoor temperature is
below -7° F. See Note 5.
Outdoor temperature is
below -7° F. See Note 5.
the learning routine could complete in the same
heating call. It is announced with a 5 flash and a 6
flash fault. After this first 15 minute soft lockout, the
system will return to normal operation. Should this
continue operating in this manner, there will be a 30
minute soft lockout and so on. At the end of the
lockout process, if a hard lock is necessary —a flash
will be announced and system operation is
interrupted. If the ambient temperature climbs
above 40 degrees F for more than 30 minutes, this
clears this fault count and resumes normal
operation.
3. Do not track if Y cycles off or if defrost takes 15
minutes (Max Time Override). Ambient Sensor
reading is monitored at the end of defrost and
should not deviate more than +/-5° F. Ambient
Sensor must report a lower temperature than the
Coil Sensor immediately after defrost (Coil Sensor
should always be higher than Ambient Sensor
when defrost terminates).
4. Do not track if Y cycles off or if defrost takes 15
minutes (Max Time Override). Coil Sensor reading
is monitored at the end of defrost and reading must
be less than Ambient Sensor after 15 minutes of run
time.
5. Once ambient drops to -7° F or lower, wait 5
minutes before soft lockout begins. During soft lock
out the Y signal passes through to the X2 output.
Resume operation when ambient temperature rises
to 3° F or higher and after a 15 minute soft lockout
period expires.
6. During Hard Lockout, the X2 relay opens so that the
Y signal does not pass through.
LPCO
Inferred HEATING Mode
LPCO
1st Trip 15 minute soft lock-out period
2nd Trip 30 minute soft lock-out period
3rd Trip 45 minute soft lock-out period
4th - 8th
18 hour soft lock-out period
Trip
9th Trip
Hard lock-out
(a)
If LPCO is open, a 3 flash can accommodate any of the faults above
(a)
and will clear when the LPCO closes.
LPCO COOLING Mode
1st Trip 15 minute soft lock-out period
2nd Trip 30 minute soft lock-out period
3rd Trip 45 minute soft lock-out period
4th - 8th
18 hour soft lock-out period
Trip
* Once the LPCO closes, the 3 flash fault will not continue
showing — only 5 flash if in the soft lock-out period.
U U n n i i t t S S t t a a r r t t u u p p
Flash Code
5 and 6 flash
5 and 6 flash
5 and 6 flash
5 and 6 flash
4 flash
Flash Code
5 and 6 flash
5 and 6 flash
5 and 6 flash
5 and 6 flash
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