American Standard 4A6H6018H1000A Service Facts page 9

Table 3. LED FAULT CODES
LED
FAULT FAULT DESCRIPTION
CODES
Ambient Temp Sensor is out
1 FLASH
of range (open/shorted)
Coil Temp Sensor is out of
2 FLASH
range (open/shorted)
Low Pressure Switch is open
3 FLASH
Hard Lock Out (can only be
4 FLASH
cleared with power cycle)
5 FLASH Soft Lock Out
Defrost cycles too close
6 FLASH
together
In Timed Defrost mode.
Check Ambient sensor
7 FLASH
placement and verify SOV is
operating properly.
In Timed Defrost mode.
Check Coil sensor
8 FLASH
placement and verify SOV is
operating properly.
Low Ambient Soft Lockout.
Outdoor temperature
9 FLASH
dropped below 3F. (OFF at
-7F/ON at 3F)
4A6H6018H-SF-1C-EN
DEFROST
CONTROL
BEHAVIOR
Initiate a 15 minute
forced Defrost after
every 60 minutes of
runtime. See Note 1 &
3.
Initiate a 15 minute
forced Defrost after
every 60 minutes of
runtime. See Note 3.
3 flash goes away
when/if LPCO closes
Occurs after 4th trip
of LPCO. Note 7
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 exists.
Implied sensor fault
(calibration/range)
set after defrost and
reset after 15 minutes
run time after defrost.
See Note 5.
Outdoor temperature
is below -7'F. See
Note 6.
Outdoor temperature
is below -7'F. See
Note 6.
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. 1st LPCO trip results in a 15 minute soft lockout
period.
• 2nd LPCO trip results in a 30 minute soft lockout
period.
• In COOLING mode, 3rd LPCO trip results in a 1
hour soft lockout period (Frozen ID coil).
• 4th LPCO trip results in a hard lockout.
• In HEATING mode, 3rd LPCO trip results in an 18
hour soft lockout period or will clear if ODT rises
above 40F for 30 minutes or more.
• 4th LPCO trip results on a hard lockout.
3. If both Coil Temp Sensor and Ambient Temp Sensor
are failed, initiate a 15 minute forced defrost after
ever 60 minutes of run time.
4. 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 +/-5F . 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).
5. 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.
6. Once ambient drops to -7F 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 3F or
higher and after a 15 minute soft lockout period
expires.
7. During a Hard Lockout, the X2 relay opens so that
the Y signal does not pass though.
D D E E F F R R O O S S T T C C O O N N T T R R O O L L
9