Lennox Core Unit Controller Setup Manual page 38

SELECTED ALARMS (MARKED WITH * IN TAbLE RESULT IN THE CLOSURE OF THE SERVICE RELAY CONTACTS (DO1).
ALARM
DISPLAY MESSAGE
CODE
5* BLOWER
6* FILTER
7 ID
8* STRIKE 3 ON BLOWER
9 RESERVED
10 24VAC POWER LOSS TB35-1
11 24VAC POWER LOSS TB34-1
12 HIGH PRESS S4 OPEN COMP
STRIKE3 HIGH PRESS S4 OPEN
13*
COMP
14 HIGH PRESS S7 OPEN COMP2
STRIKE3 HIGH PRESS S7 OPEN
15*
COMP2
16 HIGH PRESS S28 OPEN COMP3
STRIKE3 HIGH PRESS S28 OPEN
17*
COMP3
Table 11. CORE Control System Alarm and Event Codes
EVENT ACTION
Unit off. Air flow switch is normally closed. Monitoring starts 16 seconds after blower is
started. if air flow switch is detected open after 16 second delay period, all compressors
are de-energized, gas valves closed, electric heat turned off, economizer damper closed,
and blower is stopped. Alarm will automatically clear once the error timed off delay has
expired and system will resume. Check blower operation.
Dirty filter switch is detected as closed and will automatically clear once switch is detected
open. Replace filter or check filter switch S27.
Lockout is active with multiple alarm code 5 detected. Alarm can be manually cleared
through the user interface. Check blower operation. Once problem is corrected, lockout
alarm can be cleared by resetting the CORE Unit Controller.
24 VAC power loss at TB35-1 on A55 (M1) board. P111 pin 11.
24 VAC power loss at TB34-1 on A55 (M1) board. P113 pin 1.
Compressor is off. Check charge, fans and coil.
NOTE: On Ultra-High Efficiency units - if only alarm 12 is present then issue could be high
The unit controller will clear high pressure switch alarm when corresponding high pressure
switch is detected as closed. Compressor will not restart until corresponding high pressure
switch is closed and Minimum Off Delay (cooling or heating) has expired.
• Compressor is lockout. Check charge, fans and coil. Use service menu to clear
lockouts.
• User will be able to clear high pressure switch compressor lockout and alarm via user
interface. High pressure switch compressor lockout and alarm will be cleared after
the CORE Unit Controller reset.
• High pressure switch compressor lockout and alarm will be cleared on termination of
cooling demand.
• Default is 3 occurrences and can be set between 1 and 7 occurrences.
Compress is off. Check charge, fans or coil. This feature is not support in Model L at this
time.
NOTE: On Ultra-High efficiency units tandem alarms (14) compressor 2 high temperature
The CORE Unit Controller will clear high pressure switch alarm when corresponding
high pressure switch is detected as closed. Compressor will not be restarted until
corresponding high pressure switch is closed and Minimum Off Delay (cooling or heating)
has expired.
• Compressor lockout. Check charge, fans and coil. Use service menu to clear
lockouts.
• User will be able to clear high pressure switch compressor lockout and alarm via user
interface. High pressure switch compressor lockout and alarm will be cleared after
the CORE Unit Controller reset.
• High pressure switch compressor lockout and alarm will be cleared on removal of
cooling demand.
• Default is 3 occurrences and can be set between 1 and 7 occurrences.
• Compressor is off. Check charge, fans and coil.
• The CORE Unit Controller will clear high pressure switch alarm when corresponding
high pressure switch is detected as closed. Compressor will not be restarted until
corresponding high pressure switch is closed and Minimum Off Delay (cooling or
heating) has expired.
• Compressor lockout. Check charge, fans and coil. Use CORE Service application
RTU > SERVICE menu to clear lockouts.
• User will be able to clear high pressure switch compressor lockout and alarm through
the user interface. High pressure switch compressor lockout and alarm will be cleared
after the CORE Unit Controller reset.
• High pressure switch compressor lockout and alarm is cleared on removal of cooling
demand. Default is 3 occurrences and can be set between 1 and 7 occurrences.
temperature S5 switch. If alarm 12 is accompanied with alarm 14 then most likely
it is the high pressure S4 switch.
S8 switch. If accompanied with alarm 15 then most likely the S4 high pressure
switch is the issue.
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