Lennox Core Unit Controller User Manual

44
Table 11. CORE Control System Alarm and Event Codes
SELECTED ALARMS (MARKED WITH * IN TABLE RESULT IN THE CLOSURE OF THE SERVICE RELAY CONTACTS (DO1).
ALARM
CODE
DISPLAY MESSAGE EVENT ACTION
124* 24VAC SECONDARY VOLTAGE LOW
• Low output voltage on T1 transformer. alarm set when 24VAC voltage low if
calculated RMS voltage is below low voltage alarm threshold for more than two
seconds. System will stop unit operations (cooling, heating and ventilation). Low
voltage threshold is 18VAC.
• The CORE Unit Controller will clear alarm 24VAC Voltage Low if calculated RMS
voltage is above Low Voltage Alarm Threshold + 1 VAC for more than two seconds.
After the low 24VAC alarm has been cleared, the CORE Unit Controller will ignore all
service demands until the Error Time Off Delay has expired.
125* 24VAC SECONDARY VOLTAGE HIGH
• High output voltage on T1 transformer. alarm set when 24VAC voltage high if
calculated RMS voltage is below low voltage alarm threshold for more than two
seconds. System will stop unit operations (cooling, heating and ventilation). Low
voltage threshold is 30VAC.
• The CORE Unit Controller will clear alarm 24VAC Voltage HIGH if calculated RMS
voltage is above high voltage alarm Threshold + 1 VAC for more than two seconds.
After the high 24VAC alarm has been cleared the CORE Unit Controller will ignore all
service demands until the Error Time Off Delay has expired.
126* LINE PHASING MISMATCH
During power up or reset of unit, Mismatch on single or 3 phase power, or reverse rotation
on 3 phase detected. This alarm is enabled by the Phase Voltage Detection feature.
127 ALARM BUFFER OVERLFOW Alarmbufferoverow.
128 24VAC SECONDARY POWER LOSS Check transformer and wire connections.
129* VFD SHUTDOWN
VFD fault detected. Check belt and for blower overload. Fix source of fault and reset
CORE Unit Controller.
130 VFD BYPASS ENGAGED VFD bypass mode. Mode is engaged. Blower may or may not be disengage.
131 RESERVED
132 VFD BYPASS UNCONFIG VFD bypass mode has not been selected. Unit operates as if bypass is not installed.
133 RESERVED
134 LOW SUPPLY AIRFLOW
AdvancedAirowenabledRTUindicatesairowtargetcannotbeachieved.Checkcause
ofairowreductionsuchasdirtylter,changesinductwork,etc
135* NO SUPPLY AIRFLOW
Blower RPM is too low as indicates by blower status. This means that the blower is not
working. Repair blower and reset CORE Unit Controller.
136* OA DAMPER MECH FAULT Outdoor air damper stuck or actuator problem.
137 LOW OUTDOOR AIRFLOW
Outdoorairowistoolowsothebuildingisnotgettingthedesignedoutdoorairowbased
on IAQ.
138 RESERVED
139 HIGH OUTDOOR AIRFLOW Ventilation CFM is too high therefore the RTU is using excessive energy.
140 CFM TARGET TOO LOW
Verify the MSAV blower settings and set the CM targets below set CFM. The alarm value
will be displayed on the CORE Unit Controller screen.
141 CFM TARGET TOO HIGH
142 RESERVED
143* OA DAMPER ERROR
Outdoor air differential pressure sensor value not in valid range. Might be tubing problem
or high return duct resistance.
144 FIRMWARE UPDATE COMPLETED Systemupdatedwithnewrmware.
145 RESERVED
146 SERVICE EVENT Service event logged.
147* DAMPER FDBK LOSS During free cooling damper is not modulating.
148* EP CONFIG ERROR Economizer should be installed and blower should be ECM type.
149* OA DIFF PRESS SENSOR ERROR Check outdoor air damper differential pressure sensor and wiring.
150* NOT ECONOMIZING WHEN OAS May be due to the damper motor being unplugged or disconnected.
151* ECONOMIZING WHEN OANS This may be due to damper motor being blocked or stuck open and therefore not closing.
152 - 162 RESERVED
163 LIQUID PRESS OPEN
164 STRIKE3 LIQUID PRESS OPEN
165 ECN UNCONFIGURED
CongurationID1,position2issettoU.Selectapplicableoptionusingsetup/install
wizard.

Lennox Core Unit Controller Specifications

General

Brand	Lennox
Model	Core Unit Controller
Category	Controller
Language	English