| Description | Cause |
|---|---|
| C1 locked out due to high pressure | Three HPS1 trips within two hours. |
| C2 locked out due to high pressure | Three HPS2 trips within two hours. |
| C3 locked out due to high pressure | Three HPS3 trips within two hours. |
| C4 locked out due to high pressure | Three HPS4 trips within two hours. |
| C1 locked out due to low pressure | Three LPS1 trips within one hour. |
| C2 locked out due to low pressure | Three LPS2 trips within one hour. |
| C3 locked out due to low pressure | Three LPS3 trips within one hour. |
| C4 locked out due to low pressure | Three LPS4 trips within one hour. |
| C1 locked out due to coil freeze | Three FS1 trips within two hours. Occurs when evaporation coil temperature is less than evaporation coil temperature cutout SP. |
| C2 locked out due to coil freeze | Three FS2 trips within two hours. Occurs when evaporation coil temperature is less than evaporation coil temperature cutout SP. |
| C3 locked out due to coil freeze | Three FS3 trips within two hours. Occurs when evaporation coil temperature is less than evaporation coil temperature cutout SP. |
| C4 locked out due to coil freeze | Three FS4 trips within two hours. Occurs when evaporation coil temperature is less than evaporation coil temperature cutout SP. |
| Exhaust fan VFD failure | EX VFD BI trips. Set the exhaust fan up as exhaust or variable frequency fan for this to occur. |
| HS1 locked out due to limit switch | Three LS1 trips within one hour. |
| HS2 locked out due to limit switch | Three LS2 trips within one hour. |
| HS3 locked out due to limit switch | Three LS3 trips within one hour. |
| Unit shutdown due to smoke | SD input loses 24 VAC |
| Supply fan VFD failure | Fan VFD input trips. Set supply fan up as NOT single speed in order for this to occur. |
| No heat-cool due to unreliable space-T | Input unreliable. |
| 4-Stage communication failure | 4-Stage board goes from online to offline. |
| Economizer communication failure | Economizer board goes from online to offline. |
| Outputs disabled due to low input V | Blackout conditions. |
| Outputs limited due brownout input V | Brownout conditions. |
| Unit locked out due to Air Proving Switch (APS) | Three air proving switch trips within 1.5 hours. When you
configure for Constant Volume, the input is a physical air proving
switch. When you configure for Variable Volume, the input uses the duct
static pressure sensor. Note: You can adjust the threshold in Variable
Volume through the Low Pressure 1 and 2 and Time 1 ans 2
parameters.
|
| Unit locked out due to supply fan overload | Three FAN overload trips within two hours. |
| Unit locked out due to high duct-P | Duct Static Pressure is greater than the High Duct Static Pressure Setpoint. |
| Description | Cause |
|---|---|
| Evaporator coil temp 1 sensor failure | Input unreliable and number of cooling stages is less than or equal to 1. |
| Condenser Coil Temp 1 Sensor Failure | |
| Evaporator Coil Temp 2 Sensor Failure | Input unreliable and number of cooling stages is less than or equal to 2. |
| Condenser Coil Temp 2 Sensor Failure | |
| Evaporator Coil Temp 3 Sensor Failure | Input unreliable and number of cooling stages is less than or equal to 3. |
| Condenser Coil Temp 3 Sensor Failure | |
| Evaporator Coil Temp 4 Sensor Failure | Input unreliable and number or cooling stages is less than or equal to 4. |
| Condenser Coil Temp 4 Sensor Failure | |
| Building Pressure Sensor Failure | Input unreliable. |
| Outdoor Air Temperature Sensor Failure | |
| Return Air Temperature Sensor Failure | Input unreliable and the fan type is Variable Speed Fan.. |
| Supply Air Temperature Sensor Failure | Input unreliable and economizer communication status is online or mixed air sequencer is equal to DAT control. |
| Unit Shutdown Due to Supply Fan Overload | FAN OVR Trip. Less than three in one hour as that can cause Unit Locked Out Due to Supply Fan OL. |
| Main controller calibration error | Missing calibration data. |
| FDDM controller calibration error | |
| Econ controller calibration error | |
| 4-Stage controller calibration error | |
| Unit shutdown due to air proving switch | Cmd but no proof for less than or equal to 90 seconds. This alarm occurs if this happens less than three times in 1.5 hours, otherwise that would cause Unit Locked Out Due to APS. |
| FDDS controller calibration error | Missing cal data. |
| Description | Cause |
|---|---|
| Duct Pressure Sensor failure | Input unreliable and the fan type is Variable Speed Fan.. |
| Return Air Humidity Sensor failure | Input unreliable. |
| Outdoor Air Humidity Sensor Failure | |
| Supply Humidity Sensor failure | |
| Indoor Air Quality Sensor failure | |
| Outdoor Air Quality Sensor failure | |
| Fresh Air Intake Sensor failure | |
| Mixed Air Temp Sensor failure | |
| Space Indoor temp Sensor failure | |
| Space Offset Sensor failure | |
| C1 Shutdown due to high pressure | HPS1 Trip. |
| C2 Shutdown due to high pressure | HPS2 Trip. |
| C3 Shutdown due to high pressure | HPS3 Trip. |
| C4 Shutdown due to high pressure | HPS4 Trip. |
| C1 Shutdown due to low pressure | LPS1 Trip. |
| C2 Shutdown due to low pressure | LPS2 Trip. |
| C3 Shutdown due to low pressure | LPS3 Trip. |
| C4 Shutdown due to low pressure | LPS4 Trip. |
| C1 Shutdown due to coil freeze | FS1 Trip. Evap Coil Temp is less than Evap Coil Temp Cutout SP. |
| C2 Shutdown due to coil freeze | FS2 Trip. Evap Coil Temp is less than Evap Coil Temp Cutout SP. |
| C3 Shutdown due to coil freeze | FS3 Trip. Evap Coil Temp is less than Evap Coil Temp Cutout SP. |
| C4 Shutdown due to coil freeze | FS4 Trip. Evap Coil Temp is less than Evap Coil Temp Cutout SP. |
| Low Outdoor air temp cooling cutout | OAT is less than OAT cooling cutout. |
| Econ economizing when it should not | Economizer Damper percentage command is less than minimum OA position and FDD damper minimum position tolerance. |
| Econ not economizing when it should | |
| Economizer damper not modulating | Absolute Economizer Damper percentage command minus economizer damper position is less than FDD economizer damper allowed error. |
| Economizer letting in excess outdoor air | Economizer damper percentage command is less than minimum OA position and FDD damper minimum position tolerance and Ramp minimum OA or economizer damper percentage command is less than FDD damper minimum position tolerance and ramp closed. |
| HS1 shutdown due to limit switch | LS1 Trip. |
| HS2 shutdown due to limit switch | LS2 Trip. |
| HS3 shutdown due to limit switch | LS3 Trip. |
| HS1 off due to gas valve | H1 with no GV1 for less than or equal to 6 minutes. |
| HS2 off due to gas valve | H2 with no GV2 for less than or equal to 6 minutes. |
| HS3 off due to gas valve | H3 with no GV3 for less than or equal to 6 minutes. |
| Dirty Filter | DFS Trip. |
| FDD 1 communication failure | FDD Master Online to Offline. |
| FDD 2 communication failure | FDD Subordinate Online to Offline. |
| Unit has received a purge request | PURGE-S on Econ trip. |
| Excessive Supply Air temp cooling | SAT less than Excessive SAT Cooling Sp and SAT Limit for cooling enable. |
| HS1 gas valve failure | GV1 on without H1 for less than or equal to 5 seconds. |
| HS2 gas valve failure | GV2 on without H2 for less than or equal to 5 seconds. |
| HS3 gas valve failure | GV3 on without H3 for less than or equal to 5 seconds. |
| Excessive Supply Air Temp Heating | SAT is less than excessive SAT Heating SP and SAT Air Temp Limit for Heat Enabled. |
| Space temperature cooling alarm | Space Temp is less than operating cooling SP for more than 60 minutes. |
| C1 Refrigerant flow restriction | FDD alarm. |
| Hot H20 FS open to prevent coil freeze | Hydronic Heating is enabled and HW Freeze BI trip and Unreliable OAT or HW Freeze BI trip and OAT is less than 40°F. |
| Hot H20 FS opened when it should not | Hydronic Heating is enabled and OAT is greater than 40°F and HW Freeze BI trip. |
| Space temperature heating alarm | Space Temp is less than operating heating SP for more than 60 minutes. |
| Not economizing - No Supply Air Sensor | Free Cooling Available and MA Sequencer is equal to DAT Control and SAT Unreliable or SAT Unrealiable and MA Sequence is equal to Zone Control and MA State is equal to Mech and Free Cooling Available or Tstat Only and Mech and Free Cooling Available. |
| Using return instead of space temp | Effective Zone Source is equal to Return Air Temp and Not TStat Only. |
| Air proving switch is stuck closed | APS is closed, but you have not given fan command. |