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THERMISTOR ALARM
Thermistor out of range. Detects failed thermistor. Close alarm
contact, drive valves to bypass position, and disable fans.
Automatic reset.
FAN VFD FAILURE
This alarm detects a non-functioning VFD.
Manual reset.
Alarm Troubleshooting
LEAVING WATER TEMPERATURE ALARM
Alarm Criteria: Leaving water temperature is below the Low
Leaving Water Temp Alarm Limit or above the High Leaving Wa-
ter Temp Alarm Limit.
Action Taken by Controller: Alarm shown on display and alarm
output energized. For high water alarm, the valve will go to bypass
mode and the fan VFD will be disabled.
Reset Method: Automatic once temp is back in range.
Possible Causes: Bypass valve not functioning, Fans not function-
ing, Unit not enabled, Pump not on.
LEAVING WATER SENSOR FAILURE ALARM
Alarm Criteria: Sensor reading at controller is out of range.
Action Taken by Controller: Alarm shown on display and alarm
output energized.
Reset Method: Automatic once reading is back in range.
Possible Causes: Loose connection at controller, damaged sensor
wire, failed thermistor.
ENTERING WATER TEMPERATURE ALARM
Alarm Criteria: Entering water temperature is below the Low En-
tering Water Temp Alarm Limit or above the High Entering Water
Temp Alarm Limit.
Action Taken by Controller: Alarm shown on display and alarm
output energized.
Reset Method: Automatic once temp is back in range.
Possible Causes: Building return temperature beyond set limit.
ENTERING WATER SENSOR FAILURE ALARM
Alarm Criteria: Sensor reading at controller is out of range.
Action Taken by Controller: Alarm shown on display and alarm
output energized.
Reset Method: Automatic once reading is back in range.
Possible Causes: Loose connection at controller, damaged sensor
wire, failed thermistor.
OUTDOOR AIR TEMPERATURE ALARM
Alarm Criteria: Outdoor air temperature is below the Low Out-
door Air Temp Alarm Limit or above the High Outdoor Air Temp
Alarm Limit.
Action Taken by Controller: Alarm shown on display and alarm
output energized.
Reset Method: Automatic once temp is back in range.
Possible Causes: Air temperature beyond set limits.
OUTDOOR AIR SENSOR FAILURE ALARM
Alarm Criteria: Sensor reading at controller is out of range.
Action Taken by Controller: Alarm shown on display and alarm
output energized.
Reset Method: Automatic once reading is back in range.
Possible Causes: Loose connection at controller, damaged sensor
wire, failed thermistor.
FAN VFD FAILURE
Alarm Criteria: Fan VFD feedback signal not received at the con-
troller.
Action Taken by Controller: Alarm shown on display and alarm
output energized.
Reset Method: Automatic once contact closure is made.
Possible Causes: Wiring issue between fan VFD and controller.
Alarm at VFD. No power to VFD. VFD in Hand or Off position.
REVERSE LOAD WATER FLOW ALARM
Alarm Criteria: Entering water temperature is less than leaving
water temperature.
Action Taken by Controller: Alarm shown on display, alarm out-
put energized, valve will go to bypass mode, and the fan VFD will
be disabled.
Reset Method: Automatic once delta T is positive.
Possible Causes: 3-way valve not functioning, EWT and LWT
sensors swapped, damaged sensor wire, failed thermistor.
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