Daikin AWV024 - Circuit Alarms; Evaporator Pump #1 Failure; Economizer EXV Module Comm Failure; Bad Demand Limit Input

alarms and evenTs
www.DaikinApplied.com 71 IOM 1242-2 • PATHFINDER
®
MODEL AWV CHILLERS
Evaporator Pump #1 Failure
Alarm: Evaporator Pump #1 Failure
Displayed Text: Evap Pump 1 Fault
Trigger: Unit is congured with primary and
backup pumps, pump #1 is running,
and the pump control logic switches to
pump #2.
Action Taken: Backup pump is used
Reset: This alarm can be cleared manually
via the keypad or BAS command.
Evaporator Pump #2 Failure
Alarm: Evaporator Pump #2 Failure
Displayed Text: Evap Pump 2 Fault
Trigger: Unit is congured with primary and
backup pumps, pump #2 is running,
and the pump control logic switches to
pump #1.
Action Taken: Backup pump is used
Reset: This alarm can be cleared manually via
the keypad or BAS command.
Bad Demand Limit Input
Alarm: Bad Demand Limit Input
Displayed Text: Bad Demand Lim Input
Trigger: Demand limit input out of range and
Demand Limit set point is set to
On. For this alarm, out of range is
considered to be a signal less than
3 mA or more than 21 mA.
Action Taken: Demand limit function and signal are
ignored
Reset:
Auto clear when Demand Limit set
point is set to Off or demand limit input
back in range for 5 seconds.
Bad LWT Reset Input
Alarm: Bad LWT Reset Input
Displayed Text: Bad LWT Reset Input
Trigger: LWT Reset Type set point is 4-20 mA
and LWT reset input out of range. For
this alarm out of range is considered
to be a signal less than 3 mA or more
than 21 mA.
Action Taken: LWT reset signal and 4-20 mA function
are ignored
Reset: Auto clear when LWT Reset Type set
point is not 4-20 mA or LWT reset input
back in range for ve seconds.
Economizer EXV Module Comm Failure
Alarm: Economizer EXV Module Comm Failure
Text: EconExvModCommFail
Trigger: Economizer Conguration set point is set to Yes
and communication with the economizer EXV
module has failed. Specically, this means that
16 consecutive failures of read/write command
blocks for this address have occurred.
Action
Taken:
Economizer valve command is set to 0% in
control logic, though without communication the
module is left to operate per logic embedded in
it. It should be set up to automatically close the
valves when communication is lost.
Reset: This alarm can be cleared manually via the
keypad or BAS command after communication is
restored for at least 5 seconds.
Circuit Alarms
Low Evaporator Pressure
Alarm: Low Evaporator Pressure
Text: Cn EvapPressLow
Trigger: When circuit state = Start and OAT ≥ -8°C, any of
the following can trigger:
• Evap Pressure < 0 kPa for 5 seconds
• Evap Pressure < -50 kPa for 2 seconds
When circuit state = Start and OAT < -8°C, any of
the following can trigger:
• Evap Pressure < 0 kPa for 20 seconds
• Evap Pressure < -50 kPa for 5 seconds
Note: for this condition where OAT is lower than
-8°C, the rst two times any of the trigger conditions
are met in a day the circuit will only shut down and
the alarm will not trigger. On the third occurrence in
a day, the circuit will shut down and the alarm will
be triggered.
For rst 5 minutes circuit state = Run, any of the
following can trigger:
• Evap Pressure < 0 kPa for 5 seconds
• Evap Pressure < -50 kPa for 2 seconds
• Evap Pressure < Low Pressure Unload set
point for 100 seconds
After circuit state = Run for 5 minutes, any of the
following can trigger:
• Evap Pressure < 30 kPa for 5 seconds
• Evap Pressure < -30 kPa for 2 seconds
• Evap Pressure < Low Pressure Unload set
point for time > Freeze Time
Where:
• Freeze Time = 70 – 0.906 x Freeze Error,
limited to range of 20-70 seconds
• Freeze Error = Low Evap Pressure Unload –
Evap Pressure
For any trigger condition, the alarm cannot trigger if
the evaporator pressure sensor fault is active.
Action
Taken:
Rapid shutdown of circuit and lock out from running
Reset: This alarm can be cleared manually via the Unit
Controller keypad.