Daikin WGZ030DW Installation, Operation And Maintenance Manual page 36

Reset: This alarm can be cleared at anytime manually via the
keypad or via the BAS clear alarm signal.
If active via trigger condition 1:
When the alarm occurs due to this trigger, it can auto reset
the first two times each day, with the third occurrence being
manual reset.
For the auto-reset occurrences, the alarm will reset
automatically when the condenser pump state is Run again.
This means the alarm stays active while the unit waits for
flow, then it goes through the recirculation process after flow
is detected. Once the recirculation is complete, the condenser
pump goes to the Run state which will clear the alarm. After
three occurrences, the count of occurrences is reset and the
cycle starts over if the manual reset flow loss alarm is cleared.
If active via trigger condition 2:
If the flow loss alarm has occurred due to this trigger, it is
always a manual reset alarm.
Low Evaporator Pressure
Alarm description: Evap Press Low Cir N
Trigger: [Circuit State = Run AND Freezestat trip AND Low
OAT Start not active]
OR Evaporator Press < Absolute Low Pressure Limit AND
Circuit State = Run
The absolute low pressure limit is 5 psi with R134a refrigerants
and 20 psi with R410A refrigerant.
Freezestat logic allows the circuit to run for varying times at
low pressures. The lower the pressure, the shorter the time the
compressor can run. This time is calculated as follows:
Freeze error = Low Evaporator Pressure Unload – Evaporator
Pressure
Freeze time =
[60 – 2.7 x freeze error] with R134a refrigerant, limited to a
range of 20-60 seconds
[60 – freeze error] with R410A refrigerant, limited to a range
of 20-60 seconds
When the evaporator pressure goes below the Low Evaporator
Pressure Unload set point, a timer starts. If this timer exceeds
the freeze time, then a 'Evap Press Low Cir N' alarm trip
occurs. If the evaporator pressure rises to the unload set point
or higher, and the freeze time has not been exceeded, the
timer will reset.
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the keypad if
the evaporator pressure is above the absolute
low-pressure limit.
High Condenser Pressure
Alarm description: Cond Press High Cir N
Trigger: Condenser Pressure > High Condenser Pressure Set
Point
Action Taken: Rapid stop circuit
IOM 1322-1 • WATER-COOLED SCROLL COMPRESSOR
Reset: This alarm can be cleared manually via the keypad.
Mechanical High Pressure/Motor Protect
Alarm description: MHP or Motor Prot N
Trigger: MHP/MP input is low and over 150 seconds lapsed
since controller boot-up
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the keypad if
the MHP/MP input is high.
Phase Voltage Protection
Alarm description: Phase/Voltage Cir N
Trigger: PVM input is low and Phase Voltage set point =
enable.
Action Taken: Rapid stop circuit
Reset: Auto reset when PVM input is high
Ground Fault Protection
Alarm description: Ground Fault Cir N
Trigger: GFP input is low and Ground Fault set point = enable.
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the keypad.
Low OAT Restart Fault
Alarm description: Low OAT Start Fail N
Trigger: Circuit has failed three low OAT start attempts
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the keypad.
In order to avoid low evaporator pressure alarms at startup
view "Low Ambient Start (WaterCooled = NO)" on page 45
Evaporator Water Freeze Protect
Alarm description: Evap Water Freeze
Trigger: Evaporator LWT drops below evaporator freeze
protect set point AND Unit State = Auto
Action Taken: Rapid stop all circuits
Reset: This alarm can be cleared manually via the keypad
or via the BAS clear alarm signal, but only if the alarm trigger
conditions no longer exist.
Leaving Evaporator Water Temperature Sensor
Fault
Alarm description: Evap LWT Sens Fault
Trigger: Sensor shorted or open
Action Taken: Normal stop all circuits
Reset: This alarm can be cleared manually via the keypad, but
only if the sensor is back in range.
Suction Temperature Sensor Fault
Alarm description: SuctT Sensor Fail N
36
Unit Controller
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