Low Pressure Difference Or Ratio Shutdown; High Motor Current – Hold; High Motor Current - Unload; High Vfd Line Current Hold - Daikin Pathfinder AWV Series Installation, Operation And Maintenance Manual

Low Pressure Difference Or Ratio Shutdown

Trigger: This event will trigger on the first and second
occurrence of the below conditions within
2 hours. A third occurrence within a 2 hour
window triggers the alarm.
Trigger 1:
Pressure ratio is less than 1.6 for longer than
the Low Pressure Diff/Ratio Delay set point
after circuit state transition to Run. Pressure
ratio is calculated as shown with pressures in
kPa:
Ratio = (Condenser Pressure + 101.325)/
(Evaporator Pressure + 101.325)
Trigger 2:
Pressure difference is less than 180 kPa for
longer than the Low Pressure Diff/Ratio Delay
set point after circuit state transition to Run.
Pressure difference is calculated as shown
with pressures in kPa:
Difference = (Condenser Pressure) -
(Evaporator Pressure)
Alarm/event cannot trigger for 5 minutes after
circuit state transitions to Preopen if OAT <
7°C, however the trigger logic will still run
during this window.
Action Taken: Rapid shutdown of circuit
Reset:
This event resets immediately after triggering.
High Motor Current – Hold
This event will trigger when all of the following
are true for at least for 10 seconds.
• Unit mode is Cool
Trigger:
• Compressor is running
• VFD Output Current > Max Motor
Current x 0.95
Compressor will not be able to increase in
Action Taken:
capacity/speed.
This event is set when VFD Output Current
< Max Motor Current x 0.92 for at least 60
Reset: seconds. It is also reset if the compressor
is not running or the unit operating mode is
changed to Ice.
IOM 1242-2 • PATHFINDER MODEL AWV CHILLERS
®

High Motor Current - Unload

Trigger: This event will trigger when all of the following
are true for at least 3 seconds.
• Unit mode is Cool
• Compressor is running
• VFD Output Current > Max Motor
Current x 0.97
Action Taken: Compressor speed will be reduced at a rate
equivalent to 1 Hz every 2 seconds.
Reset: This event is cleared when VFD Output
Current < Max Motor Current x 0.97. It is also
reset if the compressor is not running or the
unit operating mode is changed to Ice.

High VFD Line Current Hold

Trigger: This event will trigger when all of the following
are true for at least for 5 seconds.
• Unit mode is Cool
• Compressor is running
• VFD Line Current > Compressor RLA set
point
Compressor RLA set point for each circuit is
part of the unit configuration.
Action Taken: Compressor will not be able to increase
speed/capacity.
Reset: This event is reset when VFD Line Current <
Compressor RLA set point x 0.99 for at least 3
minutes. It is also reset when the compressor
is not running or the unit operating mode is
changed to Ice.
High VFD Line Current Unload
Trigger: This event will trigger when all of the following
are true for at least for 5 seconds.
• Unit mode is Cool
• Compressor is running
• VFD Line Current > Compressor RLA set
point x 105%
Compressor RLA set point for each circuit is
part of the unit configuration.
Action Taken: Compressor speed reduced 1 Hz every 2
seconds.
Reset: This event is reset when VFD Line Current ≤
Compressor RLA set point x 105%. It is also
reset when the compressor is not running or
the unit operating mode is changed to Ice.
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