IOM 1242-8 • PATHFINDER
®
MODEL AWV CHILLERS
76 www.DaikinApplied.com
Alarms and Events
Waterside Economizer Valve Fault
Alarm:
Waterside Economizer Valve Fault
Displayed Text: WSE Valve Fault
Trigger:
If the following conditions are true for 90
seconds the alarm should be triggered:
• WSE water valve 1 command = 100%
• WSE water valve 1 position < 90%
Or, if the following conditions are true for 90
seconds the alarm should be triggered:
• WSE water valve 2 command = 0%
• WSE water valve 2 position > 10%
In addition, if the valve position signals are
out of range as follows the alarm should be
triggered:
• valve 1 signal is out of range on high
side for one second
• valve 2 signal is out of range on low
side for one second
Action Taken:
Disable and lock out chiller from running
Reset:
This alarm can be cleared manually via the
controller HMI or BAS command.
Waterside Economizer Valve Problem
Alarm:
Waterside Economizer Valve Problem
Displayed Text: WSE Valve Problem
Trigger:
If the following conditions are true for 90
seconds the alarm should be triggered:
• WSE water valve 2 command = 100%
• WSE water valve 2 position < 90%
Or if the following conditions are true for 90
seconds the alarm should be triggered:
• WSE water valve 1 command = 0%
• WSE water valve 1 position > 10%
In addition, if the valve position signals are
out of range as follows the alarm should be
triggered:
• valve 1 signal is out of range on low
side for 1 second
• valve 2 signal is out of range on high
side for 1 second
Action Taken:
Waterside Economizer disabled
Reset:
This alarm can be cleared manually via the
controller HMI or BAS command.
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 first 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 first 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.
Figure 76: Low Evaporator Pressure Fault Diagram
Evap Pressure < 0 kPa for 5
seconds
OR
Evap Pressure < -50kPa for
2 seconds
OAT
≥
-8°C
OAT< -8°C
Evap Pressure < 30 kPa for
5 seconds
Evap Pressure < 0 kPa for 5
seconds
Evap Pressure < -50kPa for
2 seconds
Evap Pressure < -30kPa for
2 seconds
Evap Pressure < 0 kPa for
20 seconds
OR
Evap Pressure < -50kPa for
5 seconds
{
5 minutes
First 2 occurrences for this
condition will shut down
circuit but do not trigger the
alarm. Third occurrence in
the day will trigger the alarm.
Evap Pressure < Low
Pressure Unload set point for
100 seconds
Evap Pressure < Low
Pressure Unload set point for
freeze time
CIRCUIT
RUN
CIRCUIT
START
