Daikin AWV024 - Troubleshooting Guides

IOM 1242-2 • PATHFINDER
®
MODEL AWV CHILLERS 72 www.DaikinApplied.com
alarms and evenTs
Figure 68: Low Evaporator Pressure Fault Diagram
High Condenser Pressure
Alarm: High Condenser Pressure
Text: Cn CondPressHigh
Trigger: Saturated Condenser Temp > Max Saturated
Condenser Value for time longer than High
Condenser Pressure Delay set point.
Action
Taken:
Rapid shutdown of circuit and lock out from running
Reset: This alarm can be cleared manually via the Unit
Controller keypad if Saturated Condenser Temp <
Max Saturated Condenser Value.
Low Pressure Difference Or Ratio
Alarm: Low Pressure Difference Or Ratio
Text: Cn LowPrDiffOrRatio
Trigger: This alarm is triggered on the third occurrence
of the below conditions within two hours. Prior
occurrences are events.
Trigger 1: Pressure ratio is < 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 = (Cond Press + 101.325)/(Evap Press +
101.325)
Trigger 2: Pressure difference is less than 180 kPa for
longer than the Low Press Diff/Ratio Delay set
point after circuit state transition to Run. Press
difference is calculated as shown in kPa:
Difference = (Cond Pressure) - (Evap 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 and lock out from
running
Reset: This alarm should auto reset every time until it has
triggered 3 times within 2 hours and be cleared
manually via Unit Controller keypad or BAS.
Mechanical Low Pressure Switch
Alarm: Mechanical Low Pressure Switch
Displayed Text: Cn MLP Switch
Trigger: The alarm is triggered if all of the
following are true for at least 40
seconds:
• Circuit state is Run
• MLP Switch input is off
The alarm also requires Evaporator
Conguration = Remote to trigger. This
means if the Evaporator Conguration
is set to Packaged, then the MLP
Switch inputs are ignored and the
alarm is disabled.
Action Taken: Rapid shutdown of circuit and lock out
from running
Reset: This alarm can be cleared manually
via the Unit Controller keypad if the
MLP Switch input is on.
Mechanical High Pressure Switch
Alarm: Mechanical High Pressure Switch
Displayed Text: Cn MHP Switch
Trigger: Compressor VFD reports Safe Disable
Input alarm. This is the case when the
alarm code reported by the VFD is
either 003BH or 003CH.
Action Taken: Rapid shutdown of circuit and lock out
from running. Note that VFD will shut
down compressor directly in response
to this alarm in the VFD. Controller
then needs to move circuit to the off
state, but compressor should already
be turned off by the VFD.
Reset: This alarm can be cleared manually
via the Unit Controller keypad after the
VFD is no longer reporting the Safe
Disable Input alarm.
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