Daikin UATYA-B, Operation Manual

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Service manual Daikin R32 Rooftops UATYA-B
ESIE21-02 – 2021.03
4.4.4 Alarm for low difference between high and low pressure
Checking of the difference between high and low pressure values takes place when at least one compressor of the circuit
involved is running.
Upon compressor start-up, a certain difference must be generated between high and low pressure in order to ensure correct
compressor rotation and oil return to the compressor.
The parameters involved are shown in the table.
The values of the parameters are representative. In specific cases, different values can be set.
Parameter Value UM Description
PAL92 3.00 bar Low pressure difference alarm threshold
PAL93 60 s Low pressure difference alarm delay on starting of compressors
PAL94 90 s Low pressure difference alarm delay at steady state
PAL95 2 - Maximum number of alarms in one hour due to low pressure difference
Alarm code AL114 for circuit 1; AL115 for circuit 2
Reason for activation
Upon start-up of one compressor in the circuit, if the pressure difference is <= than PAL92
for the number of seconds set in PAL93
After the time in PAL93 has elapsed, if the pressure difference is <= than PAL92 for the
seconds set in PAL94
Reset mode Automatic; switches to manual after the trip occurrences per hour set in “PAL95”
Alarm icon Flashing
AlarmLog Yes
Alarm relay Based on “alarm.conf” file
Devices Behaviour in the event of an alarm
Compressors Only the compressors of the circuit involved are switched off
The other devices They follow their control
4.4.5 Low superheating alarm
Where an electronic expansion valve is fitted, the controller manages the superheating of the intake gas to the compressor.
The parameters involved are shown in the table.
The values of the parameters are representative. In specific cases, different values can be set.
Parameter Value UM Description
Et30 300 s Low superheating alarm delay
Et37 2.0 °C Low superheating protection threshold
PAL4 5 - Maximum number of alarms in one hour due to low pressure
Alarm code AL170 for circuit 1; AL171 for circuit 2
Reason for activation
If the measured superheating value is lower than threshold ET37 for a time longer than the
setpoint in parameter ET30
Reset
When the measured superheating value is higher than or equal to threshold ET37 +1°C for
1 second
Reset mode
Automatic until the number of trip occurrences in one hour set in parameter PAL4 is rea -
ched
Manual as soon as the number of trip occurrences in one hour set in parameter PAL4 is
exceeded
Alarm icon Flashing
AlarmLog Yes
Alarm relay Based on “alarm.conf” file
Devices Behaviour in the event of an alarm
Compressors Only the compressors of the circuit involved are switched off
The other devices They follow their control
4 Alarms