Alarms And Troubleshooting; Unit Alerts; Badlwtreset - Bad Leaving Water Temperature Reset Input; Energymetercomm - Energy Meter Communication Fail - Daikin EWAT_B Operating Manual

5

ALARMS AND TROUBLESHOOTING

The UC protects the unit and the components from operating in abnormal conditions. Protections can be divided in
preventions and alarms. Alarms can then be divided in pump-down and rapid stop alarms. Pump-down alarms are activated
when the system or sub-system can perform a normal shutdown in spite of the abnormal running conditions. Rapid stop
alarms are activated when the abnormal running conditions require an immediate stop of the whole system or sub-system
to prevent potential damages.
The UC displays the active alarms in a dedicated page and keep an history of the last 50 entries divided between alarms
and acknowledges occurred. Time and date for each alarm event and of each alarm acknowledge are stored.
The UC also stores alarm snapshot of each alarm occurred. Each item contains a snapshot of the running conditions right
before the alarm has occurred. Different sets of snapshots are programmed corresponding to unit alarms and circuit alarms
holding different information to help the failure diagnosis.
In the following sections it will also be indicated how each alarm can be cleared between local HMI, Network (by any of the
high level interfaces Modbus, Bacnet or Lon) or if the specific alarm will clear automatically.
5.1

Unit Alerts

All events reported in this section does not produce a unit stop, but only a visual information and an item in the alarm log

5.1.1 BadLWTReset - Bad Leaving Water Temperature Reset Input

This alarm is generated when the Setpoint Reset option has been enabled and the input to the controller is out of the
admitted range.
Symptom
Unit status is Run.
Bell icon is moving on controller's display.
LWT Reset function cannot be used.
String in the alarm list:
BadLWTReset
String in the alarm log:
 BadLWTReset
String in the alarm snapshot
BadLWTReset
Reset
Local HMI
Network
Auto

5.1.2 EnergyMeterComm - Energy Meter Communication Fail

This alarm is generated in case of communication problems with the energy meter.
Symptom
Bell icon is moving on controller's display.
String in the alarm list:
EnergyMeterComm
String in the alarm log:
 EnergyMtrComm
String in the alarm snapshot
EnergyMtrComm
Reset
Local HMI
Network
Auto

5.1.3 EvapPump1Fault - Evaporator Pump #1 Failure

This alarm is generated if the pump is started but the flow switch is not able to close within the recirculate time. This can
be a temporary condition or may be due to a broken flowswitch, the activation of circuit breakers, fuses or to a pump
breakdown.
Symptom
Unit could be ON.
Bell icon is moving on controller's display.
Backup pump is used or stop of all circuits
in case of pump #2 failure.
String in the alarm list:
EvapPump1Fault
Operating Manual
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Cause
LWT reset input signal is out of range.
For this warning out of range is considered
to be a signal less than 3mA or more than
21mA.



Cause
Module has no power supply
Wrong cabling with the Unit Controller
Modbus parameters not properly set
Module is broken



Cause
Pump #1 may not be operating.
Solution
Check for values of input signal to the
unit controller. It has to be in the allowed
mA range.
Check for electrical shielding of wirings.
Check for right value of the unit's
controller output in case input signal is
into allowed range.
Solution
Refer to the datasheet of the specific
component to see if it is correctly
powered
Check if the polarity of the connections is
respected.
Referring to the datasheet of the specific
component to see if the modbus
parameters are set correctly:
Address = 20
Baud Rate =19200 kBs
Parity = None
Stop bits =1
Check if the display shows something
and the power supply is present.
Solution
Check for problem in electrical wiring of
the pump #1.
Check that electrical breaker of pump #1
is tripped.
If fuses are used to protect the pump,
check the integrity of fuses.
EWAT_B