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EWWQ090G ÷ EWWQ720L - R410a - Water-cooled scroll chillers
EWLQ090G ÷ EWLQ720L - R410a - Condenser less
EWHQ100G ÷ EWHQ400G - R410a - Heat pump scroll chillers
Water cooled scroll chillers & heat pump
Operation
Manual
Operation Manual
46
EWWQ - EWLQ - EWHQ
Water colled scroll chiller &heat pump
D-EOMWC01203-15EN
6 Alarms
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.
6.1.1 Unit Warning Alarms
6.1.1.1 External Event
This alarm indicate that a device, whose operation is linked with this machine, is reporting a
problem. This alarm can occur only if the parameter
External Alarm
is set as
Event
(see section
Symptom
Cause
Solution
Unit status is Run.
Bell icon is moving on controller’s
display.
Led on the button 2 of External HMI is
blinking
String in the alarm list:
+External EventAlm
String in the alarm log:
External EventAlm
String in the alarm snapshot:
External Event Alm
There is an external event that has
caused the opening, for at least 5
seconds, of the digital input on the
option module POL965 with address
18.
Check for reasons of external event
and if it can be a potential problem for
a correct chiller operation.
6.1.1.2 Bad Lwt Reset Input Signal
This alarm can occurs only when the function Lwt Reset is enabled (see section 4.9.1). It indicates
that the Lwt Reset signal input is out of admissible range
Symptom
Cause
Solution
Unit status is Run.
Bell icon is moving on controller’s
display.
Led on the button 2 of External HMI is
blinking
String in the alarm list:
+LwtResetAlm
String in the alarm log:
LwtResetAlm
String in the alarm snapshot:
Lwt Reset input signal is out of the
admissible range that is [3 - 21] mA
Check the electrical connection of the
Lwt Reset signal.
Check the device that produces the
Lwt Reset signal.