39
CONTROL SYSTEM
Alarms
Alarms table
Alarms activation and reset
The controller is able to perform a complete diagnosis of the unit
detecting all the operating faults and notifying different alarms.
The activation of an alarm implies :
-
involved consumers locked
-
alarm icon shown on the display
-
event recorded in the alarm history
To show the details about the active alarm press the INFO but-
ton.
Alarms that can damage the unit or the plant require a
manual
reset
that implies that the operator has to reset manually the
controller. It is advisable to verify accurately the cause that ori-
ginated the alarm and to make sure that the problem has been
solved before restarting the unit. In any case the unit will restart
only if the cause of the alarm has disappeared.
For the manual reset alarms, pressing the INFO button, along
with the details about the alarm, also the message “Reset ?” will
appear. Press the OK button. When the message “Yes” blinks
press again the OK button to confirm the alarm reset.
The less critical alarms have an
automatic reset
. As soon as the
minimum compressor switch off time has elapsed the controller
tries to reset the alarm. If the cause that originated the alarm has
disappeared, the unit starts working again and the alarm icon is
no more shown on the display. Some of these alarms become
manual reset alarms if the number of events in an hour exceeds
a fixed threshold.
It is possible to reset the active alarms also through the RESET
button. In that case the scheduled delays at the unit switch on
are ignored avoiding undesired waiting times during commissio-
ning or fault tracing. This function should NOT be used in normal
operation.
Alarm history
The controller allows to save the last 10 alarms occured during
the unit operation. For each event the following details are re-
corded :
-
alarm code
-
hour
-
date
Such details can be displayed entering the “Errors” menu (para-
meters from 6800 to 6819).
When the number of saved events is higher than 10 the following
events are saved deleting the oldest alarms.
The controller diagnostic takes into account, besides the alarms reported in the table, many other alarm codes the meaning of which
is indicated on the unit display when the corresponding alarm becomes active. Such alarms are not critical and don’t lock the heat
pump operation.
Note:
(1) A = automatic reset , M = manual reset , A / M = manual reset only if the number of events in an hour is higher than 3.
Code
Alarm
Reset
(1)
Input
Heat pump lock
10
Outdoor air temperature sensor
A
B9
No
33
Plant side flow temperature sensor
A
B21
No
35
Source side return temperature sensor (finned coil inlet)
A
B91
Yes
39
Liquid line temperature sensor
A
B84
Yes
44
Plant side return temperature sensor
A
B71
No
106
Sorce side temperature too low
M
-
Yes
134
Phase sequence controller
A
E20
Yes
201
Plant side frost protection alarm
A
B21
Yes
204
Fans overload
A / M
E14
Yes
222
High pressure during heat pump operating
A / M
E10
Yes
223
High pressure during heating circuit start
M
E10
Yes
224
High pressure during domestic hot water circuit start
M
E10
Yes
225
Low pressure
A / M
E9
Yes
247
Defrosting fault
A / M
-
Yes
356
Plant side differential pressure switch
A / M
E24
Yes
