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Technical Information
9.1
Hardware alarms
The presence of hardware alarms is queried every second and provided as silent variables via Modbus.
▪
EXV-fault (critical):
When this fault occurs, cooling is stopped and the system enters the alarm
condition.
▪
Suction pressure sensor fault (critical):
If an EXV is in use, this sensor is mandatory. When this
fault occurs, cooling is stopped and the system enters the alarm condition. Without a suction pressure
sensor, it is not possible to use the "low pressure alarm" function.
▪
Suction gas temperature sensor fault (critical):
When this fault occurs, cooling is stopped and the
system enters the alarm condition.
▪
Air in sensor fault:
This fault can only occur if an air in sensor is used. If this fault occurs, the
thermostat enters emergency operating mode (on/off cycling).
▪
Air out sensor fault:
This fault can only occur if the air out sensor is used. If this fault occurs, the
thermostat enters emergency operating mode (on/off cycling). If the air out sensor is used to determine
the end of a defrost cycle, the defrost cycle will be terminated over time. If electric defrost was
configured, the heater will be turned off due to safety reasons.
▪
Fin sensor fault:
If one or more fin sensors are used to terminate the defrost, in case of a sensor fault
in one of the sensors the defrost will be finished by time. If electrical defrost was configured, the heater
will be stopped.
▪
High pressure sensor fault:
The hybrid fans will be activated if this fault occurs.
▪
Compressor safety chain (critical):
This alarm is detected when the high or low pressure switch has
tripped. Cooling is stopped.
▪
Discharge temperature sensor:
This fault can only occur if a discharge temperature sensor is used.
▪
Cabinet temperature sensor:
This fault can only occur if a cabinet temperature sensor is used.
Refrigeration operation is not interrupted if this fault occurs.
▪
Low battery voltage:
The battery is tested after power cycling the board and afterwards every 6 hours
under load for a short period.
▪
Software Class B (critical):
The software has a safety integrated design. For this purpose, cyclical
tests are performed that may lead to this error. Refrigeration operation is interrupted when this error
occurs.
▪
EEPROM (critical):
The EEPROM is used to save the configuration parameters. If the EEPROM does
not respond, this error occurs. Refrigeration operation is interrupted when this error occurs.
▪
Modbus Master communication jam:
This alarm can only occur if one or more Modbus slave devices
are configured. When this fault occurs frequently the topology of the bus network might not accord to
RS-485 standard (termination resistors, line topology).
▪
Door open:
The maximum opening time of the door elapsed. A closed door is needed to guarantee
proper cooling.
9.2
Software alarms
•
Low pressure alarm (critical):
This alarm is evaluated depending on the type of cabinet. A lower
threshold is entered for this alarm using the
13 “Low suction pressure” alarm threshold
parameter.
A delay time can be entered using the
14
"Low suction pressure
” alarm delay
parameter. The
corresponding time is measured by an accumulation of all periods during which the suction pressure
is below the lower threshold. At the end of the delay period, the alarm is triggered. This alarm is not
triggered if there is a suction pressure sensor failure. Refrigeration operation is interrupted when this
error occurs.
•
"Low superheat" alarm (critical):
This alarm is only considered when an EXV is present. When this
fault occurs, refrigeration operation is stopped and the system enters the alarm condition.
▪
"High superheat" alarm (critical):
This alarm is only considered when an EXV is present. When this
fault occurs, refrigeration operation is stopped and the system enters the alarm condition.
▪
High cabinet temperature:
When the cabinet temperature sensor is not used, this alarm can be
deactivated (
22 “Cabinet temperature” alarm enabled
).
Is triggered when the cabinet temperature
exceeds the threshold (
24 “High cabinet temperature” alarm threshold
) for a certain amount of
time. (
25 “Cabinet temperature”
alarm delay
).
