Application guidelines
25
FRCC.PC.021.A5.22
Operating conditions
The OCS will display alarms when the compressor
is running outside the operating envelope. The
compressor will be stopped when it does not
come back to normal running conditions within a
defined delay.
High and low pressure
protection
The OCS also provides information about below
listed malfunctions.
Maintenance operations should include an OCS
diagnosis analysis, in order to check the warnings
and alarms status history provided by the OCS.
Malfunction protection
Component
Detection Criteria(s)
Alarm
Action
Crankcase heater
Resistance out of operating range
OR
Current out of range
WARNING W43
: “Crankcase
heater dysfunction”.
No action
Discharge Temperature sensor
(1 on each compressor)
Resistance out of operating temperature
range
ALARM A42
: “Discharge
Temperature sensor error”
STOP the compressor
Pressure transducers LP
(1 on compressor OR via comm.
bus)
Voltage out of sensor operating pressure
range [0,1;4,9]V
OR
broadcasting not available via CAN-Bus
ALARM A15
: “Low Pressure
transmitter error”.
Auto search for alternative sensor on the
manifold,
else
STOP the compressor.
RESTART sequence
value back to normal range, then
automatic reset.
Pressure transducers HP
(1 on compressor OR via comm.
bus)
Voltage out of sensor operating pressure
range [0,1;4,9]V
OR
broadcasting not available via CAN-Bus
ALARM A16
: “High Pressure
transmitter error”.
Auto search for alternative sensor on the
manifold,
else
STOP the compressor.
RESTART sequence
value back to normal range, then
automatic reset.
Motor PTC
Resistance out of operating range
ALARM A20
: “PTC is open”.
STOP the compressor (open Switch).
RESTART sequence
value back to normal range, then
automatic reset.
CAN-Bus
Compressor1
Compressor2
or Mainboard
Timeout 10s
WARNING W21
:
“Communication bus disabled” No action
Modbus bus
Compressor1
MAINBOARD
Timeout 1min
WARNING W21
:
“Communication bus disabled” No action
