Firmware V1.41 V1
08.11.2022
98/219
Fault on
Base load rotation output
Relay stages OFF output
Message
OFF
Stage 4, stage 5, stage 6
5.12.3 Low Pressure Monitoring
If the low pressure falls to a configurable limit value (menu 3-3
to AUS Verd
), all compressors are switched off.
If the low pressure rises to the proportional t
0
se NZ/2 pressure value, the compressors are activated
stage by stage as already described. An alarm is signalled after expiry of a delay time. Delay time (menu 3-3
Verz
to AUS
) and alarm priority can be configured. The controller calculates an absolute proportional pressure
value from this value. The LP monitor is also evaluated. If the pressure drops below the limit value of the LP
monitor, a forced shutdown of all compressors occurs.
5.12.4 High Pressure Monitoring
5.12.4.1 High Pressure Monitoring Too High
The high pressure is measured by a continuous sensor with current output / voltage output in the high pressure
line. Pressure monitoring is also performed using the high pressure safety cut-out and the high pressure limiter.
They provide a digital signal in the event of their tripping pressure being exceeded. These two digital signals
are transmitted to the controller sequentially.
If the high pressure reaches a configured limit value (menu 3-3
HP Off Comp
), up to 40% of the compressor
output stages are disabled stage by stage until the pressure has dropped to a level below the limit value. If all
the compressors are switched on, the first compressor is switched off without a time delay. Further
compressors are disabled after expiry of the basic downshift time. After exceeding the limit value (menu
3-3 HP
Off Comp
), no additional compressor is switched on until the pressure falls below the pressure limit value
(menu 3-3
HP On Comp
) even if a request exists.
Compressor switch-off for HP EMERG.-OFF
If the measured high pressure exceeds the limit value
HP EMERG.-OFF
, all compressor stages are switched
off immediately. The function "Speed reduction when HP too high" ensures that the speed has been reduced to
the minimum speed when the limit value
HP Off Comp
is reached. A compressor enable is performed when the
HP value has fallen below the limit value
HP On
again. They are then switched on stage by stage via the step
controller.
The following diagram is a graphic representation of the entire HP monitoring system:
An exception is the heat recovery mode. In this operating mode, no compressor shedding and no compressor
disablement take place. If the limit values of the HPS limiter or HP limiter are exceeded, a forced shutdown of
all compressors takes place. After mechanical unlocking of the pressure switch, the compressors are switched
on again step by step. After exceeding the limit value
HP Off Comp
(menu 3-3), the fault signal
HP too high
is