ECKELMANN VS 300, Руководство по эксплуатации

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Function of VS 300
40 Doku-Version 2.05 - Firmware 2.10 - 15. September 2017
4.3.20 Forced shutdown of compressors / oil equalization
With compressor packs serving only a single refrigeration point, the display cases are usually not fitted with a
solenoid valve. Continuous run monitoring can then be assumed by the VS 300. The forced shutdown function
(see Section 7 Parameter List and Menu Structure) has three parameters for this purpose:
Forced OFF CL1/2 , Max.RunTime and Standstill .
These parameters can be set within the ranges stated below:
Forced OFF CL1/2: Y/N Default: N
Max.RunTime: 60..180 minutes: Default 180
Standstill: 1..5 minutes: Default 2
The Max.RunTime parameter defines when (after the set run time) the pack is shut dow by fast unload. The
pack is then disabled for the time set under Standstill, at the end of which compressors are again loaded.
4.3.21 Capacity-controlled compressors
The VS 300 Pack Controller can control capacity-controlled compressors with up to three capacity stages (base
load plus two capacity stages (bypass valves)). It is also possible to operate non-capacity-controlled together
with capacity-controlled compressors in the same control loop.
Operation of capacity-controlled compressors is only supported when the controller is configured as a step con­
troller. Capacity-controlled compressors have no effect on the VS 300's control algorithm, only the actuating se­
quence changes. The base load of an available compressor is loaded first when the compressors are actuated.
Then the capacity stages of the compressor are loaded as refrigeration is demanded before the base load stage
of an additional compressor can be loaded. Unloading of capacity stages takes place in the reverse sequence.
Run time is always monitored when loading and unloading the base load stages so that the base load stage
having the shortest run time is loaded and that having the longest run time is unloaded.
If both non-capacity-controlled and capacity-controlled compressors are programmed in one control loop, the
capacity-controlled compressors will be loaded first. This again takes place in the sequence described above
(first base load stage, then associate capacity stages).
When all capacity-controlled compressors are running at 100%, the compressors without capacity control are
loaded as additional refrigeration capacity is demanded. So as to achieve finer graduation, the capacity stages
of a capacity-controlled compressor are unloaded to leave only its base load stage working when a non-capac­
ity-controlled compressor is loaded. The capacity stages are then re-loaded as additional refrigeration is de­
manded.
An example of system configuration for loading and unloading of compressors is as follows:
Control Loop 1:
S
Number of base load stages: 2
S
Number of capacity stages each capacity-controlled compressor: 3
S
Number of capacity-controlled compressors: 1
Control Loop 2:
S
Not detailed here!