ECKELMANN VS 3015 CT, Инструкция по эксплуатации, Страница: 75 / 219

Firmware V1.41 V1 08.11.2022 75/219
5.7.1 Control Algorithm for MP Control
The medium pressure measured via an A/D converter is compared with the setpoint.
The input signal for the MP control valve is calculated using a PI controller. The amplification factors for the P-
component (parameter
p-factor , menu 3-2-3) and the I-component (parameter i-factor , menu 3-2-3) can be
adjusted.
The correcting variable for the opening degree of the medium pressure valve can be limited with the
parameters
Min contr val. and Max. Con.Var. (menu 3-2-3). The specification is entered as a percentage. If Min
contr val. = 0% and Max. Con.Var. =100%, the correcting variable of the MP controller will not be limited.
If the "Schnellrücklauf-Extern AUS" digital input (terminals 84, 85) has been activated and all compressors have
been unloaded, the analogue output is set to 0 volts. The MP control valve can also be operated in manual
mode. Using the parameter
Man. op. xxx % in menu 3-2-3 MP Regulation, the valve opening degree can be set
from 0...100%. If "---" is entered, the opening degree is determined using the PI controller.
Manual mode is reserved for test and service purposes and is not stored in the controller memory, i.e. after a
power failure, controlled operation is active again. Manual operation cannot be activated via LDSWin.
5.7.2 Maintaining the MP by Limiting the HP-Valve
Depending on the medium pressure, the opening degree 0..100% of the HP valve is limited both downwards
and upwards. The limitation is performed as shown in the following graph:
Parameters
Menu Parameter Description Input Defa
ult Dim.
3-2-3 MP Min Lower limit for MP, HPV will be opened when Medium Pressure is lower 10...60 32 bar
3-2-3 dPm HP-V.Open P-range for forced opening of the HPV in the case of undercutting the
minimum medium pressure setpoint 0..20 3 bar
However, these parameters should only be adjusted by trained specialist personnel!
Since all pressure transmitters measure absolute pressure values, the mean pressure setpoint
MP
setpoint
must also be parameterised as absolute pressure and not relative to the ambient pressure.

No MP regulation can take place in the event of failure of the MP pressure transmitter. A configurable
emergency opening degree (parameter
Stellsig.Not , menu 3-2-3) is then output.
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