Mitsubishi Electric Evolution+ s-MEXT Technical Manual page 207

MA S TER
Once the Constant Head adjustment has been configured on the Priority unit and the APL has been enabled, it will enable
DeltaP adjustment on all the units in the same group.
INFORMATION:
The enabling parameters can be modified only by the Priority unit and only if parameters P11.01 and
P26.01 are set as follows:
•
•
The units remain in calculated pressure-based adjustment mode, unless one of the following conditions occur:
•
unit in protection against high/low local temperature (P26.20);
•
the unit cannot communicate with any Priority unit;
•
the time delay for the start of the adjustment of modulating fans has not been complied with (P20.03);
•
expansion disconnected or pressure transducer not working/disconnected (only if parameter P26.19 enabled).
WARNING:
While the units adjust according to the calculated pressure, the setting parameters (setpoint, band,
etc.) of the Constant head are those of the Priority unit.
If parameter P26.19 is not enabled, even in case of offline expansion alarm or pressure transducer alarm the units continue to
work based on the calculated pressure provided by the Priority, but are excluded for the purpose of this calculation.
Through parameter P26.30, it is possible to choose whether to carry the adjustment in "Control" mode, therefore increasing or
decreasing the ventilation demand depending on the pressure, or in "Limit" mode, therefore only increasing the ventilation
demand.
The calculated pressure value, the type of adjustment and the local pressure value can be viewed on the supervision system.
The parameters for enabling and configuring the function are in the "LAN" menu that can be accessed with the "Service"
password.
Version 38
UNIT 3 UNIT 4
UNIT 5
UNIT 2
LAN
Min: 19.2 pa
UNIT 10 UNIT 7
UNIT 9 UNIT 8
Figure 17-13: graph showing the APL function with minimum pressure.
P11.01 = Delta P;
P26.01 >= 2.
Units Pressure
U1 = U2 = U3 =
P: 20.2 pa P: 19.7 pa P: 20.8 pa
U6 = U7 = U8 =
UNIT 6
P: 20.4 pa P: 20.2 pa P: 19.9 pa
U4 = U5 =
P: 19.5 pa P: 20.0 pa
U9 = U10 =
P: 19.2 pa P: 20.1 pa
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