Basic Documentation

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Siemens Universal controllers RMU710B, RMU720B, RMU730B CE1P3150en

Building Technologies Sustained mode (basic type A) 03.10.2011

19.3.2 Sustained mode (Economy) for cooling

The example refers to controller 1 with a main controlled variable for room

temperature. It can be functionally be applied to controller 2 and controller 3.

At the end of occupancy, the plant switches off, i.e. the plant operating mode

changes from normal operation (Comfort) to sustained mode (Economy). The room

temperature falls or rises depending on the prevailing weather conditions and the

climatic conditions in the room.

If the room temperature exceeds the Economy cooling setpoint, sustained mode

cooling results.

In sustained mode, cooling is provided until the room temperature drops 1 Kelvin

below the Economy cooling setpoint. The plant is again switched off.

1 K

Smin

SpCEco

End of

Comfort Comfort

[°C]

Plant component state

In Economy mode, the plant is switched on when the room temperature drops

below the set Economy heating setpoint (SpHEco). When the plant operates, the

set Comfort setpoints are maintained (fan speeds and setpoints of all control

loops).

Sustained mode can only be activated when there are no fault messages that

switch off the plant.

Function diagrams

Note