Basic Documentation

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Siemens Universal controllers RMU710B, RMU720B, RMU730B CE1P3150en
Building Technologies Recirculated air op (basic type A) 03.10.2011
20 Recirculated air op (basic type A)
The recirculated air operation function (Precomfort) must control the room climate
to Precomfort setpoints during operating mode Precomfort for permanently
switched on fan(s) and 100% recirculated air operation of the mixed air dampers.
20.1 Activate function
The function recirculated air (Precomfort) can be activated in basic type A.
Main menu > Commissioning > Settings > .... or
Main menu > Settings > Operating mode >
Operating line Range Factory setting
Plant operating mode
Normal operation, Sustained
mode, Recirculated air mode
Normal operation
The recirculated air function is active as soon as the plant operation recirculated air
operation is selected and the mixed air damper is configured (see section 10.5.1).
20.2 Recirculated air operation
The plant with all configured aggregates (with the exception of the damper block)
and controllers is permanently on during recirculated air operation. The switched
on plant is controlled to the Precomfort setpoints.
Mixed air damper control:
 For recirculated air operation, the outside air damper is controlled at 0%, i.e. the
mixed air damper is open at the 100% position
 Control of supply air and extract air fans:
 The supply air fan is always switched on during recirculated air operation.
Switch-on of the extract air fan depends on the setting parameter
Sustained/Recirculated air operation (see section 10.1.13
"Sustained/recirculated air mode (basic type A)"). The two application examples
illustrate thi
s point
 For 2-speed fans and configured room/supply air or extract/supply air cascade
control, speed changeover may occur according to heating/refrigeration demand
(see section 11.6.3 "Second fan speed by heat/refrigeration demand")
Applicatio
n example 1
M
M
M
S01
Control of supply air
fan
Application example 2
M
M
M
S01
Control of supply
and extract air fans
Setting values
Notes