Basic Documentation

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Siemens Universal controllers RMU710B, RMU720B, RMU730B CE1P3150en
Building Technologies Aggregates 03.10.2011
10.5.6 Priorities
The following priorities apply to mixed air temperature control:
1. Startup circuit
2. MECH changeover
3. Mixed air temperature controller signal
4. IAQ controller signal
5. Sequence controller signal
10.5.7 Troubleshooting
Errors in operation
When you exit the Commissioning menu, a check is made to see if the mixed air
temperature sensor is connected. If the sensor is not connected at this point, the
"Mixed air temperature control" function is set inactive.
If the sensor is connected at this time but is missing later, message "Sensor fault
X.." appears and the "Mixed air temperature control" function is set inactive.
10.5.8 Maximum Economy changeover (MECH)
To activate Maximum Economy Changeover (MECH), the relevant inputs must be
assigned.
Main menu > Commissioning > Extra configuration > Aggregates > Mixed air damper >
Operating line Adjustable values / remarks
MECH input 1 ---, N.X1, N.X2, ..., Outside temperature,
[Logic1] digital, [Logic 2] digital
(only °C, kJ/kg, 100, 1000, digital)
MECH input 2 ---, N.X1, N.X2, ... , Room temperature, Extract air
temperature
(only °C, kJ/kg, 100, 1000)
Main menu > Commissioning > Settings > .... or
Main menu > Settings > Aggregates > Mixed air damper >
Operating line Range Factory setting
MECH limit value
1)
3 K, 20 °C
3 kJ/kg, 40 kJ/kg
3, 40 ---
1)
The MECH limit value operating line is used when changing over to a settable value as absolute
value, or when changing over based on a difference of two measured values as relative value. In this
case, it is used to consider heat sources in the extract air duct (e.g. dissipated heat fan)
Configuration
Setting values