Flue Gas Temperature Supervision - Siemens Synco700 RMK770 Documentation Handbook

Configuration of a pair of
terminals for a 3-position
mixing valve
Return temperature
setpoint
Fault of return tempera-
ture sensor
Slave pointer function
Building Technologies
HVAC Products
The terminals still available for selection are the free terminal pairs (Q1/Q2, Q3/Q4,
Q5/Q6) for the open and the close signal. Generally, special terminal pairs are required
for that purpose (RC units for radio interference suppression; for more detailed informa-
tion, refer to subsection 3.3.2 "Terminal assignment and properties of outputs").
By selecting "Maint boiler return temp mod", a mixing valve with DC 0...10 V output is
assigned. If required, this output can be matched to the type of mixing valve used.
Main menu > Commissioning > Settings > ... or
Main menu > Settings > Boiler ... > Limitations
Operating line
Boiler return temperature min
For adapting the control parameters to the type of plant (actuator and controlled sys-
tem), the same setting parameters as those used with the mixing heating circuit are
available.
For more detailed information, refer to section 5.7 "Mixing valve control".
Main menu > Commissioning > Settings > ... or
Main menu > Settings > Boiler ... > Return control
Operating line
Actuator running time
P-band Xp
Integral action time Tn
If a minimum return temperature shall be ensured, it is necessary to select the minimum
boiler temperature accordingly. The minimum boiler temperature must be at least a few
K higher than the minimum return temperature.
In the case of plant with a mixing valve for the maintained boiler return temperature, the
mixing valve will be driven to the fully closed position if the return temperature sensor is
faulty and then deenergized to make possible manual adjustment.
If there is no return temperature sensor configured, a fault status message will appear.
If only a return temperature sensor is configured with no mixing valve present, the sen-
sor will be used for display purposes.
7.11

Flue gas temperature supervision

If the flue gas temperature shall be monitored, a sensor must be configured in the extra
configuration.
Main menu > Commissioning > Extra configuration > Boiler ... > Inputs
Operating line
Flue gas temperature sensor
It is to be noted here that for the temperature inputs, a Ni1000 sensor is configured as
standard. However, for flue gas temperature measurements, Pt1000 sensors are often
used; for this reason, Pt1000 is set here as a default value. The type of sensor can be
adapted under Settings > Inputs at the configured terminal.
If a flue gas temperature sensor is configured, the following functions are available for
selection:
This function is active whenever a flue gas temperature sensor is selected.
Main menu > Boiler ... > Inputs/Setpoints
Operating line
Flue gas temperature maximum
Boiler Sequence Controller RMK770
7 Boiler temperature control
Range
---- / 8...140 °C
Range
1...600 s
1...100 K
0...600 s
Adjustable values / remarks
Assign input
Adjustable values / remarks
Factory setting
---- °C
Factory setting
120 s
40 K
40 K
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CE1P3132en
01.03.2005