25/81
Siemens
RDG100.., RDG110.., RDG160T.. Basic Documentation
CE1P3181en
Building Technologies
Functions
2015-07-29
4.6.1 Qx- relay switching functions (RDG160T.. only)
The following special functions are available on the RDG160T.. and allow the control
of external equipment connected to the Q1, Q2 and Q3 relay outputs.
Switch OFF external equipment when the thermostat is in Protection Mode
Switch ON external equipment during heating/cooling demand
Output heating/cooling sequence
The relay output corresponding parameters need to be set to enable the function.
Function on Q1, set parameter P72. Test relay function via diagnostic d08.
Function on Q2, set parameter P73. Test relay function via diagnostic d09.
Function on Q3, set parameter P74. Test relay function via diagnostic d10.
Those functions are available when DIP4 is set to OFF (EC fan).
It is not suggested to use those functions in combination with the On/Off valve
control (P46/P47=1) to guarantee the temperature accuracy. If this combination is
requested, the total maximum current on the relay outputs (Q1+Q2+Q3) should not
exceed 2A.
The external equipment (such as: fan coil unit) can be switched OFF via relay output,
in order to reduce energy consumption when the thermostat is in Protection mode and
no temperature control is requested.
The function can be enabled by setting the corresponding Qx- parameter to 1.
Relay contact is open when the thermostat is in protection mode.
During the heating or cooling demand, the relay contact can be energized to control
an external equipment, for example to run the pump of a water system (fan coil).
To reduce the wear and tear of the HVAC equipment, the minimum output on-time and
off-time of the Qx- relay output can be adjusted from 1 to 20 minutes via parameters
P48 and P49. The factory setting is 1 minute.
The relay output remains OFF if the heating is provided ONLY by electric heater
(application 2-pipe electric heater, heating by electric heater, cooling by fan coil) or
radiator.
2-pipe water system (with one pump):
Enable the function by selecting the corresponding output parameter to 2
Connect the external equipment to selected relay output
In case of heating/cooling demand, the output contact is energized
4-pipe water system (with two pumps):
The function can be enabled by selecting the correspondent output parameters
> set one parameter to 3. The output is energized during heating demand
> set one other parameter to 4. The output is energized during cooling demand
Connect the external equipment to the selected relay outputs
This function switches the relay output depending on the sequence, either heating or
cooling. The output can be used for the release of a heat pump compressor.
When the thermostat is in heating mode (even in dead zone):
> the correspondent Qx- output contact is closed.
When the thermostat is in cooling mode (even in dead zone):
> the correspondent Qx- output contact is open.
The function can be enabled by setting the corresponding Qx- parameter to 5.
Notes
Switch OFF external
equipment in
Protection mode
Switch ON contact
during Heat/Cool
demand
Note
Output heating/cooling
sequence