Control functions
2.3.2 Change-over detection
Change-over detection is performed either by using a PT1000 sensor that is connected to an analog input, or
by using a potential-free contact that is connected to a digital input. The PT1000 sensor is mounted so that it
senses the pipe media temperature.
When using a PT1000 sensor for change-over detection, the shift in change-over state is triggered based on
the difference between the pipe media temperature and the room temperature. The thermostat shifts the
change-over state to heating when the pipe media temperature is 3 °C (default setting) higher than the room
temperature. The thermostat shifts the change-over state to cooling when the pipe media temperature is 3 °C
(default setting) lower than the room temperature. The valve has to be at least 20 % open to run calculation
to ensure that the media temperature is correct.
When using a potential-free contact for change-over detection, the thermostat shifts the change-over state to
cooling when the contact is closed. The thermostat shifts the change-over state to heating when the contact is
open. This assumes that the digital input is set to Normally opened.
2.3.3 Change-over via display
If Parameter 9 or Holding Register 12 is set to 0, then the change-over function is set by actions from the
display. Switching from Heating to Cooling mode, and vice versa, is then done by pressing the change-over
button. This is the only configuration where the change-over button will be showed in the display.
2.3.4 Change-over settings
Parameter Description
9 The change-over mode
0 = Manual setting in display
1 = Manual Heat
2 = Manual Cool
3 = Automatic via analogue or digital input
10 Temperature difference between the room temperature and the water temperature to switch to heating
11 Temperature difference between the room temperature and the water temperature to switch to cooling
12 Sensor/detector connected to DI1
0 = No sensor connected
1-2 = Not used
3 = Presence detector (activate Occupied state)
4 = Change-over sensor
15 DI1 Normally closed (NC) / Normally open (NO)
0 = NO
1 = NC
17 Sensor connected to AI
0 = No sensor connected (Internal NTC sensor is used)
1 = Room temperature sensor
2 = Change-over temperature sensor
RCFD-230C manual, Rev. A 9
To Next Page
Loading...
Need help?
General
