Rehau Ba - Exceeded Dew Point

40
SETTING UP BA MASTER CONTROLLER
(COOLING)
7.0
Default settings on the BA master (Cooling)
Description Factory settings
Day temperature 24°C
Night temperature 26°C
Off Temperature (Frost protection) 5°C
Minimum flow water temperature 2°C (above dew point)
Floor Limit temperature, high 27°C
Floor Limit temperature, low 17°C
The controller is supplied with pre programmed settings. The adjustment
of these parameters is not possible on the BA Master Controller
7.1 Offset to Day Temperature
This provides the daytime cooling offset temperature (factory set
to 3°C). This function prevents the need to adjust the temperature
settings on the sensors from winter to summer temperatures. This
allows all the connected sensors within the controller to have a
positive offset temperature to the set day temperature set within the
controller e.g. If the Controller has heating day temperature set point
is 21°C then in cooling mode the controlled cooling temperature
within the space will be 24°C (21+ 3).
7.2 Night Setback Temperature (NSB)
The cooling setback function will operate at whatever NSB temperature set
within the master controller above the room set-point temperature when in
cooling mode. The factory set NSB temperature is 2°C.
7.3 BMS Used for Heating/ Cooling Change Over Decision
If a BMS system in being used for the heating/cooling decision, the
volt free BMS signal should be connected to the REHAU WLAC switch,
but the slider switch on the right side of the WLAC must be set to
the heating position (in this situation the BMS signal has priority and
we recommend that the slider toggle be removed to avoid incorrect
overriding) (Refer to Fig. 37).
7.4 Exceeded Dew Point
The controller calculates the dew point temperature based on room
temperature and relative humidity. If the water temperature flowing
into the underfloor heating/cooling circuits is lower than the dew point
temperature plus 2°C safety factor, the controller signals the actuators
to close, there by preventing the formation of any condensation.
The REHAU BA Master Controller is an independent floor heating / cooling control system.
It requires manual switching of the system from heating to cooling and back to heating
using a WLAC switch or a volt free signal from the BMS. Thus, being able to give an output
demand signal to boiler, chiller or a reversible heat pump.
T T
+
T
+
T
+
WLAC SWITCH
REHAU
WLAC
Connected to
sensor BUS
Connected to
sensor BUS
Volt free signal from the BMS;
When BMS relay is closed, the
system switches into cooling;
when relay is opened the system
switches to heating
T T
+
T
+
T
+
Slider switch set to heating position
(In this situation BMS has priority)
37. Wiring of BMS for Heating/Cooling change over decision