Turn off HC
Summer:
HC turns off when the summer/winter changeover (outside temperature) is exceeded.
Room:
HC is turned off when the summer/winter changeover (outside temperature) or the room setpoint temperatures
are exceeded.
Heat request
MHCC can request a heat source (burner, heat pump, ...) if the heating circuit does not have enough energy (VL temperature).
Therfor either the signal output V1 is used or the request is transferred via the CAN bus to another controller in the CAN network.
Switching:
Request is made via signal output V1.
Output signal to V1: "no request" = 0V, "request" = 10V
If a potential-free contact is required for the heat source, an external switching relay (Art. no. 77502) must be con-
nected to V1. see " External relay at signal output V(X) (0-10V / PWM) " on page 23.
Modulating:
Request is made via signal output V1. The MHCC outputs the requested temperature (calculated target VL) as a
voltage via the signal output.
Example: Calculated target VL heating circuit 43 ° C, measured VL at sensor S2 40 ° C.
If the VL sensor exceeds the setpoint VL by 2K (preferece/actual -) for more than 2 minutes, the MHCC requests a heat source
with 4.3V (corresponds to 43 ° C setpoint VL).
The requested temperature can be raised with the value "Mod.Offset". 0.1V correspond to 1 ° C. If you set an offset of 0.5V, this
results in a requested temperature of 48 ° C or 4.8V (43 ° C corresponds to 4.3V + 0.5V (offset) = 4.8V corresponds to 48 ° C)
CAN:
Request is made via the CAN bus; the heat request must be activated (switching or modulating) on a controller in the net-
work.
This controller receives the request via the CAN bus and passes it to the connected heat source.
Eco mode (during solar charge)
The economy mode for this function can be operated in 2 different variants:
Shutdown:
The function is not started with an active solar charge.
Lowering:
The Energy saving mode switches the heating on when T eco is undershot and heats up to T eco + hysteresis when
solar charge or solid fuel boiler is active.
Reference/Actual -
Switch on hysteresis for additional heating
This setting determines the allowed undershoot of the heating circuit temperature below the calculated reference fl ow tem-
perature. If the heating circuit flow temperature and the storage temperature drop below the reference flow temperature by this
value, the additional heating will start the additional heat source after a 1 minute delay.
Heat request is started when the flow temperature is continuously below reference temperature for 1 minute.
14-day Reference
If operating mode‚ 14-day reference value‘ is selected see " Operating mode " on page 15, the reference flow temperature for
each of the 14 days can be set here. In Menu 4.4.1, the starting time of the program is shown. To restart the reference program,
press ‚restart‘.
Pressing ‚restart‘ again will reset the 14-day reference program and restart it at Day 1.
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