87
DHW control functions
SMGB0066 rev.0 - 12/2009
Controller pack
Service Manual
4
Parameter Settings
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P10 DHW setpoint (default 45°C)
P11 DHW differential (default 5K)
P12 DHW supply offset (default 10K)
Configuration Specific
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CONF 1,2: Heat Pump heats the DHW storage tank directly. If the storage tank also has an internal DHW electric
heater this can also be used if necessary.
CONF 2:
The 3-stage electric heater cannot be used for DHW loading. When DHW loading starts, the 3-stage
electric heater is switched off.
CONF 3,5: If the Heat Pump is not able to reach the DHW supply setpoint by itself, the boiler may also be used to
raise the temperature of the DHW tank (see “Using the Boiler for DHW loading”).
Parameter notes
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P10: DHW setpoint
CONF 1,2: If there is no internal DHW electric heater, setting the DHW setpoint higher than 45°C may result in very
long DHW loading times, and the desired temperature may not be reached. This is because the maximum
outlet temperature from the Heat Pump is normally 55°C, and at low outdoor temperatures 50°C.
CONF 3,5: The DHW setpoint may be set higher since the boiler will also be used to heat the DHW storage tank.
P11: DHW differential
A small DHW differential will increase the frequency of the DHW loading periods while making them shorter. A large DHW
differential will reduce the frequency of the DHW loading periods, while making each period longer, and will cause larger
swings in DHW temperatures.
P12: DHW supply offset
CONF 1,2: setting a value higher than 10K will not affect the DHW loading period since the maximum outlet
temperature from the Heat Pump is 55°C.
CONF 3,5: setting a value higher than 10K will allow faster DHW loading times since the boiler can be used.
4.4.3. Maximum dHW loading Time
function
•
In case there is a continuous high demand for DHW over a very long period, or the DHW setpoint is set too high, the
Heat Pump may not be able to reach the desired temperature. In this case, to ensure that heat is provided in the living
space (heating circuit), the DHW loading is stopped after a preset time (parameter P27) and the system controller returns
to satisfy the demand from the heating circuit.
diagram
•
DHW loading starts (power-on or DHW timer signal)
Supply water temperature set to P10+P12(*)
DHW setpoint not reached after time P27
DHW loading stopped
