101
Mixing valve control functions
SMGB0066 rev.0 - 12/2009
Controller pack
Service Manual
4
Parameter Settings
•
P33 Return Temperature Limit Offset (default OFF)
Special note
•
It is highly recommended for CONF 2, that the parameter P33 is
not
left in the default OFF state.
Recommended setting is 5K.
Enable/ disable
•
This function can be disabled by setting the parameter P33=OFF.
4.7.5. Maximum outdoor Temperature for Electrical Heater operation
function
•
This function disables the electric heater control when the outdoor temperature is above the electric heater maximum
outdoor temperature setting. Above this setting it is assumed that the heat-pump is able to deliver all the requested heat
by itself and the electric heater is therefore not required.
Parameter Setting
•
P15 Maximum Outdoor Temperature for Electric Heater Operation (default 0°C)
Enable/disable
•
To disable this function and allow electric heater operation at all outdoor temperatures, set the parameter P15=OFF.
4.8. MIxInG VAlVE ConTrol fUnCTIonS
4.8.7. Mixing Valve Control
Configuration Specific
•
This function only applies to configuration 4 (CONF 4)
function
•
When heating is required, the System Controller controls the mixing valve so that the mixed water temperature is close to
the Supply Setpoint. The mixing valve position is calculated with a proportional plus integral action (P+I) control algorithm
based on the difference between the Supply Setpoint and mixed water temperature (TMIX).
Desired Mixing Valve Position = PI function ( Supply Setpoint – TRET )
The System Controller then decides how much to open or close the mixing valve to achieve the desired position of the
valve. This is dependent on the running time of the actuator used on the valve. The running time is defined as the time it
takes to drive the valve from the fully closed to the fully open position. Typically this can be between 1 and 4 minutes.
Parameter Setting
•
P9 Mixing Valve Runtime (default 120 sec)
EP1 Mixing Valve Integral factor (default 2.5)
The installer should set the parameter p9 based on his selection of actuator and mixing valve.
The value for EP1 has been chosen based on laboratory tests and it is not recommended to change it.
note
Engineering Parameters (EP) are only available for service engineers.
-
