To start defrosting the control system makes a calculation using the temperature of the refrigerant sensor1 and
the outdoor temperature. The calculation is based on a defrost curve that can be set so that the heat pump works
optimally. The defrost sequence starts when the temperature of refrigerant sensor 1 falls to the set parameter
value for the defrost curve at an outdoor temperature somewhere along the set defrost curve.
The defrost curve is adjusted using the parameter DEFROST CURVE that moves the defrost curve in parallel. Nega-
tive value moves the defrost curve down which means that it takes a longer time before defrosting starts. Positive
value moves the defrost curve up which means that it takes a shorter time before defrosting starts.
The value for DEFROST CURVE is shown by means of a graph in the display.
The value for DEFROST CURVE is the temperature that refrigerant sensor 1 reaches when a defrost must start at
different outdoor temperatures.
0
1
2
-5
0
-10
-20
Position
Description
1
Refrigerant sensor1
2
Outdoor temperature
8.5.11
Cooling
When the cooling function is activated cooling will be permitted when the outdoor temperature exceeds the set
value for COOLINGMODE ACTIVE. The cooling function is primarily temperature controlled and starts when the
return line sensor reaches the set value for START. Cooling is interrupted when the supply line sensor reaches the
set value for STOP. If the hot water heater is installed the control unit will alternate between cooling and hot water
production with prioritisation for the hot water requirement.
Caution! When cooling it is important to limit the lowest flow line temperature to prevent condensation.
To avoid condensation a dewpoint sensor can be installed (accessory). The dewpoint sensor senses when
condensation starts to form and cooling is then stopped automatically.
CUIT 1 - 2, Page 48 in the Information menu.
8.5.12
Concrete drying
When drying concrete up to ten points can be entered which define the curve that is desired when drying con-
crete. Each point is given with day number from the set date and a temperature. A straight line is drawn between
each point. This line gives the setpoint value for concrete drying.
Note! Concrete drying continues with the latest set setpoint until the program is cancelled.
Stop concrete drying by selecting another operating mode.
DAY X/Y. Displays day number X out of a total Y days.
START: day-month-year, CLOCK: hours:minutes.
HYSTERESIS. If the temperature of the setpoint value falls by more than the value of the HYSTERESIS the auxiliary
heater and the external auxiliary heater start.
Installation instructions VMGFD102 – 45
