Symbol explanation
15 INTEGRAL A3
16 External auxiliary heater
The calculation of the integral value stops during heat stop. The calculation of the integral value stops when heat
stop has stopped.
In this example INTEGRAL A3 < INTEGRAL A2. This means that the external addition will be activated earlier than
the internal addition. On the condition that these are activated.
9.8 HYSTERESIS
In order to start the heat in advance during sudden changes of the heat demand, there is a value, HYSTERESIS,
which controls the difference between the actual supply temperature, t
1
and the calculated supply temperature,
t
2
. If the difference is equal to or greater than the set HYSTERESIS value (x), i.e. there is a heat demand, or the heat
demand disappears, quicker than the usual integral calculation, the integral value is forced to either the start value
(-60) INTEGRAL A1 or to the stop value (0).
Figure 26. Conditions for HYSTERESIS to force the integral value to change.
Position Description
1 Integral
2 Supply temperature
3 t
1
4 t
2
5 Time
6 Compressor stop (0)
7 Compressor start (-60)
8 Hysteresis (Δt) ≥ x
9 Hysteresis (Δt) ≥ x
9.9 DEFR CURVE
To start defrosting the outdoor unit for DHP A/DHP AL, the control computer makes a calculation using the tem-
perature of the brine return and the outdoor temperature.
The calculation is based on a linear defrosting curve that can be set so that the heat pump and outdoor unit work
optimally. The setting of three different values can be changed: DEFR CURVE 0, DEFR CURVE -20 and OUTDOOR
STOP. The defrosting sequence starts when the temperature of the brine return reaches the set parameter value
for the defrosting curve at an outdoor temperature somewhere along the defrosting curve.
32 – Service instructions VMGFC302
To Next Page
Loading...
Need help?
General