Fujitsu WATERSTAGE WS A050DD6 Series Maintenance Document page 72

Split system single phase type
Flow control
Line no. Programming line
3720 Switching integral
3723 Locking time
Switching integral
The temperature-time integral is a continuous
summation of the temperature differential over time.
In this case, the decisive criterion is the difference by
which the temperature lies above or below the
common flow temperature setpoint.
The temperature-time integral gives consideration not
only to the period of time, but also to the extent of
over-/undershoot. This means that when the crossing
is significant, the supplementary source is released
earlier, or locked earlier, than with minor crossings.
QX2
QX3
TVx Actual value of flow temperature
TVw Flow temperature setpoint
+ Int Surplus integral
- Int Deficit integral
t1 Overrun time (not completed)
t2 Overrun time (fully completed)
QX2 Release output QX2
QX3 Control QX3
72
Locking time
The locking time enables the heat pump to reach a
stable operating state before the supplementary
source is allowed to switch on.
The supplementary source is released only when the
locking time has elapsed.
The locking time starts as soon as a valid flow
temperature setpoint is available.
Calculation of the release integral starts only when
the locking time has elapsed.
QX2
TVxSch Actual value of common flow temperature
TVwSch Setpoint of common flow temperature
A Request
QX2 Release output QX2
T Locking time
No consideration is given to the locking time, if the
heat pump malfunctions or is locked, or if the
supplementary source must end DHW charging.
Setting "- - -" can be used to deactivate the function.
Maintenance Document 1589-3