Fujitsu WSYA050ML3 Design & Technical Manual page 100

• Over-temperature protection
Overrun time of release for the external source: If the integral indicates another heat deficit before
the overrun time has elapsed, the release remains activated. If the set overrun time elapses before
the common flow temperature drops below the common flow temperature setpoint, the release is
deactivated also.
• Flow control
– Switching integral: The temperature-time integral is a continuous summation of the tempera-
ture differential over time. In this case, the decisive criterion is the difference by which the tem-
perature 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 ex-
tent 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
– 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
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 func-
tion.
3-11. Additional generator (Boiler connection)
Line
3705 Overrun time
Line
3720 Switching integral
3723 Locking time
Function
Function
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
TVxSch
TVwSch
A
QX2
T
- (03-42) -
Actual value of common
flow temperature
Setpoint of common
flow temperature
Request
Release output QX2
Locking time
3. Function table