________________________________________________________________________________
72
AST 14 C 255/00
Water heater filling function (pump OFF)
Solar pump PS is disabled in the following conditions:
Tsbc > P19
or
Tscs – Tsbs <
∆
T OFF (P21)
or
Tscs < Tmin solar collector OFF (P23 - 5°C)
or
Tscs > Tmax solar collector OFF (P22)
Warning: in case of boiler water heater probe SBC fault, the water heater filling is
managed according to the same logic, taking into account the solar water heating
probe SBS instead of the faulty one.
Collector heat transfer function
This function prevents solar collectors from remaining in a stagnation state for a
long time, which would expose them to high risk of thermal stress, when solar water
heater temperature is reached.
Therefore, the solar pump PS is reactivated (with valve VM in “boiler filling” mode)
according to the following logic:
Tscs > (P22 - 10°C)
and
Tsbc < 95°C
and stopped when one of the following conditions occurs:
Tscs < (P22 -12°C)
or
Tsbc
≥
95°C
Besides, the function is disabled with Tscs > P22 and re-activated with Tscs < P22
minus 5°C.
Warning: said function is active only if either the "DHW ONLY", or the "CH ONLY"
or "DHW + CH" mode is selected in the boiler, whereas it is not active in case of
boiler water heater probe SBC fault.
Heat discharge function
This function can be enabled only with P76=1. It allows for controlling a solar
motorised valve VM in order to discharge the solar energy on a secondary actuator.
This occurs only if the collector heat transfer function can no more be enabled since
the maximum temperature inside the water heater (95°C) has been reached.
The valve VM is supplied with power in the “heat discharge” mode according to the
following logic:
Tscs > (P22 - 10°C)
