________________________________________________________________________________
75
AST 14 C 255/00
Solar functions characteristics
Each time the solar pump becomes operational, its active state will be signalled
by the icon on the boiler display.
In case of fault of the solar water heating probe (SBS) or of the solar collector probe
(SCS), the solar pump is immediately switched off and the fault is reported through the
boiler board interface and the remote control (if connected) with the relevant error codes
(E28 and E24 respectively).
It is moreover possible to force the solar charges during maintenance by setting
parameters P90, P91 and P92. In this way, the supplementary board relays are energised
until such parameter is restored.
Supplementary board characteristics
Power supply
230 Vac -15/+10% 50Hz
Load output
230 Vac, 1° max
Flow probe
NTC 10 kOhm @25°C B3435
Max. 3 metres
Solar probe
PT1000 Max. 100 metres
Flow probe operation correct range
-5°C +120°C
Solar probe operation correct range
-40°C +290°C
Mixing valve disabling range for reached set-point
Set+1.5°C / Set-2°C
Mixing valve opening total timer
From 0 to 300 s (P74)
Initial closing timer with powered board
P74 + 40 s
Request end closing timer
P74 + 20 s
Post-circulation timer
From boiler with P13
Circulation pump anti-shut-down timer
3 s each 24 hours
Anti-freeze function timer
15 min
Anti-freeze triggering temperature
< 5 °C
TEMPERATURE PROBE INTEGRITY CHECK
The system checks for any faults in the probes connected to the modulation board,
signalling any detected faults with the relevant error code. The failure condition occurs
when probe is not supplied with power (except for the external probe), or when it detects a
temperature value outside probe correct operating range:
Double flow probe
(E05)
fault: the burner is immediately switched off whereas the
fan is still supplied with power.
The pump circulates water until the fault is reset, with deviating valve in heating
position, if before the fault a heating, flow-return anti-freeze, flue cleaning request
was present, or if the boiler does not feature any request.
The pump circulates with deviating valve in DHW position only if before the fault
there was a request in DHW or DHW anti-freeze mode.
With P17=1 and P17=3 (multifunction relay), the relay remains energised until the
fault is reset in case a heating, flow-return anti-freeze, flue cleaning request, or no
requests were present.
