________________________________________________________________________________
51
AST 14 C 255/00
In case of probes not correctly set or installed in an improper position, the ambient probe
reading can be corrected with the parameters P53 (for SA1) and P56 (for SA2). Ambient
probe value is the result of the value read by ambient probe plus or minus the value of the
two parameters given above (from -5°C to +5°C).
WARNING: in case the probes are damaged (short-circuit, open circuit or out of range
value) error E44 will be displayed for SA1 and error E45 for SA2. Any active heating
circuit(s) will be interrupted.
In case two ambient probes are used, the setting of daytime and of night-time
temperatures must be the same for both probes. To set different temperatures, it is
necessary to correct the reading with the specific parameters.
Modulation types with ambient probe
By setting parameter P57, it is possible to use the ambient probes and have the boiler
work in CH mode using the type of modulation which is most suitable for the system.
The differences are given below, pre-condition being that the two zones must be managed
at the same temperature, with ambient probe (zone1) and heating thermostat (zone2)
respectively. According to the above described condition, parameters P17, P60 and P61
must be set to 1, 0 and 03 respectively.
P57=0
Modulation on-off
In this case, an external probe is not necessary and flow temperature is set with “+/-
heating" key at fixed point (35-45°C or 35-78°C) for both circuits.
P57=1 Ambient probe modulation
External probe is not necessary.
Zone 2 works at a fixed temperature selected with "+/- heating” key (35-45°C or 35-78°C)
and follows programme 2. Instead, the set-point requested by zone1 (ambient probe) is
calculated according to the temperature detected by the probe, and of the “Sun or moon
temperature” selected in the heating programme 1.
In case both zones request heat, the flow set-point calculated will be the highest of the two
requested.
P57=2 External probe modulation
In this case, it is necessary to use the external probe with the relevant thermoregulation
curve setting (P10).
Zone 2 works at sliding temperature, calculating the set-point as a function of the external
temperature, of the set curve and of the "Fictitious ambient temperature" set with “+/-
heating” key, according to the specific programme.
Instead, the set-point requested by the ambient probe (zone1) is calculated as a function
of the external temperature, of the set curve and of the “Day and night temperatures”
selected in the heating programme 1.
In case both zones request heat, the flow set-point calculated will be the highest of the two
requested.
P57=3 Ambient probe and external probe modulation
Also in this case, the use of the external probe is necessary,with the relevant setting of the
thermoregulation curve (P10).
