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50
AST 14 C 255/00
ADJUSTABLE HEATING MAXIMUM OUTPUT
During operation in heating mode, the maximum output supplied to the burner is equal to
the one set by parameter P7.
This parameter represents the percentage (default 100%) of maximum admissible current
supplied to the modulation coil (120 mA for natural gas and 170 mA for LPG).
CH WITHOUT AMBIENT PROBES
(P57=4)
With the boiler set on the "DHW + CH" or "Heating only" operating mode, the closing up of
ambient thermostat electric contact (or the enabling signal from the remote control) will
result in a request in the heating mode, making heating modulation start.
It is possible either to manage the heating zones with the relevant control devices only
(manual operation), or to set the heating times (automatic operation) of zones 1 and 2
directly from the boiler. In the latter case, the "timer" function is logically connected in
series with the inputs of the climate control devices.
WARNING: with parameter P16 it is possible to delay the ambient thermostat reading to allow the
zone valves (if available) to open before the boiler pump starts (from 0 to 199 seconds).
CH WITH AMBIENT PROBES
(P57
≠
4)
To allow for managing the heating zones using the ambient probes, they have to be
enabled, i.e. value of parameter P57 must be different from 4.
Ambient probe 1 (
SA1
) is associated with zone 1 and with heating programme 1, whereas
ambient probe 2 (
SA2
) is associated with zone 2 and with heating programme 2.
WARNING: it is possible to connect two ambient probes only if a zone supplementary
board is present, otherwise it is not possible to manage ambient probe 2 (SA2).
Operating logic
The CH function is enabled only if the boiler is in the "DHW + CH” or “Heating only” mode.
The “Ambient set-point” setting is on two levels: daytime temperature and night-time
temperature, represented respectively by the symbols
and
. During manual operation,
only the daytime level is taken into account, while in the automatic operation (weekly
programming) the levels correspond to the enable/disable times.
Ambient probe requests heat when ambient temperature is lower than or equal to
“Ambient set-point” minus “triggering differential ON” value (parameter P52 for SA1 and
P55 for SA2). Request stops when ambient temperature is higher than or equal to
“Ambient set-point” plus “triggering differential OFF” value (parameter P51 for SA1 and
P53 for SA2).
Example:
Tset-point SA1=20°C ; P51=0.2;
P52=-0.3
Heating is enabled when ambient temperature SA1
≤
19.7
Heating is disabled when ambient temperature SA1
≥
20.2
