The pump has 2 speeds that are operated by
the control of the heating delivery-return ΔT. It
is operated as follows:
ΔT del-ret < ΔT – 2°C → V2 pump speed;
Δt del- ret > ΔT → V3 pump speed;
where: ΔT= 20°C (default value can be
sent by parameter 239 between 10 and
30°C).
Speed switching is carried out with a 5 minute
delay (non-settable value) raising or
diminishing.
Performed from the thermostat with
automatic reset (102±4°C) located on heating
delivery, (even while the burner if off). After
opening the thermostat a safety shot down
occurs (not indicated) and after 5 sec if the
thermostat is already open a block shutdown
of the boiler occurs (non volatile), indicated
on the display with 1 01.
After flame detection the boiler is free to
modulate the power according to the required
thermal load. Modulation is carried out
between the maximum heating power values
(adjustable from the control panel with
parameter 231) and the minimum power value
(set made on the gas valve). The shut down
temperature of the burner is operated as
follows:
1° min after flame detection:
T off = T set-point + 8°C
2° min after flame detection:
T off = T set-point + 6°C
starting from the 3
rd
min after flame
detection: T off = T set-point + 4°C
This logic is used to prevent the burner from
shutting down too quickly with the system at
temperature.
Next ignition can be delayed from 0 to 7
minutes (default value = 2 min., adjustable
from the control panel with parameter 236)
N.B. Starting from heating request, the “limit temperature” (88°C, not adjustable fixed
value) remains on executed by the primary exchanger outlet probe (NTC 1).
If there is bad circulation through the heating system, the automatic by-pass can be
opened (max capacity 350 l/h).
To Next Page
Loading...
