Sime BRAVA DGT HE 12 T Instrucciones De Instalación Y Mantenimiento página 108

3.3 EXTERNAL SENSOR (fig. 14)
If there is an external sensor, the heating
settings SET can be taken from the climatic
curves (PAR 12) according to the external
temperature and, in any case, limited to
with the range values described in point 3.2
(parameters PAR 13 and PAR 14).
The climatic curve to be set can be selected
from a value of 3 and 40 (at step 1).
Increasing the steepness of the curves of
fig. 14 will increase the output temperature
as the external temperature decreases.
3.5 CARD FUNCTIONING
The electronic card has the following func-
tions:
– Antifreeze protection of the heating cir-
cuits.
– Ignition and flame detection system.
– Control panel setting for the power and
the gas for boiler functioning.
– Anti-block for the pump which is fed for
a few seconds (10") after 48 hours of
inactivity.
– Chimney sweep function which can be
activated from the control panel.
– Temperature which can be shifted with
the external sensor connected.
– Automatic regulation of the ignition
power and maximum heating.
Adjustments are managed automati-
cally by the electronic card to guaran-
tee maximum flexibility in use of the
system.
– Interface with the following electronic
systems: remote control CR 73 or CR
63 combined with expansion card kit
code 8092240.
3.6 TEMPERATURE
DETECTION
SENSOR
Table 4 shows the resistance values of the
heating, D.H.W. and fumes sensor.
If the heating sensor (SM) and fumes sen-
sor (SF) is faulty or open circuit, the boi-
ler will not function on either heating or
D.H.W.
If the D.H.W. sensor (SB) is faulty or open
circuit, the boiler set in winter mode will
only work with heating function; if set in
summer mode, D.H.W. function will be
enabled only.
TABLE 4 (SM - SF - SB sensors)
Temperature (°C) Resistance (Ω)
20
30
40
50
60
70
80
108
3.6 ELECTRONIC
IGNITION
Ignition and flame detection is controlled
by a single electrode on the burner which
guarantees reaction in the case of acci-
dental extinction or lack of gas within one
second.
3.6. 1 Functioning cycle
Burner ignition occurs within max. 10
seconds after the opening of the gas
valve. Ignition failure with consequent acti-
vation of block can be due to:
– Lack of gas
The ignition electrode persists in
discharging for max. 10 seconds. If the
burner does not ignite, the anomaly is
signalled.
This can happen the first time the boi-
ler is switched on after a long period of
inactivity due to the presence of air in
the gas pipes
12.090
It can be caused by a closed gas tap or
8.313
by a broken valve coil (the interruption
5.828
does not allow for opening).
4. 1 61
3.021
– The electrode does not discharge.
2.229
In the boiler, only the opening of the gas
1.669
ATTENTION: curves are calculated at an ambient temperature of
20°C. Using the key on the control panel, the user can change
the set ambient by ± 5°C for which the curve is calculated.
to the burner can be detected. After
10 seconds the anomaly is signalled. It
can be caused by an interruption in the
electrode wire or if it is incorrectly
anchored to the connection points.
Or the electrode may be earthed or
strongly worn: it must be replaced. Or
the electronic card may be defective.
– No flame detected
After start-up the electrode continues
to discharge even when the burner is
on. After 10 seconds, the discharge
stops, the burner is switched off and a
fault is generated.
This fault is sometimes caused by the
shorting of the electrode cable or by its
improper fixing to the connection
points. The electrode is connected to
the earth or badly worn and must be
replaced. The electronic board is faulty.
In the case of a sudden lack of voltage, the
burner will immediately switch off. When
voltage returns, the boiler will automatically
start up again.
3.7 HEAD AVAILABLE TO SYSTEM
(fig. 15 - fig. 15/a)
Residual head for the heating system is
Fig. 14