Sime MURELLE EV 25/55 BF, Manual

Page: 96 / 108

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3.4 EXTERNAL SENSOR
(fig. 15)
If there is an external sensor, the heating
settings SET can be taken from the climatic
curves according to the external tempera-
ture and, in any case, limited to with the
range values described in point 3.3 (para-
meters PAR 25 for zone 1 and PAR 26 for
zone 2).
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. 15 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 and
sanitary water circuits (ICE).
– 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 after 24 hours of inacti-
vity.
– Antifreeze protection for boilers with an
accumulation boiling unit.
– Chimney sweep function which can be
activated from the control panel.
– Temperature which can be shifted with
the external sensor connected.
It can be set from the control panel and
is active on the heating systems of both
circuit 1 and circuit 2.
– Management of two independent hea-
ting circuit systems.
– 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: climatic regulator CR 53,
remote control CR 73, thermal regula-
tor RVS and connected to a manage-
ment card of a mixed zone ZONA MIX
cod. 8092234.
NOTE: If using CR 53 or RVS set para-
meter 10 to 2 (PAR 10 = 2).
– Function anticondensig, preheat the body
("+" sign in front of the main digits) and
anti inertia.
3.6 TEMPERATURE
DETECTION SENSOR
Table 3 gives the values of the electrical
element (
Ω
) obtained on the heating and
sanitary water sensors according to the
variations in temperature.
When the heating sensor (SM) is inter-
rupted, the boiler will not function for
both services.
With the D.H.W. sensor (SB) interrupted,
the boiler, in modality "winter", functions
only in phase C.H., modality "summer",
functions only in D.H.W. phase.
3.7 ELECTRONIC IGNITION
Ignition and flame detection is controlled by
a single electrode on the burner which gua-
rantees reaction in the case of accidental
extinction or lack of gas within one second.
3.7.1 Functioning cycle
Burner ignition occurs within max. 10
seconds after the opening of the gas valve.
Ignition failure with consequent activation of
block can be due to:
– Lack of gas
The ignition electrode persists in dischar-
ging for max. 10 seconds. If the burner
does not ignite, the anomaly is signalled.
This can happen the first time the boiler
is switched on after a long period of inac-
tivity due to the presence of air in the gas
pipes
It can be caused by a closed gas tap or by
a broken valve coil (the interruption does
not allow for opening).
– The electrode does not discharge.
In the boiler, only the opening of the gas
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 ancho-
red to the connection points.
Or the electrode may be earthed or
strongly worn: it must be replaced.
Or the electronic card may be defective.
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.
3.8 FUMES THERMOSTAT
vers. 25/55 OF
This is a safety measure against the return
of the fumes into the environment due to
an inefficient or partially blocked chimney
(11 fig. 3). It reacts by blocking the functio-
ning of the gas valve when the fumes are
continually forced back into the environ-
ment, in a quantity that can be dangerous.
If the boiler repeatedly stops, it will be
necessary to carefully check the chimney,
and to carry out all modifications and take
all measures necessary to restore it to an
efficient working state. After every inter-
vention carried outon the device, check cor-
rect functioning. In the case of replace-
ment, use only original spare parts.
TABLE 3
Temperature (°C) Resistance (
Ω
)
20 12.090
30 8.313
40 5.828
50 4.161
60 3.021
70 2.229
80 1.669
Fig. 15
ATTENTION: curves are calculated at an ambient temperature of
20°C. The user can act on the boiler controls to change the environ-
ment set for which the bend has been calculated by ±5°C.