Sime Format 25/60 OF Manual De Instrucciones página 87

the burner of around 90 seconds, both
at the beginning when the plant is cold
and in subsequent restartings.
This is so to avoid startings and swit-
ching off with very short intervals, that
may in particular be found in plants with
high losses.
At every restarting, following the period
of slow starting, the boiler will position
itself for around 1 minute to the mini-
mum modulating pressure to then return
to the set value of heating pressure.
With the insertion of the bridge both the
technical pause programmed and the
period of functioning at minimum pressu-
re in the starting phase will be elimina-
ted. In such a case, the time that runs
between the switching off and the next
starting will be in function of a variance
of 5°C, as detected by the heating sen-
sor (SM).
ATTENTION: All of the operations descri-
bed above must be carried out by authori-
sed personnel.
3.2 TEMPERATURE DETECTION
SENSORS
In Table 3 the resistance (Ω) values are
given. They are obtained by the sensors
when the temperature varies.
With the C.H. sensor (SM) interrupted
the boiler will not function with both ser-
vices. With the D.H.W. sensor (SB)
interrupted the boiler functions only
with heating.
TABLE 3
Temperature (°C) Resistance (Ω)
20 12.090
30 8.313
40 5.828
50 4. 1 61
60 3.021
70 2.229
80 1.669
3.3 ELECTRONIC IGNITION
The ignition and flame sensing are control-
led by a single electrode on the burner that
guarantees the maximum safety, with a
time of intervention of one second for acci-
dental switching off or lack of gas.
3.3. 1 Functioning cycle
Turn the rotary switch to summer or winter
and note, from the lighting up of the green
led, whether electricity is present. We can
summarise the manifestations of a failure
to start, with consequent activation of the
failure signal as follows:
– Lack of gas
The ignition electrode continues to spark
for a maximum of 10 seconds, the pilot
burner does not start, the apparatus is
blocked.
This may occur at the first ignition
attempt or after long periods of inactivity
with the presence of air in the tubing.
May be due to the gas tap being closed
or a break in the valve coil, which do not
allow opening.
– The ignition electrode does not spark.
In the boiler only the gas opening to the
burner is noted, after 10 seconds the
block signal lights up.
May be due to the fact that the cable of
the electrode is interrupted or is not well
fixed to the terminal of the ignition tran-
sformer. The electrode is earthed or
very worn and needs to be substituted.
The electronic board is faulty.
Due to a sudden fall in electricity the burner
is immediately arrested, once the electricity
is restored, the boiler will automatically
restart.
3.4 SMOKE SAFETY
DEVICE "25/60 OF"
It is a safety measure against the outflow of
smoke into the environment due to ineffi-
ciency or a partial clogging up of the flue (9
fig. 3). It acts by blocking the gas valve when
the release of smoke into the environment
is continuous and in such a quantity as to be
dangerous. To restart the boiler, and reacti-
vate the button of the thermostat. If the
blockage occurs repeatedly a thorough con-
trol of the flue will be necessary, making all
the modifications and taking all the precau-
tions necessary in order for it to be efficient.
600
500
400
300
200
100
0
200
3.5 SMOKE PRESSURE SWITCH
"25/60 BF -30/60 BF"
The smoke pressure switch with fixed set-
tings 4.5-6 mm H
10-13 mm H
2
guarantee the functioning of the boiler even
with suction and discharge tubing at the
maximum limit length permitted (10 fig. 3).
Impurities and the formation of condensa-
tion, most probable during the colder
periods of the season, could cause starting
failure of the boiler.
3.6 WATER PRESSURE SWITCH
A water pressure switch intercepts,
blocking the functioning of the burner
when the pressure in the boiler is less
than 0.5 bar (6 fig. 3).
To restore the functioning of the burner,
press on the charging key (fig. 7) and take
the pressure to a value between 1-1.2 bar.
3.7 SYSTEM AVAILABLE HEAD
The residual prevalence for the heating
plant is represented, according to flow, by
the graph in fig. 23.
3.8 TIME PROGRAMMER
OPTIONAL (fig. 24)
The control panel allows a time program-
mer to be utilised for the management of
the heating, supplied on request in the kit
code 8092203.
For the assembly of the time programmer
remove the control panel and the cover for
the positioning and, with the panel open, fix
the clock to the panel with the screws spe-
25/60
400 600 800 1000
O (vers. "25/60") and
2
O (vers. "30/60") is able to
30/60
1200 1400 1600
FLOW RATE (l/h)
PORTATA (l/h)
Fig. 23
85