Operating Cycle - Sime Format Dewy.zip 25 BF Manual De Instrucciones

gas, check that the pressure for hea-
ting is still at the value previously set.
– "JP1" connector (pos. 10)
In the heating phase, the electronic
board is programmed to include a bur-
ner technical delay interval of approx.
180 seconds, that occurs every time it is
restarted after a forced shutdown. For-
ced shutdown means when turned off
due to overhearting 5 degrees C over
the temperature set on the heating
potentiometer. The aim is to overcome
the problem of repeated ignitions and
turning off with very short time intervals
between. This could occur in particular in
systems presenting high head losses.
At each restart after the period of slow
ignition, the boiler will set itself for about
1 minute at the minimum modulation
pressure, and will then move to the hea-
ting pressure value set.
When the connecting link is inserted,
both the programmed technical pause
and the period of operation at minimum
pressure in the startup phase will be can-
celled.
In this case, the times elapsing between
turning off and subsequent re-ignition will
depend on a temperature difference of
5°C detected by the SM sensor (heating
flow sensor).
– "JP2" connector (pos. 9)
Bridge inserted when the diverter valve
is used. When the system uses the boi-
ler pump the bridge must be off.
– "MAX" fan speed trimmer (pos. 2)
Sets maximum fan speed.
– "MIN" fan speed trimmer (pos. 4)
Sets minimum fan speed.
ATTENTION: It is essential that the opera-
tions described above be carried out by
authorized technical staff.
3.2 TEMPERATURE SENSOR
Antifreeze system made up of the NTC hea-
ting sensor that activates when the water
temperature reaches 6°C.
The heating sensor also works as a limit
thermostat turning off the burner when the
detected temperature is over 80°C. Reset
temperature is set at 75°C.
Neither boiler services will work when the
sensor (SM) is cut off.
Tables 4 show the resistance values (Ω)
that are obtained on the sensor as the
temperature varies and the transducer
values obtained as the pressure varies.
3.3 ELECTRONIC IGNITION
Ignition and flame detection is controlled
by two electrodes located on the burner.
These guarantee maximum safety with
intervention times, for accidental swit-
ching off or gas failure, of within one
second.
TABLE 4
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. 1

Operating cycle

Rotate the selector knob to summer or win-
ter, and verify that green led (
confirm the presence of voltage.
The boiler is now ready to start working
upon demand for heating or drawing off
of D.H.W.; a discharge current is sent to
the ignition electrode through the pro-
grammer, and the gas valve opens at the
same time. The burner must be ignited
within 10 seconds. However, it is possible
for ignition failures to occur, with conse-
quent activation of signal indicating that the
control box has "locked out".
– Gas failure
The ignition electrode continues sparking
for max. 10 seconds. If the burner does
not ignite, the board, after a 5-second
fan pause, will restar t sparking for
another 10 seconds. This cycle is repea-
ted 5 times after which the red release
led lights.
This may occur upon first ignition or
500
400
300
200
100
0
200
after long periods of boiler lay-off when
there is air in the pipes. It may be caused
by the gas cock being closed or by one of
the valve coils having a break in the win-
ding, so that the valve cannot open.
– No detection of flame
Only the gas is opened in the boiler. The
block light will turn on after 60 seconds.
It may be caused by the fact that the
electrode wire is cut-off or not well
secured to the ignition transformer
terminal board.
The electrode is grounded and badly
worn, needing replacement. The elec-
tronic board is defective.
When there is a sudden voltage failure, the
burner shuts out immediately; when power
) lights up to supply returns, the boiler will start up again
automatically.
3.4 FLOW SWITCH SAFETY VALVE
A flow switch safety valve (8 fig. 5) interve-
nes, blocking the operation of the burner if
the boiler is without water due to the for-
mation of an air lock in the heat exchanger
or if the circulator is not working, or becau-
se the "Aqua Guard" filter is obstructed with
impurities.
NOTE: If replacing the flow switch valve,
make sure that the arrow stamped on the
valve points in the same direction as the
flow of water.
3.5 SYSTEM AVAILABLE HEAD
The head available for the heating plant is
400 600 800
FLOW RATE (l/h)
25 BF
30 BF
BFR
1000 1200
PORTATA (l/h)
Fig. 18
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