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unblock the burner, press the special
push-button and return the pressure
switch regulator to a sufficient value
in order to measure the air pressu-
re existing during the pre-ventilation
phase.
12) The pressure switches which con
-
trol the gas pressure (minimum and
maximum) have the job of stopping
the burner functioning when the gas
pressure is not within the values spe
-
cified. From the specific functions of
the pressure switches, it is evident
that the pressure switch controls the
minimum pressure must make use of
the contact, which is closed, when it
measures a pressure which exceeds
that at which it has been set. The ma
-
ximum pressure switch must make
use of the contact, which is closed,
when it measures a pressure below
that at which it has been set. The mi
-
nimum and maximum gas pressure
switches should be regulated during
the burner’s general inspection and
should be in function with the pres
-
sure found each time. Theinterven-
tion (by this we mean the opening
of the circuit) of any one of the gas
pressure switches, will prevent the
control box and thus the burner from
starting up. When the burner is ope
-
rating (flame lit), the intervention of
the gas pressure switches (opening
of the circuit) determines the imme-
diate arrest of the burner. During the
burner’s general inspection, check
the correct functioning of the pres-
sure switches. By operating the re
-
spective regulating device, it is pos-
sible to control the pressure switch’s
intervention (opening
of circuit) which causes the burner’s
arrest.
13) Check the efficiency of the flame
detector (ionisation electrode) by
detaching the wire coming from the
electrode and by turning on the bur
-
ner. The control box should carry out
completely its cycle and two secon
-
ds after the ignition flame (pilot) is
formed, it should go to “shut down”.
This control should also be carried
out when the burner is already ope
-
rating. By detaching the wire that
comes from the ionisation electrode,
the control box should go immedia-
tely to “shut down”.
14) Check the efficiency of the boiler
thermostats and pressure switches
(this should result in the burner co-
ming to a standstill).
N.B. Check that that ignition takes place
correctly because if the mixer is not
in the correct position, it may happen
that the speed of the delivery air is so
high that ignition becomes difficult. If
this happens the mixer must be mo-
ved back by degrees until it is in a
position at which ignition takes place
normally, at which point this can be
taken as the final position.
We remind you that it is advisable, as
regards the ignition flame, to restrict
the quantity of air to the minimum
necessary for safe ignition, even in
the most difficult cases.
MANUAL MODE BURNER
INSTRUCTIONS
Combustion control can be carried out
over the whole modulation range whi
-
le manually controlling the MPA 22
equipment. For this use modulation
connector (B) in the diagram, which is
provided with the burner as standard.
After disconnecting the 4-pole plug (A)
which takes the signals from the ther
-
mostat or the RWF 40 adjustor, insert
the connector in position (B). Use the +
button to increase the gas and air sup-
ply or - to reduce it.
After the check, put the 4-pole plug (A)
back in so as to reset automatic mode
modulation.
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