baltur BGN 40 DSPGN-ME Mode D'emploi page 30

10) We recommend that you carry the out combustion tests with the appropriate instrument at all intermediate
points in the modulation range (from P1 to P9); also check the gas flow delivery rate via the meter
(see the "READING THE METER" section).
11) Check that modulation function automatically by putting the AUT - O - MAN switch in the "AUT" position and
he MIN - O - MAX switch in the "O" position. In this way, modulation is activated exclusively by the automatic
command of the boiler's probe, if the burner is a BGN...M (modulating) version, or on the command of the
termostat or pressure switch of the 2nd stage, if the burner is a BGN...DSP GN (two-stage progressive)
version. (See instruction "Electronic Potentiality Regulator RWF ... for the modulating version).
12) The air pressure switch has the job of bringing the control box to a safety shut down if the air pressure is not
at the correct value. Therefore, the air pressure switch must be regulated in such a way as to intervene by
closing the contact (foreseen to by closed while working) when the air pressure in the burner has reached a
sufficient level. The pressure switch is self-controlled and therefore it must close the contact (fan stops and
consequently there is an absence of air pressure in the burner) if it does not, the control box will be inserted
(the burner remains at a stadstill).It must be specified that if the contact is not closed during working (insufficient
air pressure), the control box will carry out its cycle, but the ignition transformer will not be inserted and the
gas pilot valves will not open. Consequently, the burner will go to "shut down". Check that the air pressure
switch functions properly with burner at minimum delivery, increase the regulating value until it reaches
intervention point and the burner should go to shut down. To unblock the burner, press the special push-button
and return the pressure switch regulator to a sufficient value in order to measure the air pressure existing
during the pre-ventilation phase.
13) The pressure switches which control the gas pressure (minimum and maximum) have the job of stopping the
burner functioning when the gas pressure is not within the values specified. 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 maximum 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 minimum and maximum gas pressure switches should be regulated
during the burner's general inspection and should be in function with the pressure found each time.
Theintervention (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 operating (flame lit), the
intervention of the gas pressure switches (opening of the circuit) determines the immediate arrest of the
burner. During the burner's general inspection, check the correct functioning of the pressure switches.
By operating the respective regulating device, it is possible to control the pressure switch's intervention (opening
of circuit) which causes the burner's arrest. (see also the MPA 22 instructions on the following pages).
14) Check the efficiency of the flame detector (ionisation electrode) by detaching the wire coming from the electrode
and by turning on the burner. The control box should carry out completely its cycle and two seconds 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 operating. By detaching the wire that comes from the ionisation electrode, the control box
should go immediately to "shut down". In the case of the UV photoelectric cell, slide the wire out of its seat on
the burner and verify the "shut down".
15) Check the efficiency of the boiler thermostats and pressure switches (this should result in the burner coming
to a standstill).
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