Electrical Connections; General Information - baltur BGN 40 DSPGN-ME Mode D'emploi

ELECTRICAL CONNECTIONS

The three-phase or single-phase electric supply line of the minimum section, in proportion to the power absorbed
by the burner, must be equipped with a fused switch. Furthermore, regulations require a switch on the burner's
feed line which should be located outside the boiler room in an easily accessible position.
All electric lines must be protected by flexible sheaths, be firmly secured and be laid a long way from high tempe-
rature parts. For the electrical connections (line and thermostat) see the relevant diagram.

GENERAL INFORMATION

These burners are of the blown air type which have a mixture of gas/air at the combustion head. They are suitable
for use with combustion chambers which are either raising high pressure or reducing pressure, according to the
relative work curves. Together with excellent flame stability, these burners are safe and highly efficient.
It is equipped with a steel flange which slips on the burner head.
When fastening the burner to the boiler it is necessary to correctly position the flange so that the burner head
enters the combustion chamber to the extent specified by the boiler manufacturer.The burner has an electronic
cam mod. MPA 22. The microprocessor-controlled MPA 22 provides intermittent operation, controls and monitors
the electronically-modulated fan-equipped gas burners and features two (air/gas) adjuster motors. When working
as an automatic burner valve seal control is activated; (for a better understanding of the MPA 22 read the instructions
in the attached manual, code 0006080902).
DESCRIPTION OF OPERATIONS AT 2-STAGE PROGRESSIVE (see 0002910830)
Operation of is of the progressive two-stage type, so called because the switch from primary flame to secondary
flame (from minimum to the set maximum) occurs gradually as regards the delivery of both combustion air and
fuel; this gives considerable advantages in terms of the pressure stability in the gas feed line. Delivery rate
ranges, approximately, from 1 to 1/3. Ignition is preceded by pre-ventilation of the combustion chamber as per
standards, with the air open: this lasts about 36 seconds. If, at the end of the ventilation stage, the air pressure
switch detects that pressure is sufficient, the ignition transformer comes on and, after 3 seconds, the safety and
main valves open in sequence. The gas reaches the combustion head, is mixed with the air being delivered by the
fan, and is ignited. Delivery is regulated by the gas throttle valve. Three seconds after the (main and safety) valves
are opened the ignition transformer is switched off. The burner is now on at the ignition point (P0). The flame is
detected by the relative control device (an ionisation sensor positioned inside the flame, or a UV photocell).
The programming relay goes beyond the shutdown position and powers the air/gas delivery regulation servomotors,
which go to minimum (P1). If the 2 stage boiler thermostat (or pressure switch) – adjusted by a temperature or
nd
pressure greater than that in the boiler) – allow, the air/gas delivery servomotors start running and cause a
gradual increase is the delivery of gas and combustion air until the maximum flow rates to which the burner has
been set have been reached (point P9).
N.B. Electronic cam MPA 22 controls the burner by adjusting the combustion air and gas servomotors
according to a pre-set curve.
The burner remains in the maximum delivery position until the temperature or pressure reaches the limit set for
the intervention of the boiler thermostat (or pressure switch) of the 2 stage and makes the servomotors regulating
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gas/air delivery rotate in the opposite sense of direction. Thus gas delivery and the relative combustion air are
gradually reduced until they reach minimum value. Even with delivery at a minimum, if the limit (temperature or
pressure at the shut down device (thermostat or pressure switch) has been regulated is reached, the burner will
be brought to a standstill. When the temperature or pressure drops below the intervention limit set on the shut
down device, the burner will star up again, according to the programme previously described.
During normal operations, the boiler thermostat (or pressure switch) of the 2 stage fitted to the boiler detects the
nd
variations requested and automatically proceeds with adapting the fuel and combustion air delivery by inserting
the servomotors which regulates delivery (gas/air). This will rotate in such a way as to obtain an increase or a
decrease. With this manoeuvre, the gas/air delivery regulating system try's to equilibrate the quantity of heat
supplied to the boiler with that which the boiler gives to be utilised. If the flame does not appear within THREE
seconds of the opening of the gas valve, the control box goes to "shut down" (the burner stops completely and the
relative indicator light is turned on). To unblock the control box, press the appropriate push-button.
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