Combustion Control - baltur BTG 20 LX Notice D'instructions

DESCRIPTION OF THE MODULATION OPERA-
E
TION
N
When the burner is on at the minimum flow rate, if the modulation
sensor allows it (adjusted to a higher pressure or temperature
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value than that in the boiler), the air regulation servomotor start
L running, thus determining a gradual increase of the combustion
air supply, and consequently, of gas, until the maximum supply at
I
which the burner is regulated is reached. The air pressure increa-
se in the ventilator is detected by the gas valve sensor, model
S
MB-VEF..., which gradually adjusts the gas supply to the also
gradual air pressure variation.
H
The burner remains in the maximum supply position until the
temperature or pressure reaches a sufficient valve to determine
the intervention of the modulation sensor, which makes the air
regulation servomotor run in the reverse direction with respect
to the previous one. The backward rotation and the air and gas
supply reduction occur at short time intervals. With this operation,
the modulation system attempts to balance the quantity of heat
supplied to the boiler with that yielded by the same during use.
The modulation probe applied to the boiler detects the request
variations and automatically provides to adjusting the fuel and the
combustion air supply by enabling the air regulation servomotor
with increasing or decreasing rotation. If the limit value (tempera-
ture or pressure) is reached also with minimum supply to which
the total shut down device is set (thermostat or pressure switch),
the burner is shut down by the intervention of the same. As the
temperature or pressure fall below the shut down device enable
value, the burner is started again according to the previously
described program. If the flame does not appear, the control
box "locks" (total burner shut down and lighting of the relevant
warning light).
To "unlock" the control box, press the special push button.

COMBUSTION CONTROL

For a correct air/gas ratio, the methane carbon dioxide (CO2)
value must be at least 8% at the minimum burner supply, up to an
optimum value of 10% for maximum supply.
It is advisable not to exceed a 10% value so as to prevent opera-
tion with too limited air excess, which could cause (atmospheric
pressure variation, presence of dust in the air ducts) a sensible
CO (carbon oxide) quantity.
To prevent dangerous situations, the carbon oxide (CO) per-
centage in the flue gas must always measured with the special
instrument to make sure that it does not exceed the maximum
admissible value of 0.1%.
IGNITION AND GAS REGULATION (METHANE)
1) Make sure that the combustion head penetrates into the com-
bustion chamber by the quantity required by the manufacturer.
Check that the device that turning off the air on the combustion
head is in the proper position for the required fuel supply (the air
passage between disk and head must be sensibly reduced in
case of low fuel supply. In the contrary case, if the fuel supply
is quite high, the air passage between disk and head must be
opened). See chapter "Combustion head regulation".
2) If not already done when connecting the burner to the gas
pipes, taking the necessary measures and opening doors and
windows, it is necessary to bleed the air contained in the pipes.
Open the union on the pipes close to the burner, and slightly
open the gas stop cock(s). Wait until you smell the typical gas
smell, and then close the cock. Wait for the necessary time,
according to the specific conditions, until the gas present in
the room is dispersed outside and then restore the connection
of the burner to the gas piping.
3) Check that there is water in the boiler and that the plant dampers
are open.
4) Make sure that the combustion product discharge can occur
freely (boiler and chimney dampers open).
5) Check that the electrical line voltage corresponds to that
required for the burner, and that the electrical connections
(motor and main line) are preset for the available voltage value.
Check that all electrical connections implemented on the spot
are properly executed as per our wiring diagram.
6) Apply a pressure gauge with suitable scale to the gas
pressure take- of f to measure the regulation value
(if the expected pressure rate allows it, it is preferable to use
a water column instrument, do not use hand instruments for
low pressures).
7) Regulate the air for the ignition flame, for minimum flame and
high flame, following the instructions for regulating air damper
control electrical motor shown in the following pages. In prac-
tice, set the low flame and high flame air regulation cams to
the suitable positions according to the desired thermal power
for low and high flame.8) By acting on the special screw for
adjusting the gas and air pressure ratio, on the gas valve mod.
MB-VEF...., set the desired value (see the specific instructions
for the gas valve MB-VEF.... in the following pages). In practice,
you must act on the adjusting screw of the ratio between the
gas pressure (at the combustion head) and the air pressure (at
the combustion head) to set the reference index between the
values of 0.4 and 0.8 so as to have a greater air supply than
gas.
10) Now enable the control panel switch and set the modulation
switches to MIN (minimum) and MAN (manual). The control
box thus receives voltage, and the programmer determines
the enable of the burner as described in chapter "description
of the operation".
Note: Pre-ventilation is carried out with open air and thus, during
the same, the regulation servomotor is enabled, and it runs
a complete opening stroke up to the "maximum" set. Only
when the regulation servomotor returns to the "ignition"
position, the control box continues its ignition program
by enabling the transformer and the ignition gas valves.
During the pre-ventilation step, make sure that the air pressu-
re control switch changes position (from off position without
pressure detection it must switch to the off position with air
pressure detection). If the air pressure switch does not detect
the sufficient pressure (it does not switch position), the ignition
transformer and the flame gas valves are not enabled, and thus
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