baltur COMIST 180 Manual Installation, Use, Maintenance page 54

GAS (METHANE) STARTING AND REGULATION
N.B. See last pages for specific description of the operations neces-
sary for regulating gas delivery according to the type of valve
applied to the burner.
1) If you did not do it while connecting the burner to the gas pipe,
blow off the air contained in the gas pipe.
Do it carefully and with open doors and windows. Open the
pipe fitting close to the burner and, then turn on the gas cut-off
cock (or cocks) slightly. Wait until you notice the typical smell
of gas and then turn off the cock. Wait for a certain period of
time, depending on specific conditions, until the gas in the
room is dispersed outside and, then, connect again the burner
to the gas pipe.
2) Be sure there is water in the boiler and the equipment gates
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are open.
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3) Be sure that combustion products can be blown off freely (boiler
and flue dampers must be open).
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4) Turn on the combustion air regulator by the amount you pre-
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sumably need (see BT 8653/1) and open the air way between
head and disk by one third (see 0002922520).
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5) Operate on "first flame" and safety valve built-in regulators
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so as to supply the amount of gas (flow rate on starting) you
presumably need.
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N.B. See last pages for specific description of the opera-
tions necessary for regulating gas delivery according to the
type of valve applied to the burner.
6) Disconnect the second flame thermostat and give cur-
rent to the burner by turning on the main switch and the
burner switch (gas position). The burner is therefore con-
nected and carries out the preventilation phase.
If the air pressure control device detects that pressure is
higher than the regulated value, the starting transformer
will be turned on, followed by gas valves (safety and first
flame valves). Valves are turned on completely and gas
delivery is limited by the position in which the flow regula-
tor built in the (pilot) first flame valve has been set by hand.
First starting could be followed by "stopping" in service due to
poor air purging from gas pipes: in this case gas supply is not
enough for a stable flame. "Stopping" with flame could also be
caused by instability of the flame due to a wrong air/gas ratio.
This can be solved by changing the amount of air and/or gas
supplied so as to find the right ratio. This problem could also be
caused by a wrong air/gas distribution in the combustion head.
You can solve it by acting on the combustion head adjusting de-
vice by closing (pushing forward) or opening (pulling backward)
more the air way between head and flame disk.
7) With the burner running, adjust delivery to the desired value for
"first flame by reading it on the meter. This rate of flow can be
changed by adjusting the valve built-in regulator, as described
above.
8) Be sure that combustion is being carried out correctly by
checking the relative instruments. Maximum carbon oxide (CO)
allowed = 0,1 % with carbon dioxide value (CO
8 to 10%.
9) After this regulation, stop the burner and start it again several
times for being sure that starting is correct.
10) With the burner turned off from the main switch, connect the
second flame thermostat terminals directly (bridge). Set the
combustion air regulator in the position you presumably need
for adding the second flame (see BT 8653/1). Turn on also the
gas flow regulator built in the second valve in order to supply
the amount of gas you presumably need for the main flame.
11) Now turn off the main switch for starting the burner. When
the burner is running, with the second flame, you should
check gas delivery (read the meter) as described above.
On the basis of checks carried out, change if necessary gas
delivery in order to adjust it to the desired value according
to specific case (boiler power). Be sure that combustion is
being carried out correctly by checking the relative instru-
ments (CO
In order to optimize combustion and for good stability of the
flame (no pulsation's) you could need to operate on the com-
bustion head adjusting device. Normally, you need to decrease
the air flow between disk and head when the burner is running
with reduced fuel delivery. This air way must be proportion-
ally larger when the burner is working with an increased fuel
delivery. If the combustion head is pushed forward (narrower
way between disk and head) you must avoid complete closure.
While adjusting the combustion head, you must center the head
to the disk perfectly. Remember that imperfect centering of the
combustion head to the disk may result in bad combustion and
overheating of the head with its subsequent rapid deterioration.
Check centering by looking through the inspection hole placed
on the back part of the burner, then, tighten firmly the two screws
fastening the combustion head in its position. disk perfectly.
Remember that imperfect centering of the combustion head to
the disk may result in bad combustion and overheating of the
head with its subsequent rapid deterioration. Check centering
by looking through the inspection hole placed on the back part
of the burner, then, tighten firmly the two screws fastening the
combustion head in its position.
12) The purpose of the air pressure switch is to prevent fuel.
(natural gas or light oil) valves opening if air pressure is not as
planned. The pressure switch must therefore be set to close
the contact (closed during operation) when air pressure in the
burner is sufficient. The pressure switch connection circuit
is self controlling.Therefore, the contact which is meant to
be closed in non operting state (fan stopped and thus no air
pressure in burner), should in fact be in this state, otherwise
the command/control equipment will not be switched on (burner
remains inoperative). Please note that if the contact meant to be
closed during operation does not close, the equipment carries
out its cycle but the ignition transformer is not switched on and
the fuel valves do not open. As a result, the burner stops in
"blocked" state. To verify that air pressure switch is operating
correctly, while the burner is ignited on first flame only, icrease
adjustment value until the switch triggers instant "blocked"
stoppage of the burner.
) ranging from
2
16 / 34
0006080095_200902
= 8 to 10% for methane - max. CO = 0,1%).
2