baltur comist 36 Instructions Manual page 51

ELECTRICAL CONNECTIONS
Electric lines should be kept well away from hot parts. All connections should be carried out with flexible electric wiring
with cross-section suitable for available voltage and power drain.
N.B. The burner is provided of a switch to change manually from 1st to 2nd stage.
NOTES ON IGNITION OF DUAL FUEL BURNER
It is advisable to ignite first with liquid fuel because in this case fuel supply depends on the nozzle used. Natural gas
supply can instead be varied by operating the flow regulator.
PREPARATIONS FOR IGNITION WITH LIGHT OIL
Ensure that the nozzles fitted are suitable for the output of the boiler. Light oil supply values in kg/h are shown in the
table
These depend on nozzle size and pump pressure (usually 12 bar for the first and second flames). Bear in mind that 1
kg of light oil is equal to about 10.200 kcal. When selecting nozzles (spray angle 60°) remember that fuel supply with
the first valve should not be much lower than minimum burner flow rate (see burner plate).
Make sure that the blast tube penetrates the combustion chamber as per boiler manufacturer's instructions.
Check that the tank return pipe is not blocked, that gates are closed, etc. Any obstacle would in fact break the seal on
the pump or hose shaft. Open the stop cock on the suction pipe. Eliminate the connection or "bridge" of the second
flame thermostat. Open the pump air bleed valve. Switch on the main switch (burner switch must remain set to "0"
- off) and manually close (see figure) the pump motor remote switch to verify that rotation direction is correct.
If necessary, change over two wires of the main line at remote switch output in order to reverse motor rotation direc-
tion.
Manually switch on the pump motor switch again to operate the pump and suck light oil from the tank. When light oil
can be seen coming out from the air bleed device, stop the motor and close the air bleed.
The burner is now ready for light oil ignition.
LIGHT OIL IGNITION AND ADJUSTMENT
1) Ensure that motors (fan and pump) rotate in correct direction.
2) Make sure discharge of combustion waste occurs without any hindrance (chimney gate open) and that there is
water in the boiler.
3) Open the combustion air regulator to the extent you consider necessary (see BT 8653/1). Then open by one third
the air passage between blast tube and disk,using flame disk screw.
4) Switch on main and burner (light oil setting) switches to cut-in and await ignition. If the air pressure control pressure
switch reads a value above preset pressure, first switch on the ignition transformer and then the light oil valves
(relief and first flame). While burner is operating on first flame, adjust combustion air supply, if necessary. After
adjusting, switch off burner and then switch on again in order to ensure that ignition is correct. Remember that
for smooth ignition air should be adjusted as little as possible. If ignition is smooth, switch off burner and make a
bridge connection between the terminals of the second flame thermostat and set the 1st and 2nd stage switch in
"2nd stage" position.
5) Adjust combustion air to the setting considered necessary for cutting-in the second flame (see BT 8653/1).
6) Now switch on the burner once again. It will operate on first and second flame. Operate the second flame air
adjustment cam to adapt supply to actual conditions.
7) The burner is provided with a device that improves combustion by reducing or increasing air passage between
disk and blast tube. Maximum permitted smoke intensity is n° 2 on the Bacharach scale, with carbon dioxide
(CO ) value within range of 10 to 13%. To improve combustion and for good flame stability (no pulsations) it may
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be necessary to operate the blast tube adjustment device. If burner operates on low fuel supply, the air passage
between disk and blast tube should be reduced (unscrew the blast tube position adjustment screw in the case of
COMIST 36 and move forward the blast tube fixing knobs in the case of COMIST 72 and COMIST 122).
When the burner is operating at a higher fuel supply level, this passage should be opened proportionately (screw the
blast tube position adjustment screw in the case of COMIST 36 and move backward the blast tube fixing knobs in the
case of COMIST 36 and move backward the blast tube fixing knobs in the case of COMIST 72 and COMIST 122).
If flame disk position is modified, it is usually also necessary first to correct the positions of the first and second
flame air regulation gates. Then, check that ignition is correct.
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0006080093 ed2006/07