baltur COMIST 20, Instruction

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ELECTRIC CONNECTIONS
The electrical lines should be at an adeguate distance from hot parts.
It is advisable to make all the connections with flexible electric wire.
Conductor’s minimum section 1,5 mm
2
.
DUAL FUEL BURNER’S FIRING INDICATIONS
We suggest to start the burner with the liquid fuel, as in this case the
delivery is bound to the nozzle size whilst the gas delivery can be
easily changed by acting on the relative capacity adjuster.
If the burner is in the automatic version, the selector for the fuel
change connects a cyclic relay which inserts, thanks to an auxi -
liary relay, components for the use of both fuels (valves, pressure
switches, pump etc.).
After having changed the position of the selector from gas to light oil
and viceversa, it occurs to leave it stopped for at least 10 seconds
which is the time the cyclic relay needs to carry out its program.
Note : If the selector is moved from a position to another before the
period of 10 seconds, the cyclic relay stops in the middle
of its program not allowing to use the burner both with gas
and with light oil.
PREPARATIONS FOR IGNITION WITH LIGHT OIL
Make sure that the nozzle with spraying angle at 45° is suitable to
the boiler’s capacity.
In the list hereunder you find the delivery values in kg/h of light oil
related to the nozzle’s size and to the pump’s pressure (normally
12 bar). (Please note that 1 light oil kg corresponds to 10.200 kcal
about).
Make sure that the protrusion of the combustion head inside
the combustion chamber is according to boiler manufacturer’s
instructions.
Make sure that the return pipe in tank has no obstructions, such as
gates closed, caps etc. Probable obstructions could cause faults
on the pump’s shaft or flex pipe. Open slightly the air purge device
of the pump.
When the light oil flows the air purge device open the main switch
so as to stop the motor.
The burner is thus ready to operate at light oil.
LIGHT OIL IGNITION AND ADJUSTMENT
1) Make sure that the motors (fan and pump) turn in the correct
sense.
2) Make sure that the discharge of combustion products takes
place freely (boiler and chimney gate valves open) and that
there in water in the boiler.
3) Open of the necessary quantity the combustion air regulator
and open about half the air passage between disc and head
by acting on the regulating screw of the flame disc.
4) Close the main switch and the burner switch so as
to obtain the connection and wait the burner starting.
If the control pressure switch of the air pressure detects a
pressure higher than the value to which it’s adjusted , the
ignition transformer connects and further to this also the light
oil valve. With the burner on operation correct, if necessary, the
combustion air delivery.
5) The burner is equipped by a device which allows to
set combustion at best by reducing or increasing the
air passage between disc and head. The maximum al -
lowed smokes’ intensity is n° 2 of Bacharach scale, with
a carbon diaxide value (CO
2
) between n° 10 ÷ 13 %.
As a rule it’s necessary to reduce the air passage between
disc and head when the burner operates with a reduced fuel
delivery; this passage must be proportionally more opened
when the burner operates with an higher fuel delivery. When
this position has been changed, it’s necessary to check that
ignition occurs cerrectly.
NATURAL GAS IGNITION AND ADJUSTMENT
(METHANE)
Before firing it’s indispensable to make the air purge from the pipes
and check.
After this, da as follows:
1) Make sure that the combustion product’s discharge may take
place freely (chimney gate open) and that there is water in the
boiler.
2) Open of the necessary quantity the combustion air regulator
and open of 1/3 about the air passage between head and disc
acting accordingly on the regulating screw of the flame disc.
3) Act on the regulators joint to the gas valves so as to allow the
necessary gas delivery.
Note : Please refer to the last pages where specific instructions
are given with regard to regulating the gas delivery in function
with the type of valve fitted on the burner.
4) Energize the burner connecting the main switch and the
burner switch. The burner thus is connected and makes the
prewashing phase. If the control pressure switch of the
air pressure detects a pressure higher then the value
to which it’s adjusted , the ignition transformer connects
and further to this also the gas valves. The safety valve
opens completely while the main valve, which includes the
regulation devices, opens in two times. The first opening
time makes the starting capacity and happens at once.
The second opening time happens slowly and at its end, the bur -
ner is in the maximum capacity allowed by the position in which
the maximum capacity adjuster has been positioned.
During the first ignition some “clampings” may happen due to
following reason:
a) The gas line has not been purged by the air sufficiently
and therefore the gas quantity can’t grant a stable flame.
b) Clamping with flame on, can be caused by insta -
bility of the same, owing to a wrong ratio air/gas.
This can be remedied by varvying the quantity
of air and/or gas delivered so as to find the cor-