Safety Checks - Maintenance - Uv Cell - Air Pressure Switch - Gas Pressure Switch - baltur COMIST 36 Instrucciones

proceed as follows:
1) Ensure that combustion waste can
be discharged without any hin-
drance (chimney gate open) and
that there is water in the boiler.
) Open the combustion air re-
gulator (see BT 8653/1) to the
extent considered necessary
and open to about one third the
air passage between blast tube
and disk, using the flame disk
adjustment screw.
3) Operate the relief valve and "first
flame" regulators so that desired
quantity (start-up flow rate) of gas
in supplied.
N.B. See end pages for detailed
description of gas supply adjust-
ment depending on type of valve
fitted to burner.
4) Switch off the second flame ther-
mostat and switch on the burner
by operating main and burner
(natural gas setting) switches. In
this way the burner is cut-in and
carries out the pre-ventilation
phase. If the air pressure control
pressure switch reads pressure
above its preset value, first
switch on the ignition transfor-
mer and then the gas valves (re-
lief and first flame). The valves
open fully is limited to the setting
to which the flow rate regulator
(built-into the first flame valve
(pilot) has been manually set.
On first ignition, further "blocks"
can occur due to insufficient air
clearance of gas pipes. There
is therefore not enough gas to
give a stable flame. A "Block"
with flame present can also be
caused by flame instability due
to incorrect air/gas ratio. This
can be remedied by varying
quantity of air/gas supplied in or-
der to find correct ratio. This can
be remedied by operating the
blast tube adjustment device,
closing (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
7 and COMIST 1) or opening
(screw the blast tube adjustment
screw in the case of COMIST 36
and move backward the blast
tube fixing knobs in the case of
COMIST 7 and COMIST 1)
more the air passage between
blast tube and flame disk (see
BT 8608/1 and BT 8608/3).
5) While burner is operating, adjust
supply to desired value for "first
flame" (natural gas = 8550 kcal/
3
m ), taking a reading at the me-
ter. This flow rate can be modified
by using the regulator built-into
the valve, as described above.
6) Check that combustion occurs
correctly (use the appropriate
instruments). Maximum permitted
level of carbon monoxide (CO) is
0,1% whereas permitted range for
carbon dioxide (CO ) is 8 ÷ 10%.

7) After adjusting, switch burner on
and off several times to check
that ignition is correct.
8) Switch off burner via the main
switch to make a direct (brid-
ge) connection between the
terminals of the second flame
thermostat. Adjust combustion
air to setting considered suitable
for switch-on of second flame
(see BT 8653/1). Also open the
gas flow regulator (built-into the
second valve) to obtain a sup-
ply considered suitable for the
main flame and set the 1st and
nd stage switch in "nd stage"
position.
9) Now switch on main switch to
ignite burner. While burner is
operating on second flame, che-
ck gas supply (meter reading) as
previously described. Depending
on readings, adjust gas supply if
necessary, to adapt it to actual
value required (boiler output).
Using suitable instruments, che-
ck that combustion is correct
(CO = 8 ÷ 10 % for natural gas

- CO max. = 0,1%). To improve
combustion and for good flame
stability (no pulsations) it may
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
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0006080093_00709
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
7 and COMIST 1). When the
burner is operating at a higher
fuel supply level, this passage
should be opened proportiona-
tely (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 7
and COMIST 122). If flame disk
position is modified, it is usually
also necessary first to correct
the positions of the first and se-
cond flame air regulation gates.
Then, check that ignition is
correct.
SAFETY CHECKS
After adjusting, always check the
following:
1) Burner stop: open air and gas ther-
mostats and pressure switches.
) "Blocking": shadow the photocell
(UV).
To unblock, push the appropriate
button.
TENANCE
At the end of the heating season,
it is good practice to clean the gas
and light oil filters, the combustion
head (disk, insulators, nozzles), the
combustion air passages and the
photoelectric cell (UV). It is advisa-
ble to use wooden or plastic instru-
ments to clean the nozzle passages.
Nozzle should be replaced after 1
months' use.
UV CELL
If flame detection is carried out with
the UV cell, the following should be
taken into consideration. Even the
slightest greasiness will compromise
the passage of the ultraviolet rays
through the UV photoelectric cell