Air Pressure Switch - baltur COMIST 36 Instrucciones

bulb, thus preventing the sensitive
internal element from receiving the
quantity of radiation necessary for it
to function properly.
Should the bulb be fouled by light
oil, fuel oil, etc., it is indispensable
to clean it thoroughly.
It should be pointed out that even
by simply touching the bulb with the
fingers, it is possible to leave a slight
greasiness which could compromise
the working of the UV photoelectric
cell. The UV cell does not "see"
daylight or light from an ordinary
lamp. It is possible to verify its sensi-
bility with a flame (or cigarette lighter
or a candle) or with the electric spark
that occurs between electrodes in an
ordinary ignition transformer.
To ensure that the UV cell works
properly, its current value should be
sufficiently stable so as not to fall
below the minimum value required
for the specific control box. It may be
necessary to search experimentally
for the best position by sliding (axial
or rotation movement) the body that
contains the photoelectric cell in
respect to the fastening clamp.
An inspection can be carried out
by inserting a microammeter, with
an adequate scale, in series to one
of the two UV photoelectric cell
connection wires. It is obviously
necessary to respect the polarity
(+ e -).
AIR PRESSURE SWITCH
The air pressure switch has the job
of bringing the control box to a safety
shut down if the air pressure is not at
the correct value. Therefore, the air
pressure switch must be regulated
in such a way as to intervene by
closing the contact (foreseen to be
closed while working) when the air
pressure in the burner has reached
a sufficient level.
The pressure switch is self-control-
led and therefore it must close the
contact (fan stops and consequently
there is an absence of air pressure in
the burner; if it does not, the control
box will not be inserted (the burner
remains at a standstill). It must be
specified that if the contact is not
closed during working (insufficient
air pressure), the control box will
carry out its cycle, but the ignition
transformer will not be inserted and
the gas pilot valves will not open.
Consequently, the burner will go
to "shut down". Check that the air
pressure switch functions properly
with burner at minimum delivery,
increase the regulating valve until it
reaches intervention point and the
burner should go to shut down.
To unblock the burner, press the
special push-button and return
the pressure switch regulator to a
sufficient value in order to measure
the air pressure existing during the
pre-ventilation phase.
GAS PRESSURE SWITCH
The pressure switches which control
the gas pressure (minimum and
maximum) have the job of stopping
the burner functioning when the gas
pressure is not within the values
specified.
From the specific functions of the
pressure switches, it is evident that
the pressure switch which controls
the minimum pressure must make
use of the contact, which is closed,
when it measures a pressure which
exceeds that at which it has been
set. The maximum pressure switch
must make use of the contact, whi-
ch is closed, when it measures a
pressure below that at which is has
been set.
The minimum and maximum gas
pressure switches should be regu-
lated during the burner's general
inspection and should be in function
with the pressure found each time.
The pressure switches have been
electrically connected in series and
therefore the intervention (by this
mean the opening of the circuit)
of any one of the gas pressure
switches, will prevent the control box
and thus the burner from starting
up. When the burner is operating
(flame lit), the intervention of the gas
pressure switches (opening of the
circuit) determines the immediate
arrest of the burner.
During the burner's general inspec-
tion, check the correct functioning of
the pressure switches.
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0006080093_00709
By operating the respective regula-
ting device, it is possible to control
the pressure switch's intervention
(opening of circuit) which causes
the burner's arrest.