baltur TBL 1200 ME Instruction Manual For Installation, Use And Maintenance page 52

ENGLISH
SAUTER DIESEL PRESSURE SWITCH
The burner is equipped with a safety pressure switch on the diesel
return circuit. It is installed in series to the air pressure switch and is
enabled only during diesel operation. It intervenes if it detects an incre-
asing diesel pressure equal to the preset value (5 bar).
Every time it occurs, the pressure switch opens its contact simulating
an overpressure of the liquid fuel, determining the lock-out of the flame
control equipment and therefore of the burner.
FLAME SENSOR
The flame detecting UV photocell must be able to trigger upon system
operation if the flame turns off (this check must be carried out after at
least one minute from the ignition).
The photocell current value required for a correct operation of the equi-
pment is indicated in the wiring diagram.
Even the slightest greasiness will compromise the passage of rays
through the photocell bulb, thus preventing the sensitive internal ele-
ment from receiving the quantity of radiation necessary for it to work
properly. If the bulb is fouled with diesel, fuel oil, etc... it must be pro-
perly cleaned.
CAUTION / WARNINGS
Even simply touching the bulb with fingers may leave a slight
greasiness which could compromise photocell operation.
The UV photocell does not detect daylight or the light from a common
lamp.
Sensitivity can be checked with a flame (lighter) or with the electric
discharge between the electrodes of a common ignition transformer.
To ensure a proper operation, the UV photocell current value must be
sufficiently stable and not go below the minimum value required for the
equipment.
It may be necessary to tentatively find the best position by sliding (axial
or rotational movement) the casing that contains the photocell with re-
spect to the fastening clamp.
This can be checked by connecting a micro-ammeter, with a suitable
scale, in series to one of the two UV photocell connection cables. Ob-
viously the + and - polarity must be respected.
The burner should be capable of locking out and remain in that con-
dition when, during the ignition sequence in the time pre-set by the
control box, the flame does not regularly appear.
The lock-out condition leads to an immediate fuel shut-off, the system
stops and the lock warning light comes on.
To check the photocell and lock-out efficiency, proceed as follows:
1 Start the burner
2 After at least one minute from ignition remove the UV photocell
from its seat, and simulate a flame failure. The burner flame
must turn off, the equipment will immediately shut down in "lock-
out" condition.
3 The equipment can only be reset manually by pressing the reset
button. The shut-down efficiency test must be performed at least
twice.
Check the efficiency of the thermostats or boiler pressure switches
(they should shut down the burner when triggered).
BT 3..
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