The capacity of Selectos SG burners
using natural gas has been
determined at a minimum supply
pressure of 17.8mbar (max 40mbar).
For LPG the supply pressure should
be between 25mbar and 40mbar.
These burners will operate
satisfactorily on gas supply
pressures lower than those quoted
above, but burner capacity will be
reduced accordingly.
Any LPG high pressure regulator
fitted must be equiped with over
pressure shut off protection.
Turn off the gas supply at the manual
shut off valve upstream of the gas
valve inlet.
Fit an approved pressure measuring
instrument at the pressure test point
on the inlet of the gas MultiBloc. Turn
on the gas supply. Check gas
pressure, this will record static
pressure which will be higher than
running pressure, which should not
be less than 17.8mbar when running
on main flame.
INNER ASSEMBLY
Ensure that the ignition electrode
and ionisation probe are correctly
adjusted. Correct positioning is
shown on the Component
Identification page.
Ensure that the head has been
positioned according to the gas rate.
GAS TYPE
Ensure that the burner head is correct
for the type of gas to be used. Check
the burner data plate.
PURGING
The gas line is purged by loosening
the screw on the inlet pressure test
nipple. Connect a plastic hose and
conduct the gas into atmosphere.
After purging the gas line re-tighten
the screw.
LEAKAGE TESTING
When making a leak test of the gas
supply system the gas valve should
be closed. Connect a pressure gauge
to the test nipple on the gas valve.
The test pressure in the system
should be 1.5 x maximum inlet
pressure or minimum 150 mbar. If
there is any leakage, locate the
source by means of soapy water or a
leak detection spray. After tightening
repeat the test
DRY RUN
Turn off the electricity supply to the
burner. Close the manual gas shut-
off valve.
To prevent the gas pressure (if fitted)
switch from locking out, remove the
cover and fit a temporary link.
Adjust the thermostats to call for
heat and switch on the electrical
supply to the burner, the pre-purging
period will begin (24-40 seconds). At
the end of this period the pre-ignition
period starts (3 seconds).
The gas valve is energized and opens
and the flame would be established.
At the end of the safety time (3 to 5
seconds) the control box will go to
lockout. The gas valve will be de-
energised and the motor will stop
running. The dry run is complete.
Ensure to remove the link from the
gas pressure switch after the test is
finished.
PRE-COMMISSIONING CHECKS
IMPORTANT
After each adjustment, the gas flow rate and flue gas analysis should be checked.
ALWAYS
Use approved test equipment (Continually monitoring electronic equipment is recommended).
NEVER
Rely on a visual inspection of the flame as a guide to combustion quality.
SG10090501
