12
AIR RATE SETTING
ATTENTION: During commissioning operations, do not to let the burner operate with insufficient air flow (danger of forma-
tion of carbon monoxide); if this should happen, shut down the burner, increase the opening of the air damper and start up the
burner again to ensure the purging of the carbon monoxide from the combustion chamber.
Calibration of minimum gas pressure switch
Calibration is carried out as follows:
z
Remove the transparent plastic cap.
z
With the burner in operation test the pressure on the pressure port at the input of the gas filter; slowly close the manual
shut-off valve (see gas train installation diagram) until the detected pressure is reduced by 50%.
z
Verify CO emissions of the burner; if the measured value is less than 80 ppm screw down the adjusting ring nut until the
burner lockout. If CO emissions are greater than 80 ppm open the shut off valve until the CO value is reduced to 80 ppm,
then screw down the adjusting ring nut until the burner lockout.
z
Fully open the manual shut-off valve
WARNING: carry out this operation ONLY with the burner turned off!
z
Refit the transparent plastic cover on the pressure switch.
Adjusting the combustion head
To adjust the combustion head rotate the ring nut VR. Rotate clockwise toclose the combustion head or turn counterclockwise
to open it.
Slacken the screw VBS and manually rotate the air
damper as needed.
At the end of settings tight the screw VBS.
Fig. 16
Calibration of air pressure switch (single stage
burners)
Calibration is carried out as follows:
z
Remove the transparent plastic cap.
z
After air and gas setting have been completed,
start the burner.
z
The pre-purge phase starts; wait 10 sec. then
slowly turn the adjusting ring nut VR in the
clockwise direction until the burner lockout, read
the value on the pressure switch scale and reduce
it by 0.5 mbar.
z
Repeat the start up cycle of the burner and check
it runs properly.
z
Refit the transparent plastic cover on the pressure
switch.
Fig. 17
Fig. 18a
Fig. 18b
-
+
VBS
VR
VR
VR
