PART III: OPERATION
36
z
Remove the transparent plastic cap.
z
Once air and fuel setting have been accomplished, startup the burner.
z
During the pre-purge phase o the operation, turn slowly the adjusting ring nut
VR
in the clockwise direction (to increase the adju-
sting pressure) until the burner lockout, then read the value on the pressure switch scale and set it to a value reduced by 15%.
z
Repeat the ignition cycle of the burner and check it runs properly.
z
Refit the transparent plastic cover on the pressure switch.
6.9 PGCP Gas leakage pressure switch (witn Siemens LDU/LME7x burner control/Siemens LMV Bur-
ner Management System)
z
remove the pressure switch plastic cover;
z
adjust the PGCP pressure switch to the same value set for the minimum gas pressure switch;
z
replace the plastic cover.
6.10 Adjusting the combustion head
The burner is factory-adjusted with the combustion head in the "MAX" position, accordingly to the maximum power. To operate the bur-
ner at a lower power, progressively shift back the combustion head, towards the "MIN" position, screwing the screw
VRT
. The ID index
shows how much the combustion head moved.
Attention! if it is necessary to change the head position, repeat the air and fuel adjustments described above.
CAUTION: perform these adjustments once the burner is turned off and cooled.
VRT
ID
