C.I.B. UNIGAS
- M039203CC
20
10 The burner is factory-set with the head in its MAX position (maximum output). To let the burner operate at a lower output, turn
clockwise the
VRT
screw and move progressively the combustion head back towards the MIN position.
Attention!
if it is necessary to change the head position, repeat the air and gas adjustments described above.
11 the air and gas rate are now adjusted at the maximum power stage, go on with the point to point adjustement on the
SV1
(gas
side) adjusting cam as to reach the minimum output point.
12 as for the point-to-point regulation, move the low flame microswitch a little lower than the maximum position (90°);
13 set the
TAB
thermostat to the minimum in order that the actuator moves progressively towards the low flame position (as far as
fully-modulating burners, see the related paragraph);
14 move the low flame cam to the minimum to move the actuator towards the low flame until the two bearings find the adjusting screw
that refers to the lower position: screw
V1
to increase the rate, unscrew to decrease.
15 Move again cam III towards the minimum to meet the next screw on the adjusting cam and repeat the previous step; go on this way
as to reach the desired low flame point.
Now adjust the pressure switches (see next par.).
Calibration of air and gas pressure switches
Calibration of air pressure switch
To calibrate the air pressure switch, proceed as follows:
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.
Calibration of low gas pressure switch
As for the gas pressure switch calibration, proceed as follows:
z
Be sure that the filter is clean.
z
Remove the transparent plastic cap.
z
While the burner is operating at the maximum output, test the gas pressure on the pressure port of the minimum gas pressure
switch.
z
Slowly close the manual cutoff valve (placed upstream the pressure switch, see gas train installation diagram), until the detected
pressure is reduced by 50%. Pay attention that the CO value in the flue gas does not increase: if the CO values are higher than the
limits laid down by law, slowly open the cutoff valve as to get values lower than these limits.
z
Check that the burner is operating correctly.
z
Clockwise turn the pressure switch adjusting ring nut (as to increase the pressure value) until the burner stops.
z
Slowly fully open the manual cutoff valve.
z
Refit the transparent plastic cover on the pressure switch.
The
air pressure switch
locks the control box if the air pressure is not the one requested. If it happens,
unlock the burner by means of the control box unlock pushbutton, placed on the burner control panel.
The
gas pressure switches
check the pressure to avoid the burner operate when the pressure value
is not in the requested pressure range.
“MAX” head position
“MIN” head position
VRT
SC
SV1
V1
ID1
V1
SV1
Gas throttle valve open
Gas throttle valve closed
VR
