Unigas HTP512A, Installation, User'S, And Maintenance Manual

Page: 29 / 60

C.I.B. UNIGAS - M039219CA
29
Note: once the procedure is perfomed, be sure that the blocking nut RA is fasten. Do not change the position of the air damper
rods.
10 the air and gas rate are now adjusted at the maximum power stage, go on with the point to point adjustement on the SV adjusting
cam as to reach the minimum output point.
11 as for the point-to-point regulation, move the gas low flame microswitch (cam III) a little lower than the maximum position (90°);
12 Set the TAB thermostat to the minimum in order that the actuator moves progressively towards the low flame position;
13 move cam III 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 V to increase the rate, unscrew to decrease.
14 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.
15 If it is necessary to change the burner output in the low flame stage, move cam III: the low flame position must never match the
ignition position, that is why cam III must be set 20°-30° more than cam II.
16 Now adjust the pressure switches (see next par.).
.Adjustment by the Siemens SQL33.. actuator
1 set GAS fuel by means of the burner CM switch (it is placed on the burner control panel);
2 check the fan motor rotation (see “Rotation of fan motor” on page 23).
3 Start the burner up by means of the thermostat series and wait until the pre-purge time comes to an end and that the burner starts
up;
4 the burner starts up with the actuator on the ignition position, set it to the MAN (manual mode), by the MAN/AUTO selector (ignition
position= read on the air damper index ID1 - see picture on previous page);
5 disconnect the TAB thermostat removing the wire from the terminal no. 6 or by setting MAN on the RWF40 modulatore or by set-
ting 0 by means of the CMF switch (only for fully-modulating burners);
6 set the actuator on the manual mode (MAN) by means of the MAN/AUTO switch (see next pictures).
7 manually drive the adjusting cam SV to the high flame position and set the actuator to the AUTO mode (by the related switch - see
picture) to lock the adjusting cam.
8 Go on adjusting air and gas flow rates: check, continuosly, the flue gas analisys, as to avoid combustion with little air; dose the air
according to the gas flow rate change following the steps quoted below;
9 acting on the pressure stabiliser of the valves group, adjust the gas flow rate in the high flame stage as to meet the values
requested by the boiler/utilisation:
- Siemens VGD valves group: remove cap T and act on the VR adjusting screw to increase or decrease the pressure and conse-
quently the gas rate; screwind VR the rate increases, unscrewing it decreases (see next figure).
Keys
GV
gas valves group
ID1
air damper index
ID2
index
PA
air pressure switch
SC
actuator
SV
adjusting cam
V
adjusting screws
VF
butterfly valve
SQL330.. actuator cams
BF = Low flame
B = plastic cam
G = cam locking lever
VRA
RA
TR
ID1
VF
PA
SC
SV
GV
ID2
V
SV
Gas butterfly valve closed Gas butterfly valve open
MAN
AUTO
BF
B
G