pag.21
LB972
MULTICALOR 300.1-400.1 PR/AB
B
The ionization current is checked by inserting a
microammeter with an end of scale of 1000 µA (d.c.) in
series with the UV CELL. A faulty position of the elec-
trode can lead to a reduction in the ionization current
and cause a safety cut-out of the burner due to a flame
detection failure. In this case, check the position of the
electrode, its electric connection and the earthing of the
burner. The ionization current is normally > 70 µA.
IONIZATION CURRENT
22 23
LANDIS
LFL 1.622
Fotocellula
min 70
µ
A
Microamperometro
fondo scala 1000
µ
A
REMOVING THE BLAST TUBE
REMOVING THE FIRING HEAD
ADJUSTMENT OF GAS MINIMUM PRESSURE SWITCH
Unscrew off and remove cover M. - Set regulator N to a value equal to 60% of gas nominal
feed pressure (i.e. for nat. gas nom. pressure = 20 mbar, set regulator to a value of 12 mbar;
for L.P.G. nom. pressure of G30/G31- 30/37 mbar, set regulator to a value of 18
mbar).Screw up cover M
ADJUSTMENT OF THE AIR PRESSURE SWITCH
Unscrew screws A and B and remove cover C.- Set the pressure switch to the mini-
mum by turning regulator D to position 1.
- Start the burner and keep in low flame running, while checking that combustion is
correct. Through a small cardboard, progressively obstruct the air intake until to
obtain a CO2 increase of 0,5÷0,8% or else, if a pressure gauge is available, connected
to pressure port E, until reaching a pressure drop of 1 mbar (10 mm of W.G.). -
Slowly increase the adjustment value of the air pressure switch until to have the bur-
ner lockout. Remove the obstruction from the air intake, screw on the cover C and
start the burner by pressing the control box rearm button.
Note: The pressure measured at pressure port E must be within the limits of the pressu-
re switch working range. If not, loose the locking nut of screw F and gradually turn the same:
clockwise to reduce the pressure; counterclockwise to increase. At the end tighten the locking nut.
2,5
5
10
15
50
25
3
5
3
0
40
45
20
0,4
0,6
0,9
3
,0
1,
5
2,1
1,
8
2,4
2,7
1,2
I
L
M
N
A
B
C
D
E
F
G
H
gas pressure
switch
air pressure switch
