B 420010243300 Blu 500.1 ÷ 1200.1 P AB Low Nox
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.Screw up cover M
DJUSTMENT OF THE AIR PRESSURE SWITCH
Unscrew screws A and B and remove cover C.- Set the pressure switch to the minimum
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 pres-
sure port E, until reaching a pressure drop of 1 mbar (10 mm of W.G.). - Slowly increa-
se the adjustment value of the air pressure switch until to have the burner 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 pres-
sure 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.
With the burner switched off, connect a DC microammeter with a 0÷50 or 0÷100 µA dial. When the burner is run-
ning, and is properly adjusted, the value read must be steady and never be smaller than 3 µA.
DESCRIPTION OF THE CONTROL PANEL OF THE BURNER
7
FLAME DETECTION SYSTEM CHECK
1
2
3
4
I
5
0
6
LGB21-LGB22 min. 3 µA
LMG21-LMG22 min. 2 µA
1
LANDIS & STAEFA
1 - fuse
2 - termal lock-out lamp
3 - 1 st. stage working lamp
4 - 2 nd. stage working lamp
5 - high-low flame switch
6 - main switch I / O
7 - reset key
pag.14
N
M
I
L
D
C
A
G
B
F
H
E