Roca CRONO 4-G COMPACT Instructions D'installation page 25

4.4 ELECTRODE PROBE POSITIONING
Make sure that the ceramic
is behind the diffuser disc
and level with it.
Probe
D4575
4.5 COMBUSTION CHECK
It is advisable to set the burner according to the type of gas used and following the indications of the table:
EN 676
Theoretical max. CO
GAS
0 % O
2
G 20 11.7
G 25 11.5
G 30 14.0
G 31 13.7
IONIZATION CURRENT
The minimum current necessary for the con-
trol box operation is 5 µA.
The burner normally supplies a higher cur-
rent value, so that no check is needed.
To measure the ionization current, open the
connector CN1 (see electrical scheme page 8)
and insert your microammeter.
4.6 AIR PRESSURE TEST POINT
ATTENTION
Should the air pressure test point device
(A) come loose by accident, you are
advised to turn it to the correct position as
illustrated in figure 10.
Connect air pressure test point (A) to
the pressure switch (C) inlet (-).
Connect air pressure test point (B) to
the pressure switch (C) inlet (+).
NOTE
There is a gauged diaphragm inside the
pipes, located near the air pressure test
points. If pipes are replaced, reuse the
above-mentioned diaphragms.
3217
All manuals and user guides at all-guides.com
Ionization
probe Diffuser
1,7
max. output λ ð 1.2 – min. output λ ð 1.3
Setting CO
2
λ = 1.2
9.7
9.5
11.6
11.4
Fig. 9
Terminal block
of control-box
D4244
10 GB
Ignition electrode
WARNING 2,5 ÷ 3,5 mm
AIR EXCESS:
%
CO
2
λ = 1.3
mg/kWh
9.0 ð 100
8.8 ð 100
10.7 ð 100
10.5 ð 100
Connector
1
Fig. 10
A
Electrode
NO
x
mg/kWh
ð 170
ð 170
ð 230
ð 230
Probe
D5006
B
C