5861
8
COMBUSTION CHECKS
CO
2
It is advisable to not exceed 10% of CO
2
(gas with calorific value of 8600 kcal/m
3
), in order to avoid
the risk that small changes of the adjustments due, for instance, at draught variation, may cause com-
bustion with insufficient air and consequently formation of CO.
CO
For safety reason the value of 0.1% (one thousand p.p.m.) must not be exceeded.
IONIZATION CURRENT
The minimum current necessary for the control box operation is 3 ±A.
The burner normally supplies a higher current value, so that no check is needed.
However, if a measurement of the ionization current is required, it is necessary to disconnect the
probe lead and insert a d.c. microamperometer.
MOTOR LOCK-OUT
This is caused by the thermal protector relay, in case of overloading, or by the lacking of the phase.
To clear, pushdown the appropriate knob, after having removed the protective cover
BURNER START-UP
If during operation the flame shuts off, lock-out occurs within 1 sec.
+
-
Lead
Probe
S7511
Normal
Lock-out because no ignition
Thermostat
Motor
Ignition transf.
Start valve
Adjust. valve
Lock-out
2 s
40 s
10 s
2 s
40 s
3 s max.
D1798
