PART IV: MAINTENANCE
32
6.5 Replacing the ignition electrode
To replace the ignition electrode, proceed as follows:
1
remove the burner cover
2
disconnect the electrode (E) cable (CE);
3
remove the combustion head (see par. “Removing the combustion head”);
4
loose screw (B) that fasten the ignition electrode (E) to the burner pilot (P);
5
remove the electrode and replace it, referring to the values quoted on figure.
6.6 Checking the detection current
To check the detection signal follow the scheme in the picture below. If the signal is less than the value indicated, check the position of
the detection electrode or detector, the electrical contacts and, if necessary, replace the electrode or the detector.
6.7 Cleaning and replacing the detection photocell
To clean/replace the detection photocell, proceed as follows:
1
Disconnect the system from the electrical power supply.
2
Shut off the fuel supply;
3
remove the photocell from its slot (see next figure);
4
clean the bulbe if dirty, taking care not to touch it with bare hands;
5
if necessary, replace the bulb;
6
replace the photocell into its slot.
ATTENTION: avoid the electrode to get in touch with metallic parts (blast tube, head, etc.), otherwise the boiler
operation would be compromised. Check the electrode position after any intervention on the combustion head.
Fig. 18: Detection by photocell QRA..
P
E
CE
B
Control box
Minimum detection signal
Siemens LME7...
70µA with UV detector)
