Unigas C85A Manual Of Installation - Use - Maintenance page 37

Replacing the detection electrode (if provided)
ATTENTION: avoid the ignition electrodes to contact metallic parts (blast tube, head, etc.), otherwise the boiler's operation
would be compromised. Check the electrodes position after any intervention on the combustion head.
To replace the ignition electrodes, proceed as follows:
1 remove the burner cover
2 disconnect the electrodes cables (CR);
3 loose the screw of the electrodes support (VR);
4 remove the electrodes and replace them paying attention to the measures shown in
figure.
Checking the detection current with electrode (natural gas) (versione LME / LGK)
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.
Flame
Detection electrode
Checking the detection current with photocell (LME) (L.P.G.)
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.
Control box
Siemens LME21-22
LGK16
Connector
*
LME: 1
LGK: 24
µA DC SCALE
Minimum detection signal
200 µA
12 µA
*
Control box
Siemens LME21-22
LGK
GP/SB
R/W
N
37
PART IV: MAINTENANCE
VR
Detection electrode
Minimum detection signal
:
AGQ3...
br
br rt sw
AGQ3...
sw
QRA...
CR
3 µA
12 µA
bl rt sw
sw bl