45
Cleaning and replacing the detection photocell (RX515-RX520)
To clean/replace the detection photocell, proceed as follows:
1
Disconnect the system from the electrical power supply.
2
Shut off the gas 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.
Check of the detection current (with printed circuit)
Checking the detection current (for models without
printed circuti board)
To check the detection signal follow the scheme in Fig. 32 or
Fig. 33. 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 detec-
tor.
Fig. 32: Detection by electrode
Fig. 33: Detection by photocell QRA..
To check the detection signal remove the bridge on “TEST ER” or
“TEST UV” and connect a micro ammeter when Fig. 34. If the
signal is less than the value indicated, check the position of the
detection electrode or detector, the electrical contacts (one ER
terminal for the electrode, two FC terminals for the UV probe - see
pictureon the side) and, if necessary, replace the electrode or the
UV detector.
Fig. 34
Control box
Minimum detection signal
Siemens LFL1.3..
6µA (with electrode)
Siemens LFL1.3.. 70µA with UV detector)
TERMINAL BOARD MC
SCALA µA DC
27
TERMINAL BOARD
MC
Control box
Minimum detection
signal
Siemens LFL1.3..
6µA (with electrode)
Siemens LFL1.3.. 70µA (with UV detector)
ER
FC
+ µA -
- µA +
UV detector
electrode
