Cleaning And Replacing The Detection Photocell; Checking The Detection Current - Unigas RX90 Installation Manual

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.
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.
TERMINAL BOARD MC
Fig. 32: Detection by electrode
Check of the detection current (with printed circuit)
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.
Minimum detection
Control box
6µA (with electrode)
Siemens LFL1.3..
Siemens LFL1.3.. 70µA (with UV detector)
27
SCALA µA DC
signal
Control box Minimum detection signal
Siemens LFL1.3..
Siemens LFL1.3.. 70µA with UV detector)
TERMINAL BOARD
MC
Fig. 33: Detection by photocell QRA..
ER
- µA +
+ µA -
electrode UV detector
45
6µA (with electrode)
Fig. 34
FC