Pepperl+Fuchs LCR20, Техническая информация

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20
21
-0
6
18
Level Radar LCR20
Electrical Connection
8.6 Connecting the Device
4 to 20 mA HART block diagram
Connection of the device with HART communication, power source and 4 to 20 mA display
Figure 8.3 Block diagram of HART connection
8.7 Cable Specification
Unshielded cable, wire cross-section 0.75 mm
2
• Resistant to UV and weather conditions as per ISO 4892-2
• Flame resistance according to IEC 60332-1-2
According to IEC/EN 60079-11 section 10.9, the cable is designed for a tensile strength
of 30 N (6.74 lbf) (over a period of 1 h).
The device is supplied with 5 m (16 foot) cable length as standard.
Cable lengths 10 m (33 foot) and 20 m (66 foot) are optionally available.
Lengths can be selected by the user up to an overall length of 300 m (980 foot)
and are available by the meter (order option 8 ) or foot (order option A ).
8.8 Overvoltage Protection
The device is equipped with integrated overvoltage protection.
1 Device with HART communication
2 HART resistor
3 Power supply
2
3
Y
+
-
+
-
I
1
mA
Note
The HART communication resistor of 250  in the signal line is always necessary in the case
of a low-impedance power supply.
The voltage drop to be taken into account is:
Max. 6 V for 250

communication resistor