Wiring Setups For Hazardous Area Installations - Siemens SITRANS LR250 Compact Operating Instructions

Note
Lid-lock set screw not applicable to 3-A Sanitary approved device.
Connecting HART
Typical PLC/mA configuration with HART
①
②
③
Note
● Depending on the system design, the power supply may be separate from the PLC, or
integral to it.
● HART resistance (total loop resistance, that is, cable resistance plus 250 Ohm [resistor])
must be limited according to the allowable operating area.
5.3

Wiring setups for hazardous area installations

In all cases, check the device nameplate, full operating instructions, and process connection
tag to confirm the approval rating, and perform installation and wiring according to your local
safety codes.
For installation across Zone 0 and Zone 1 boundary:
LR250 (mA/HART)
Compact Operating Instructions, 06/2018, A5E33469191-AB
1
3
2
④
Power supply
⑤
SITRANS LR250
⑥
R = 250 Ω
5.3 Wiring setups for hazardous area installations
4
5
6
Active PLC
HART modem
HART communicator
Connecting
29