Endress+Hauser Micropilot FMR50, Operating Instructions Manual

Page: 40 / 184

Electrical connection Micropilot FMR51, FMR52 HART
40 Hauser
Connection examples for the switch output
3+
+
-
4-
A0015909
 15 Connection of a relay
Suitable relays (examples):
• Solid-state relay: Phoenix Contact OV-24DC/480AC/5 with mounting
rail connector UMK-1 OM-R/AMS
• Electromechanical relay: Phoenix Contact PLC-RSC-12DC/21
3+
2
1
+
4-
A0015910
 16 Connection of a digital input
1 Pull-up resistor
2 Digital input
For optimum interference immunity we recommend to connect an external resistor
(internal resistance of the relay or Pull-up resistor) of < 1 000 Ω.
7.1.2 Cable specification
• Devices without integrated overvoltage protection
Pluggable spring-force terminals for wire cross-sections 0.5 to 2.5 mm
2
(20 to 14 AWG)
• Devices with integrated overvoltage protection
Screw terminals for wire cross-sections 0.2 to 2.5 mm
2
(24 to 14 AWG)
• For ambient temperature T
U
≥60 °C (140 °F): use cable for temperature T
U
+20 K.
HART
• A normal device cable suffices if only the analog signal is used.
• A shielded cable is recommended if using the HART protocol. Observe grounding concept
of the plant.
• For 4-wire devices: Standard device cable is sufficient for the power line.