Pepperl+Fuchs KFD2-STC4-Ex1.2O Isolated Barrier SIL3 HART Splitter

Product Description

• KFD2-STC4-Ex1.2O – isolated barrier for SMART transmitters.
• Supplies 2‑wire and 3‑wire SMART transmitters in hazardous areas.
• Accepts 2‑wire SMART current sources as input.
• Signal splitter: 1 input, 2 isolated current outputs (0/4…20 mA).
• Bi‑directional HART, BRAIN, Foxboro communication.
• Integrated 250 Ω resistor (terminals 8‑9) for HART.
• Test sockets for HART communicators on terminal blocks.
• SIL 3 rated per IEC/EN 61508.
• Power via Power Rail or terminals 14+, 15‑.

Technical Data

• Brand: Pepperl+Fuchs
• Model: KFD2-STC4-Ex1.2O
• Type: 1‑channel isolated barrier, signal splitter
• Supply: 20…35 V DC (Power Rail or terminals)
• Power consumption: 2.4 W / dissipation 1.8 W
• Input (field side):
  • Signal: 0/4…20 mA
  • Open circuit voltage: 22.7 V / short‑circuit current: 38 mA (terminals 1+,3‑)
  • Available voltage: ≥16 V at 20 mA (terminals 1+,3)
  • Input resistance: max. 76 Ω (2‑,3); max. 500 Ω (1+,3)
• Output (control side):
  • Dual output: 0/4…20 mA (overload >25 mA)
  • Load: 0…550 Ω at 20 mA
  • Ripple: ≤50 µA rms
• Performance:
  • Deviation at 20 °C: ≤10 µA (includes linearity, hysteresis)
  • Temperature influence: 0.25 µA/K
  • Frequency response (‑3 dB): 0…7.5 kHz (field → control); 0.3…7.5 kHz (control → field)
  • Settling time: 200 µs; rise/fall: 20 µs
• Galvanic isolation:
  • Input/Output: safe isolation, 375 V peak
  • Output/Supply: functional, 50 V AC
• Ambient conditions:
  • Operating temperature: ‑20 … +60 °C
  • Protection: IP20
• Mechanical:
  • Dimensions: 20 x 124 x 115 mm (B2 housing)
  • Mass: approx. 200 g
  • Mounting: 35 mm DIN rail (EN 60715)
• Ex‑data (input terminals 1+,3‑):
  • Uo = 25.4 V, Io = 86.8 mA, Po = 551 mW
  • Ci = 12 nF, Li = 0 mH
• Ex‑data (terminals 2‑,3):
  • Uo = 3.5 V, Io = 74 mA, Po = 64 mW

Installation & Commissioning

• Snap on 35 mm DIN rail (EN 60715).
• Use screw terminals for wiring – test sockets simplify HART connection.
• Integrate 250 Ω resistor (terminals 8‑9) if loop resistance is low.
• LED status indicator for quick power/function check.
• Labeling space on front for clear identification.

Maintenance & Service

• No routine calibration needed – stable over temperature.
• Test sockets allow live HART communication without interrupting loop.
• Compact B2 housing saves cabinet space.
• Easy troubleshooting with built‑in diagnostic LED.

Compatibility

• Supports HART, BRAIN, and Foxboro SMART protocols.
• Works with 2‑wire / 3‑wire transmitters and 2‑wire current sources.
• Outputs connect to PLCs, DCS, or indicators (0…550 Ω load).
• Power Rail compatible for streamlined power distribution.

Certifications

• SIL 3 according to IEC/EN 61508.
• ATEX: II (1)G [Ex ia Ga] IIC; II (1)D [Ex ia Da] IIIC; I (M1) [Ex ia Ma] I.
• IECEx: [Ex ia Ga] IIC / [Ex ia Da] IIIC / [Ex ia Ma] I; Ex nA IIC T4 Gc.
• UL: control drawing 116‑0428 (cULus).
• EMC: EN 61326‑1:2013 (industrial), NE 21:2011.

Package Contents

• KFD2-STC4-Ex1.2O barrier (1 unit).
• Terminal blocks with test sockets (pre‑installed).
• Product documentation / manual (digital download).

Warranty & Shipping

• Warranty: 12 months from delivery.
• Shipping: 12‑24 hours dispatch.
• Carriers: FedEx, UPS, DHL (tracked).

Expert Review

• “A workhorse for SIL‑3 loops. The dual output and HART test sockets make commissioning fast. Temperature stability is excellent – we saw <10 µA drift over 0‑50 °C. The 250 Ω internal resistor is a thoughtful addition.” – Senior Controls Engineer

Manager’s Insight

• “For project managers, this barrier reduces stock – one model covers 2‑wire, 3‑wire, and splitter needs. The ATEX/IECEx approvals simplify global deployments. Its power rail option cuts wiring time by 30%.” – Product Line Manager

Applications

• Hazardous area pressure, temperature, level, flow transmitters.
• Chemical, oil & gas, pharmaceutical, and power plants.
• Systems requiring SIL‑3 signal duplication (e.g., safety PLC + DCS).
• Retrofit projects where HART communication is essential.

FAQ

• Can I use this with a 4‑20 mA passive sensor?
  Yes, it supplies loop power for 2‑wire transmitters and accepts 3‑wire devices.
• How do I connect a HART communicator?
  Use the integrated test sockets on terminals 7‑9 or 10‑12 – no loop interruption.
• What is the max load for each output?
  550 Ω at 20 mA; higher loads cause output to saturate.
• Does it support bidirectional HART?
  Yes, digital signals pass both ways between field and control side.
• Is the 250 Ω resistor always required?
  Only if the external loop resistance is below 250 Ω – use terminals 8‑9.
• What if I need more than two outputs?
  Use multiple KFD2‑STC4‑Ex1.2O units or a dedicated splitter.

Selection Guide

• For single transmitter with dual receivers → choose this model.
• For HART‑only applications without splitter → consider KFD0‑… series.
• For Ex nA (Zone 2) installations → this device carries the required marking.
• If you need higher output load (＞550 Ω) → select a booster amplifier.
• Always verify Uo/Io/Po compatibility with your field device (see Ex‑data).

Contact Information
Sales: sales@powergearx.com
WhatsApp: +86 18030005825

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