Pepperl+Fuchs KFD2-STC5-EX1 – SMART Transmitter Power Supply Module | KFD2 Series
Engineering Background
The KFD2-STC5-EX1 is a 2-wire SMART transmitter power supply and signal conditioner from Pepperl+Fuchs’ industry-proven KFD2 series. Designed for intrinsically safe (Ex ia) applications in Zone 0/1/2 hazardous areas, it provides loop power, HART signal transparency, and galvanic isolation in a compact DIN rail package. This module is the backbone of countless process instrumentation loops in oil & gas, chemical, and pharmaceutical plants worldwide.
Product Positioning
Targeting process automation engineers who require certified, drop-in-compatible isolation barriers for 4–20 mA HART transmitters, the KFD2-STC5-EX1 eliminates ground loop interference while maintaining full HART communication pass-through. It is a direct replacement for legacy Zener barriers in safety-critical loops where galvanic isolation is mandatory per IEC 60079-11 and IEC 61508 requirements.
Complete Technical Specifications
| Parameter | Value |
|---|---|
| Manufacturer | Pepperl+Fuchs (P+F) |
| Part Number | KFD2-STC5-EX1 |
| Series | KFD2 (24 VDC powered, DIN rail) |
| Function | SMART Transmitter Power Supply / Signal Conditioner |
| Input (Field Side) | 2-wire 4–20 mA HART transmitter, Ex ia IIC |
| Output (Safe Side) | 4–20 mA, max. load 500 Ω |
| Supply Voltage | 20–30 VDC (24 VDC nominal), via Power Rail or terminals |
| Current Consumption | ≤ 70 mA |
| Isolation | Galvanic, 500 V AC (field / power / output) |
| HART Transparency | Yes – full HART pass-through (FSK signal) |
| Hazardous Area Certification | ATEX: II (1) G [Ex ia Ga] IIC; IECEx; FM; CSA |
| SIL Rating | SIL 2 (IEC 61508), suitable for use in safety loops |
| Ambient Temperature | -20 °C … +60 °C |
| Mounting | DIN rail (EN 60715 TH35), 20 mm width |
| Housing | Plastic, IP20 |
| Dimensions (W×H×D) | 20 × 119 × 115 mm |
| Weight | ~100 g |
| Indicators | Green LED (power), Red LED (fault/line fault) |
| Connections | Screw terminals, 0.14–2.5 mm² |
| Standards | IEC 60079-11, IEC 61508, EN 50020 |
Proven Application Environments
- Oil & Gas: Wellhead pressure/temperature transmitter loops, HIPPS safety systems
- Chemical & Petrochemical: Reactor vessel level measurement, flow metering in Zone 1 areas
- Pharmaceutical: CIP/SIP process monitoring with FDA-compliant loop integrity
- Power Generation: Boiler drum level, turbine inlet pressure isolation
- Water & Wastewater: Pump station instrumentation in classified wet areas
- Pulp & Paper: Digester pressure loops requiring SIL 2 compliance
Engineering Advantages
- True Galvanic Isolation: Eliminates ground loops and common-mode interference — critical in large plant installations with multiple earthing points.
- Full HART Pass-Through: Supports HART 5/6/7 multidrop and point-to-point; no signal degradation for asset management or remote configuration.
- SIL 2 Certified: Pre-assessed for use in IEC 61508 safety instrumented systems, reducing SIL verification engineering effort.
- Power Rail Compatible: Snap-on connection to Pepperl+Fuchs Power Rail bus eliminates individual power wiring per module.
- Compact 20 mm Width: High channel density in marshalling cabinets — up to 36 channels per 720 mm DIN rail.
- LED Diagnostics: Instant visual fault indication for open-circuit and short-circuit field conditions.
- Long-Term Availability: Active production status; backward-compatible with KFD0/KFD2 series infrastructure.
System Architecture & Signal Flow
The KFD2-STC5-EX1 operates as a loop-powered isolator in a standard DCS/PLC architecture:
- Field Side (Ex ia): 24 VDC loop power supplied to 2-wire HART transmitter in hazardous area. HART FSK signal superimposed on 4–20 mA loop current.
- Isolation Barrier: Galvanic isolation stage separates field and safe-area circuits. Certified to 500 V AC, preventing fault propagation in either direction.
- Safe Side Output: Reproduced 4–20 mA signal (max 500 Ω load) fed to DCS AI card or safety PLC. HART signal simultaneously available for handheld communicator or HART multiplexer.
- Power Supply: Module powered from 24 VDC bus via Power Rail or direct terminal connection. Shared power rail reduces cabinet wiring complexity.
Compatible DCS/PLC platforms: Emerson DeltaV, Honeywell Experion, ABB 800xA, Siemens PCS 7, Yokogawa CENTUM VP, Rockwell PlantPAx.
Sourcing & Quality Verification
- Origin: Genuine Pepperl+Fuchs product, sourced through authorized industrial distribution channels.
- Traceability: Each unit carries P+F factory serial number and date code for full lifecycle traceability.
- Certification Marks: ATEX, IECEx, FM, CSA markings verified on housing label prior to shipment.
- Functional Test: Loop continuity and isolation resistance verified before dispatch.
- Packaging: Original P+F retail packaging with datasheet and EU Declaration of Conformity included.
- Counterfeit Prevention: Holographic label and factory seal intact — any unit without these should be rejected.
Procurement Process
- Submit RFQ via [email protected] or add to cart directly.
- Receive quotation with lead time confirmation within 1 business day.
- Issue PO — accepted formats: PDF PO, email confirmation, or Alibaba Trade Assurance order.
- Payment: T/T (wire transfer), PayPal, or credit card via Shopify secure checkout.
- Shipment: DHL Express / FedEx International Priority — typical transit 3–7 business days worldwide.
- Documentation package: Commercial invoice, packing list, COO certificate, and P+F datasheet provided with every shipment.
Technical FAQ
Q: Can the KFD2-STC5-EX1 be used with 3-wire transmitters?
A: No. This module is designed exclusively for 2-wire (loop-powered) 4–20 mA transmitters. For 3-wire or 4-wire devices, refer to the KFD2-STV4-Ex1 or KFD2-UT2-Ex1 series.
Q: Is HART communication affected by the isolation barrier?
A: No. The KFD2-STC5-EX1 provides transparent HART pass-through. The FSK signal (1200/2200 Hz) is reproduced on the output side with no degradation. HART handheld communicators can be connected on either the field or safe side.
Q: What is the maximum cable length to the field transmitter?
A: Per ATEX/IECEx entity parameters: maximum field cable capacitance 83 nF, inductance 3 mH. Consult P+F entity parameter documentation and IEC 60079-14 for site-specific cable calculations.
Q: Can multiple KFD2-STC5-EX1 modules share a Power Rail?
A: Yes. The Power Rail (e.g., P+F Power Rail F-LB-POWER) supports up to 40 modules per segment at 24 VDC. Ensure total current draw does not exceed the power supply rating.
Q: Is this module SIL 2 capable as a single device?
A: Yes, when used in accordance with the P+F Functional Safety Manual (document number available on request). The module achieves SIL 2 in a 1oo1 architecture for the signal conditioning function.
Q: What is the typical delivery time from Konmask.com?
A: In-stock units ship within 1–2 business days. Lead time for non-stock quantities is confirmed at order placement, typically 5–15 business days.
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