Pepperl Fuchs KFD2-STC4-Ex2 Isolated SMART Transmitter Power Supply

Description Are you looking to maximize cabinet density without sacrificing the safety of your hazardous area instrumentation? The KFD2-STC4-Ex2 provides two independent, intrinsically safe channels in a single 20 mm wide housing. This module functions as an isolated barrier, providing power to 2-wire SMART transmitters located in Zone 0, 1, or 2 (Class I, Div 1) while transferring the 4–20 mA signal to the non-hazardous control room side. It is fully transparent to HART communication, allowing bidirectional data flow for remote device management. Inventory Status and Commercial Logistics Product Condition: New Original (Factory Sealed). Availability: In stock at our global distribution hubs. Lead Time: Ships within 1 to 2 business days via international air express. Warranty Protection: 12-month replacement warranty from date of shipment. Commercial Note: Because this is a dual-channel safety barrier, it is a high-demand item for plant expansions. Listed prices are for reference; please request a formal quote for current spot-market pricing and volume-based discounts. Technical Specifications and Safety Parameters In field deployments of safety-instrumented systems (SIS), the “Ex2” variant is prized for its ability to reduce rail space by 50% compared to single-channel barriers. Core Electrical and Safety Specifications Parameter Technical Value Model Designation KFD2-STC4-Ex2 Channels 2 (Fully Independent and Isolated) Input (Hazardous Side) 4 mA to 20 mA (SMART/HART) Output (Safe Side) 4 mA to 20 mA (Sink or Source) Transmitter Supply $\ge$ 16 V at 20 mA per channel Supply Voltage 19 V DC to 30 V DC (via Power Rail or Terminals) HART Transparency Bidirectional (0.5 Hz to 40 kHz) Safety Integrity Level SIL 2 (IEC/EN 61508) Intrinsically Safe Marking [Ex ia Ga] IIC, [Ex ia Da] IIIC, [Ex ia Ma] I Integrated Functional Capabilities This module acts as a high-security gateway between your volatile field environment and your control infrastructure. Galvanic Isolation: It provides 3-port isolation (input/output/power) per channel, which prevents ground loops from corrupting your process variables—even if the two field transmitters are at different ground potentials. SMART Compatibility: The barrier is optimized for the frequency-shift keying (FSK) used in HART protocols. This ensures that your handheld maintenance tools can “talk” to the transmitters through the barrier without signal attenuation. Fault Detection: It features a dedicated fault bus. If a field-side wire breaks or shorts, the module signals a collective error through the Power Rail, allowing for rapid troubleshooting. Global Procurement and Customs Compliance Notes Shipping intrinsically safe equipment internationally requires meticulous documentation to satisfy both trade and safety regulators. Regulatory and Trade Classifications US ECCN: EAR99 (Generally unrestricted, but requires end-user verification). HS Code: 85437090 (Electrical apparatus with individual functions). Certification Documentation: We provide ATEX, IECEx, and UL certificates upon request to facilitate local inspections. Country of Origin: Usually Germany or Singapore; check the module side-label for exact Certificate of Origin (COO) verification. Shipping and Logistics We offer FCA (Free Carrier) and DAP (Delivered at Place) terms. For emergency facility repairs, we utilize priority air services (DHL/FedEx). The module is lightweight (approx. 200 g), making air freight highly efficient. We utilize specialized ESD-safe and shock-resistant packaging to ensure the internal safety-limiting components remain within factory calibration during transit. Engineering Notes for Field Deployments Critical Safety Warning: The blue terminals (1-6) are the intrinsically safe side. You must maintain a minimum of 50 mm clearance between the blue IS wiring and the non-IS (green) wiring to comply with IEC 60079-14. Failure to maintain this physical separation can invalidate your safety rating and pose a significant ignition risk in hazardous areas. Well, technically the module supports two channels, but to be frank, the heat dissipation is higher than the single-channel version. In our experience, if you are mounting 20 of these side-by-side in a high-ambient cabinet, you should leave a 5 mm air gap every 5 modules or use a fan tray to prevent the internal thermal fuses from drifting. On a recent project in a refinery, we found that field technicians were confused by the “Source/Sink” settings. For most modern PLC analog inputs, you will want the output set to “Source” (the barrier provides the 24V). However, if you are using an older DCS that provides its own loop power, you must set the DIP switches on the side of the KFD2-STC4-Ex2 to “Sink” mode to avoid “fighting” the DCS power supply. Frequently Asked Questions Can I use the KFD2-STC4-Ex2 with 3-wire or 4-wire transmitters? The STC4 series is specifically designed for 2-wire transmitters. While it can sometimes be adapted for 3-wire devices, it is not ideal. For 4-wire (self-powered) signals coming from a hazardous area, you should use an isolated current driver like the KFD2-SCD2-Ex2. What happens if I only use one channel on the dual-channel module? The module will function perfectly fine with only one channel connected. There is no need to jump or terminate the unused channel, though we recommend labeling it as “Spare” to prevent future wiring errors. How do I request an official pro forma invoice for my project? Submit your inquiry with the required quantity and your full delivery address. Our global trade team will provide a comprehensive quote, including HTS codes, estimated freight costs, and transit times, within one business day. Are you planning to mount these using the Power Rail for centralized fault monitoring and power distribution? 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