Product Overview

The Pepperl+Fuchs KFD2-SH-Ex1 stands as a premier fail-safe switch amplifier designed for high-integrity safety applications within the K-System. This single-channel isolated barrier transfers digital signals from NAMUR sensors or dry contacts located in hazardous areas to the safe control environment. Unlike standard amplifiers, the KFD2-SH-Ex1 specializes in safety-critical loops, such as emergency shutdown (ESD) and flame monitoring, meeting stringent SIL 3 requirements according to IEC/EN 61508. The module provides three distinct outputs: one safety-related relay output for critical control and two standard transistor outputs for status signaling and fault diagnosis. By ensuring a defined "off" state during power loss or field faults, this unit protects high-value assets like steam turbines and chemical reactors from catastrophic operational failures.

Core Technical Advantages

This amplifier utilizes an advanced dual-processor architecture to provide continuous self-monitoring and redundancy, which enables its SIL 3 functional safety rating. The KFD2-SH-Ex1 incorporates sophisticated Line Fault Detection (LFD) that instantly recognizes lead breakage or short circuits in the field loop, triggering an immediate safety response. Its hardware design supports both 24V DC terminal power and Power Rail integration, reducing complex wiring while maintaining high availability. The module also features a unique "Fail-Safe" relay design where the output de-energizes upon detecting a fault or signal change, ensuring the system defaults to its safest possible state. This active diagnostic capability eliminates the "hidden fault" risks associated with traditional switching components.

Technical Specifications

Installation Guide

Engineers must mount the KFD2-SH-Ex1 on a 35 mm DIN rail, preferably in a vertical orientation to optimize heat dissipation. For intrinsic safety compliance, maintain a clear 50 mm separation between the hazardous area input terminals (top) and the safe area output/power terminals (bottom). When connecting mechanical switches, technicians must install a 10 kΩ shunt resistor and a 1 kΩ series resistor to ensure the Line Fault Detection (LFD) functions correctly. Always verify that the cable capacitance and inductance do not exceed the specific entity parameters listed in the Ex-certificate to preserve the integrity of the explosion protection. For SIL 3 applications, use the dedicated fault output to feed diagnostic data back to the safety PLC, enabling real-time monitoring of the barrier's health.

Engineering Advantages

The KFD2-SH-Ex1 excels in environments where "nuisance tripping" is unacceptable yet safety is paramount. Its high immunity to electromagnetic interference ensures stable signal transmission near large motors and high-voltage switchgear. The module's robust galvanic isolation prevents ground loops and protects sensitive PLC I/O cards from atmospheric surges and field-side transients. Its compatibility with the K-System Power Rail allows for hot-swapping during maintenance, ensuring that process uptime remains maximized while safety protocols are strictly enforced. This amplifier represents the gold standard for engineers who require a non-compromise approach to functional safety and equipment longevity.

Delivery & Logistics

Delivery Time: 3-5 days once payment is finalized.

Shipping Carriers: Shipped via DHL, FEDEX, or UPS. All units are shipped in anti-static packaging to protect sensitive electronic components during transit.

Technical FAQs

Q1: What makes the KFD2-SH-Ex1 different from the standard KFD2-SR2-Ex1?

A1: The KFD2-SH-Ex1 is a SIL 3 rated "Fail-Safe" module, whereas the SR2 series is typically SIL 2. The SH model includes self-monitoring and three outputs (1 relay, 2 transistor) to provide the higher safety integrity required for ESD systems.

Q2: Can I use this module for high-speed pulse counting?

A2: No, this unit is designed for safety switching. The relay output has a mechanical response time. For high-speed pulse applications or frequency measurement, the KFD2-UFC series is the correct engineering choice.

Q3: How does the "Fail-Safe" relay behave during a power failure?

A3: The safety relay is normally energized during healthy operation and de-energizes (opens) immediately upon power loss. This ensures that the control loop recognizes the power failure as a "stop" or "safe" command.

Q4: What is the purpose of the two transistor outputs?

A4: One transistor provides a duplicated signal of the primary input for non-safety monitoring, while the second acts as a dedicated fault output that stays active as long as the field loop and module are healthy.