Pepperl Fuchs KFD2-SR2-Ex2.W Relay Output Module

Pepperl+Fuchs KFD2-SR2-Ex2.W Relay Output Module (Switch Amplifier / Isolated Barrier)

 

The KFD2-SR2-Ex2.W is a 2-channel switch amplifier (signal isolator with relay outputs) from Pepperl+Fuchs K-System. It is designed to safely transfer NAMUR sensor or dry contact signals from hazardous areas (Ex zone) to relay outputs in the safe area, typically for PLC or control system inputs.

Basic Information

• Part Number: KFD2-SR2-Ex2.W
• Brand: Pepperl+Fuchs
• Type: Switch Amplifier / Signal Isolator / Relay Output Module
• Function: Converts NAMUR / dry contact signals → relay switching outputs with isolation

Key Technical Specifications (confirmed)

• Channels: 2-channel isolated barrier
• Supply Voltage: 19–30 VDC (via Power Rail or terminals)
• Input Type: NAMUR sensor or mechanical switch (intrinsically safe input)
• Output Type: Relay contact output (changeover contacts)
• Switching Frequency: ≤ 10 Hz
• Delay Time: ~20 ms ON/OFF
• Safety Rating: SIL 2 (IEC 61508)
• Mounting: 35 mm DIN rail (Power Rail system)
• Line Fault Detection: Yes (open/short circuit monitoring)

Key Features

• Accepts NAMUR sensors or dry contact inputs
• Provides relay output isolation (safe switching for PLC inputs)
• Built-in line fault detection (LFD)
• Selectable operating modes (NO/NC logic via DIP switch)
• LED status indicators for diagnostics
• Intrinsically safe input side for Ex environments

System Role (Simple Explanation)

This module is used to convert low-level field signals into usable PLC signals:

NAMUR sensor / switch (Ex zone)

So it functions as:

• Signal isolator
• Safety barrier
• Relay interface module
• Logic signal converter

Application Areas

• Oil & gas instrumentation systems
• Petrochemical plants
• Power plants
• Hazardous area sensor monitoring
• Valve / limit switch feedback
• Pump and motor status monitoring
• Safety interlock systems (ESD)

Advantages

• Strong electrical isolation between field and PLC
• Compatible with NAMUR standard sensors
• Relay output suitable for wide PLC compatibility
• High reliability in harsh industrial environments
• Built-in diagnostics reduce downtime
• Safe use in Ex-rated systems

Precautions

• Must be installed according to Ex safety regulations
• Only use with approved NAMUR or dry contact devices
• Do not exceed relay contact rating
• Ensure correct 24V DC supply (19–30V range)
• Proper grounding required for Power Rail system