Pepperl Fuchs KFD2-SL2-Ex2 Signal Isolator Module

Pepperl+Fuchs KFD2-SL2-Ex2 Signal Isolator Module (Solenoid / Digital Output Barrier)

 

 

The KFD2-SL2-Ex2 is a 2-channel intrinsically safe signal isolator / solenoid driver used in Pepperl+Fuchs K-System, designed to safely transfer digital ON/OFF control signals (24 VDC logic) from a PLC/DCS to field devices such as solenoid valves, alarms, and actuators, especially in hazardous (Ex) areas.

Basic Information

• Part Number: KFD2-SL2-Ex2
• Brand: Pepperl+Fuchs
• Type: Signal Isolator / Solenoid Driver / Intrinsically Safe Barrier
• Function: Digital signal transmission + electrical isolation + Ex protection

Technical Specifications (Key Data)

• Channels: 2-channel isolated output
• Input Signal: 0/24 V DC logic (PLC side)
• Output Signal: Safe-area / field-side switching output (Ex ia protected)
• Supply Voltage: 20–30 V DC (via Power Rail or terminals)
• Output Current: up to 45 mA per channel
• Output Voltage: approx. 11.7–24 V depending load
• Switching Delay: ≤ 20 ms
• Mounting: 35 mm DIN rail (K-System Power Rail)
• Protection Level: IP20
• Safety Rating: SIL 2 (IEC 61508)
• Hazardous Area Approval: Ex ia (intrinsically safe circuits)

Key Features

• Converts PLC digital output → safe field switching signal
• Provides galvanic isolation between control and field side
• Built-in line fault detection (LFD)
• Supports intrinsically safe (Ex ia) circuits
• Dual-channel compact design
• LED status indication for diagnostics

System Role (Simple Explanation)

This module is used when a PLC wants to control a device in a hazardous area:

PLC DO signal (24V)
➡️ KFD2-SL2-Ex2 (isolates + limits energy)
➡️ Solenoid valve / actuator / alarm device

So it provides:

• Signal isolation
• Explosion safety limitation
• Reliable ON/OFF switching in Ex zones

Application Areas

• Oil & gas automation systems
• Petrochemical plants
• Refineries
• Offshore platforms
• Power plants
• Solenoid valve control systems
• Emergency shutdown (ESD) systems
• Hazardous area instrumentation cabinets

Advantages

• High safety (Ex ia intrinsic safety design)
• Reliable switching for solenoid loads
• Compact DIN rail installation
• Reduces risk of ignition in hazardous zones
• Strong diagnostic capability (fault detection)
• Long-term industrial reliability

Precautions

• Must be installed according to ATEX / IECEx rules
• Do not exceed 45 mA output current per channel
• Correct 24 VDC supply (20–30 V range only)
• Ensure proper grounding of Power Rail system
• Only use with approved Ex field devices