Pepperl+Fuchs KCD2 Series Modules: KCD2-SR-EX2

Technical Dossier

Product Details And Specifications

Pepperl+Fuchs KCD2 Series: Comprehensive Module Range and Technical Overview

The Pepperl+Fuchs KCD2 series represents one of the most widely deployed families of DIN-rail-mounted signal conditioners and switch amplifiers in global heavy industry. Installed across petrochemical complexes, nuclear power stations, offshore platforms, and large-scale refinery operations, the KCD2 platform provides intrinsic safety barriers and galvanic isolation for field signals operating in Zone 0/1/2 hazardous areas. Its 22.5 mm slim-line housing format, K-Bus power rail system, and compatibility with the KF-RS-232 remote configuration interface have made it a standard reference in IEC 60079-compliant process automation architectures. The series is certified to ATEX, IECEx, and FM standards, and remains the backbone of legacy DCS and PLC I/O marshalling cabinets in facilities with 20+ year operational lifespans.

The Evolution of KCD2 Architecture

The KCD2 series was introduced as a successor to the earlier KFD2 and KFA5 families, consolidating signal conditioning, switch amplification, and solenoid driver functions into a unified 22.5 mm form factor. Early KCD2 variants relied on passive K-Bus power distribution without active diagnostics. Subsequent generations introduced NAMUR sensor compatibility per IEC 60947-5-6, line fault detection (LFD) for open/short circuit monitoring, and relay output configurations with SPDT contacts rated to 250 V AC / 2 A. The current production range supports both single-channel (SR) and dual-channel (2SR) topologies, with EX-suffix variants certified for use with sensors located in Ex Zone 0. Compatibility with the KF-RS-232 and USB-RS-232 configuration adapters allows parameter storage and cloning across large marshalling installations. As the KCD2 series enters its mature lifecycle phase, Pepperl+Fuchs has introduced the KFD2 and LB series as long-term migration paths; however, the KCD2 remains in active production for the core catalog and is supported under Pepperl+Fuchs extended lifecycle policy.

KCD2 Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly stocked models within the KCD2 series, organized by functional category. Each model is a discrete, independently orderable line item.

Switch Amplifiers — Single Channel

• KCD2-SR-EX2: Single-channel NAMUR switch amplifier, relay output, Ex Zone 0 certified, 22.5 mm housing
• KCD2-SR-EX1: Single-channel switch amplifier, 1 relay output, NAMUR/mechanical contact input, ATEX Zone 1
• KCD2-SR-EX1.LB: Single-channel switch amplifier with line fault detection, relay output, ATEX/IECEx
• KCD2-SR-EX2.LB: Dual-relay output switch amplifier with LFD, NAMUR input, Ex Zone 0

Switch Amplifiers — Dual Channel

• KCD2-2SR-EX2: Dual-channel NAMUR switch amplifier, 2 relay outputs, Ex Zone 0, 22.5 mm
• KCD2-2SR-EX1: Dual-channel switch amplifier, 2 relay outputs, ATEX Zone 1 certified
• KCD2-2SR-EX1.LB: Dual-channel switch amplifier with line fault detection, 2 relay outputs

Solenoid Drivers

• KCD2-SOT-EX2: Single-channel solenoid driver, Ex Zone 0, 22.5 mm, 24 V DC output
• KCD2-SOT-EX1: Single-channel solenoid driver, ATEX Zone 1, short-circuit protected output
• KCD2-SOT2-EX2: Dual-channel solenoid driver, Ex Zone 0, independent channel control

Analog Input / Signal Conditioners

• KCD2-STC-EX1: 2-wire transmitter power supply and signal conditioner, 4–20 mA, ATEX Zone 1
• KCD2-STC-EX2: 2-wire transmitter supply, galvanic isolation, 4–20 mA output, Ex Zone 0
• KCD2-UT2-EX1: Universal temperature converter, thermocouple/RTD input, 4–20 mA output

Analog Output / Current Repeaters

• KCD2-SCD-EX1: Current driver for Ex Zone 1 field devices, 4–20 mA, galvanic isolation
• KCD2-SCD-EX2: Current driver, Ex Zone 0 rated, 4–20 mA, DIN rail mount, 22.5 mm

Power Supply / Bus Modules

• KCD2-PW: K-Bus power rail module for KCD2 series, 24 V DC distribution, no field wiring

Sourcing Hard-to-Find & Obsolete KCD2 Parts

Quality Control for the KCD2 Range

KCD2 modules undergo a structured test protocol prior to dispatch. Each unit is bench-tested for K-Bus power rail continuity, NAMUR input threshold response (per IEC 60947-5-6: 1.2 mA / 2.1 mA switching thresholds), relay output contact resistance (500 V DC, 1 minute). For EX-certified variants, enclosure integrity and terminal torque compliance are verified against the original ATEX/IECEx certificate parameters. Solenoid driver modules are load-tested at rated output current. All test records are retained and available upon request for regulatory audit purposes.