Pepperl+Fuchs KFD2-SR2-Ex1.W Switch Amplifier

Product Introduction

The Pepperl+Fuchs KFD2-SR2-Ex1.W is a high-quality 1-channel isolated barrier serving as a switch amplifier for proximity sensors and mechanical contacts. This model operates with a 24 V DC supply via Power Rail or direct terminals, making it highly versatile for cabinet installations.

This switch amplifier accepts input from dry contacts or NAMUR proximity switches (acc. to EN 60947-5-6) located in hazardous zones. It then provides a relay contact output for safe-area control systems. Furthermore, the KFD2-SR2-Ex1.W includes line fault detection (LFD) to monitor for broken wires or short circuits, enhancing diagnostic capabilities. Its reversible mode of operation allows configuration for normally open or normally closed behavior.

Technical Specifications

The KFD2-SR2-Ex1.W is engineered with precise electrical characteristics to ensure dependable switching performance in demanding environments.

Input Characteristics

• Input Type: Dry contact or NAMUR proximity switches (acc. EN 60947-5-6).

• Terminals: 1+, 3- for field connection.

• Open Circuit Voltage: approx. 8 V DC.

• Short-Circuit Current: approx. 8 mA.

• Switching Point: 1.2 ... 2.1 mA with a hysteresis of approx. 0.2 mA.

• Pulse/Pause Ratio: Minimum 20 ms / 20 ms for reliable signal detection.

• Lead Monitoring: Breakage detected when I ≤ 0.1 mA, ensuring line fault identification.

Output Characteristics

• Output Type: Relay contact output (terminals 7, 8, 9).

• Contact Loading: 253 V AC / 2 A (cos ϕ > 0.7) or 40 V DC / 2 A resistive.

• Energised/De-energised Delay: approx. 20 ms each.

• Mechanical Life: 10⁷ switching cycles, ensuring long-term reliability.

• Switching Frequency: < 10 Hz.

Supply and Power

• Rated Voltage: 20 ... 30 V DC (nominal 24 V DC).

• Ripple: ≤ 10 % within supply tolerance.

• Rated Current: 20 ... 23 mA.

• Power Consumption: < 1 W, with power loss of only 0.4 W.

Functional Safety and Approvals

Safety integrity is a core feature of this switch amplifier. Consequently, the Pepperl+Fuchs KFD2-SR2-Ex1.W is certified up to SIL 2 (SC 3) according to IEC/EN 61508.

Moreover, it carries extensive hazardous area approvals:

• ATEX: [EEx ia] IIC for circuits in Zone 0/1/2.

• FM & CSA: Approved for installation in Division 2 environments.

• IECEx: Compliant with relevant intrinsic safety standards.

The galvanic isolation between input, output, and power supply provides safe electrical isolation with a voltage peak value of 375 V (input/output), adhering to EN 50020.

Mechanical and Environmental Data

This device is built to withstand typical industrial conditions.

• Ambient Temperature: -20 ... 60 °C (253 ... 333 K).

• Degree of Protection: IP20.

• Mass: approx. 150 g, making it lightweight for DIN rail mounting.

• Mounting: Standard 35 mm DIN mounting rail.

Installation and Configuration Guide

Installing the KFD2-SR2-Ex1.W is a straightforward process. Begin by mounting the unit on a 35 mm DIN rail inside a control cabinet. Next, connect the 24 V DC power supply via the Power Rail or terminals 14+ and 15-.

For the input side, wire the NAMUR sensor or dry contact to terminals 1+ and 3-. Similarly, connect the relay output to terminals 7, 8, and 9 according to your control logic requirements. The reversible mode of operation allows you to select between normally open or normally closed output behavior. Additionally, the line fault detection (LFD) feature will automatically indicate a wire break or short circuit, simplifying maintenance and troubleshooting.

Packaging and Shipping

Each unit is carefully packaged to ensure safe delivery.

• Packaging List:

  • 1 x KFD2-SR2-Ex1.W Switch Amplifier

  • 1 x Labeling Set for front panel marking

  • 1 x Installation Instructions (Digital Download)

• Shipping Methods: Fedex, UPS, DHL

Frequently Asked Questions (FAQ)

Q1: What types of input devices can I connect to this amplifier?
A: The KFD2-SR2-Ex1.W supports both dry mechanical contacts and NAMUR proximity sensors (acc. to EN 60947-5-6) located in hazardous areas.

Q2: How does the line fault detection (LFD) work?
A: The LFD continuously monitors the input circuit. It detects a wire break when the current drops to ≤ 0.1 mA and identifies short circuits, providing valuable diagnostic feedback.

Q3: Can I use this unit for SIL-rated safety applications?
A: Yes, this switch amplifier is certified for functional safety up to SIL 2 (SC 3) according to IEC/EN 61508, making it suitable for safety-related control loops.

Q4: What is the maximum switching frequency of the relay output?
A: The relay output supports a maximum switching frequency of < 10 Hz, suitable for most process control and monitoring applications.

Q5: How do I configure the reversible mode of operation?
A: The reversible mode allows you to select between normally open and normally closed output behavior. This can be configured via the internal settings, providing flexibility for your specific control logic requirements.