KFD2-SR2-EX1.W NAMUR Relay Output with LFD – Installation Guide
Product Introduction
The KFD2-SR2-EX1.W belongs to Pepperl+Fuchs' K-System of intrinsic safety barriers. It features a compact 20 mm housing for DIN rail mounting. This module processes digital input signals from the field. It accepts NAMUR proximity sensors (per EN 60947-5-6) or simple dry contact switches. The KFD2-SR2-EX1.W then drives a mechanical relay output on the control side. This relay provides a potential-free contact for your PLC or DCS. Moreover, the device offers reversible mode operation via DIP switches. You can configure it for energized or de-energized safety states easily.
Core Value
The KFD2-SR2-EX1.W delivers reliable signal conversion with integrated diagnostic intelligence. Firstly, it provides galvanic isolation between the field, output, and power supply circuits. This isolation protects your control system from hazardous area voltages. Moreover, the line fault detection (LFD) continuously monitors the field wiring. It identifies both short-circuit and open-circuit conditions. Therefore, you can quickly pinpoint wiring issues without additional troubleshooting tools. Besides, the SIL 2 rating ensures this module meets functional safety requirements. Its reversible operation adds flexibility for normally-open or normally-closed logic configurations.
Technical Insights
The KFD2-SR2-EX1.W operates on a 19 to 30 V DC supply via the Power Rail or terminals 14+ and 15-. The field input connects to terminals 1+, 2+, and 3-. It provides an open-circuit voltage of approximately 8 V DC and a short-circuit current of 8 mA. The switching point lies between 1.2 mA and 2.1 mA with a hysteresis of 0.2 mA. Specifically, the line fault detection triggers at I ≤ 0.1 mA for wire breakage and I > 6 mA for short-circuit conditions. The relay output connects to terminals 7, 8, and 9. It supports contact loads up to 250 V AC at 2 A or 40 V DC at 2 A resistive. The switching frequency goes up to 10 Hz with a minimum pulse/pause ratio of 20 ms each.
Installation & Maintenance
Mount the KFD2-SR2-EX1.W on a standard 35 mm DIN rail per EN 60715. Snap the device onto the rail securely to ensure proper grounding. Connect the field wiring to terminals 1+, 2+, and 3- according to your sensor type. Use the DIP switches on the front panel to configure the operating mode. Select either NAMUR or dry contact input and set the relay behavior to energized or de-energized state. Crucially, you must observe the line fault detection indicators via the front LEDs. For maintenance, regularly check the LED status for fault indications. Always de-energize the device before performing any wiring changes in hazardous areas.
Buyer's Guide FAQ
1. What is the primary function of the KFD2-SR2-EX1.W?
The KFD2-SR2-EX1.W transfers digital switching signals from hazardous areas to safe areas. It accepts NAMUR sensors or dry contacts and provides a relay contact output.
2. Does the KFD2-SR2-EX1.W support line fault detection?
Yes. This module includes integrated line fault detection (LFD). It monitors for wire breakage (I ≤ 0.1 mA) and short-circuits (I > 6 mA) in the field wiring.
3. Can I use this module in a safety instrumented function?
Yes. The KFD2-SR2-EX1.W is rated for SIL 2 per IEC/EN 61508 with systematic capability SC 3. It is suitable for safety-related switching applications.
4. How do I configure the operating mode on this device?
You configure the KFD2-SR2-EX1.W using the front DIP switches. This allows you to set the input type and reversible relay operation.
5. What types of field devices can connect to the KFD2-SR2-EX1.W?
You can connect NAMUR proximity sensors (EN 60947-5-6) or dry contact switches to the field input terminals. The device also supports line fault detection with both types.
