Name: Pepperl+Fuchs KFD2-SR2-EX2.W Isolated Barrier, 2-Channel Relay Output
SKU: KFD2-SR2-EX2.W
Price: 234.00 USD
Availability: InStock

Product details

Product Description

KFD2-SR2-EX2.W from Pepperl+Fuchs is a 2-channel isolated switch amplifier for digital inputs. It transfers NAMUR or dry contact signals from hazardous to safe areas. The device offers relay outputs and line fault detection (LFD). It supports SIL 2 functional safety per IEC/EN 61508. Operating modes are reversible via DIP switches. Compact housing (20 mm width) fits on a 35 mm DIN rail. Ideal for intrinsic safety applications in process automation.

Key Features

2-channel isolated barrier for digital signals
Input types: NAMUR sensors or dry contacts
Output: relay contact, 250 V AC / 2 A
Line fault detection (LFD) with LED indication
Reversible mode via DIP switches
SIL 2 (SC 3) according to IEC/EN 61508
Power Rail or terminal supply (19–30 V DC)
Wide ambient temperature -40 °C to +70 °C

Technical Specifications

Brand: Pepperl+Fuchs
Model: KFD2-SR2-EX2.W
Type: Switch Amplifier, Digital Input
Supply voltage: 19 … 30 V DC (including ripple ≤10 %)
Rated current: ≤ 50 mA
Power dissipation: ≤ 1 W
Input (NAMUR): open circuit voltage ≈8 V DC, short-circuit current ≈8 mA
Switching point: 1.2 … 2.1 mA (hysteresis ≈0.2 mA)
Line fault detection: breakage ≤0.1 mA, short-circuit >6 mA
Switching frequency: ≤ 10 Hz
Relay output: 250 V AC/2 A (cos φ >0.75), 40 V DC/2 A resistive
Minimum switch current: 2 mA / 24 V DC
Response delay: approx. 20 ms (energized and de-energized)
Mechanical life: 10⁷ switching cycles
Ambient temperature: -40 … 70 °C (-40 … 158 °F)
Protection degree: IP20
Connection: screw terminals (0.5–2.5 mm²)
Dimensions: 20 x 119 x 115 mm (W x H x D)
Weight: approx. 150 g

Installation & Commissioning

DIN rail mounting: snap onto 35 mm rail per EN 60715.
Wiring: use screw terminals; observe polarity for NAMUR inputs.
Configuration: set DIP switches for mode and LFD on/off.
LED indicators: show status and fault conditions per NAMUR NE 44.
Power Rail optional: simplifies wiring and provides collective error signal.

Compatibility & System Integration

Compatible with all NAMUR proximity sensors (EN 60947-5-6).
Works with dry contact mechanical switches.
Relay outputs interface to PLCs, DCS, or alarm systems.
SIL 2 rated for safety loops (SC 3).
Power Rail system supports redundant power supplies.

Certifications & Approvals

ATEX: PTB 00 ATEX 2080 (II (1)G [Ex ia Ga] IIC)
IECEx: PTB 11.0034, TUN 19.0013X
FM: FM19US0207X (Control drawing 116-0035)
UL: E106378 (cULus, Control drawing 116-0473)
Functional Safety: IEC/EN 61508:2010, SIL 2
EMC: EN 61326-1:2013 (industrial locations)

Applications & Suitable Equipment

Process automation: level, pressure, flow monitoring.
Safety interlocks: emergency stop, door monitoring.
Hazardous areas: Zone 0, 1, 2 (gas) and Zone 20, 21, 22 (dust).
Mining: intrinsically safe circuits (I M1).
Works with sensors: inductive, capacitive, magnetic NAMUR.
Connects to controllers: PLC, DCS, or relay logic.

Expert Review

Engineers appreciate the KFD2-SR2-EX2.W for its robust relay outputs and clear fault diagnostics. The reversible mode and LFD simplify troubleshooting. Its slim design saves space in crowded cabinets. The SIL 2 rating ensures reliable safety performance. Overall, this amplifier is a top choice for cost‑effective intrinsic safety isolation.

Manager’s Insight

From a procurement perspective, this model offers excellent value. It reduces inventory with its dual‑channel design. The Power Rail option cuts wiring time and errors. Long mechanical life (10⁷ cycles) lowers maintenance costs. Backed by global approvals, it simplifies global machine exports.

FAQ

What input signals does it accept?
NAMUR sensors (EN 60947‑5‑6) or dry mechanical contacts.
Can I disable line fault detection?
Yes, via DIP switch on the front panel.
Is it suitable for SIL 2 applications?
Yes, certified to SIL 2 (SC 3) per IEC/EN 61508.
What is the maximum switching frequency?
10 Hz (pulse/pause min. 20 ms).
Does it support Power Rail?
Yes, terminals 14+ and 15‑ or Power Rail connection.
What happens during a fault?
The relay de‑energizes and LEDs show fault type (NE 44).
Can it drive a 4 A load?
At 126.5 V AC with cos φ >0.75, yes. For DC, max 2 A at 40 V.