Configured for discrete NAMUR sensor signal isolation and relay switching in hazardous area interface loops, the Pepperl+Fuchs KFU8-SR-Ex2.W (KFU8-SR Switch Amplifier) provides direct physical/electrical execution.

Functional Suffix Architecture

• KFU8: Wide-range universal power supply housing designator (115/230 VAC or 24 VDC).
• SR: Switch amplifier relay output module classification.
• Ex2: Galvanically isolated intrinsically safe interface for 2 field channels.
• .W: Changeover relay output contacts (SPDT execution per channel).

Electrical & Environmental Specs

Intrinsic Safety and Network Barrier Protection

Built-in intrinsic safety (Ex i) barriers enforce energy limitation to prevent ignition in explosive gas or dust atmospheres. The enclosure maintains DIN-rail mounting stability under mechanical vibration, suppressing voltage transients and line fault conditions (LFD) while keeping protocol conversion latencies near zero during discrete signal transmission across safety loops.

Package Component Set

• 1 x Pepperl+Fuchs KFU8-SR-Ex2.W Switch Amplifier
• 1 x Removable Screw Terminal Block Set
• 1 x Housing Side Cover Plate

Cabinet Installation & Field Wiring

Mounting Track Assembly

Latch the barrier unit onto a standard 35 mm DIN rail inside a safe area enclosure or Zone 2 local cabinet. Ensure minimum 6 mm clearance between intrinsically safe and non-intrinsically safe field wiring terminals.

Sensor Loop Termination

Connect Field NAMUR proximity switches or dry contacts to blue intrinsically safe terminals 1-2 (Channel 1) and 4-5 (Channel 2). Enable internal fault detection via DIP switches if line fault monitoring is required.

Power Supply and Output Wiring

Wire supply voltage (20 to 90 VDC or 90 to 253 VAC) to power terminals 14 and 15. Connect control system digital inputs or alarm circuits to the SPDT relay contacts at terminals 7-8-9 and 10-11-12.

Technical FAQ

• Can line fault detection be configured for dry contact input signals?

  Line fault detection requires external resistors wired across and in series with dry contacts to distinguish normal open/close states from short/open circuits.

• What voltage range does the universal power supply input support?

  The universal power interface accepts either 20 to 90 VDC or 90 to 253 VAC without requiring manual voltage selection jumpers.

• Is hot-swapping allowed for terminals located in hazardous areas?

  Blue intrinsically safe field terminals may be disconnected under power, but power input terminals must be de-energized before removal.

• How are the SPDT relay outputs affected by a detected line fault?

  When line fault detection is enabled, a broken or shorted field wire de-energizes the corresponding channel relay and lights the red diagnostic LED.

• What galvanic isolation level is maintained between input circuits and supply power?

  The module provides complete 3-way galvanic isolation rated for reinforced insulation up to 253 VAC between input, output, and power supply.

• What is the maximum switching frequency supported by the internal output relays?

  The mechanical relay outputs support a maximum switching frequency of 10 Hz under resistive load conditions.

• How are direction of operation and fault detection mode configured on the module?

  DIP switches located on the front panel set normal/inverted output logic and enable/disable line fault detection for each channel.

• What grounding procedure applies to the field sensor cable shielding?

  Ground cable shields at the safe area side only; do not ground shields inside hazardous areas to prevent ground loop currents.