Pepperl+Fuchs KFU8-UFC-EX1.D Frequency Converter

Technical Overview

1-channel isolated barrier frequency converter with 1 mHz-5 kHz digital input, 0/4-20 mA output, trip alarms, SIL 2. DIN rail mountable.

Key Features

1-channel isolated barrier for intrinsic safety applications.
Universal usage with different power supplies (AC/DC wide range supply).
Input for NAMUR sensors or dry contacts.
Input frequency range from 1 mHz to 5 kHz.
Current output of 0/4 mA to 20 mA.
Configurable relay contact and potential-free transistor outputs.
Outputs can be configured for trip value display (min/max alarm), serially switched output, pulse divider output, and error signal output.
Start-up override function.
Line fault detection (LFD) for enhanced safety.
Safety Integrity Level (SIL) 2 compliant according to IEC/EN 61508 / IEC/EN 61511.
Configurable via integrated keypad or PACTware configuration software.
DIN rail mounting for easy installation and integration into existing systems.
Built-in LED indicators for fault indication and output status.
Removable terminals for rapid change-over and wiring.

Technical Specification Matrix

Parameter	Value
Signal Type	Digital Input
Functional Safety Level	SIL 2 acc. to IEC/EN 61508 / IEC/EN 61511
Input Sensor Type	NAMUR sensors or dry contacts
Input Frequency Range	1 mHz ... 5 kHz
Output Type	Current Output (0/4 mA ... 20 mA), 2 Relay Outputs, 1 Transistor Output
Supply Voltage (DC)	20 ... 90 V DC
Supply Voltage (AC)	48 ... 253 V AC (50 ... 60 Hz)
Power Dissipation	≤ 2 W
Power Consumption	2.5 VA / 2.2 W ; 3 VA
Number of Channels	1-channel isolated barrier
Degree of Protection	IP20
Mounting Type	DIN Rail
Galvanic Isolation	Reinforced insulation according to IEC/EN 61010-1, rated insulation voltage 300 Veff (Input I/other circuits, Output I, II/other circuits)
Physical Weight (kg)	0.3
Dimensions L x W x H (cm)	11.9 x 4 x 11.5

Industrial Applications

1. Hazardous Area Flow Rate Monitoring

Monitoring and converting frequency signals from turbine flow meters equipped with NAMUR sensors in explosive gas or dust atmospheres to a standard 4-20 mA analog signal for process control systems.

Problem Solved

Safely converts intrinsically safe frequency signals from flow meters in Zone 0/1/2 or Div. 1/2 hazardous areas into proportional analog signals for control systems, while providing SIL 2 rated trip alarms for critical flow conditions and line fault detection.

Intrinsic SafetyNAMUR SensorFrequency to Current ConversionFlow MeterHazardous AreaSIL 24-20 mA OutputLine Fault Detection

2. Conveyor Speed Safety Interlock

Providing safety-rated speed monitoring for conveyor belts in potentially explosive environments by converting frequency pulses from a NAMUR proximity sensor into an analog speed signal, with integrated trip alarms for over/under-speed conditions.

Problem Solved

Ensures reliable and safety-rated (SIL 2) speed monitoring for conveyor systems in hazardous locations. The device triggers configurable relay outputs as safety interlocks to activate emergency stops or alarms if conveyor speed deviates from safe operating parameters.

NAMUR Proximity SensorSpeed MonitoringFrequency InputConveyor SystemSafety InterlockTrip AlarmSIL 2Explosive Atmosphere

3. Pump Operational Status & Anomaly Detection in Chemical Plants

Monitoring pump runtime or operational status in chemical processing plants using dry contacts or NAMUR sensors, converting these signals into an analog representation for central control systems and triggering alerts for abnormal conditions.

Problem Solved

Provides isolated and safety-compliant (SIL 2) monitoring of pump activity in hazardous chemical environments. It converts digital pulses to an analog signal for process control and uses trip outputs to notify operators of pump failures or unusual operational patterns, thereby maintaining process safety and integrity.

Dry Contact InputNAMUR SensorPump MonitoringRuntime TrackingAnalog OutputTrip OutputsChemical ProcessingIntrinsic Safety