Pepperl+Fuchs KFD2-UFC-1.D Frequency Converter with Trip Values

KFD2-UFC-1.D frequency converter for speed and pulse signals

The KFD2-UFC-1.D converts a pulse or frequency signal into a proportional 0/4 to 20 mA output and, in the same housing, offers two relay outputs and one transistor output for limit and pulse functions. It is the module to consider when a proximity sensor, a NAMUR sensor or a contact generates a pulse train that represents speed, flow or a count, and the control system needs an isolated analog value and alarm contacts.

Seven Star LLC supplies the KFD2-UFC-1.D in Oman and the GCC as an independent supplier in Muscat. Below you will find the input and output details, the zone marking quoted in the datasheet and the main selection points.

KFD2-UFC-1.D designation

The KFD2-UFC-1.D is a type designation of the Pepperl+Fuchs K-System, named in the datasheet as a frequency converter with trip values and described as a 1-channel signal conditioner with 24 V DC supply through the Power Rail. The datasheet states that the module provides isolation for non-intrinsically safe applications and that it can act as a switch amplifier and a trip alarm.

The datasheet lists a hazardous-area marking of II 3G Ex nA nC IIC T4 Gc with certificate PF 08 CERT 1216 X, and an ambient temperature of -20 to 50 °C for that use, together with a UL approval. This indicates the module can be installed in Zone 2 under the stated conditions; the field side itself remains non-intrinsically safe.

Technical specifications of the KFD2-UFC-1.D

How the KFD2-UFC-1.D processes pulse signals

The input counts pulses from a two- or three-wire proximity sensor, a NAMUR sensor or a dry contact over a measuring time shorter than 100 ms. It reports the frequency with an accuracy of 0.1 % of the measured value, from 0.001 Hz up to 10 kHz, which covers slow rotating machinery as well as fast flow turbines. A line fault detection function recognises a broken or shorted sensor cable.

The result drives an adjustable current output between 0/4 and 20 mA. The two relays and the transistor output can be assigned functions such as trip value with minimum or maximum alarm, serial switching, pulse divider and error signalling. This flexibility allows the same module to give an analog speed signal and an overspeed relay together.

A start-up override input blocks the alarm outputs for an adjustable period of 1 to 1000 seconds, which prevents false underspeed alarms while a machine is still accelerating.

Where the KFD2-UFC-1.D belongs

It complements the KFD2-USC-1.D for analog signals and the KFD2-GUT-1.D for temperature signals. The NJ2-12GK-SN NAMUR inductive sensor, already part of the Pepperl+Fuchs sensor program supplied by us, is a typical source of a pulse signal for this converter when the sensor is installed in a non-hazardous location.

For speed supervision of pumps, fans and motors, the converter and a toothed wheel or a target on the shaft form a simple, robust measuring chain.

Selection and ordering checklist for the KFD2-UFC-1.D

• Define the sensor type and the maximum frequency, which must be 10 kHz or below
• Define the analog output span that corresponds to the frequency range
• Define alarm functions for relay I, relay II and the transistor output
• Decide whether a start-up override is required
• Check the Zone 2 marking and the 50 °C ambient limit if installed in a hazardous area
• Check the SIL requirement

Installing and setting up the KFD2-UFC-1.D

Wire sensor input I to terminals 1, 2 and 3 as required by the sensor type, the start-up override to terminals 13 and 14, and the outputs to the output terminals. Set the frequency range, scaling, relay functions and delays on the keypad or via PACTware.

Test with a signal generator: apply low and high frequencies and confirm the current output and relay actions. Check the line fault behaviour by disconnecting the sensor cable. Keep the configuration file for later replacement.

Typical applications in Oman and the GCC

Pulse conversion is a standard task in rotating-equipment monitoring, in turbine flowmeter signal conditioning and in conveyor or crusher speed checks at mining, cement and desalination plants. Where the module is installed in a Zone 2 area, the temperature limit of 50 °C in the marking must be respected, which in outdoor Gulf shelters is a significant restriction.

Frequency converter against other D-series modules

Comparison from the datasheets.

Information to send with an RFQ for the KFD2-UFC-1.D

Please send the following.

• Sensor type and frequency range
• Analog output span and alarm logic
• Hazardous-area requirement, if any
• Quantity and delivery date

Documents and quotation

The manufacturer datasheet for the KFD2-UFC-1.D is attached on this page, so the electrical data, terminal assignment and ambient limits quoted above can be checked against the original document before an order is placed.

Seven Star LLC supplies Pepperl+Fuchs products in Oman and the GCC as an independent supplier in Muscat. Send the quantity, the signal types and the project delivery date, and we will confirm availability and lead time in a written quotation.