Pepperl+Fuchs KFD2-USC-1.D Signal Converter with Trip Value

KFD2-USC-1.D universal current and voltage signal converter with trip relay

The KFD2-USC-1.D is a configurable isolator for standard analog signals. It accepts a current, voltage or millivolt input from a field device, converts and scales it into a current or voltage output for the control system, and adds a relay contact that works as a trip value switch. A display and a front keypad let a technician set the ranges on site, with no configuration cable or PC needed.

Seven Star LLC supplies the KFD2-USC-1.D in Oman and the GCC as an independent supplier in Muscat. The sections below show where the converter belongs, what its measurement limits are and what to settle before ordering.

KFD2-USC-1.D designation and intended use

The KFD2-USC-1.D is a type designation of the Pepperl+Fuchs K-System, and the datasheet names it a signal converter with trip value, 1-channel, 24 V DC supply through the Power Rail. The display-and-keypad configuration is part of the feature list. The manufacturer states that the device provides isolation for non-intrinsically safe applications, which is an important limit: the module is for the safe area and does not replace an intrinsically safe barrier.

The input ranges named on the datasheet are 0 to 20 mA, 0 to 10 V and 0 to 60 mV, and any sub-range of these can be selected. Outputs are 0/4 to 20 mA, 0/2 to 10 V or 0/1 to 5 V.

Technical specifications of the KFD2-USC-1.D

How the KFD2-USC-1.D converts and monitors a signal

The input stage digitizes the field signal at 15 bit resolution and the converter rescales it to the output range chosen at the keypad. Because the output ranges and the input sub-ranges are independent, the same module can convert a 4-20 mA transmitter signal into 1-5 V for an old recorder, or turn a 0-10 V position feedback into a 4-20 mA value for a PLC card. A line fault detection function monitors the field wiring.

The relay works as a trip value contact. The user sets the switching threshold, and the display can show the process value in engineering units, which makes the module useful as a local indicator-and-alarm point as well as an isolator. The datasheet quotes a reaction time of not more than 300 ms, so the relay is suited to alarming, not to fast protection.

All three circuits, input, outputs and supply, are separated by reinforced insulation rated at 300 V rms, which protects the receiving system from common-mode voltages and ground loops between the plant and the control room.

Where the KFD2-USC-1.D fits

The module belongs to the display-and-keypad branch of the K-System, alongside the KFD2-GUT-1.D temperature converter, the KFD2-UFC-1.D frequency converter and the KFD2-CRG2-1.D transmitter supply. All of them share the same family of Power Rail, KFD2-EB2 power feed and K-DUCT wiring accessories.

Use the KFD2-USC-1.D when the field device is a non-Ex source that already has its own power: a drive output, a variable-speed signal, a mV shunt or an analog output from a package unit. When the field device needs loop power, the KFD2-CRG2-1.D or the STC5 transmitter supplies are the right choice.

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

• Define the input signal type and range: current, voltage or millivolt
• Define the required output signal and check the 550 Ω current or 1 kΩ voltage load limits
• Specify the trip value and the relay contact rating needed
• Confirm that the application is in the safe area, since the module is not for intrinsically safe circuits
• Confirm the 20 to 30 V DC supply and rail arrangement
• Confirm the cabinet ambient range against -20 to 60 °C

Setting up and maintaining the KFD2-USC-1.D

After mounting and wiring, set the input range, output range, scaling and trip point with the keypad. Check the line fault behaviour against the plant philosophy and verify the relay state during start-up and when power is lost. Record the settings on the loop sheet because a replacement module will need the same configuration.

For maintenance, use a calibrator at the input and verify the output and the relay threshold. With a deviation limit of 0.1 % of full scale, periodic verification only needs to be as frequent as the plant instrument policy requires.

Typical applications in Oman and the GCC

Typical places for a converter of this type include utilities and packaged equipment where drives, rectifiers or analyser panels deliver 0-10 V or 4-20 mA signals to a plant control system, and boiler and water treatment systems where a local alarm contact is needed at a measured value. In Gulf cabinets the 60 °C upper ambient limit of this module is lower than some other K-System modules, so confirm the actual cabinet temperature.

KFD2-USC-1.D and related display-type K-System modules

Based on the manufacturer datasheets.

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

Provide these details for a quick quotation.

• Input and output signal types and ranges
• Trip value and relay requirement
• Whether a display and keypad variant (.D) is required
• Quantity and delivery date

Documents and quotation

The manufacturer datasheet for the KFD2-USC-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.