Pepperl + Fuchs STC4 – Intrinsically Safe Transmitter Power Supply Phase-Out

Pepperl + Fuchs are phasing out their older range of transmitter power supply and intrinsically safe isolation barriers the STC4 range in favour of an upgraded, more capable model, the STC5 range.

The Next Generation

STC5 – the next generation of Transmitter Power Supplies from Pepperl + Fuchs has been designed as an upgraded replacement for their older sibling, the well-known STC4 range. These innovative transmitter power supply isolation barriers and signal conditioners are suitable for the protection of intrinsically safe circuits in hazardous areas, providing galvanic isolation between field circuits and control circuits. The STC5 range is feature-packed, providing all the necessary current and voltage limitations and additional electrical isolation (all contained in a diminutive 20 mm housing) that is demanded between a field circuit and control mechanism within an intrinsically safe installation.

Isolation Barrier K-Series

Improved Flexibility

The recently designed STC5 range of transmitter power supply isolation barriers and signal conditioners offers more flexibility than their predecessors, using a double output function to the control side, whereas with the STC4 range the end-user had to decide between 2 different modules. Featuring newly designed circuitry with reduced power dissipation in the device when in sink output mode lowers cabinet temperatures, which can lead to an increased lifetime of the installed modules.

STC5 Range is Feature-Packed – Ideal for high-channel density installations

  • Highest packing density on the market
  • Compact 20 mm housing width offers higher performance compared to small 12.5 mm devices
  • Higher power dissipation capability than the STC4
  • More terminals than the STC4 with connectivity for 3-wire transmitters
  • Supplies 2-wire and 3-wire SMART transmitters and can be used with 2-wire SMART current sources
  • Digital signals may be superimposed on the input signal in the hazardous or non-hazardous area and transferred bidirectionally
  • Sink mode or a source mode output on the safe area terminals
  • Internal resistor for use if the HART communication resistance in the control circuit is too low
  • Test sockets for the connection of HART communicators integrated into the device terminals

A selection of Isolation Barriers

Make the Change

Kempston Controls, a supplier partner for Pepperl + Fuchs, is ready to help you transition from the STC4 range of transmitter power supply isolation barriers to the latest iteration, the STC5, we can help you source a suitable alternative to your existing STC4 application. Whether you are retrofitting or building an entirely new intrinsically safe installation the STC5 is ideal for all of your intrinsically safe requirements.

Many of the STC4 range of transmitter power supplies will be stocked until their supply becomes exhausted, call or email us for further details and please ensure you make provision for their eventual removal from sale when making your order.

Kempston Controls has access to the complete Pepperl + Fuchs product portfolio, so whatever your installation requirements we have you covered. Give Kempston Controls a call on +44 (0) 1933 411411 or email us at to discuss how the Pepperl + Fuchs product changeover may affect you and for all your other intrinsically safe product requirements.

View the STC5 Range


Have you read these articles?

IET Wiring Regulations – are you up to date?

Know your ATEX Zones…

Kempston Controls

Kempston Controls is committed to finding you the ideal solution for your application. Call us today on +44 (0) 1933 411 411, email us at, or alternatively contact us here, we will be happy to help.

Kempston Controls

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes:

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>