The Pepperl+Fuchs KFD2-STC5-Ex1.H, also cataloged as the KFD2-STC5-Ex1.H SMART Transmitter Power Supply, operates as a dedicated hardware component for supplying 2-wire and 3-wire SMART transmitters and transferring 0/4-20 mA signals within hazardous field locations.

Hardware Specifications

Intrinsic Safety Barriers and Protection Limits

The module integrates certified intrinsic safety (Ex i) barriers rated up to Ex ia IIC for direct interface with field instrumentation located in Zone 0, 1, or 2 hazardous areas. High galvanic isolation isolates the hazardous field circuit from non-hazardous control system I/O and auxiliary power networks. Internal safety barriers enforce strict voltage, current, and power limits under worst-case fault conditions, preventing thermal or spark ignition in flammable dust or gas atmospheres.

Field Installation Guidelines

DIN-Rail Mounting and Thermal Clearance

• Snap the module vertically onto a 35 mm DIN mounting rail (EN 60079-15) or position directly onto an integrated Power Rail system busbar.
• Maintain a minimum vertical clearance of 50 mm above and below the housing to facilitate natural thermal dissipation.

Wiring Isolation and Shield Grounding

• Maintain a minimum separation distance of 50 mm between intrinsically safe blue terminals and non-intrinsically safe power or signal lines.
• Route field cables using twisted-pair shielded cabling and terminate the shield to a single ground point on the main enclosure ground bar.

Ordering Information

• Primary Product Code: KFD2-STC5-Ex1.H
• Box Contents: 1x KFD2-STC5-Ex1.H SMART transmitter power supply module, 1x set of removable screw terminals, 1x quick start manual.
• Compatible Rail Accessories: Power Rail UPR-03, Power Feed Module KFD2-EB2.

Frequently Asked Questions

Q: Does the KFD2-STC5-Ex1.H support bi-directional HART communication signals? A: Yes, the module supports HART communication protocols by passing bi-directional high-frequency digital signals over the 4-20 mA analog loop.

Q: Can this module power both 2-wire and 3-wire transmitters? A: Yes, terminal connections allow wiring configurations for both 2-wire powered transmitters and 3-wire current source instruments.

Q: How is the module powered during standard cabinet operation? A: Auxiliary 24 VDC power can be applied directly to terminals 14+ and 15- or supplied through the DIN-rail mounted Power Rail system.

Q: What is the maximum peak isolation voltage for the internal barrier? A: Safe galvanic isolation provides voltage peak isolation up to 375 V between hazardous field inputs, control side outputs, and supply terminals in compliance with EN 60079-11.