Power Supplies & Barriers

Power Supplies & Barriers

Power supplies and barriers are DIN-rail interface components that provide stable power to transmitters and sensors and, when required, transmit galvanically isolated measurement signals - often as part of a structured marshalling and interface layer. They support reliable loop operation, help manage grounding and noise, and enable compliant signal transfer between hazardous and non-hazardous areas.

A typical architecture powers 2-wire or 4-wire transmitters, then isolates and transfers the 4–20 mA signal to downstream control or monitoring systems. Active barriers combine power supply and safe separation of current circuits in one device, reducing wiring complexity while maintaining isolation integrity. Bidirectional HART transmission options preserve digital communication on top of analog signaling for configuration and diagnostics.

Operational benefit increases when device status is accessible at the interface layer. With optional HART monitoring, transmitter status can be monitored and even briefly occurring errors can be located more easily—valuable for intermittent faults that might not persist long enough for conventional troubleshooting. Communication sockets and integrated HART resistors simplify field device access for configuration activities.

Power distribution is commonly supported by compact, high-efficiency switch-mode supplies that deliver reliable 24 VDC for interface systems and accommodate wide-range AC/DC inputs, improving resilience across varying site power conditions. This stabilizes the instrument power domain and supports consistent performance of downstream interface modules and barriers.

Typical applications include intrinsic safety loop interfacing, HART-enabled marshalling cabinets, signal isolation to prevent ground-loop induced errors, and standardized power distribution for dense I/O assemblies. They are also central to brownfield upgrades where existing loops must be preserved while improving maintainability, signal quality, and diagnostic access.

George E. Booth Co., an exclusive authorized representative of sales and service for Endress+Hauser.