Power Supplies & Barriers

Power Supplies & Barriers

Power supplies and barriers are DIN-rail interface components that provide reliable loop power, electrical separation, and hazardous-area interfacing for measurement circuits. In many architectures they also serve as the boundary between field wiring and control systems, shaping how signals are powered, protected, and monitored.

An active barrier can supply a connected transmitter (including in hazardous areas when approved) while passing the 4–20 mA signal through galvanic isolation. Optional HART transparency and monitoring features can preserve digital communications and provide additional status visibility, helping to identify transient issues that might otherwise be missed.

Passive barriers are typically used when the supply originates from a host system and the barrier’s role is to limit energy into the hazardous area and provide safe separation. Because they draw operating power from the loop, they can be deployed without adding a dedicated auxiliary supply, simplifying cabinet design in certain cases.

Benefits include improved signal integrity via isolation, safer integration of Ex-area devices, and reduced commissioning risk by standardizing loop powering and diagnostic access. Where HART functions are supported, integrated resistors and communication sockets can streamline field configuration without rewiring or temporary adapters.

Typical applications include powering head transmitters in temperature assemblies, isolating analog loops, interfacing NAMUR signals, and enabling safe connectivity between Ex and non-Ex domains. Selection considerations typically include loop type (2‑wire/4‑wire), isolation needs, Ex approvals, HART requirements, and whether relay-based alarming or early-warning monitoring is desired.

Vector, your Authorized Endress+Hauser Representative.