MTL Simplex Fieldbus Barriers

The MTL simplex fieldbus barriers are field-mounted wiring hubs that create up to twelve intrinsically safe spur connections from a high-energy trunk, for connection to suitably certified Foundation fieldbus H1 instruments. Capable of supporting heavily loaded fieldbus segments and long trunk cable lengths, the Fieldbus barriers may be installed in Zone 1 (gas) or Zone 21 (dust) hazardous areas, with the trunk wiring implemented using suitably protected cable and increased safety (Ex e) connection facilities.

Each intrinsically safe spur can support a FISCO or ‘Entity' certified fieldbus device located in a Zone 0 or 1 hazardous area. The short-circuit protected spurs are galvanically isolated from the trunk and require no protective ground connection in the field.

Unlike conventional Fieldbus barrier products that are based on stand-alone modules, the 937x-FB2 range is supplied as complete, factory-assembled systems in glass reinforced polyester (GRP) or stainless steel (SS) enclosures that do not require additional wiring, customized housing or complex ancillary components. Electrical and mechanical aspects of the design are integrated for an ergonomic solution for high energy trunk applications in hazardous areas.

The key modular components of the system of Fieldbus Barriers and surge protectors may be hot-plugged by design and without gas clearance procedures or separate isolating switches. This virtually eliminates the risk associated with hazardous area maintenance activities, speeds module replacement and avoids the need for specialist operator training.

Enclosure systems for 6 or 12 spurs are supported. For added flexibility, the 12-spur enclosure can be specified partially populated with one 6-spur barrier module installed. This permits future expansion from six to twelve spurs simply by plugging in an additional module.

The 937x-FB2 range of Fieldbus barriers are bus-powered and requires no additional power supply in the field. When used with a fieldbus host control system, power for the trunk may be provided by MTL F800 or 9180 range of fieldbus power supplies in redundant or non-redundant format.