• Protects intrinsically safe spurs on MTL 937x-FB range fieldbus
  • 20kA maximum surge current per line
  • ±32Vdc working voltage
  • 62V @ 3kA 8/20μs limiting voltage
  • BS EN 61326-1:2013 EMC compliance
  • BS EN 61643-21:2001 electrical safety
  • Plug connectors for quick and easy connection or rewiring
  • IEC61158-2:2004


The MTL FS32 surge protector prevents surges and transient over-voltages conducted along the trunk or spurs of fieldbus systems from damaging the associated electronics such as terminators, spur blocks and the bus control equipment. Designed to fit Eaton's latest MTL fieldbus barrier product to protect spurs, the FS32 can also be used to protect spurs on Megablock wiring hubs. This space-saving design helps reduce the size of junction boxes and ease installation.

The multi-stage hybrid surge protection network at the heart of the FS32 uses a combination of solid state electronics and a gas-filled discharge tube (GDT) to provide surge protection up to 20kA. This surge protection circuit is designed to exhibit exceptionally low line resistance and has negligible voltage drop to the spurs.

The FS32 does not adversely affect the performance or operation of the fieldbus or connected equipment. It allows signals to pass with little attenuation while diverting surge currents safely to earth (ground) and clamping output voltages to safe levels.

The FS32 devices are fully automatic and react immediately so that the equipment is never exposed to damaging surges between lines or the lines to earth (ground). The FS32 reacts instantaneously, redirecting surges safely to earth (ground), and then resets automatically.

The MTL FS32 represents the next generation of surge protection to be fitted on Foundation fieldbus systems. The space-saving form factor allows the FS32 to be connected directly to the terminal receptacle on the module carrier of the 9370 fieldbus barrier. The earth (ground) is connected through the mounting screw in one simple operation. The field spur cable termination block plugs directly into the FS32, allowing fast and effective retrofitting with no additional hardware required.