Surge protectors approved for Foundation Fieldbus

Edited by the Engineeringtalk editorial team Mar 25, 2005

Emerson Process Management has agreed that MTL's Fieldbus protectors can be applied to Foundation Fieldbus systems without the performance limiting effects normally associated with surge protectors.

After extensive testing, Emerson Process Management has agreed that MTL's dedicated Fieldbus protectors are unique in that they can be applied to Foundation Fieldbus systems without the performance limiting effects normally associated with surge protectors.

MTL Surge Technologies' Fieldbus protector range consists of the TP32 and the FP32.

Emerson has approved both devices for use on their Fieldbus solutions.

The FP32 prevents surges occurring on the trunk or spurs entering the control area or damaging terminators, and the TP32 provides protection for field instruments.

The multistage hybrid surge protection network at the heart of the FP32 uses a combination of solid-state electronics and a gas filled discharge tube (GDT), to provide surge protection up to 20kA.

This impressive surge protection circuit is design to exhibit exceptionally low line resistance and adds only a tiny voltage drop to the bus.

As a result, no matter how many FP32 devices are connected to a Trunk or spur the system will still be able to support its full 32 transmitters as specified by IEC61158-2.

In operation the FP32 device does not adversely affect the performance or operation of the Fieldbus or connected equipment, it allows signals to pass with very little attenuation while diverting surge currents safely to earth and clamping output voltages to safe levels.

The FP32 meets IEC61158-2:2000 for 31.25Kbyte/s systems such as Foundtion Fieldbus, Profibus-PA and WorldFIP, whereas the TP32 meets the additional requirements of ANSI/ISA-50.02-2 1992 for 31.25Kbyte/s systems.

The TP32 protection network is a hybrid design consisting of high-power, solid state electronics and a gas discharge tube, which are capable of diverting surges up to 10kA.

Encased in a stainless steel enclosure, the TP32 exhibits unparalleled mechanical durability providing years of maintenance free operation in harsh environments.

The enclosure is available threaded for all the common conduit entries.

To provide complete protection it is strongly recommended that the AC power input to the power supply and host be protected.

MTL has many options here, but the most popular product is the MA15 (UL1449 recognised and approved for Class I, Division2 Groups A, B, C and D).

The MA15 provides state of the art surge protection and RFI filtering to completely protect Fieldbus equipment.

All MTL Surge Technologies products come with a 10-year warranty.