The MTL compact fieldbus barrier module provides a compact and economic solution for Foundation fieldbus networks in hazardous area applications.
The field-mounted barrier receives power and Foundation fieldbus H1 communications via a non-intrinsically safe trunk and converts this to a number of
galvanically isolated, intrinsically safe, spur connections.
The trunk terminals are implemented as increased safety (Ex e) and the spur terminals as intrinsically safe (Ex ia) for connection to IS fieldbus instruments in IIC,
Zone 0 hazardous areas. The spur connections are compatible with both FISCO and Entity-certified field instruments.
For Zone 1 hazardous area mounting, the fieldbus barrier must be mounted in a suitable, increased safety (Ex e) enclosure that will segregate spur and trunk cabling
in accordance with hazardous area requirements. The barrier module has a separate compartment, which contains increased safety (Ex e) trunk wiring terminals where the
incoming trunk wiring terminates. This compartment has a protective cover to deter interference, and carries a warning to the user not to work on trunk wiring without
first isolating the power. A fieldbus terminator is included and can be disabled where the fieldbus trunk is extended to a second fieldbus barrier module.
A single barrier module provides 12 spur connections. Each spur is short circuit protected, so that other devices continue to operate in the presence of field wiring faults.
The fieldbus barrier module is bus-powered and requires no additional power supply in the field. When used with a fieldbus host control system, power for the trunk must be
provided only by a supply conforming to IEC 61158-2.
The module has four mounting lugs with holes, enabling it to be mounted to a suitable mounting plate inside an enclosure using either bolts or fixed studs.
Alternatively, it has built-in mounting clips to permit it to be mounted onto a top-hat DIN rail, 35mm x 7.5mm, complying with EN60715 or similar local standards.
