In common with conventional Fieldbus Barriers, each

intrinsically safe spur is capable of supporting 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.

The 9372-FB redundant fieldbus barrier is based on our

revolutionary 9370-FB range of products, which are supplied

as complete, factory-assembled enclosure systems that do not

require additional wiring, customised housings or complex

ancillary components. Electrical and mechanical aspects of the

design are integrated, providing the industry’s first complete,

ergonomic solution for ‘High Energy Trunk’ applications in

hazardous areas.

Uniquely, the key modular components of the system (Fieldbus

Barrier, Terminator 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.

Optional features include pluggable surge protection

components for the fieldbus trunk and individual spurs.

The 9372-FB may therefore be selected for critical process

applications where failure of the Fieldbus Barrier would

otherwise result in unacceptable downtime or lost production.

It is also ideal for use in Fieldbus Safety Instrumented Function

(SIF) networks in which nuisance trips cannot be tolerated.

Failure annunciation to the host control system is provided by

means of an integrated Foundation™ fieldbus device with Digital

Input Function Block capability.

In common with conventional Fieldbus Barriers, each

intrinsically safe spur is capable of supporting 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.

The 9372-FB redundant fieldbus barrier is based on our

revolutionary 9370-FB range of products, which are supplied

as complete, factory-assembled enclosure systems that do not

require additional wiring, customised housings or complex

ancillary components. Electrical and mechanical aspects of the

design are integrated, providing the industry’s first complete,

ergonomic solution for ‘High Energy Trunk’ applications in

hazardous areas.

• For For Foundation™ fieldbus networks in hazardous areas

• Redundant configuration for super-high system availability

• Complete enclosure systems for up to 6 intrinsically safe spur connections

• Failure alarm direct to host control system via integrated fieldbus device

• Mount in Zone 1 (gas) or 21 (dust) with spurs connected into Zone 0

• Compatible with FISCO and Entity certified fieldbus instruments

• Ergonomic mechanical design

• Pluggable system components, without ‘gas free’ constraints

• Optional, integrated surge protection for trunk and spurs

The 9372-FB Redundant Fieldbus Barriers are field-mounted wiring

hubs that create up to six intrinsically safe spur connections

from a high-energy trunk, for connection to suitably certified

Foundation™ fieldbus H1 instruments. They 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 enclosure system uses duplicated Fieldbus Barrier

modules in a redundant configuration to achieve significantly

higher system availability than equivalent ‘simplex’ units.

MECHANICAL

Enclosures

An enclosure is required to house and protect the Megablock device coupler and the

F30 Ex ic adaptor for field operation. The type of enclosure must be chosen to suit

both the hazardous atmosphere likely to be encountered and the general conditions

appropriate to its environmental exposure. For installation in hazardous areas, the

enclosure must meet the requirements of a recognised method of protection

according to IEC 60079-0. clause 1.  In addition, the following conditions should

always be considered to ensure safe and reliable operation.

a) Prevent any form of pollution that could compromise the operation.

b) Provide an adequate level of mechanical protection. This can be achieved

by selecting a protected location, a suitable enclosure, or a combination of

both.

c) Ensure that all cable entries and connections are secure by making

provision for the careful routing and securing of all cables.

d)Provide adequate security against unauthorized interference.

e) Conform to the permitted ambient operating temperature range of  –40°C to +70°C.

The F30 adaptor

The F30 adaptor is connected in series with the trunk wiring to the Megablock (see

Figure 2.1) and limits the voltage to ensure that the ‘Uo’ at the Megablock spurs is

less than the 17.5V value required for compatibility with FISCO-certified instruments.

Where the voltage arriving at the F30 is higher than this (for example, if the trunk

cable is only short in length resulting in only a small voltage drop in the cable), the

F30 regulates the voltage to less than 17.5V.  Final current limiting for each spur is

provided by the short-circuit limiting circuits built in to the F300 Megablock, for which

Ex ic approval already exists. As a result, the combination of F30 and F300 meets the

requirements for Ex ic voltage and current limitation.

The F30 is designed for use only with MTL F304. F308 and F312 Megablock types,

typically providing up to twelve Ex ic spurs per fieldbus segment.  These spurs

may be all from one F312 Megablock in one enclosure, or distributed between two

separate enclosures – see Section 4.7.

The spurs are compatible with FISCO and Entity certified fieldbus instruments, and

where FISCO instruments are selected, cable parameter calculations are not required.

Power supplies

For Ex ic spur applications, the F30 and associated Megablock must be supplied by

9192-FP power supply modules in simplex or redundant configuration. The 9192

FP module has the necessary voltage limiting and is designed to fit on one of the

backplanes from the 918x-x2 range of fieldbus power supply systems, all of which

are capable of providing n+1 redundancy for maximum availability.

The 918x family of redundant power supplies contains a range of solutions to suit

different host interfaces, consult Eaton for the model appropriate to the host and

install the chosen model in accordance with the instructions provided with it.

DESCRIPTION

The Ex ic concept

In May 2013 the Ex nL certification method was removed from the IEC60079-15

standard, and replaced by intrinsic safety method Ex ic in IEC60079-11.  Although Ex

ic and Ex nL are broadly similar, Ex ic brings with it additional requirements that are

associated with the wider intrinsic safety approach.

Ex ic is a new level of protection under the intrinsic safety protection method,

suitable for use in Zone 2 only, where Ex ic circuits may be ‘live-worked’ in the

presence of a flammable atmosphere.  It follows the same energy-limitation principles

as all intrinsically safe circuits, but safety is maintained only in ‘normal operation’.

Host H1 control system

In a typical network installation using the F30 Ex ic Adaptor, F300 Megablock and

9192-FP power supply module, the H1 interface of the host control system is

electrically connected in parallel with the fieldbus trunk circuit. The H1 interface

and host control system are not required to carry hazardous area certification in

this application, but they must comply with electrical safety standards IEC61010 or

IEC60950.  Apparatus carrying a CE mark will comply with this requirement. This

requirement also applies to any other apparatus that is connected electrically in

parallel with the fieldbus trunk circuit.

OVERVIEW

This manual explains the installation and maintenance procedures for the F30 Ex ic

Adaptor and should be read in conjunction with the product datasheet that contains

the electrical data.

The F30 Ex ic Adaptor is an accessory that works with MTL F300 range of DIN-rail

mounted, passive device couplers and extends their usage by enabling them to

provide Ex ic spur connections in Zone 2 hazardous areas. The F300 device couplers

provide a simple means of connecting a group of local field devices to the network

trunk cable that carries the signal and provides the necessary power supply.

This manual also introduces the concept of the Ex ic intrinsic safety method of

protection and explains how it applies to the F300 device couplers and the F30 Ex ic

adaptor.  Other topics will include the trunk power supply and suggested enclosures

for housing the adaptor and hubs in the hazardous area.

NOTE

The user/installer should also refer to the following datasheets and installation manuals:

• F300 range of Megablocks data sheet, EPS F300

• F300 range of Megablocks installation manual, INM F300

• 918x  Redundant Power Supply data sheets, EPS 918x

• Redundant Power Supply installation manuals, INM 918x in order to obtain

details of their installation, operating parameters and usage.

Overview

Certifications and compliances

• For a complete listing of certification and approvals across our MTL Megablock range,

download the product datasheets in the resources section of this family page.

Design features

• A green power LED on each unit indicates whether at least 9V dc is present.

• Available in two, four, eight, ten and twelve drop versions

• Multiple Megablocks are easily wired to one another to allow larger segments to be

constructed

• Choice of rising cage-clamp screw terminal or spring clamp type connections simplifies

commissioning and maintenance

• Available with built-in SpurGuard™ protectors that prevent a short circuit in any of the

individual transmitters or spur

cable runs from bringing the entire fieldbus segment down

• A red LED near each spur connection indicates that a spur is shorted and is in

“over-current” mode

Standard materials

• Housing:  Polycarbonate

Crouse-Hinds series MTL Megablock™ is a DIN-rail mounted passive hub

designed for use in FOUNDATION™ fieldbus H1 and Profibus PA networks.

Megablocks minimize hand wiring and allow individual devices to be added

to and removed from the segment without disrupting network communication.

The SpurGuard™ option provides short circuit protection for the segment.

Hazardous area approvals permit installation in a variety of configurations in

Zone 1 or 2 and Division 1 or 2. Within Zone 2 or Division 2. Megablocks may

be installed as part of non-sparking (non-arcing) or energy-limited

(non-incendive) circuits.

• F2xx-IS models: Intrinsically Safe Megablocks for Zone 1 applications

• F2xx-XE models: Megablocks for Zone/Div 1 applications

• F300 models: Megablocks for Safe Area and Zone/Div 2 applications