Eaton Crouse-hinds series User manual

9387-FB-Px-R
5-spur, Open Frame,
Redundant Fieldbus Barrier
November 2016
INM 9380-RD Rev 2
Instruction manual
MTL fieldbus networks

ii
INM9380-RD Rev 2
DECLARATION OF CONFORMITY
A printed version of the Declaration of Conformity has been provided separately within the original shipment of
goods. However, you can find a copy of the latest version at http://www.mtl-inst.com/certificates

iii
INM9380-RD Rev 2
CONTENTS
DECLARATION OF CONFORMITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . II
GENERAL SAFETY INFORMATION . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV
1 OVERVIEW ........................................................................1
2 DESCRIPTION ......................................................................2
2.1 General ................................................................................2
2.2 Configuration options ....................................................................2
2.3 Trunk Terminal Assembly ..................................................................3
3 MECHANICAL INSTALLATION.........................................................3
3.1 Mounting overview ......................................................................3
3.2 Preparation .............................................................................4
3.3 Mounting the assembly in a suitable enclosure ...............................................4
4 INITIAL ELECTRICAL INSTALLATION ...................................................5
4.1 Overview ...............................................................................5
4.2 Grounding ..............................................................................5
4.3 Trunk connections .......................................................................8
4.4 Trunk Terminator module 9378-FT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
4.5 Trunk Surge module 9376-SP .............................................................10
4.6 Spur connections .......................................................................10
4.7 Final checks............................................................................11
5 MAINTENANCE ...................................................................12
5.1 General ...............................................................................12
5.2 Fieldbus Barrier maintenance procedures ...................................................12
5.3 Spur connections .......................................................................15
5.4 Trunk connections ......................................................................16
5.5 Regular Maintenance checks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
6 TROUBLESHOOTING ...............................................................17
7 ALARM MODULE - OPERATION & CONFIGURATION .....................................18
7.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
7.2 Device details ..........................................................................18
7.3 Alarm module fitting or replacement.......................................................19
8 ATEX INFORMATION ...............................................................21
8.1 General ...............................................................................21
8.2 Installation ............................................................................21
8.3 Inspection and maintenance .............................................................22
8.4 Repair ................................................................................22
8.5 Marking ...............................................................................22
9 APPENDIX 1 - ENCLOSURE WIRING DIAGRAM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

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INM9380-RD Rev 2
GENERAL SAFETY INFORMATION
Safety instructions for installation and operating personnel
The operating instructions provided here contain essential safety instructions for installation personnel and those
engaged in the operation, maintenance and servicing of the equipment.
WARNING!
Failure to comply with these instructions can endanger the lives or health of
personnel and risk damage to the plant and the environment.
WARNING!
The responsibility for planning, installation, commissioning, operation and
maintenance, particularly with respect to applications in explosion-hazard areas,
lies with the plant operator.
Before commencing installation or commissioning:
• Read and understand the contents of this manual
• Ensure installation and operating personnel have received adequate training for this task
• Ensure that any operating instructions are fully understood by the personnel responsible.
• Observe national and local installation and mounting regulations (e.g. IEC 60079-14).
WARNING!
These assemblies may not be used in explosion-hazard area applications if they
have been used previously in general electrical installations.
During operation:
• Make the relevant instructions available at all times to the operating personnel.
• Observe safety instructions.
• Observe national safety and accident prevention regulations.
• Operate the equipment within its published specification.
• Servicing, maintenance work or repairs not described in this manual must not be performed without prior
agreement with the manufacturer.
• Any damage to this equipment may render its explosion protection null and void.
• No changes to any of the components that might impair their explosion protection are permitted.
If any information provided here is not clear:
• Contact Eaton’s MTL product line or one of its representatives.
Note: Improper installation and operation of the enclosure can result in the invalidation of the guarantee.

1
INM9380-RD Rev 2
1 OVERVIEW
This manual explains the installation and maintenance procedures for the
9387-FB-Px-R Open-Frame Redundant Fieldbus Barrier and must be read in association
with the product datasheet that contains the electrical data.
The 9387-FB-Px-R assembly is a wiring hub that creates five* intrinsically safe spur
connections from a high-energy trunk, for connection to suitably certified Foundation™
fieldbus H1 instruments. The assembly is bus-powered and requires no additional
power supply in the field.
When installed and certified inside a suitable Ex enclosure (see Section 3.1 on page 3),
an assembly may be installed in a Zone 1 or a Zone 2 hazardous area.
Each assembly uses a pair of Fieldbus Barrier modules in a “redundant spur“
configuration in order to achieve significantly higher system availability than
equivalent ‘simplex’ units. The 9387-FB-Px-R 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.
The baseplate on which the carrier and trunk terminal assembly is mounted is 316
stainless steel for protection against corrosion.
The following types are available by ordering the appropriate model number.
9387-FB-Px-R Redundant Fieldbus Barrier assembly, 5-spur
Where Px = PS (pluggable screw terminal connectors) or
PC (pluggable spring clamp connectors)
* See section 2.2
9387-FB-Px-R 5-Spur Open-Frame
Redundant Fieldbus Barrier
Figure 1.1 - Example of model 9387-FB-Px-R

2
INM9380-RD Rev 2
2 DESCRIPTION
2.1 General
The assembly consists of a stainless steel baseplate, together with a trunk-wiring
terminal assembly (TTA), two carrier-mounted fieldbus barriers and a fieldbus alarm
module. Each barrier module can convert a single, non-intrinsically safe fieldbus trunk
into six, galvanically isolated, intrinsically safe (IS) spur connections for connection to
Foundation™ fieldbus H1 fieldbus instruments. However, only six spurs are available at
any one time because they are configured as “redundant pairs”. On power-up the spurs
in one barrier are configured to be in “active” mode, while the spurs in the other barrier
remain in “standby”. In the event of a spur circuit failure in the “active” barrier module,
an automatic switchover ensures that the external spur field circuit continues to be
supported by the corresponding spur in the “standby” module.
Figure 2.1 illustrates an example where Module A- on the left- is the active barrier and
Module B the standby. Spurs 1,2, 4, 5 and 6 of Module A are shown as active (‘A’) but
spur 3 has failed (and effectively gone into standby) so module B has automatically
taken control of spur 3 (‘A’) to maintain full service to the affected field circuit.
++++++

Spur Electronics Spur Electronics
= Active
S= Standby
0V 0V







     

SS SSS
AlarmAlarm
S



Figure 2.1 - Redundant spurs block diagram + optional alarm module
The spurs are galvanically isolated from the trunk allowing the user to choose the type
of grounding scheme most suitable to their system.
Spur short-circuit protection is provided by the barrier and surge protection can also
be added on individual outgoing spurs by the use of individual Spur Surge protection
modules (part no. FS32).
The baseplates are supplied pre–drilled for mounting on any surface capable of
supporting the assemblies.
2.2 Configuration options
There are six spur outputs from each barrier and, as described above, these can
operate in a redundant fashion, supporting each other to maintain continuous
availability. However, if a spur “fails-over” to the other barrier, the situation might
go undetected without frequent inspection of the status of the barrier LEDs.
For this reason, a “failure-reporting” configuration is provided, where Spur 6 is
assigned to an internally located Alarm Module (model 9379-ALM) - see Figure 2.1.

3
INM9380-RD Rev 2
Consequently, if a spur ‘fail-over’ occurs, an alarm is signalled quickly to the host, via
the fieldbus connection, to facilitate any necessary remedial action. The five remaining
spurs are available to the user for connection to field devices.
2.3 Trunk Terminal Assembly
The incoming trunk wiring is terminated inside a separate compartment, called the
Trunk Terminal Assembly (TTA), that contains increased safety (Ex e) trunk wiring
terminals. This compartment has a protective cover to deter interference, and carries
a warning to the user about working on trunk wiring without first isolating the power.
A fieldbus Terminator module (part no. 9378-FT) is supplied pre-fitted on the TTA. This is
to remain installed if the assembly is at the end of the segment. If the incoming fieldbus
trunk will be onward linked to a further node on the segment the terminator can be
removed. See Section 4.4 on page 10 for additional information.
An optionalTrunk Surge module (part no. 9376-SP) can be plugged into theTTA to protect the
fieldbus barrier against damaging voltage and current surges on the incoming trunk wiring.
The 9387-FB-Px-R Fieldbus Barriers are bus-powered and require 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, e.g. MTL-Relcom F800
or 918x range of redundant power supplies.
3 MECHANICAL INSTALLATION
See Figure 3.1 for the dimensions, fixing locations and cable gland positions.
!
ABB AxxxxxxxPxxxxx Gxxxxx
Mxxxxx xxxxxxxxxxxxxx
TTH300
TRUNK
IN
TRUNK
OUT
ABB
AB
230.0
385.0
355.0
240.0 260.0
266.0
410.0
99.3
Mounting slot size 14 x 6
Figure 3.1 - Dimensions and mounting hole positions for the assembly (9387-FB-Px-R)
3.1 Mounting overview
Before mounting an assembly, consider the following points.
a) When planning the layout of any protective enclosure for an assembly, ensure that
adequate space is provided for suitable cable management (e.g. trunking).
b) The permitted ambient temperature range for the assembly (–40°C to +75°C) must
not be exceeded. Avoid radiant heat by positioning an assembly and its enclosure
away from direct sunlight or local sources of heat.

4
INM9380-RD Rev 2
c) An assembly has limited ingress protection and must be provided with protection
appropriate to the environment in which it is located.The following table provides
guidance on minimum environmental protection for specific locations.
Location Minimum environmental protection
Safe area IP20
Zone 1 or
Zone 2
Ex e or Ex d certified enclosure; ≥IP54 - increase level for more
severe conditions
Note: For installation in Zone 1 or 2, the combination of a 9387-FB-Px-R open frame
assembly and its protective Ex e or Ex d enclosure will require certification as a
complete assembly by a third-party certifying authority.
d) An assembly will provide the best thermal performance when mounted on a
vertical surface. Other orientations are possible but may require some de-rating of
the permitted operating temperature range.
e) Adequate security should be provided against unauthorised interference with the
equipment.
f) If the chosen protective enclosure is liable to encounter significant levels of
condensation, it is advisable to incorporate a drain/breather to minimise moisture
accumulation.
3.2 Preparation
NOTE: The weight of an assembly must be considered when chosing a suitable
mounting location. Use the following figures for guidance.
Assembly/Component Guide weight (kg)
Baseplate, carriers and TTA (no modules) 2.8
Fieldbus barrier module 9377-FB-R 0.95
Alarm module 9379-ALM (including connectors) 0.07
Trunk terminator module (max. 1 per assembly) 0.12
Trunk surge suppressor module (max. 1 per assembly) 0.16
Spur surge suppressor module (max. 1 per spur) 0.04
a) Remove any temporary protection or packing materials.
b) The assembly can be mounted on any suitable structure via the mounting holes in
the corners- see Figure 3.1 for details.
c) All fixings must be suitable for the mounting surface and the environmental
conditions that are likely to be encountered.
3.3 Mounting the assembly in a suitable enclosure
WARNING!
To minimise the risk of ignition by electrical apparatus in hazardous
areas, efficient installation, inspection and maintenance of apparatus
and systems is essential, and the work should be carried out by suitably
trained personnel in accordance with the prevailing code of practice.
The certification documents specify “Conditions for safe use” that
must be adhered to and the copy certificate supplied should be
studied and understood. Additionally it is recommend that a working
knowledge of IEC EN 60079 -14 be attained, as this standard provides
guidance in respect to the installation of electrical equipment in
hazardous areas.
3.3.1 Fixing the assembly
Either define hole or stud positions based upon the dimensions given in Figures 3.1,
or use the baseplate as a template. Prepare the fixings being used, then attach the
assembly.

5
INM9380-RD Rev 2
After mounting the assembly check that:
• none of the component parts have suffered any damage,
• the baseplate of the assembly is not distorted
• the mounting bolts/nuts are all tightened as recommended above.
4 INITIAL ELECTRICAL INSTALLATION
WARNING!
Before starting any electrical installation work, ensure that the
incoming trunk connection is isolated from any source of power.
CAUTION
Assembly temperatures could rise to 75°C. Ensure that all cables and cable glands
fitted are rated to withstand these temperatures.
4.1 Overview
• The assembly receives power from the incoming trunk cable and requires no
further source of power.
• It shall only be powered from supplies conforming to IEC 61158.
• The environment/enclosure in which an assembly is mounted must ensure
adequate separation of the trunk and spur wiring. This may be provided by
means of separate cable trunking or clear physical separation as defined by local
rules. Blue cable trunking is recommended for the IS spur cables to identify that
they are intrinsically safe circuits, while grey or black trunking is recommended for
the non-IS trunk cables. The cable routing should ensure that trunk and spur cables
do not cross each other inside the enclosure.
• Type ‘A’ fieldbus cable is recommended for fieldbus trunk connections.
• The TTA can accommodate trunk cables with outer diameters between
approximately 5 and 13mm - see Section 4.3.1 for further details regarding
protection rating.
• The terminal blocks for the trunk fieldbus cables have either screw terminal
connectors or cage clamp connectors according to the model specified, but both
are suitable for cables from 0.5mm2/AWG 20 up to 2.5mm2/AWG 14.
For details of the wiring for the two system types see Appendix 1.
4.2 Grounding
Two distinct ground concepts should be recognised before wiring of the assembly
begins:
a) Protective local ground- mandatory
b) Cable shield ground
These two concepts and their implementation are explained below.
4.2.1 Protective local ground
This ground connection is required to ensure that any exposed metalwork of the
assembly does not present a hazard to personnel; it also provides a low impedance
earth grounding circuit for any surge protection items used on the assembly. An M10
earth-grounding stud is provided on the assembly baseplate, which must be bonded
to the body of any protective enclosure and from there to the local plant structure.
Where multiple assemblies are installed inside one final enclosure, the grounding
studs for the individual baseplate must be connected in a “star” formation to the
grounding point on the enclosure.
Note: It is important to prevent these connections from loosening and also to protect
them from corrosion against the stainless steel grounding stud.

6
INM9380-RD Rev 2
4.2.2 Cable shield ground
The cable shield is normally electrically isolated from the protective earth ground,
although the two may be deliberately interconnected in some grounding arrangements.
The cable shield wiring of both the trunk and spur cables should be connected to the
local terminals marked with an ‘S’.
WARNING!
The following may involve changes to wiring in the Trunk Terminal
Assembly. No part of the Trunk Terminal Assembly may be worked
while the enclosure is powered, unless the environment is known to
be non-hazardous.
The user has the option of two grounding methods for the assembly; the one adopted
should be the one that conforms to the system’s normal grounding method.
Whichever method is used, it is important to connect the screen/shield to a ground at
only one end of the cable.
The following options are available to the user.
4.2.2.1 Single point of grounding at host; trunk & spur shields interconnected








 


  








Figure 4.1 - Option 1
In many installations, the preferred method of grounding is to ground the fieldbus cable
shields at one point only, normally at the fieldbus power supply. In this case, the trunk
and spur cable shields are connected to each other at the Fieldbus Barrier and are not
connected to ground in the field. For this arrangement, connect the carrier shield ground
wire (marked A) into Terminal 2.
Note: this is the default grounding method for factory-supplied 9387-FB-R enclosures.
IMPORTANT NOTE
9387-FB-XX-R assemblies are factory-supplied with Option 1 grounding. If power
is applied locally, for example during commissioning, when the trunk cable shield
is NOT providing a ground connection, the spur cable shields must be grounded
according to Option 2.
When the trunk cable shield ground has been fully instated (or restored), the
grounding method should be returned to Option 1.
4.2.2.2 Trunk shield grounded at host; spur cable shields grounded at barrier












  






 
Figure 4.2 - Option 2

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INM9380-RD Rev 2
Figure 4.3 - Trunk Connection Options
T
Host
Control
System
Fieldbus
Power
Supply
9387-FB-R
5-spur, open frame assembly
9387-FB-R
5-spur, open frame assembly
9387-FB-R
5-spur, open frame assembly
9377-FB-R Fieldbus Barrier
module
(5/6-spur)
123
Fieldbus instruments
Non-
intrinsically
safe trunk
T
9377-FB-R Fieldbus Barrier
module
(5/6-spur)
Alarm module
6
Alarm module
6
Alarm module
6
Intrinsically
safe spur
45
T
Host
Control
System
Fieldbus
Power
Supply
9377-FB-R Fieldbus Barrier
module
(5/6-spur)
123
Fieldbus instruments
Non-
intrinsically
safe trunk
9377-FB-R Fieldbus Barrier
module
(5/6-spur)
Intrinsically
safe spur 45
9377-FB-R Fieldbus Barrier
module
(5/6-spur)
123
Fieldbus instruments
9377-FB-R Fieldbus Barrier
module
(5/6-spur)
Intrinsically
safe spur
45
T

8
INM9380-RD Rev 2
With this arrangement, the fieldbus trunk shield is separated from the spur cable shields.
It should be adopted if plant or local regulations require that the spur cable shields be
grounded at the Fieldbus Barrier. For this arrangement, connect the carrier shield ground
wire (marked A) into Terminal 3.
Note: After configuring the required grounding option, tighten all screw terminals to a
recommended torque of 0.6 Nm.
4.2.3 Permitted assembly combinations
The maximum number of redundant intrinsically safe spurs that can be supported on
a trunk segment is 12. The permitted assembly combinations are shown in Figure 4.3.
Note that a fieldbus terminator (9378-FT) must be fitted (see Section 4.4) to the last/
furthest assembly on the segment. See also Figure 4.6.
4.3 Trunk connections
Each Trunk Termination Assembly (TTA) is provided with two access holes and
grommets for trunk wiring; one for the incoming trunk and another for onward linking
to an additional assembly, if necessary.
WARNING!
No part of the Trunk Terminal Assembly may be worked while the
enclosure is powered, unless the environment is known to be non-
hazardous.
4.3.1 Trunk Terminal Assembly
The trunk cables are terminated in the Trunk Terminal Assembly (TTA). This is a sub-
enclosure with a protective lid, secured with a single screw. This assembly, together
with its warning label, is intended to deter a user from working on the trunk connections
without isolating trunk power. See Figure 4.6.
Trunk cables enter the TTA through grommets and these must be cleanly cut with a
sharp knife to ensure the IP30 rating is maintained (see Section 4.3.2). The grommet
is supplied with the cone facing into the TTA, but the user is free to reverse this and
allow the cone to extend outwards.
Terminals are provided to allow a variety of wiring arrangements, according to the
particular requirements of the installation:
– “Trunk In” cable only
– “Trunk In” and “Trunk Out” cables
– Active and spare “Trunk In” cables
– Active and spare “Trunk In” cables with overall cable shield
– Active and spare “Trunk In” cables and “Trunk Out” cable
CAUTION
The ‘+’ and ‘–’ wires of a ‘spare’ trunk in cable must be connected only to terminals
marked ‘NC’. This ensures that the spare cable is not electrically connected in parallel
with the ‘active’ trunk in or trunk out cables. The cable shield of the spare cable
should be connected to an ‘S’ terminal.
All ‘spare’ trunk-in connections (‘+’, ‘–’ and shield) must be firmly grounded at the
host.
4.3.2 Trunk cable wiring
Connect the trunk cable(s) in the following way.
a) Loosen the captive screw of the transparent protective cover on the TTA. Slide out
the cover and move it to one side to obtain access.

9
INM9380-RD Rev 2
Figure 4.4 - Trunk Termination Assembly (TTA)
  
Active
Spare
    
  
Overall
shield
Trunk in
(with Active + Spare cable pairs)

  


    
  



Figure 4.6 - Active & Spare ‘Trunk In’ cables plus
‘Trunk Out’ cable
Figure 4.5 - ‘Trunk In’ with Active & Spare cable
pairs
Position of
Trunk Surge
module
(optional)
Position of
Trunk Terminator
module
(if required)
Cover
retaining
screw
Trunk
wiring
terminals
Carrier
Protective
ground
stud
Baseplate
edge
Slide
protective
cover in this
direction
to remove
Trunk cable
entry area
Trunk cable
grommets

10
INM9380-RD Rev 2
b) The trunk cable(s), which will be free of any armouring and presented as a shielded
pair, should be fed through the supplied grommet, which should have been
cut cleanly with a sharp knife to ensure that the IP30 rating for the TTA will be
maintained.
c) Cable ferrules must be fitted to any stranded cable or screen wiring that is being
used
d) Connect the prepared ends of the fieldbus trunk cable(s) into the appropriate ‘+’
, ‘–‘ and ‘S’ terminals, shown in Figure 4.7, and tighten the screw terminals to a
recommended torque of 0.6 Nm.
Note: Figure 4.7 shows the screw-terminal ‘-PS’ assembly option, but the ‘-PC’
cage-clamp terminal arrangement is similar.
Check Section 4.2.2 to confirm that the chosen fieldbus-ground option is correctly
wired, and adjust if necessary.
e) Replace the transparent protective cover over the terminal block and secure it with
the retaining screw to a recommended torque of 0.6 Nm.
4.4 Trunk Terminator module 9378-FT
If the assembly provides the last (or only) spur connections on the segment, the trunk
must be terminated correctly to ensure that the optimum signal quality is maintained.
The Trunk Termination Assembly (TTA) has provision for an 9378-FT Terminator module
to be fitted when required.
NOTE
A terminator should be used only at the end points of the trunk wiring.
Connecting a terminator at any other point on the trunk will degrade the signal.
Refer to Figure 4.3 for additional information.
The 9378-FT is a two-pin module that plugs into the upper end face of the Trunk
Terminator Assembly. See Section 5.3 for fitting and removal details.
4.5 Trunk Surge module 9376-SP
The 9376-SP Trunk Surge module can be fitted to the TTA to prevent damage to the
equipment from voltage and current surges that could occur on the trunk wiring.
The 9376-SP is a four pin module that plugs into the upper end face of the Trunk
Terminator Assembly. See Section 5.4 for fitting and removal details.
4.6 Spur connections
Refer to Figure 4.7 for additional details.
The spur cables can be connected directly onto the fieldbus barrier carrier or through
a Spur Surge module (FS32). If Spur Surge modules are not used, sub-section 4.6.2
can be ignored.
4.6.1 Connecting the spur cables
The spur cables, which will be free of any armouring and presented as a shielded pair,
IMPORTANT
• If spur surge modules are fitted, it is recommended that a small (approx. 15mm)
length of additional cable is allowed for. This will permit cable adjustments if a
Spur Surge module is subsequently removed.
• Cable ferrules must be fitted to any stranded cable or screen wiring that is being
used.
Connect the prepared ends of the fieldbus spur cables into the ‘+’, ‘S’ and ‘–’ terminals on
the carrier (or surge module, if fitted), making sure that the same polarity is observed for all
spurs.

11
INM9380-RD Rev 2
4.6.2 Fitting FS32 spur surge-protection modules
FS32 modules are pluggable surge-protection units that integrate easily with the
standard pluggable connector and which direct excessive spur surge currents to the
protective local ground.
Figure 4.7 - FS32 spur surge-protection module fitted on spur connector
To fit an FS32:
1. Unscrew the two captive screws securing the standard pluggable connector
(supplied on the carrier) and remove it from its socket.
2. Insert the FS32 module into the now vacant socket on the carrier, tighten the two
side securing screws, and the central “protective ground” screw, to a recommended
torque of 0.4 Nm.
3. Fit the connector (removed at Step 1 above) into the socket on the FS32 and
tighten its two securing screws also to a recommended torque of 0.4 Nm.
Removal of a Spur Surge module is the reverse of the fitting process. See also Section
5.3.1 on page 15 for information on cable ‘adjustment’ if one of these modules is
taken out of use.
4.7 Final checks
Check:
• that there are no loose cable ends that could cause an open or short circuit.
• that the protective trunk wiring cover is in place on the Trunk Terminal Assembly.
• that no tools (e.g. screwdrivers) or loose items are present.
• that if, and only if, the assembly is the last one on the fieldbus segment, that a
9378-FT Terminator module is fitted into the socket on the TTA.
• that the required grounding link is securely connected.

12
INM9380-RD Rev 2
5 MAINTENANCE
When the enclosure is installed in a hazardous area it is important for personnel to
understand what activities are permissible when fieldbus power is present and what are
not.
WARNING!
Read and understand what work is permitted on the equipment.
Failure to comply with these instructions can endanger the lives
or health of personnel and risk damage to the plant and the
environment.
5.1 General
The following assembly items may be installed, removed or disconnected while the
trunk is powered.
• 9377-FB-R Fieldbus Barrier module(s)*
• 9378-FT Terminator module
• 9376-SP Trunk Surge module
• 9379-ALM Alarm module
• FS32 Spur Surge modules and any spur wiring
All other wiring in or to the assembly requires the trunk power to be isolated, or a gas
clearance certificate to be obtained before any work is carried out.
* NOTE
The earlier, non-redundant 9377-FB barrier model cannot be fitted in place of the
9377-FB-R; it has built-in mechanical differences to prevent its substitution.
5.2 Fieldbus Barrier maintenance procedures
The 9387-FB Fieldbus Barrier is designed to tolerate the failure of one or more spur
circuits in either Fieldbus Barrier module. However, a failed module should be replaced
as quickly as possible to avoid any loss of power or communication to the spurs from
subsequent failures. If a barrier module has one or more LED indicators showing solid
red, meaning that the internal spur circuits have failed (see “Troubleshooting”), then
it should be replaced.
5.2.1 Fitting and removal techniques
The individual 9377-FB-R Redundant Fieldbus Barrier module(s) may be fitted or
removed without isolating the trunk power.The trunk connections to the barrier module
on the carrier have spark suppression by design and cannot cause ignition while they
are being connected or disconnected. This section should be read to understand the
physical removal or installation of a barrier, but read section 5.2.2 on page 13 to
understand the recommended procedure for replacing a barrier when powered.
5.2.1.1 Removing a Fieldbus Barrier module (refer to Figure 5.1)
a) Loosen the three captive fixing screws (C & D) on the module to release it. The
screws are all spring-loaded and should retract when the thread has disengaged.
b) Slowly pull the 9377-FB-R Fieldbus Barrier module away from its connections on
the carrier until the safety retaining clip (B) stops further removal.
c) Press the clip (see bold black arrow) towards the module until the barrier is released
and can be removed completely.
5.2.1.2 Fitting a Fieldbus Barrier module (refer to Figure 5.1)
Note: Before fitting a 9377-FB-R Fieldbus Barrier module check the connection pins on
its underside to ensure that they have not been bent or damaged in any way. Do not
use, or attempt to repair, a barrier module that has any of its pins bent or damaged,
because this might affect its safety and will invalidate the certification.

13
INM9380-RD Rev 2
a) Engage the locating guides (A) of the 9377-FB-R Fieldbus Barrier module into the
sockets provided on the carrier and push the module fully into place.
b) Tighten the three captive fixing screws (C & D) to a recommended torque of
0.9Nm to secure it.
A
B
D
C
C
Fail-over
button
AB
Figure 5.1 - Fieldbus Barrier module – fitting & removal
5.2.2 Use of Fail-over button when replacing a barrier
Although direct removal of the “active” barrier of a redundant pair will cause all spurs
to be redirected automatically to the “standby” barrier, the following technique is
recommended for the replacement of a barrier.
Two fail-over buttons are provided on the module carrier to permit a manual transfer of
spur control from one barrier module to another- A >B or B >A. These are used during
module replacement to ensure that all spurs remain powered. The following four-step
example illustrates a typical “hot-swap” procedure.
1 2 3 4 5 6
Barrier A
Acve
1 2 3 4 5 6
Barrier B
Standby
Situaon 1
1. Spur 3 on Barrier A has failed and shows red. Control of this spur has transferred
automatically to Spur 3 of Barrier B, which now shows a solid, not flashing, green.
Barrier A should therefore be replaced to ensure continued redundant service.
1 2 3 4 5 6
Barrier A
Standby
1 2 3 4 5 6
Barrier B
Acve
Situaon 2
2. Pressing theA>B fail-over button beside BarrierA, passes all spur control to Barrier B.
All spur LEDs on Barrier A now flash, while those on Barrier B are solid green; this
indicates that Barrier A is now in “standby” and Barrier B is “active”.
3. BarrierAcannowberemovedfromthecarrier(followingtheprocedureinSection 5.2.1.1
on page 12) and replaced with a known good module. On replacement, Barrier A
remains in “standby”.
= Acve, healthy
= Failed
= Standby, healt
hy
= Standby, Failed

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INM9380-RD Rev 2
4. To restore Barrier A to the “active” mode, press the B>A fail-over button located
beside Barrier B. Control of all spurs now returns to Barrier A while Barrier B goes
into “standby” mode.
* NOTE
Operating the fail-over buttons will not allow active spurs to be transfered to a
missing or failed barrier module.
Terminator and Trunk Surge Protection modules












Figure 5.3 - Module connectors and retaining clips
5.2.3 Fitting and removal
Both modules have connectors that are designed to prevent an ignition-capable spark
when the module is installed or removed.The modules are not interchangeable but the
method of installing and removal is the same.
Do not use, or attempt to repair, a module that has any of the pins on its underside bent
or damaged, because this might affect its safety and will invalidate the certification.







Figure 5.4 - Mounting a module- e.g. Trunk Surge Protection module

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INM9380-RD Rev 2
5.2.3.1 Mounting a module
Refer to Figure 5.4.
Orientate the module so that the smaller front clip is facing the user, then:
• lower the module so that the safety retaining clip on the TTA housing fits into the
loop on the module
• locate the terminal pins into their contact sockets on the TTA housing and
• push the module home until front and rear retaining clips engage.
5.2.3.2 Removing a module
Refer to Figures 5.3 and 5.4 for further information.
Removal is a two-step process that first breaks the electrical connection, followed by
the physical removal of the module from the TTA.
• Press the clip at the rear of the module and tilt the module forward until the clip
disengages at the rear.
• Press the front clip and withdraw the module from its socket until it is stopped by
the safety retaining clip, then press down on the safety retaining clip enough to
release it and pull the module away from the TTA body without rotating or twisting
it.
5.3 Spur connections
All of the spur connections are intrinsically safe and therefore may be live-worked in a
hazardous area without ‘gas clearance’, while complying with normal ‘permit to work’
procedures. If spur wiring is removed from a connecting plug, ensure that the same
polarity is observed when it is reconnected.
For addtional information refer to Section 4.6 on page 11.
5.3.1 Removing a Spur Surge module & spur cable adjustment
If an FS32 Spur Surge module needs to be removed from circuit, use the following
procedure.
a) Loosen the two screws securing the pluggable, spur-wiring connector to the
Spur Surge module and unplug it.
b) Loosen all three of the Spur Surge module’s fixing screws and unplug it from the
carrier.
c) Plug the spur connecting plug into its mating socket on the barrier carrier and
tighten the fixing screws to a recommended torque value of 0.4 Nm.
5.3.2 Adding a Spur Surge module & spur cable adjustment
If an FS32 Spur Surge module is added, follow this simple procedure. Refer also to
Section 4.6.1 for further fitting details.
a) Loosen the two screws securing the pluggable, spur-wiring connector to the carrier
and unplug it.
b) Plug the Spur Surge module into the vacant socket on the carrier and tighten the
two fixing screws and its grounding screw, all to a recommended torque of 0.4
Nm.
c) Plug the spur connecting plug into its mating socket on the Spur Surge module and
tighten the fixing screws to a recommended torque of 0.4 Nm.

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INM9380-RD Rev 2
5.4 Trunk connections
WARNING!
No part of the Trunk Terminal Assembly may be worked while the
assembly is powered, unless the environment is known to be non-
hazardous.
Before any work starts on theTrunkTerminal Assembly the trunk power to the enclosure
must be isolated, or a gas clearance certificate obtained.
Once the conditions are known to be safe, the protective plastic cover of the Trunk
Terminal Assembly (TTA) may be removed. Unscrew its securing screw, slide it out
until it becomes free and then move it to the side to obtain access.
Refer to Section 4.3 and 4.2 for additional information about trunk wiring connections.
When any changes or checks have been carried out, ensure there are no loose
implements left inside the TTA before replacing its protective cover. Slide the cover
into its locations and tighten the securing screw to a recommended torque of 0.6 Nm.
5.5 Regular Maintenance checks
Check the general condition of the installation occasionally to ensure that no
deterioration has occurred. At least every two years (and more frequently for harsh,
dusty or dirty environments) check:
• the condition of all wire connections/terminations/screens.
• that all of the fixing screws are secure.
• that there are no signs of damage or corrosion.
In addition, take advantage of plant maintenance shutdown periods or whenever the area
is known to be non-hazardous, to check wiring quality by confirming that the dc voltage
on the fieldbus trunk, when measured at the assembly, is >16V. This can be performed
using a multimeter or an FBT-6 fieldbus tester.
5.5.1 Proof testing of redundancy mechanism
TheFieldbus Barrierisdesigned toautomaticallytransferspurs betweenthe ‘active’to the
‘standby’ barrier modules in the eventof internal electronic failures.This mechanism may
be proof-tested by manually forcing the transfer of all spurs between the modules using
the Fail-over buttons located on the module carrier (see clause 5.2.2 and diagram 5.1).
Pressing the A >B button will force all spurs to transfer from module A to module B.
Pressing the B >A button will return the spurs to module A.
Operating the Fail-over buttons will reliably transfer all spurs without interrupting the
fieldbus communication; however, repeated operation is not advised if the Fieldbus
Barrier is operating in a live fieldbus segment. Use of the Fail-over buttons is therefore
recommended only for periodic proof-testing during plant shutdowns, and for the
purpose of module replacement.
NOTE
Operation of the Fail-over buttons will not cause active spurs to be transfered to a
missing or failed barrier module.