MTL Instruments FS32 Operating Manual

Instruction sheet

MTL Fieldbus Networks

FS32

Fieldbus Surge Suppressor

1. INTRODUCTION

The FS32 protects Fieldbus components complying with IEC
61158-2 physical layer and associated sensitive electronics from the
degradation and damage caused by surges and transients. Designed
for ease of installation, the FS32 can be used at both ends of the trunk
and on spurs where mounting type and configuration allows. More
details of this are shown throughout this instruction sheet.

IMPORTANT: The FS32 is designed specifically for use with fieldbus
apparatus manufactured by Measurement Technology Ltd where the
trunk and spur connections are organised as shown in Figure 1.

July 2014
INS 801741 B

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2. IMPORTANT SAFETY INFORMATION

WARNING

• The FS32 must be installed, operated and maintained by trained
competent personnel. The FS32 unit must not be subjected to
mechanical or thermal stresses in excess of those outlined in the
ATEX specifications.

• The FS32 range must not be installed in an area where it may be
attacked by aggressive substances.

• The protected equipment must be electrically isolated during
the installation procedure, except where the FS32 is used in an
intrinsically safe circuit.

• All installation and maintenance must be carried out in
accordance with all appropriate international, national and local
standard codes of practice and site regulations, which may
include reference to the IEC code of practice IEC 60079 -14, and
in accordance with the instructions contained here.

Measurement Technology Limited,
Great Marlings, Butterfield, Luton
Beds, LU2 8DL, UK.
Tel: + 44 (0)1582 723633 Fax: + 44 (0)1582 422283
E-mail: [e-mail]
www.mtlsurge.com

© 2014 MTL
All Rights Reserved
Publication No. INS 801741 B 240714
July 2014

Figure 1 - Spur & Trunk connec tions

Figure 2 - FS32 dimensions

1

FS32 Fieldbus Surge Suppressor

July 2014

3. INSTALLATION

When used with MTL 937x-FB Series Fieldbus Barriers

The FS32 may be used to protect the fieldbus spurs in 9370 -FB
Series Fieldbus Barriers supplied by Measurement Technology Ltd.
One FS32 is required for each protected spur.

Note: Insertion of an FS32 into the spur circuit does not require

the spur circuit to be powered down or isolated in a hazardous area
because the spur is intrinsically safe. However, communication with
the connected field instrument will be lost during installation.

3.1 Remove the existing 3-position connector plug and insert the

FS32 in its place - securing it with the two side screws and
the central grounding screw - do not over-tighten. Insert the
existing connector plug into the top of the FS32 and tighten
the two connector fixing screws. If the wiring is not connected,
insert the wires into the appropriate terminals ‘+’, ‘S’ ‘-’ and
tighten their securing screws.

3.2 Reconnect circuit and test system to verify operational status.

When used with Megablocks

Spurs will be intrinsically safe if the Megablock is powered from
an intrinsically safe source of supply such as MTL’s 912x-IS FISCO
power supplies. See also ‘Note’ at the bottom of previous page.

3.3 Remove the existing 3-position connector plug and insert the

FS32 in its place - securing it with the two side screws. Insert
the existing connector plug into the top of the FS32 and tighten
the two connector fixing screws. If the wiring is not connected,
connect to the appropriate terminals ‘+’, ‘S’, ‘-’.

3.4 Determine length required for the grounding bar (FS32-BAR)

and using tools (e.g. pliers), break at the score marks. Tighten
the FS32 ground screw into the grounding bar. Do not over­tighten.

3.5 Connect an Earth wire, (minimum 3mm2) with a ring terminal

to the M4 threaded hole. Ensure this wire is connected to the
chassis or the Earth reference of the protected equipment.

3.6 Reconnect the circuit and test the system to verify

operational status.

4. MAINTENANCE

At intervals of not more than one year (more frequently for particularly
harsh environments) visually check the installation and ensure that:

i) the device and /or its enclosure is firmly attached to its mounting

ii) there are no signs of external damage or corrosion

iii) the interconnecting cables are not frayed or otherwise damaged

iv) all connections are properly made with clear labelling.

If the unit has suffered damage, send it back to MTL Surge
Technologies for evaluation, which should be carried out only by MTL
Surge Technologies. This product is not repairable.

5. APPROVALS

In hazardous locations check the marking on the device to ensure
that it is appropriate for the application. Place a mark in the applicable
box (see Figure 4) to indicate the type of protection being utilized.
For marking use an indelible marker. The product range has been
designed to meet the fault tolerant requirements of Electrical
Apparatus for Category ‘ia’. Entity parameters: See Cer tificate number
Baseefa0 9ATEX0180X and/or IECEx BAS 09.0083X

ATEX and IECEx Special Conditions for Safe Use:

1. The FS32 Fieldbus surge suppressor may not be capable
of withstanding the 500V voltage withstand test for one
minute without breakdown to earth. This must be taken into
consideration in any installation.

2. When the FS32 Fieldbus surge suppressor is mounted within a
Hazardous Area, the plastic enclosure is considered to present a
potential electrostatic risk. Do not rub or clean with solvents.

3. The FS32 Fieldbus surge suppressor does not meet the
requirements of IP 20 at the top and bottom connectors. This must
be taken into consideration in any installation and once installed
the overall assembly must meet the requirement of IP20.

Figure 3 - Nickel-plated steel grounding bar

Measurement Technology Limited,
Great Marlings, Butterfield, Luton
Beds, LU2 8DL, UK.
Tel: + 44 (0)1582 723633 Fax: + 44 (0)1582 422283
E-mail: [e-mail]
www.mtlsurge.com

© 2014 MTL
All Rights Reserved
Publication No. INS 801741 B 240714
July 2014

Applicable
boxes

Figure 4 - ATEX certification details

EUROPE (EMEA):

[phone]

[e-mail]

THE AMERICAS:

[phone]

[e-mail]

ASIA-PACIFIC:

[phone]

[e-mail]

+

Unprotected

–

Shield

(S)

Ground/Earth screw

The given d ata is only intended as a p roduct
descrip tion and shou ld not be regard ed as a legal
warrant y of properties or gu arantee. In the i nterest
of further technical developments, we reserve the
right to make de sign changes.

+

Protected

–

Shield

(S)

2