No. of FISCO barriers on single segment

[Dinesh]

Hello.!!

1. Can FISCO barriers be installed in Hazardous area?

2. Is it possible to have more than one FISCO barriers ( say 3 ) per segment of Field bus installations?

3. If installation of FISCO barriers is allowed in Hazardous area then, how power fed to FISCO barriers is controlled as per Intrinsic Safety requirements?


Thanks and Regards,

Dinesh bhurke

[sheusel]

Hello Dinesh,

there are several possibilities to create "FISCO" outputs in the hazardous area.
For example you can use a standard fieldbus power supply with Ex e wiring into the hazardous area (Zone 2 or Zone 1) and then install a Pepperl+Fuchs Fieldbarrier directly in Zone 1 or Zone 2 with 4 FISCO intrinsically safe outputs and short-circuit protection.
Another possiblity would be to install a KLD2-PR-Ex1.IEC FISCO Power repeater in a Zone 2 area to make the output side of the fieldbus segment intrinsically safe according to FISCO.

For more details check out http://www.fieldconnex.info or contact me.

Best regards / mit freundlichen Grüßen

Stefan Heusel

Technical Support Manager Bus Systems
Process Automation Division

Pepperl+Fuchs GmbH
Koenigsberger Allee 87
D-68307 MANNHEIM
Phone: +49 621 776-1299
Directfax: +49 621 776-27 1299
Department Fax: +49 621 776-1429
E-Mail: <mailto:sheusel@de.pepperl-fuchs.com>
<http://www.pepperl-fuchs.com/>
Signals for the world of automation

[rhighton]

Dinesh

The range of FISCO power supplies from MTL Instruments is approved for installation inside Zone 2 or Class I, Division 2 hazardous areas, with field wiring connected into Zone 1 or Division 1. In this case, 24V power is connected to the FISCO power supply using Ex nA, "non-arcing" wiring techniques, using suitable protected cable. The 24V power wiring must not be interrupted while energised. The FISCO power supply should be installed inside a suitably rated enclosure when installed in a hazardous area, typically Ex n or Ex e in IEC countries or a general purpose enclosure in the US.

The MTL 9121-IS and 9122-IS FISCO power supplies incorporate a repeater function, so many supplies may be connected in 'multi-drop' from a single host fieldbus port. In many applications a single FISCO power supply is used to power the typical 8 to 12 devices installed/host fieldbus port but you can certainly multi-drop 3 FISCO supplies when this is required.

For more information, visit www.mtl-fieldbus.com

Regards

Roger Highton
Senior Product Manager
MTL Instruments
Power Court
Luton
LU1 3JJ
UK
Phone: +44 (0)1582 407200
Fax: +44 (0)1582 407467

For further information on MTL, visit our web site
http://www.mtl-inst.com

[Stephen Mitschke]

Hello Denish,

You may also want to check out our newly revised Intrinsically Safe Application Guide Posted here:

http://www.fieldbus.org/About/FoundationTech/Resources/

It has a significant amount of information on FISCO and different topologies.

[Mike ONeill]

The P+F FieldBarrier is exactly that; 4x FISCO barriers in a box suitable for field mounting. You can daisy-chain these units together as many as you need (and the power supply can support). Power is fed to that unit as Exe (IEC) or Non-Incendive (NEC).
Of course, there are alternatives that give you completely IS solutions at 350mA per segment for devices in any gas - see www.ehawke.com/fieldbus.

[jberge]

I think all the questions have been answered. Just one additional comment: it is OK to multidrop FISCO barriers on the safe size where power is supplied to the barrier, but not on the hazardous side where the instruments sit.

For an indepth view, take a look at chapter 3 of the book "Fieldbuses for Process Control: Engineering, Operation, and Maintenance" (buy online in hardcopy or download immediately in softcopy):
http://www.isa.org/fieldbuses

[rhighton]

Jonas

As you imply, the FISCO power supplies can be multidropped on the non-IS fieldbus connection (this may still be in a Zone 2 hazardous area) which is normally connected to the host fieldbus card. You cannot connect the IS outputs of FISCO power supplies together, as FISCO is based on one IS power supply on each IS fieldbus trunk.

Regards

Roger Highton
Senior Product Manager
MTL Instruments
Phone: +44 (0)1582 407200
Fax: +44 (0)1582 407467

For further information on MTL, visit our web site
http://www.mtl-fieldbus.com