Intrinsic Safety

Can anyone point me to a website that demonstrates on how to select the correct intrinsic safety barriers to suit instruments and cables (showing
cable calculations) for an intrinsically safe system design. I have googled through many pages, but have been unable to find what I am looking for. TIA
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intrinsic safe is a huge galaxy. There are no general rules. There are only specific requirements. Intrinsic safe in a flammable gas atmosphere (hydrogen for example) would be some what different than a flammable liquid situation (gasoline for example).
Placement, voltages, current, are all considerations and apply.
Narrow your issue down to a county and maybe we can help
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Country UK Zone 1 Gas Classification IIC Instrument Supply 24VDC Loop Current 4-20mA
This is an academic exercise that I will need to do for college. Only need to look at how we select IS barriers for a particular instrument, considering supply voltage, current, etc. Then need to select the correct cable, considering cable capacitance based on conductor size/cable length, etc. TIA
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BIGEYE wrote:

[%X]
Take a look at:-
http://www.hse.gov.uk/comah/sragtech/techmeasureaclas.htm
I hope your college library can give you access to some of the EN500xx standards referenced by this document as the finer details will be in those documents (probably EN50020, 2002).
Other things that may be worth searching on are:-
DSEAR and ATEX.
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A useful reference book in UK is Intrinsically Safe Instrumentation: a guide by Robin Garside. 3rd Edition Revised 1997. Covering this important protection concept in detail, this book explains the key criteria including associated apparatus, system selection and design, cabling, earthing, certification etc. The use of Simple Apparatus (which may be installed without certification) is explained and the procedure for assessing systems which do not have system certification is covered in detail. 325 pages, extensively illustrated. A5 format ISBN 0 9516848 1 7
Jaybetec

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Whilst Robin's book is OK, there are also free application notes available from http://www.mtl-inst.com/mtlsupport.nsf
Don't forget that when choosing a barrier for an application, you need to find a barrier/instrument combination that is safe but one that works in the way you want it to as well.
Steve
John B Smith wrote:

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You first need to determine the hazardous location requirements and classification.
http://www.omega.com/techref/intrinsic.html
BIGEYE wrote:

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You first need to determine the hazardous location requirements and classification.
http://www.omega.com/techref/intrinsic.html
BIGEYE wrote:

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http://www.mikeholt.com
Long Ranger wrote:

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ISA may help you out.
Try http://www.isa.org/MSTemplate.cfm?MicrositeID 4&CommitteeIDF16
Mark

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