Sorry. I just spotted an error in my original post (isn't that always the way
!!)
In the paragraph relating to Gas groups, the first line should read 'Gas group
D equates to Group IIA (propane)'
Neil Barker
-----Original Message-----
From: Barker, Neil
Sent: 29 July 2008 08:02
To: 'John Cochran'; [email protected]
Subject: RE: Are ATEX, IEC and UL Zone classifications equivalent?
John
There are similarities, but they are not equivalents. I'll try to
explain as
concisely as I can.
Class I is for gases, vapours or liquids, and consequently equates to a
G
atmosphere under ATEX/IECEx
Class II is for dusts and equates to a D atmosphere under ATEX/IECEx
Class III is for fibers and flyings and has no ATEX/IECEx equivalent,
but
would be treated as Dusts.
Division 1 covers both the situation where ignitable concentrations of
flammable gases, vapours or liquids can exist all or some of the time under
normal operating conditions and consequently encompasses both Zone 0 and Zone
1.
Division 2 covers the situation where ignitable concentrations of
flammable
gases, vapours or liquids are not likely to exist under normal operating
conditions, and consequently covers Zone 2.
Gas group D equates to Group IIC (propane)
Gas group C equates to Group IIB (ethylene)
Gas group B (hydrogen) is included in Group IIC (acetylene & hydrogen)
Gas group A (acetylene) is also included in Group IIC (acetylene &
hydrogen)
Protection concepts are limited for Division 1 to Explosionproof,
Intrinsic
Safety, or Purged/Pressurized covered by UL1203, UL913 or NFPA496 respectively.
Protection concepts for Division 2 include Hermetically Sealed,
Non-incendive, Non-sparking (all covered by UL1604), any Division 1 method,
and any IECEx method
Both ATEX and IECEx standards are now aligned, based on IEC 60079
Series.
These standards have also now been adopted by UL and CSA for USA and Canada,
but are not yet as widely accepted as the existing standards. However, if you
look at UL913 Seventh edition, for example, you will find that it is much more
closely aligned with IEC 60079-11, and it is probably just a question of time
before we have truly global standards for hazardous locations technology.
Similarly, UL1203 is similar to IEC 60079-1. The IEC 60079-x standards must be
read in conjunction with IEC 60079-0, which covers general requirements.
I hope this helps.
Neil Barker
Manager
Central Quality
e2v
106 Waterhouse Lane, Chelmsford, Essex, CM1 2QU, England
Tel: +44 (0)1245 453616
Mobile: +44 (0)7801 723735
Fax: +44 (0)1245 453571
www.e2v.com <http://www.e2v.com/>
P Consider the environment: do you really need to print this e mail?
-----Original Message-----
From: John Cochran [mailto:[email protected]]
Sent: 28 July 2008 22:17
To: [email protected]
Subject: Are ATEX, IEC and UL Zone classifications equivalent?
My company has a UL Listing for hazardous classified Industrial
Control
Panels. In the file, UL equates the Class/Division/Group listings to
Class/Zone/Group equivalents. Are these different from ATEX Zone listings or
IEC Zone listings? What different standards are used for ATEX or IEC listings?
John Cochran
Compliance Engineer
Strongarm Designs
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