ISA12.22, Explosionproof and Flameproof Enclosures
The committee shall survey and monitor national and international practices, as related to explosionproof and flameproof enclosures and related matters, (e.g., the effects of corrosion on such enclosures) and promote the understanding of the use of such equipment.
To summarize current practices for explosionproof and flameproof electrical enclosures intended for use in hazardous (classified) locations.
To publish standards and practices for the selection, installation, and maintenance of explosionproof and flameproof enclosures.
To submit proposals, as needed, for revision to standards and practices relating to explosionproof and flameproof enclosures.
ISA12.22 met on Monday, 22 October 2012, in Seattle, Washington with 20 members and 5 guests in attendance.
The committee spent the majority of its session reviewing the primary reasons for the negative vote on the FDIS for the seventh edition of IEC 60079-1, which closed in September 2012. The majority of negative votes were prompted by the conversion of embedded Notes in the document into normative text. This action was taken without the knowledge of the convenor or maintenance team, who been completed their work in Melbourne in November 2011. As a result, informative text now created new requirements which were not intended and are not acceptable.
Other issues prompting negative comments included:
The United Kingdom, France, and Norway are strongly against the addition to clause 6.1.2 allowing for leaky cemented joints, aka “drips and squirts”, even with additional testing requirements.
The concept of protection type ‘da’ covering catalytic sensors was questioned along with clarification that type ‘ia’ wiring methods are required.
Clarification of ignition sources in a multiple chamber enclosure for group IIC.
Requirement that internal labeling for an Ex component enclosure be retained in all instances, even when a single manufacturer is also the equipment certificate holder.
MT60079-1 will be meeting in Northbrook from November 1-2, 2012 to generate a new CDV. The US TAG will attempt to limit any revisions to simply correcting the problems with the Notes. This may allow the CDV to be published directly upon its approval, if no negative ballots are received.
Steve Blais reviewed progress made in the harmonization of UL1203, CSA C22.2 no.30, no.25 and no. 159. He also discussed progress made by the NEMA HazLoc/OSHA Task Group in having OSHA lift its restriction on permitting Hazardous Location Test Data under the NRTL test lab accreditation program. Progress has been made, but more work remains.
Greg Steinman and Jon McCormick were proposed to be added as voting members. Warren Bennett, Glenn Black, and Hunain Dattu were proposed to be added as information members. Steve Blais, from EGS Group, requested that Bill Leber be removed as his alternate voting member.
No sessions are planned for the Spring 2013 ISA12 meeting in San Diego, since voting on the CDV for IEC 60079-1:7th ed. will not be completed.
For information about all upcoming ISA12 meetings, please visit www.ISA12.org.