Is Barrier Gland Selection Still Confusing?
Key Issues with the use of Barrier Glands in Potentially Explosive Atmospheres to meet IEC 60079:14 2013 (Edition 5)
The difference between the current IEC 60079-14 Standard and previous versions is that currently IEC allows the use of a ‘standard’ Ex certified flameproof gland as long as cables and glands meet all of the following:
- Cable glands complying with IEC 60079-1
- Cables used to comply with (Clause) 9.3.2 (a)
- The connected cable is at least 3m in length.
This is as opposed to an Ex certified ‘barrier gland’ without the requirement to apply the previous flowchart used (which identified glanding requirements based on gas group / zone / enclosure size).
There is credible independent evidence that this approach poses a risk of fire propagation through the cable sheath so may pose an ignition risk if the latest IEC Standard is applied (i.e. no barrier gland is used).
A significant change was also that the selection chart only applied to flameproof enclosures which contained a source of ignition in normal operation, but the 3m rules seems to apply to all flameproof enclosures.
Previously all junction boxes and indirect entry terminal boxes did not require barrier glands; however, under the new edition, unless the cable is at least 3m in length, a barrier gland seems to be required.
In the UK in order to ensure that this risk is suitably controlled, the HSE defined the ‘Informative’ National Annex of BS EN 60079-14: 2014 as an ‘Established Standard’ so the Annex could be applied as Good Practice when assessing the requirements for fitting a barrier gland to electrical equipment in potentially explosive atmospheres.
ATEC fully supports the HSE & the findings of the BSI Technical Committee however based on information received throughout our industry/committee participation, it seems we may see a re-appearance of the flowchart in the standard main body at next revision!
About ATEC Services
We are a group of companies focused on services related to Hazardous Area Awareness and Asset Integrity. We provide specialized safety training and inspection services for companies who deal with the world of Potentially Explosive Atmospheres. From our inception over 11 Years ago, ATEC has without a doubt, been the go-to company for hazardous area compliance around the world.
With Office’s, Training and Inspection Centers in Houston and Singapore, the group is dedicated to the safety of personnel and asset protection by supplying International NEC / IEC Electrical Cables & Hazardous Area Accessories, Atex, IECEx competence training, including CompEx assessments, facility compliance and equipment inspection services.