Intrinsic Safety
Intrinsic Safety
SAFA has formed a sub-committee for discussion of matters concerning intrinsic safety. Mr. Rowan Humphries of Sasol Technology is currently the chairman of this sub-committee and invites interested parties to contact him at rowan.humphries@sasol.com with any suggestions or comments (or contact Gary Friend of Extech Safety Systems (Pty) Ltd at gary@extech.co.za).
The group will meet every two months, and has set its objectives as follows:
- To communicate on a regular basis.
- To gain and exchange knowledge and experience between end users, suppliers, vendors, test houses, and legal authorities.
- To share and implement best practices.
- To ensure practical IS installations and standardize on IS loops.
- To identify and discuss typical problems and concerns in the industry and solve them.
- To get feedback from the test houses and trends in the international arena.
- To fill the gap in the knowledge of role players.
- To provide information on local IA certification & the implications.
- To work towards full compliance with IECEx.
Exic Clarification From IS Sub-Committee Meeting
These questions were raised at the IS meeting on 18 August. Herewith follows the questions and answers:
Q - Where does it say that Exic is for zone 2 only?
A - The relationship is identified in 60079-14 section 5.3 and 5.4 - (please click here for 60079-14 section 5.3 and 5.4)
Q - Where does it say that it does not require a barrier/isolator?
A - This statement isn't true, you will need an IS interface - barrier, isolator or I/O card or a device with suitable IS safety parameters declared.
Q - Where does it say that you can run Exic wiring with Exia & Exib wiring?
A - It appears in both 60079-14 and Draft 60079-25 - (Please click here for the latter)
Q - What is necessary for loop drawing approvals? i.e. how do you do calcs?
A - It will follow the same process that we have now. However, as per Chris T note cable parameters are not likely to cause a problem for most installations.
Please Click Here for the 'Comparison of the techniques of Intrinsic Safety ‘ic’ and Energy Limitation ‘nL'
