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The IET is to publish a new amendment – the second - to the IET Wiring Regulations Seventeenth Edition (BS7671:2008. Originally planned to be released in late 2012, this is thought to be nearing its final stages for release sometime this year – possibly this month. It will be available as a stand-alone document and will be not be consolidated into a new edition of BS 7671. The idea is that the amendment’s printed pages could be inserted into the bound copy of BS 7671; together forming the latest version of BS 7671. This new amendment, which will include a new Part 722 on electric vehicle (EV) charging points, will be a free download available from the IET website (www.theiet.org) when launched, as Voltimum UK managing editor James Hunt explains:
When introduced in 2008, the 17th Edition - BS 7671 (Requirements for Electrical Installations) - was completely restructured compared with the 16th Edition to include changes necessary to maintain technical alignment with CENELEC harmonisation documents.
The 17th Edition, therefore, introduced a new IEC decimal point numbering system to make it easier to embody future changes and additions resulting from ongoing international standards work within IEC and CENELEC. As CENELEC also uses a '100' numbering system to indicate that the requirement is of CENELEC origin, this conflicts with the UK's numbering system. Therefore, to accommodate future international, European and UK changes, it has been decided to use the '100' numbering system to indicate regulations of CELEEC origin, and to introduce a '200' numbering system into the Second Amendment for UK developed regulations.
New section on EV infrastructure:
EV charging points - the points at which EV are connected to fixed installations - come in four basic types, and these will be covered in the Second Amendment. They are Modes 1, 2, 3 and 4 charging. EV charging Modes 1 and 2, as defined in BS EN 61851, can be achieved by connecting the EV to mains socket outlets. EV charging modes 3 and 4 are also defined in BS EN 61851, and note that a dedicated final circuit must be provided for EV charging installations.
Where Mode 1 charging is concerned, if re-charging the EV away from the user's installation, there is no certainty that RCD protection is provide. According to BS EN 62196-2, mode 1 charging is considered to be unsafe, but note that proposed Section 722 does not prohibit mode 1.
For more information on these charging modes, and on the EV charging infrastructure generally, see the earlier VoltiTECH on EV infrastructure and charging at www.voltimum.co.uk/news/18237/infopro.newsletter.bulletin/electric-vehicle--ev--infrastructures---how-to-understand-them.html.
However, it is believed that inductive wireless charging will not covered in the Second Amendment to BS 7671:2008.
Other aspects of EV charging circuits likely to be included in the Second Amendment within Section 722 include the following:
- Assessment of general characteristics
- Purposes, supplies and structure
- Maximum demand and diversity
- Conductor arrangement and system earthing
- TN-systems
- Protection for safety - Protection against electric shock
- Protective measure - electrical separation
- Selection and erection of electrical equipment - common rules
- Operational conditions and external influences
- Devices for fault protection
- Isolation and switching.
Amendment 3:
Further changes will be included in Amendment 3 to BS 7671:2008. This will likely involve a new BS 7671 Edition for planned issue on 1st of January 2015, coming to effect on 1st of July 2015. Many changes are expected, largely because of changes at the IEC and CENELEC levels.
As we understand it, Amendment 3's possible changes include:
Section 442 - Protection of low voltage installations against temporary overvoltages because of earth faults in the high-voltage system, and due to faults in the low voltage system
Section 444 - Measures against electromagnetic disturbances
Chapter 51 - Selection and erection of electrical equipment - common rules
Section 557 - Auxiliary circuits
Section 559 - Luminaires
Chapter 56 - Selection and erection of electrical equipment - safety services
Section 708 - Caravan parks.
IET Guidance:
For further information and IET Guidance, note that, to obtain information on the current IET Guidance Notes Suit, go to http://electrical.theiet.org/books/index.cfm.
To see the ECA's guide to the 17th Edition, go to: https://www.eca.co.uk/shop/ECACart/ProductDetail.aspx?PID=e5972468-6a2c-4188-9d07-a03d00fa23f0 , but note that a new version, covering the Second Amendment is planned.