17th- Amendment 3 The Changes Update

by Editor on October 25, 2014

This post updated June 2015.

The 3rd amendment to the 17th edition of the wiring regulations BS7671 was published in January 2015 and any installations designed after June 2015 must comply.

BS7671 17th Edition Amendment 3 2015

Check out price to buy at Amazon BS7671 Amendment 3. Make sure you order the new yellow book and not the Amd 2 green version.

The Main Changes in Amendment 3

The significant changes to be  included in the amendment 3 are:

  • Some layout changes
  • Expanded definitions
  • Some new regs
  • UK specific regs
  • Some new special locations
  • Alterations to test certificates

UK Specific Regs-  There are now some new regulations which are specific to the UK. Any new UK regs will end in a .200 number.

Definition of Competent-  “Competent” persons will now be defined as “Instructed” persons.

RCDs for ALL Sockets-  Reg 411.3.3 now refers to RCD protection for ALL socket outlets unless i) it is specifically labeled ii) a documented risk assessment has been carried out.

Lower Max Earth Loop Impedance Values-  Zs values to take into account the Cmin factor which is for Minimum Voltage Factor. For low voltage supplies Cmin is given as 0.95 which will lower all the permitted values.

Plastic Consumer Units- Reg– Reg 421.1.200 – Consumer Units, Switch Boards and assemblies in domestic electrical installations are now to be made of non-combustible material such as metal, or enclosed in a fire proof boxing or enclosure. There is a proposed extended implementation period until January 2016 (presumably to allow the manufacturers to sell off all their plastic stock and make lots of metal ones!).

Electro Magnetic Compatibility-  Reg 512.1.15 – The designer of an installation must ensure that all  fixed electrical equipment is designed and manufactured in accordance with the EMC Directive. Manuals for equipment should be kept as proof of compliance. An CE marked apparatus would conform to this. An example would be of a power supply to a motor inducing an EMF in adjacent cabling or equipment.

Escape Route Wiring-  Wiring on escape routes should be supported and fixed so it is not liable to collapse in the event of a fire. This would include the use of metal cable ties, metal containment and support fixings which would not fail due to excessive heat.

RCDs for Cables In Walls-  Regs 522 – Any cable in a wall or partition, even commercial or industrial, would likely require RCD protection. Note that some types of lighting (fluorescent or LED) may cause RCDs to trip. RCD would not be required if the cabling had an earthed metal sheath such as SWA.

RCDs for Special Locations-  Reg 701.411.3.3 – Cables “passing through” the zones of a Special Location are to be RCD protected.

RCDs for Generator Sets– Reg 551.7.1 – RCDs providing additional protection on circuits connecting a generator to the installation will now be required to isolate all phases including the neutral conductor.

Auxillary Circuits-  Chapter 55 changes regarding auxillary control circuits.

Skilled Person Test/Insp-  Part 6 Chapter 61- Change to “Skilled Person (electrically)” being competent in inspection, testing and certification.

Inspection & Testing Schedule– Part 6 Chapter 61- Schedule Of Inspections for new work has been replaced by a 2 page list and requires a Risk Assessment where RCDs are not used for sockets.

Inspection & Testing EICR– Part 6 Chapter 61- Electrical Installation Condition Repert now includes for inspection to be made in any accessible roof spaces.

Lighting General Requirements–  Section 559 now only covers the general requirements for fixed lighting. Changes include protecting cable which run through luminaires against radiation and heat. Display stand lighting must have either SELV, ELV or RCD protection.

Exterior Lighting Special Location-  Part 7 new sections 714 & 715  – Requirements for outside lighting and ELV installations moved here from section 559. 715 also has requirement regarding switching and control of lighting installations.

Users of the IET Wiring Regulations should be aware of the changes contained in Amendment 3 to the 17th Edition (BS 7671:2008+A3:2015). Potentially life-saving changes are proposed making this a vital update. These changes are expected to include (but are not limited to) amendments in the following areas: Consumer units (to come into effect January 2016) Wiring in escape routes Changes to earth fault loop impedances for all protective devices Updated EIC and EICR forms Changes to definitions throughout the Regulations Amendment No. 3 publishes on 5 January 2015 and comes into effect on 1 July 2015. All new installations from this point must comply with Amendment No. 3 to BS 7671:2008.


{ 4 comments… read them below or add one }

Ramin March 21, 2016 at 10:38

Dear Mr Richard
Reg 134.1.1 changed from:
“Good workmanship by competent persons or persons under their supervision and proper materials shall be used in the erection of the electrical installation. Electrical equipment shall be installed in accordance with the instructions provided by the manufacturer of the equipment.”


“Good workmanship by skilled (electrically) or instructed (electrically) persons and proper materials shall be used in the erection of the electrical installation. The installation of electrical equipment shall take account of manufacturers’ instructions.”

It dose not mean any non qualified person can carry out electrical work, in both cases it should be under the supervision of whoever is responsible for that work.

secondly, bad workmanship and dodgy electrical works can be done by anybody, regardless of their nationality. (the last company that I am aware of which convicted of negligence in Bristol had not any Iraqi employee.)

And finally if we and our yankee cousins in first place did not invaded Iraq for WMD!! (that I can call BOLLSHIT) and left it in chaos, in expense of our precious young soldiers, maybe that Iraqi guy did not need to jump of the HGV in Dover.
Fully qualified and proud British electrician, Originally from IRAN

Ian Macdonald August 14, 2015 at 13:45

Agree with fact that plastic CUs should never have been allowed, seen a case where an ancient wire-fuse/ceramic carrier unit was replaced with an ostensibly safer modern unit, only to have a loose terminal set the thing on fire. Though, the bureaucracy in these regs is getting completely out of hand. The effect will be to drive electrical work underground and off the radar, into the hands of the cowboys.

Paul April 29, 2015 at 13:27

useful article, shame that the regs will be ignored as usual, and the poor state of the industry will continue with no enforcement. nice jobs for people in suits making money off the backs of people at the sharp end. Not that I’m cynical ha ha.

Richard November 13, 2014 at 20:18

Definition of a competent person is an instructed person. That’s Ballshit. So I instruct an Iraqi guy who dropped off the bottom of a HGV in Dover and he is ok to carry out electrical work!


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