How Has Amendment 3 to the 17th Edition Changed Your Use of RCD’s?

Amendment 3 to the 17th Edition was published in January 2015, and it has changed the way you use RCD’s.

The 17th Edition is used to achieve compliance with the relevant parts of the statutory Electricity at Work Regulations. It sets the standard for electrical installations in the UK. Amendment 3 was published in January 2015. All installations designed after 30th June 2015 are to comply with BS 7671:2008 Amendment 3 (2015).

An RCD, or residual current device, is a life-saving device designed to prevent you from getting an electrical shock if you touch something live, such as a bare wire and it also provides some protection against electrical fires. Amendment 3 now requires that additional protection, by an RCD, should be provided for socket outlets with current ratings not exceeding 20A, irrespective of the status of the person using the socket outlet and its intended purpose.

This means additional protection by means of an RCD in compliance with Regulation 414.1 shall be provided for 1) socket outlets with a current rating not exceeding 20A and 2) mobile equipment with a current rating not exceeding 32A for use outdoors. An exception to 1) is permitted: “Where other than for an installation in a dwelling, a documented risk assessment determines that the RCD protection is NOT necessary”.

According to regulation 522.6.202 of Amendment 3, a cable installed in a wall or partition at a depth of less than 50mm from a surface of the wall or partition shall, be installed in a cable zone etc. and where this applies, the cable shall be provided with additional protection by means of a suitably rated RCD.

This regulation also means that irrespective of its buried depth, a cable concealed in a wall or partition, the internal construction of which includes metallic parts other than metallic fixings such as nails and screws and the like must be provided with additional protection by means of a suitably rated RCD. If the depth is less than 50mm it shall be installed within the zone or incorporate an earthed metallic covering, or installed in earthed conduit, earthed trunking or be protected with mechanical protection against damage sufficient to prevent penetration of the cable by nails, screws etc.

For locations containing a bath or a shower, additional protection shall be for all low voltage circuits “serving or passing through zones 1 and 2” of the location by the installation of one or more RCDs having the characteristics specified in Regulation 415.1.1.

You can download the free white paper ‘Your Ultimate Guide to Amendment 3’ on the Amtech website:

Intersafe have been delivering tailored solutions and safeguarding organisations for 20 years. They are specialist in Periodic Insepction and Testing, PAT Testing and Thermal Imaging. Contact Angus by calling 02380 610101 or email to book an appointment.