Impacts of 18th Edition Wiring Regulations on the Event Industry and for Portable Power Distribution BS7671:2018

Impacts of 18th Edition Wiring Regulations on the Event Industry and for Portable Power Distribution BS7671:2018

These brief notes are designed to give the reader an insight of the new regulations indicating the key areas where changes in the regulations will affect portable power distribution and the events industry. It is only an insight and is not designed to replace a full understanding of the complete regulations.


RCDs See Regulation 411.3.3

Sockets Rated 32 Amps or less require RCD /RCBO protection to 30mA

Under the new 18th Edition, all final circuits rated 32A or less need RCD protection to at least 30mA earth leakage. There is no exclusion for 3 phase circuits, so this will cover all 16-amp, 32 amp, single and three phase sockets.

We do supply and manufacture distribution boards where there is no RCD protection on some 32A or 16A sockets, these can still be used, but not for final user circuits, i.e. they can only be used as feeder circuits to secondary distribution boards which in turn have their own 30mA RCDs.  The designer of the electrical system needs to be aware of this and implement the regulation into the electrical design. See regulation 411.3.3


Time Delayed Trips / RCDs See Regulation 411.3.2

Care must be used when selecting or using delayed time trips on final circuits, RCDs MCBs MCCBs RCBOs etc. Disconnection times are now clearly stated for circuits rated 63 Amps or less.

230v – 400v AC, max time delay for trip is 0.2s (for TN earthing) or 0.07s (for TT Earthing)


RCDs Supply Cables for Exhibition Stand and Public Shows   See Regulation 711.410.3.4

Cables to supply temporary structures need to be protected at origin by an RCD rated 300mA or less, with time delay as BS EN 60947-2 or S Type.


RCDs MCBs and Components in Distribution Boards   See Regulation 536.4.203

Don’t mix components from Different Manufacturers.  All electrical and mechanical devices and components should only be used accordance with the manufacturer’s instructions. This will apply to all circuit breakers, components, busbars etc.

In practice this means that you must not mix components from different manufactures within the same enclosure. The regulation was bought about because components can affect other components in unplanned ways, i.e. heat build-up in an MCB may cause a neighbouring component to malfunction. Using components from a single manufacturer, and following their installation guidelines will ensure  the correct function of the complete distribution board.

All components need to have their compatibility and final arrangement verified by the original manufacturer.


Cables for Exhibition Stand and Public Shows   See Regulation 711.52

Armoured cables or cable protection (i.e. Ramps) to be used in areas where there is a risk of mechanical damage.

Flexible cables not to be used in public accessible areas, unless protected against mechanical damage.


Festoon Lighting for Exhibition Stand and Public Shows   See Regulation 711.559.4.3

Festoon lighting cable must be of the type with fixed moulded lamp holders, not removable lamp holders.


Sleeping Portacabins / Accommodation See Regulation 421.1.7

Recommendation to use ARC fault detection trips, in areas like sleeping accommodation and buildings where combustible materials are stored, or buildings made of combustible materials like timber sheds.


Caravan & Campsites See Regulation Complete Section 708*

  1. RCD Protection, for every socket outlet
  2. Interlocked Sockets to be used
  3. Socket Height above ground: Between 0.5m to 1.5m above ground level
  4. Socket to be within 20m of the Caravan Inlet
  5. Max 4 outlets per enclosure
  6. Connection Cables: 16A Rating use min 2.5mm Cable either HO5 RN-F, HO7 RN-F or equiv.
  7. Plugs & Sockets to be BS EN 60309—2 Type IP44+