16th Edition (reference only) – NOW superseded by the 17th Edition IEE Regulations.

chapter 5

chapter 6

Special Installations
  --1. - Introduction --2. - Bath tubs and shower basins
  --3. - Swimming pools --4. - Sauna rooms
  --5. - Installation on construction sites --6. - Agricultural & horticultural
--7. - Restrictive conductive locations --8. - Earthing for function & protection
--9. - Caravan, motor homes, caravan parks 10. - Highway power & street furniture
11. - Heating appliances & installations 12. - Discharge lighting
13. - Underground & overhead wiring 14. - Outdoor installations & garden buildings
15. - Installations of machines & transformers 16. - Reduced voltage systems
17. - Marinas 18. - Medical locations
19. - Exhibitions, shows and stands

7.10.2 - Highway and street furniture regulations

The equipment covered by these regulations is always, by definition, accessible to people of all kinds; however, maintenance must only be carried out by skilled and/or instructed persons. Thus, certain measures for protection in areas only open to skilled or instructed persons are not appropriate here. For example. protection by barriers or by placing out of reach must not be used, because those using the areas may not be aware of the dangers which follow from climbing over barriers or reaching up to normally untouchable parts. The equipment considered here usually has doors which give access to the live parts inside. Such doors must not allow unauthorised access to live parts, and must therefore either:

1. - be opened only with a special key or tool, or

2. - be arranged so that opening the door disconnects the live parts. The doors of street furniture, such as lamp standards, are often damaged or even totally removed. Therefore, live parts within must be protected by enclosures or barriers to give protection to IP2X, to ensure that they cannot be touched.

Many types of street furniture and street located equipment are fed using overhead cables. The usual protection against direct contact by 'placing out of reach' is acceptable for such systems, but special regulations apply to the equipment fed. Where uninsulated low voltage overhead conductors are more than 1.5 m vertically from the equipment, it may be maintained by a suitably instructed person. If the vertical clearance is less than 1.5 m, only a skilled person who has been trained in live working may be involved. All cables buried directly should have a marker tape placed above them, 150 mm below the ground surface. To prevent disturbance, burial depths are usually 450 mm below verges and 750 mm below the highway. Very careful plans and records must be kept to show exactly where such cables are buried.

Protection against indirect contact (metalwork not normally expected to be live) cannot be achieved in these installations by a non-conducting location, earth-free equipotential bonding or electrical separation. The danger to the people who may touch metalwork is no more in this case than with electrical equipment indoors, so a 5 s disconnection time is acceptable where earthed equipotential bonding and automatic disconnection of the supply is employed. To prevent the effects of a fault being 'imported' or 'exported', adjacent metal structures should not be bonded to the circuit protection system.

Installations of this type are usually simple, often consisting of a single circuit feeding lighting. Provided that there are no more than two circuits, there is no need to provide a main switch or isolator, the supply cut-out (main supply fuse in most cases) being used for this purpose if not rated at more than 16 A, but only by instructed persons. However, where the supply is provided by a separate supplier (the Electricity Supply Company), their consent to use of the cut-out for this purpose must first be obtained as with any other installation.

Internal wiring in all street electrical equipment must comply with the normal Regulations concerning protection, identification and support (see {4.5, 4.6 and 4.4.1}). Attention is drawn particularly to the need to support cables in vertical drops against undue stress. The notice indicating the need to provide periodic testing is unnecessary where an installation is subject to a planned inspection and test routine.

Temporary installations such as those for Christmas or summer external lighting schemes are usually connected to highway power supplies. In many cases, street furniture is equipped with temporary supply units from which such installations can be fed. The temporary supply unit must have a clear external label indicating the maximum current it is intended to supply. Attention is drawn to the possibility of damage to existing cable connections by the frequent connection and disconnection of temporary supplies. It is recommended that a socket outlet, especially intended to feed temporary installations, should be part of the temporary supply unit and should be fixed within the street furniture enclosure. Such installations must comply with the requirements for construction site installations (see{7.5}) and must not reduce the safety of the existing installation.

Highway equipment is usually subjected to vibration, corrosion and condensation, and sometimes to vandalism. It should be chosen with such problems in mind. The heat produced by lamps and control gear will usually be sufficient to prevent condensation and corrosion, but thought should be given to the provision of a low power heater in other cases.

Inspection and testing is necessary as for all electrical installations, and should be synchronised with other maintenance work, such as white lining and re lamping, to avoid inconvenience to highway users as far as is possible. In general, a period of six years between tests is acceptable for fixed installations, and three months for temporary systems.


Return to top of page

Extracted from The Electricians Guide Fifth Edition
by John Whitfield

Published by EPA Press Click Here to order your Copy.

Click here for list of abbreviations