SECTION 13: TEMPORARY ELECTRICITY SUPPLIES IN CONSTRUCTION AND BUIILDING SITES

 SECTION 13
 TEMPORARY ELECTRICITY SUPPLIES IN CONSTRUCTION AND BUIILDING SITES

Due to the adverse conditions obtaining at construction and building sites, temporary installations, including supply cables, conductors, and portable appliances, are subject to accelerated wear and tear.
 The reliability and adequacy of circuit protection, both mechanical and electrical, and earthing arrangements shall be ensured at all times.  Frequent periodic maintenance including inspections and tests shall be carried out by the electrical contractor.

Supplies for portable hand-lamps and portable tools shall be operated at 1 10 volts or less, through a double wound transformer specially manufactured for this purpose. The primary winding terminal must be enclosed in insulating material and earthing terminal provided. The secondary winding shall terminate in a suitable socket outlet attached to the transformer or its enclosure.

CABLES

Wiring for, semi-permanent parts of the site installation, such as site offices and buildings, shall comply with these Regulations.  For all other parts of the installation the following additional precautions shall be taken.

1. Underground cables shall be of a type having a continuous and earthed metal sheath or armour. The metal sheath or armour shall not be used as the sole earth conductor.
2. Except for situations where the risk of mechanical damage is slight, armoured cable should be used for the wiring.
3. Overhead Fines shall be fully insulated and supported at suitable intervals, and where necessary suspended by catenary wires at a height not less than 5 metres from the ground at vehicle crossing points.
4. All joints shall be mechanically and electrically sound, fully insulated, inaccessible to workmen, and clear of all materials.

EARTHNG

 Earthing shall be in accordance with these Regulations.
 SWITCHES, SOCKERS, COUPLERS

All switches, switched socket outlets, plugs and cable couplers shall be contained in weatherproof enclosures unless they are-of the weather-proof type.

LIGHT FIXTURES  Light fixtures used outdoors, or at locations where there ' is likelihood that such fixtures are subject to splashing water, shall be of the weatherproof type. 

PORTABLE APPARATUS
All metal-clad portable apparatus shall be effectively earthed at all times.

FLAMABLE OR EXPLOSIVE LOCATIONS 
All appliances or accessories intended for use in flamable/explosive locations and the associated wiring there of, shall be in accordance with B.S. specification BS 5345 and CP 1003.