Importance Of Regulations For Electrical Installations

Installations of residential, commercial, public, industrial, agricultural and horticultural premises, prefabricated buildings, construction sites, exhibitions and other temporary buildings as well as of outdoor lighting are regulated governed by wiring regulations.

The purpose of the regulations is to set rules for the design and erection of electrical installations so as to provide for safety and proper functioning for the intended use. All electrical installations in Zimbabwe must conform to the wiring regulations.

The regulations are important because they provide for safety of persons, livestock, and property against dangers and damage which may arise in the reasonable use of electrical installations. Risk of injury may result from:

1. Shock currents

2. Excessive temperatures likely to cause burns, fires, and other injurious effects

3. Mechanical movement of electrically actuated equipment

4. Explosion Protection against electric shock

Persons and livestock must be protected so far as is reasonably practicable against dangers that may arise from live parts of the installation. This protection can be achieved by one of the following methods: a. Preventing a current from passing through the body of any person or any livestock b. Limiting the current which can pass through the body to a value lower than the shock current c. Automatic disconnection of supply in a determined time on the occurrence of a fault likely to cause a current flow through a body in contact with exposed-conductive parts, where the value of that current is equal or greater than the

Shock Current

Protection against thermal effects

As far as is reasonably practicable the electrical installation must be so arranged that the risk of ignition of flammable material due to high temperature or electric arc is reduced. In addition, during normal operation of the electrical equipment, the risk of burns to persons or livestock shall be reduced so far as is reasonably practicable.

Persons, fixed equipment and fixed materials adjacent to electrical equipment must also be protected against harmful effects of heat or thermal radiation emitted by electrical equipment, particularly the following consequences: a. Combustion, ignition or degradation of materials b. Risk of burns c. Impairment of the safe function of installed equipment

Electrical equipment should not present a fire hazard to adjacent materials. Protection against overcurrent, fault current, and over-voltage.

Over-currents are likely to arise in live conductors and these may cause injury to life and damage to property due to excessive temperatures or electromechanical stress. The wiring regulations therefore seek to deliver protection from such damage.

In addition to following the laid down regulations it is critical that good materials, particularly cables, are applied. The Zimbabwean cable manufacturer produces a wide range of quality cables. Consumers are urged to avoid sub-standard and smuggled cables making their way into the Zimbabwean marketplace.

Text by Perry Kaande