10 - Electrical Systems

This Risk Factor is used to assess the risks associated with electrical systems and equipment, including electrical machinery and portable electrical appliances. The electrical system is defined as extending from the third party supply through to the last connection before the electrical equipment and portable appliances.

Faulty, overloaded, improper, or inadequately maintained electrical equipment are a common cause of fires. Electrical sources are often cited as the basis of major fires, with the US NFPA attributing 10% of non-residential fires to electrical causes.

What do we look for?


  • The type, amount and extent of the electrical system present and available to cause or support a fire
  • Electrical systems introducing an unusual (higher or lower) degree of exposure to the occupancy compared to normal expectations.


  • Periodic, visual, and recorded inspections. Frequency suited to age of system, type of equipment and environmental conditions. Inspections are intended to identify and manage systems with conditions such as:
    • Aged switchgear, cables or equipment
    • Signs of damage or poor condition
    • Overloaded circuits
    • Inappropriate components for the occupancy (e.g. humidity and corrosion)
    • Inadequate physical protection (guarding)
    • Exposures from combustibles too close to equipment
    • Accumulations of dusts or oily residues
    • Inappropriate electrical lighting arrangements or configurations
    • Identification of Type “S” high intensity discharge lamps (lamps not meeting ANSI Standard C78.398 for containment testing) in non-enclosed fixtures
  • Annual testing of the electrical system such as:
    • Thermo graphic testing
    • Dielectric fluid testing for transformers (where appropriate)
  • Maintenance of electrical machinery and portable appliances
    • Comprehensive activities with scope and frequency based upon manufacturer's recommendations
    • Replacement of Type “O” high intensity discharge lamps (lamps meeting ANSI Standard C78.398 for containment testing) before reaching estimated life expectancy
    • Replacement or enclosure of Type “S” high intensity discharge lamps in open fixtures
  • Programs to ensure ongoing safety of electrical systems such as:
    • Limiting use of extension cords
    • Weekly de-energizing of Type ‘O’ high intensity discharge lamps in non-enclosed fixtures

Risk improvement ideas

  • Implement a program for periodic, visual and recorded inspections, based on the age of the system, equipment and environmental conditions.
  • Conduct regular testing of the electrical systems, including thermo graphic testing and dielectric fluid testing of transformers where appropriate.
  • Maintain electrical equipment and have a program of testing for portable appliances.
  • Implement a management program to verify the correct use of electrical appliances, turning off electrical equipment when not required.
  • Select qualified contractors to provide comprehensive electrical testing and maintenance programs.

Risk topics

RT Template

Type: pdf (107Kb)