worker in electrical room

Don’t Work On Energized Equipment


When working with electricity, no hazard should be overlooked. If the power is on, there is danger. The best protection against the risk of electrocution is to turn the power off before starting the task and ensure that you confirm the absence of voltage. Every year the Electrical Safety Authority undertakes incident investigations where workers have been injured or killed working on energized electrical equipment.

Hazards present when working on electrical equipment:

  1. Shock
    Electricity going through the body or “shock”, can sometimes cause external and internal burns, cardiac rhythm disorders and injuries to organs. In severe cases, when injuries lead to death, this constitutes an electrocution.
  2. Burns
    The catastrophic failure of electrical equipment may result in an arc flash, which could result in a significant amount of energy being released which might burn a worker. The amount of energy released during an electrical failure is referred to as “incident energy”. The amount of incident energy released is dependant on three factors:
    • The fault energy at the circuit location
    • The voltage of the system
    • The performance of the overcurrent protective devices (clearing time)
  3. Explosions
    Explosions represent an additional risk for workers during an incident. Explosive forces may rupture eardrums, crush the lungs and throw debris including molten metals that can severely injure the workers.

5 Key Steps Towards Electrical Safety at Work

  1. Workers, supervisors and facility/ business owners must follow safety requirements defined by the Ontario Electrical Safety Code & the Occupational Health and Safety Act
  2. Safety procedures and requirements must be followed by anyone working on electrical equipment.
  3. Workers should lock and tag out all sources of energy when working on electrical equipment
  4. Electrical equipment should be tested to confirm the absence of voltage by first testing a known source, confirming the absence of voltage on all phases and confirming the operation of the meter by once again testing the known source
  5. All documented procedures should include requirements for Personal Protective Equipment.

The majority of electrical incidents occur as a result of incorrect procedure and human error

Electrical incidents associated with working on energized electrical equipment impact all electrical workers and those who interact with electrical equipment. The Ontario Electrical Safety Code, Rule 2-304, Disconnection, stipulates that no repairs or alterations shall be carried out on energized electrical equipment, and that adequate precautions such as locks on circuit breakers and switches, warning signs, etc. shall be taken.

Rule 2-304 also addresses situations in which it is not practical to disconnect because the disconnection of electrical power will create a higher level of safety risk to workers or the public.