Safe Isolation Procedure for Electrical Isolations

blog author iconColton Rossiter
date icon2023 / 05 / 05
blog views icon144
Safe Isolation Procedure for Electrical Isolations

At Leaf Electrical, we understand the importance of safety when working with electrical equipment.

That's why we want to empower your team to properly execute the electrical isolation procedure.

This procedure is critical in preventing electrical hazards such as shocks and fires.

Let's take a closer look at this essential safety measure and learn how to do it right!




What Is Electrical Isolation?

Electrical isolation is the process of disconnecting a piece of electrical equipment or circuit from its power source.

This process is essential when working on or near electrical equipment as it prevents the flow of electrical energy and reduces the risk of electrical shock.

Electrical isolation can be achieved in several ways, including voltage isolation, power isolation, and galvanic isolation.

  • Voltage isolation involves physically separating the electrical equipment from its power source. This may involve switching off a circuit breaker, unplugging the equipment, or removing a fuse to ensure that no voltage is present.
  • Power isolation involves ensuring that the electrical equipment is completely de-energized by disconnecting all sources of electrical energy. This may involve isolating both the power and control circuits of the equipment to ensure that no energy is stored in the capacitors, inductors, or other components.
  • Galvanic isolation involves using isolation transformers or optocouplers to separate the electrical equipment from its power source. This type of isolation is often used in sensitive electronic equipment to prevent noise, voltage spikes, or other unwanted signals from affecting the equipment.

Regulations and Standards

Electrical isolation is required by law to prevent electrical hazards in the workplace.

In the United States, the Occupational Safety and Health Administration (OSHA) requires employers to develop and implement safe work practices, including electrical isolation.

The International Electrotechnical Commission (IEC) and the National Electrical Manufacturers Association (NEMA) have also developed standards for electrical isolation.

In Canada, one of the most important standards is the CSA Z462 Workplace Electrical Safety Standard.

This standard outlines the requirements for electrical safety programs and provides guidance on electrical safety practices and procedures, including electrical isolation.

The CSA Z462 standard requires companies to establish a written electrical safety program that includes procedures for identifying electrical hazards, assessing risks, and implementing controls to mitigate those risks.

Electrical isolation is an essential control measure that should be included in every electrical safety program, and compliance regulations and standards is essential to ensure workplace safety.

Common Hazards and Risks Associated With Electrical Isolation Procedures

  • Failure to properly lock out equipment can result in unexpected energization, which can cause serious injury or death.
  • Stored energy in capacitors, inductors, or other components can still pose a hazard even after the equipment is disconnected from its power source.
  • Workers may be exposed to electrical hazards when using testing equipment or performing maintenance on electrical equipment.

Electrical Isolation Procedure

A safe electrical isolation procedure involves several steps to ensure that all electrical energy is removed from the equipment or circuit before work begins. The following are the steps involved in a typical electrical isolation procedure:

  • PPE Application: it is essential to have proper PPE on before starting the electrical isolation procedure to protect against any potential electrical hazards. This includes wearing appropriate Shoch and arc flash protection. Calculating the arc flash hazard is an important step in determining the appropriate PPE to wear when working with electrical systems. Once the arc flash hazard has been calculated, it can be used to select the appropriate level of PPE required to protect against the potential hazards of an arc flash. This may include selecting specific types of gloves, clothing, and other equipment that are rated for the expected incident energy levels.
  • Identify the isolation point: The isolation point is the point at which the electrical equipment or circuit is disconnected from its power source. This may involve switching off the main disconnect, circuit breaker or unplugging the equipment from the power source.
  • Lock off procedure: The lockout tagout (LOTO) procedure involves securing electrical equipment to prevent accidental activation during maintenance or repair work. To do this, a lockout device is attached to the energy source to prevent it from being turned on. The device should be secured in a way that prevents it from being bypassed or removed. Additionally, a lockout tag should be affixed to the device to provide further information and warn other workers. The tag should indicate that the equipment is locked out and provide details such as the name of the person who installed the lockout device, the time and date of the lockout, and the reason for it. The tag should also warn that the equipment should not be operated until the tag is removed and an authorized worker has properly removed the lockout device.
  • Isolation procedure: The isolation procedure is the process of verifying that all sources of electrical energy have been removed from the equipment or circuit. This may involve physically testing the circuit to ensure that no electrical energy is present.

    Note: It is important to test the voltage detector or multimeter on a known voltage source prior to use to ensure that it is functioning properly.

  • Residual energy isolation procedure: The energy isolation procedure is the process of isolating all stored energy sources in the equipment or circuit. This may involve discharging capacitors or removing batteries.
  • Off Load checks: Off-load checks are performed to ensure that the equipment or circuit is safe to work on. This may involve checking for the presence of residual electrical energy or verifying that the equipment is completely de-energized.
  • Proof of electrical isolation: Proof of electrical isolation is required to verify that all sources of electrical energy have been removed from the equipment or circuit. This may involve using a line isolation monitor to detect any residual voltage or performing an electrical dead test to verify that no electrical energy is present.
    • A line isolation monitor is a device that measures the electrical impedance of the circuit and alerts workers if any voltage is detected. Workers should verify that the monitor is functioning properly, and that no voltage is detected before proceeding with work.
    • An electrical dead test involves using a voltage detector or multimeter to test each conductor in the circuit and verify that no voltage is present. Workers should test each conductor individually and verify that the test equipment is functioning properly before proceeding with work.

Note: A line isolation monitor, and a voltmeter are different types of devices that measure different electrical parameters. A voltmeter measures voltage directly, whereas a line isolation monitor measures the impedance of the circuit to detect the presence of voltage indirectly.

A line isolation monitor is specifically designed to detect the presence of electrical energy that may be leaking through the insulation of the circuit or equipment. This can happen when the insulation is damaged or deteriorated, allowing electricity to flow through unintended paths. In such cases, a voltmeter may not detect the voltage, as the voltage levels may be too low or too high for the voltmeter to measure accurately.

It is important to note that the testing procedure may vary depending on the specific type and model of the line isolation monitor. Therefore, it is crucial to consult the manufacturer's instructions for specific testing procedures and best practices.

  • Restore power: After the work has been completed, the equipment or circuit can be re-energized by following the reverse steps of the isolation procedure.

It is essential to follow a safe electrical isolation procedure to prevent electrical hazards in the workplace. An electrical isolation checklist can be used to ensure that all necessary steps are followed.


  • If unexpected energization occurs, workers should immediately stop work and notify their supervisor. They should not attempt to remove the lockout device or work on the equipment until the hazard has been mitigated.
  • If a worker is injured or experiences an electrical shock, other workers should immediately call for emergency medical assistance and follow established first aid protocols. Workers should also report the incident to their supervisor and document the details of the event for future investigation.

Get the right training and prevent arc flash injuries

Safety Disclaimer

It's important to note that the safe isolation process described in this article is intended to provide general guidance only and is not meant to be used as an official procedure.

To ensure the safety of yourself and others, it's important to undergo proper training and to follow the procedures and guidelines set forth by your employer or regulatory agency.

Safe isolation can be a complex process and requires a thorough understanding of the equipment, systems, and hazards involved. It's crucial to have the necessary training, knowledge, and experience before attempting to perform any safe isolation procedures. Failure to do so can result in serious injury or even death.

If you are unsure about any aspect of safe isolation, consult with one of our qualified experts or seek guidance from your employer or regulatory agency. Remember, safety should always be your top priority.


I hope this article has helped you understand the importance of safe isolation and how to carry out the process properly. Remember, electricity can be dangerous, and taking shortcuts or neglecting safety measures can have serious consequences.

Always follow the correct procedures when working with electrical equipment, and never attempt any repairs or maintenance unless you are competent and authorized to do so.

If you know anyone who would benefit from this information, feel free to share it with them. And if you have any questions or concerns about safe isolation, don't hesitate to reach out to me at

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