Electrical Maintenance and Lockout Tagout Procedure

control of hazardous energy in electrical maintenance

Electrical maintenance is the preservation and repair of electrical equipment and systems in a residential or industrial establishment. The work is done by inspecting, testing, monitoring, and/or replacing the machines to ensure all are in good condition and safe to operate.

It may be conducted either by the owner or a contracted maintenance electrician and is usually scheduled based on the following:

  • Age of the structure
  • Complexity of the electrical system
  • Necessity

Types of Electrical Maintenance

There are three types of electric maintenance, and each differs in purpose and procedure.


Corrective maintenance is required to identify, isolate, and repair any equipment that has malfunctioned or is already worn out to bring it back to good working condition. It is highly prioritized as it may affect workplace safety or impede productivity.
This type is reactive in nature in that whenever there’s a system failure, repair or restoration must follow right away. This is the primary disadvantage of corrective maintenance other than its inherent uncertainty.


Preventive maintenance is performed at predetermined intervals to prevent unexpected system failure and downtime. This is just like automobile periodic maintenance.

It’s not easy to find a system that holistically covers all damage and malfunction possibilities but there is a preventive maintenance management software that could significantly help.

The following are the basic procedures included in a preventive maintenance program:

  • A thorough inspection of inlets, panelboards, circuit breakers, and electrical distribution systems.
  • Detailed examination of residential feeders and different service equipment.
  • Survey and restoration of commercial transformers, capacitors, and wiring manifolds.
  • Inspection of indoor and outdoor lighting fixtures, relays, and control panels.
  • Observation of running electrical systems (Class 1, 2, and 3).
  • Initial and final monitoring of special occupancy units.
  • Inspection for all signs of electrical malfunctions like short circuits, loose connections, apparent burning and arcing, and minor (serial) explosions.


Predictive maintenance is done by closely monitoring the condition and performance of electrical equipment to detect and correct issues before unscheduled downtime or accidents happen. As such, this is also known as condition-based maintenance.

There are four online predictive maintenance tests that efficiently evaluate electrical system health:

  • Visual observation
  • Partial discharge examination
  • Infrared/thermographic inspection
  • Insulating fluid sampling and analysis

How to Do Electrical Lockout Tagout Procedure

lockout tagout for control of hazardous energy sources

Lockout Tagout (LOTO) or the Control of Hazardous Energy is the process of disabling electrical equipment or machinery to avoid the unplanned release of hazardous energy while electrical maintenance procedures are being performed. Knowing the basics of LOTO is critical to ensuring the safety of everyone while conducting this potentially dangerous task.

9 General Steps of System Lockout Tagout:

1. Prepare to Shutdown

An authorized person identifies the following:
  • Equipment/machine or process that needs lockout
  • Sources of energy at hand that requires control
  • Lockout devices to utilize

2. Notify Every Concerned Personnel

An authorized person notifies all affected personnel with the following information:

  • All equipment that requires locking and tagging and the reason for doing so
  • Time span of the whole operation
  • Persons responsible for the locking and tagging
  • Contact person should more queries arise

3. Equipment Shutdown

This step involves:

  • Making sure that controls are fixed in the OFF position
  • Confirming that every single moving part (gears, flywheels, spindles) has come to a full stop

All shutdown procedures established by the manufacturer or owner must be strictly observed.

4. De-energization

Follow the defined lockout procedure for each identified equipment/machine or process.

Here’s a quick guide to safely isolating different forms of hazardous energy:

Electrical energy

  1. Place electrical disconnects to the off position.
  2. Verify that the breaker connections are locked in the off position.
  3. Lock the disconnects into the off position.

Important Reminder: Only disconnect devices that you are trained or authorized to do so, particularly at high voltages.

Hydraulic and pneumatic potential energy

  1. Place the valves in the closed position and lock them in.
  2. Slowly open the pressure relief valves and carefully release the energy.

There are procedures for pneumatic energy control that may need pressure relief valves to be locked in the open position.
There are procedures for hydraulic energy that may need blocking.

Mechanical potential energy

  1. Cautiously bleed off energy from springs that may still be compressed.

Note: If not feasible, create blockage for the parts that may move if there is a chance that the spring can transmit energy to it.

Gravitational potential energy

  1. With a safety block or pin, prevent the part of the system from falling or moving.

Chemical energy

  1. Set chemical supply lines to the system and close and lockout the valves.
  2. Where possible, take chemicals off the system by bleeding lines and/or cap ends.

5. Dissipation of Stored Energy

Methods of dissipating or restraining stored or potential energy include: grounding, repositioning, bleeding, venting, and blocking.
Review the following procedural examples of removing residual energy:

Electrical energy

  • Most systems with electrical mechanisms, motors, or switch gears contain capacitors. Capacitors are where electrical energy is stored. Capacitors must be released in the lockout process to protect workers from electrical shock.

It is best to contact the manufacturer to find a specific method of discharging a capacitor for the system.

Hydraulic and pneumatic potential energy

  • Placing the valves in the closed position and locking them into place only keeps the lines from more energy entering the system. Usually, there will still be potential energy remaining in the lines, such as fluid or pressurized air. You may remove this stored energy by bleeding the lines through pressure relief valves. It is important to verify depressurization or use flange-breaking techniques.

It is best to contact the manufacturer for more information, or if no pressure relief valves are available, what other methods can be utilized.

Gravitational potential energy

  • Bring the equipment or machine to ground level if at all possible.

Chemical energy

  • Remove chemicals from the system by bleeding lines and/or cap ends, if available.

6. Lockout Tagout

There are established rules that must be obeyed to ensure that the lock cannot be removed and the system cannot be unintentionally operated when the system’s energy sources are still locked out.
These rules include:
  • Each lock should only have one individual key (master keys are not permitted).
  • All keys must be pulled out from locks and be kept by the same person who installed the lock.
  • The ratio of locks on the system to the people working on it should be 1:1. For instance, if a maintenance project needs 3 workers, then there should be 3 locks. Meaning that each worker must place their OWN lock on the system. Locks can only be taken out by those who applied them and should only be removed following a specific procedure (refer to step 9 below).
  • Each lockout device should be installed with lockout/tagout tags to clearly identify the hazardous or potentially hazardous condition of the serviced or maintained equipment.

7. Verify Isolation

After implementing the lockout tagout procedure and before starting any maintenance activity, make sure that the system is perfectly locked out.

Verification can be done in various ways:

Activate the equipment/machine or process controls. Wait for the result. No response means isolation is verified. Put the controls back to the safe position (off).

  • Visually inspect the following:
    • Electrical connections - make sure they are open
    • Suspended parts - lowered to a resting position or blocked to prevent movement
    • Other devices that restrain machines or process movement
    • Valve positioning for double block and bleed - closing two valves of a section of a line and then bleeding/venting the section of the line between the two closed valves.
    • Solid plate - to securely close a line (called line blanking)
    • Any other acceptable method of energy isolation.
  • Test the equipment
  • Circuitry testing should be performed by an authorized electrician only
Note: Capacitor-equipped equipment must be cycled until all energy is depleted.
  • Check pressure gauges to ensure that hydraulic and pneumatic potential energy has been discharged.
  • Check temperature gauges to ensure that thermal energy has been eliminated.

Select the process that ascertains that the energy to the system has been isolated without triggering other hazards while doing the verification.

8. Execute Maintenance Activity

Commence and complete the operation that required the system to be locked out.

9. Remove Lockout/Tagout Devices

When systems are finally ready for operations again, it’s time to remove the lockout tagout devices used by following this general procedure:

  1. Inspect the workplace to ensure that all tools and items have been properly removed.
  2. Verify that every worker is safely kept away from danger zones.
  3. Confirm that controls are in a neutral position.
  4. Remove devices in the opposite direction in which they were installed and re-energize the system.
  5. Confirm that every concerned personnel is duly notified that maintenance is completed.


Electrical maintenance is more than just replacing all electrical parts as needed; it also includes electrical system inspection, testing, and monitoring to keep systems and machines running smoothly. It is critical not only for the safety of equipment but also for industrial facilities, especially the workers involved.

We hope that through this article, it has been made clear that providing safety demands adopting safety precautions. This means that any type of electrical maintenance should never begin without proper preparation and safety lockout tools.

So, the next time you perform service or maintenance, whether as an employer authorizing others to do it or as a maintenance worker yourself, make sure you have TRADESAFE lockout/tagout kits and devices on hand to ensure a safe and 100% OSHA-compliant lockout tagout procedure.

The material provided in this article is for general information purposes only. It is not intended to replace professional/legal advice or substitute government regulations, industry standards, or other requirements specific to any business/activity. While we made sure to provide accurate and reliable information, we make no representation that the details or sources are up-to-date, complete or remain available. Readers should consult with an industrial safety expert, qualified professional, or attorney for any specific concerns and questions.


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Author: Herbert Post

Born in the Philadelphia area and raised in Houston by a family who was predominately employed in heavy manufacturing. Herb took a liking to factory processes and later safety compliance where he has spent the last 13 years facilitating best practices and teaching updated regulations. He is married with two children and a St Bernard named Jose. Herb is a self-described compliance geek. When he isn’t studying safety reports and regulatory interpretations he enjoys racquetball and watching his favorite football team, the Dallas Cowboys.