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HVAC: Lockout Tagout (LOTO)

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Lockout Tagout (LOTO) is a procedure that prevents employees from releasing stored energy or starting a piece of equipment accidentally. In the field of HVAC this is used when doing maintenance on or servicing equipment. It works by disconnecting the power source and locking or tagging it in the off position while work is performed.

Steps for Performing LOTO
Before shutting down equipment:

  • Notify co-workers and anyone who will be affected by shutting down the equipment that it is going to occur.
  • Locate energy sources, procedures to be followed, and any hazards present.

Shutting down the equipment:

  • Follow procedures in place for the company to lock down the equipment.
  • Isolate equipment.
  • Identify all energy sources for the equipment.
  • Disconnect or isolate the energy for each one.
  • Release any stored energy.
  • Lockout or tagout the equipment.
    • Place a lock or tag on the equipment to prevent it from being switched to an on position and keep it in a de-energized state.
  • Test the equipment.
  • Ensure the equipment is isolated by trying to start the equipment.
  • Before proceeding, ensure the lock or tag is still in the appropriate place with equipment in the off position.

Removing LOTO Devices:

  • Ensure all equipment or machines are back in their appropriate places.
  • The work area should be clear, and employees should be notified before starting up equipment.

Failure to follow specific LOTO procedures could lead to serious injury or death and is an imperative part of staying safe for HVAC workers.


This article is provided solely as a reference tool to be used for information purposes only. The information in this article shall not be construed or interpreted as providing legal or any other advice. The information material does not amend the provisions of any insurance policy issued by CompSource Mutual. It is not a representation that coverage does or does not exist for any particular claim or loss under any such policy. Coverage depends on the facts and circumstances involved in the claim or loss, all applicable policy provisions, and any applicable law.

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