Lockout is a procedure that prevents the release of hazardous energy. It often involves workers using a locking device to keep a switch in the “off” position, or to isolate the energy of moving parts. This procedure prevents electric shock, sudden movement of components, chemical combustion, falling counterweights, and other actions that can endanger lives. Lockout is a physical way to ensure that the energy source is de-energized, deactivated, or otherwise inoperable.
Tagging tells others that the device is locked out, who has locked it out, and why. Tagged devices and systems must not be re-energized without the authority of those named on the tag.
Electrical work performed on or near electrical transmission or distribution systems must be performed in accordance with the “Electrical Utility Safety Rules” published by the Infrastructure Health and Safety Association. Workplaces are required to take every reasonable precaution to prevent hazards from energized electrical equipment, installations and conductors.
All electrical hazards must be identified. Electrical hazards then must be removed as to not create a hazard to workers. If electrical hazards cannot be removed, workers must be adequately protected from the electrical hazards. Workers must follow written procedures and apply measures to ensure that workers do not become injured from the electrical hazards.
Hazardous stored electrical energy must be adequately discharged or contained before the work begins, and kept this way while the work continues. Workers must verify that the power supply and the hazardous stored energy have been disconnected, discharged or contained and will remain so as the work continues.
Test before touch, and follow safe work procedures to ensure electrical energy has been discharged though the lock out tag out procedures.
When there are multiple workers using machinery or energized systems, workers must have a way to communicate the status of the hazardous stored electrical energy and electrical equipment, installation or conductor.
There are times when disconnecting conductors, installations or equipment is not practical or possible. See the document Electrical Hazards – Working on energized systems for more information.
O. Reg. 213/91
Part II GENERAL CONSTRUCTION
181. (1) Except where otherwise required by this Regulation, electrical work performed on or near electrical transmission or distribution systems shall be performed in accordance with the document entitled "Electrical Utility Safety Rules" published by the Infrastructure Health and Safety Association and revised 2014.
(2) Sections 182, 187, 188, 189, 190, 191 and 193 do not apply to electrical work that is performed on or near electrical transmission or distribution systems if the work is performed in accordance with the document referred to in subsection (1).
[O. Reg. 631/94, s. 6; 627/05, s. 4; 443/09, s. 5; 345/15, s. 22]
183. Every reasonable precaution shall be taken to prevent hazards to workers from energized electrical equipment, installations and conductors.
[O. Reg. 143/99, s. 1; 627/05, ss. 5, 6]
190. (1) This section applies if work is to be done on or near energized exposed parts of electrical equipment or of an electrical installation or conductor.
(2) An employer shall,
(a) establish and implement written measures and procedures for complying with this section to ensure that workers are adequately protected from electrical shock and burn; and
(b) make a copy of the written measures and procedures available to every worker on the project.
(3) The worker shall follow the written measures and procedures.
(4) Subject to subsection (9), the power supply to the electrical equipment, installation or conductor shall be disconnected, locked out of service and tagged in accordance with subsection (6) before the work begins, and kept disconnected, locked out of service and tagged while the work continues.
(5) Hazardous stored electrical energy shall be adequately discharged or contained before the work begins and shall be kept discharged or contained while the work continues.
(6) The following rules apply to the tagging of the power supply under subsection (4):
1. The tag shall be made of non-conducting material and shall be installed so as not to become energized.
2. The tag shall be placed in a conspicuous location and shall be secured to prevent its inadvertent removal.
3. The tag shall indicate,
i. why the equipment, installation or conductor is disconnected,
ii. the name of the person who disconnected the equipment, installation or conductor,
iii. the name of the person's employer, and
iv. the date on which the equipment, installation or conductor was disconnected.
4. The tag shall not be removed unless it is safe to do so.
(7) A worker, before beginning work to which this section applies, shall verify that subsections (4) and (5) have been complied with.
(8) If more than one worker is involved in work to which this section applies, a means shall be provided to communicate the purpose and status of,
(a) the disconnecting, locking out and tagging of the electrical equipment, installation or conductor; and
(b) the discharging and containment of any hazardous stored electrical energy.
(9) Locking out is not required under subsection (4) if,
(a) in the case of a conductor, it is adequately grounded with a visible grounding mechanism;
(b) in the case of equipment or an installation,
(i) the power supply is less than 300 volts, the equipment or installation was not manufactured with provision for a locking device for the circuit breakers or fuses, and a written procedure has been implemented that is adequate to ensure that the circuit is not inadvertently energized, or
(ii) the power supply is 300 or more volts but not more than 600 volts, the equipment or installation was not manufactured with provision for a locking device for the circuit breakers or fuses, a written procedure as to how work is to be done has been implemented and the work is supervised by a competent worker to ensure that the circuit is not inadvertently energized.
[O. Reg. 627/05, s. 7]