De‐energizing Live Parts
Electrical parts operating at 50 volts or more must be deenergized and locked and tagged out to the maximum extent feasible before they are maintained or repaired, or if parts are exposed at or beyond the limited approach boundary.
If deenergized, but not locked and tagged out, parts must be treated as live.
Note. Except equipment with a cord and plug that is under the direct control of the employee performing the work.
Situations/conditions when de‐energizing is not required are:
- Increased or additional hazards, such as interruptions of life support systems, shutdown of hazardous location ventilation equipment, removal of illumination for an area, or deactivation of emergency alarms.
- If the risk is minimal, such as an inspection where no part of the inspector’s body passes beyond the restricted or prohibited boundaries.
- Infeasibility due to equipment design or operational limitations that include:
- Testing of electric circuits that can only be performed with the circuit energized.
- Work on the circuits that form an integral part of a continuous process that would otherwise need to be completely shut down, creating a greater hazard, in order to permit work on any circuit or equipment.
Energized parts that operate at less than 50 volts need not be de‐energized if there is no increased exposure to electrical burns or to explosion due to electric arcs.
If deenergizing parts introduces additional risk or is impractical (due to the design of the equipment or operational limitations), a documented plan (a detailed Job Safety Analysis [JSA]
Stored electrical energy that might endanger for the working person must be released. Discharge capacitors shall be used for this purpose.
Field conditions and planning documents must be verified as “matching.” Resolve differences before releasing the work. If there are unresolved differences that could result in an inadvertent reenergization from another source, work may continue provided extra precautions are taken during the potential exposure; precautions include the following:
- Verify the circuit is de‐energized.
- Conduct work using the safeguards required for energized systems for the remainder of the work.
- Use positive measures including approved grounds on both sides of the work, or where required, removal of circuit elements.
Note: An EWP is not required in cases where no possibility of re‐energization exists.
It is acceptable practice to physically disconnect the energy sources of systems, equipment, or components to remove hazards (such as lifting cables from circuit breakers in an energized panel). However, this physical disconnect must be left in a condition that prevents inadvertent reconnection (such as cutting back the cables in the energized panel), or physically identify the disconnection (such as tagging the cables left coiled in the energized panel) and communicate system status to affected workers and the controlling organization.
Safe condition (zero energy) checks must be performed on any system, equipment, or component disconnected from its energy source immediately prior to performing work.
Tripped circuit breakers and GFCIs/ ELCBs may not be reenergized until it has been determined that the equipment and circuit can be safely reenergized.
Only authorized electrical workers or electrical engineers are authorized to reset GFCIs/ ELCBs that trip more than once.