Establishing an electrically safe work condition is NFPA 70E terminology for executing a lockout/tagout (LOTO) of electrical sources.
An electrically safe work condition shall be achieved when performed in accordance with the following procedures and verified by the six step process.
Electrical Lockout/Tagout Procedures
The employer shall develop and document lockout/tagout policies and procedures for the company. The employer shall also provide training to the employees so they can properly and safely implement these procedures. On at least an annual basis the execution of these procedures and the procedures itself shall be audited.
The following will establish the minimum requirements for lockout/tagout of electrical energy sources. All employees will comply with these procedures. All equipment and/or circuits will be locked or tagged to protect the worker against exposure to hazardous electrical energy.
Do not attempt to operate any switch, breaker, or other electrical energy isolating device bearing a lock or tag. Any employee found to be working, or causing others to work on, equipment and or/circuits that, in the opinion of management should have been locked out, will be subject to severe disciplinary actions up to and including termination.
There are two types of electrical lockout/tagout procedures, simple lockout/tagout and complex lockout/tagout.
Simple lockout/tagout involves one or more qualified persons and deenergizing only one electrical supply.
Complex lockout/tagout involves but not limited to more than one craft, more than one energy source and/or more than one disconnecting means.
The primary responsibility for establishing an electrically safe work condition of equipment and/or circuits on a lockout/tagout belong to the company/contractor supervisor, foreman, and/or a designated employee. However, this does not alleviate the employees from insuring that proper lockout procedures are followed at all times.
Simple lockout/tagout does not require a written plan for each application. Each individual shall be responsible his or her own lockout/tagout during a simple lockout/tagout.
Complex lockout/tagout requires a single person with overall responsibility and a written plan prepared in advance for each lockout/tagout application.
Employees will be certain as to which switch, breaker, or other energy isolating devices apply to the equipment and/or circuits being locked. More than one energy source (electrical, mechanical, or others) may be involved. Any questionable identification of sources will be cleared by the employees with their Supervisor or Foreman.
Before lockout commences, authorization from the customer and project Supervisor will be obtained.
Six Step Process
The following steps shall be used to verify that you have established an electrically safe work condition. Until this verification is performed the equipment conductors/circuit parts shall be considered energized.
(1) Identify all sources of electric to the equipment being locked out. This will be done by checking one line diagrams, equipment tags and/or other documentation.
(2) Before properly opening the disconnecting device(s) ensure that the load(s), (i.e. motor, heating elements) are off.
(3) If possible ensure that the disconnecting devices blades are visibly open and/or the drawout type breakers are in their drawout position.
(4) Attach the lockout/tagout devices according to documented policies and procedures.
(5) Verify the conductor or circuit part is deenergized with proper test devices and only by a qualified person. Test each phase conductor or circuit part both phase-to-phase and phase-to-ground. Before and after each test, determine that the voltage detector is operating satisfactorily.
(6) The conductors or circuit parts shall be grounded if there is the possibility of induced or stored electrical energy by documented grounding procedures.
Restoring Electrical Power
When the task/job is complete and the equipment or circuits are ready for testing or normal service, check the equipment and/or circuits to insure that no one is exposed and all tools and grounds are removed.
When the equipment and/or circuits are clear, remove all locks. The energy isolating devices may be operated to restore energy to the equipment and/or circuits.
IMPORTANT DISCLAIMER: The above is only an overview of the requirements for establishing an electrically safe work condition and not intended in any way to represent the complete requirements. When developing or revising your policies and procedures always consult an expert and refer to the latest edition of the NFPA 70E.