Useful Definitions

The following are a few definitions you'll need to know in order to understand lockout/tagout:

Authorized employee: An employee who actually locks/tags machines or equipment in order to perform servicing or maintenance. Examples of Authorized employees are: electricians, plumbers, energy facility operators, etc. Authorized employees must be trained in the recognition of hazardous energy sources, the type and magnitude of energy sources in their work area, and the procedures that are used for energy isolating and control.

Affected employee: An affected employee is not qualified to lock/tagout a piece of equipment, but uses/operates a machine or piece of equipment which made need maintenance or servicing. An affected employee can also be a person who works in/around an area where equipment may be locked/tagged out. Examples of an Affected employee are: housekeeping staff, grounds staff, roofers, office employees, etc.

Energy source: Any source of electrical, mechanical, hydraulic, pneumatic, chemical, thermal, or other energy. Energy sources are what makes the piece of equipment or machinery run, move or operate. Equipment may have a single energy source, or may have many different sources of energy.

Energized: Machines and equipment are energized when they are connected to an energy source, or they contain residual or stored energy. An example of stored energy could be a steam line. Even though you may have isolated a section of steam line by closing valves, pressure will remain in the line until it is properly bled-off.

Energy-isolating device: A mechanical device that physically prevents the transmission or release of energy. Examples of energy-isolating devices include: A manually operated electrical circuit breaker; a disconnect switch; a manually operated switch by which the conductors of a circuit can be disconnected from all ungrounded supply conductors and, in addition, no pole can be operated independently; a line valve; a block; and any similar device used to block or isolate energy. Push buttons, selector switches and other control circuit type devices are not energy isolating devices.

Capable of being locked out: A energy-isolating device must be locked-out if it is available on the piece of equipment you are performing maintenance tasks. An energy-isolating device is considered capable of being locked out if it:

• Is designed with a hasp or other means of attachment to which a lock can be affixed.
• Has a locking mechanism built into it.
• Can be locked without dismantling, rebuilding, or replacing the energy-isolating device or permanently altering its energy control capability.

 

Lockout: The placement of a lockout device on an energy-isolating device which ensures that equipment being controlled cannot be operated until the lockout device is removed.

Lockout device: examples include locks, chains, blank flanges and bolted slip blinds. Lock out devices are used to hold an energy-isolating device in a safe position and to prevent the start-up of machinery or equipment. Whenever possible a lockout device must be used along with a tagout device. An example of this is when you lockout a electrical disconnect, you must attach the warning tag to the lock shackle and then attach both the lock and tag to the disconnect. Never remove a lockout that does not belong to you.

Tagout device: A tag and a nylon tie that is securely fastened to an energy-isolating device to indicate that the machine cannot be operated until the tagout device is removed. A tag alone will only serve as a warning device - people can easily remove tags, putting you at risk. Never remove a tagout that does not belong to you.