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This section provides an overview of energy sources within the workplace and the hazards associated with each type and the importance for each to be tagged and locked as required by law.

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Types of Energy in the Workplace

Before working on any machinery or equipment, you must have a good understanding of the various types of energy that may be present within or around your work area.  Part of Locking out is to de-energize and block all associated equipment and bleed all pressurized lines in order to ensure that the area is safe. Energy is categorized as only being Kinetic or Potential.  It is imperative that you understand these two classifications of energy, as they will aid you in determining what specific procedures must be followed in order to prevent accidents.

Kinetic Energy

This is energy that is in motion or the controlling force behind motion. Examples of kinetic energy in an industrial setting are flywheels, blades, lathes, cogs, fans, flowing liquids or gases, belts, motors, presses etc.  The hazards associated with kinetic energy include pinching, cutting, crushing, trapping, grinding and impalement.

Potential Energy

<\pIt is energy that is stored in an object that is not currently moving, and may not be as evident as kinetic energy.  Potential energy can be more dangerous then kinetic energy due to the built up forces that may be present and hidden.  When released, potential energy converts quickly to kinetic energy and the resulting motion is more dramatic.  Examples of potential energy are hydraulic or air pressure, pressure in pipes, clamps, brake springs, actuators, raised loads, chains, braces and counterweights. 

Sources of Energy in the Workplace

Understanding what type of energy source powers your machinery or equipment is the first step in creating a workplace that is free from potential hazards.  Energy comes in five basic sources, but may manifest itself through sudden movement, heat, electrical current, heat, fire and explosions.  The four main sources of industrial energy are:

1. Electrical Energy: energy that is transferred through wires, motors, transformers, batteries and circuit breakers.  Machinery can be operated through a Direct Energy Source, meaning that the machine or equipment is powered by electricity, or an Indirect Energy Source, meaning that the electric energy powers the hydraulic or pneumatic pumps.  In addition, Electrical energy can also be stored in a built up in a capacitor.
2. Hydraulic Energy: energy that is created by putting fluid under pressure.  In most cases, hydraulic oil is used in cylinders, which may be found in elevating devices, lift trucks, and compactors.  The hydraulic oil or other liquid substance is generally under a lot of pressure while in the cylinder or hydraulic lines, and the resulting spray from an unfit hose or cylinder is sufficient to cause serious injuries or death if adequate protection is not taken.
3. Pneumatic Energy: energy that is created by placing air under pressure.  This is usually accomplished by the use of a compressor, but may be achieved by fans, or negative pressure (Vacuum).  The cycle time is much faster than hydraulic cycles as air is much less dense than liquid therefore; the drop in pressure is usually quite dramatic when an air compressor is stopped.
4. Pressurized Liquids or Gases: energy that is created by steam, water, or chemical liquids or gases found in pipes, tanks, supply lines, exhaust venting, and vats.  Always take the time to learn about the chemicals that may be flowing or stored in these pipes or vessels, and take all safety precautions.

Note, gravity is also a  concern in the workplace as in some cases the energy source that was holding the equipment or parts of the equipment in place may release and the natural force of gravity may take over and change in to kinetic energy and hit or strike a worker. Example: hydraulic brakes on a roller coaster parked on a hill, brakes release and the cars will move and fall.