Grounding Electricity

Agricultural Tailgate Safety Training for Operators and Supervisors
AEX-591.8.3
Agriculture and Natural Resources
Date: 
05/24/2019
Agricultural Safety and Health Program

Objective: To encourage the safe use of electricity on the job.

Trainer’s Note

The combination of voltage, amperage, resistance to the flow of the current and duration of contact makes working with electricity dangerous. Electricity follows an uninterrupted path. If the body becomes part of the path, electricity will pass through it. Even though dry hands and feet offer more resistance to electrical current than do wet hands or feet, the current can be lethal under either condition. This is especially true if the electricity passes through vital organs, such as the heart or lungs. Review the true or false quiz.

Background

Electricity always follows the path of the least resistance. Grounding electricity means that there is an easy path for the current to follow.

For your safety:

  • Have only qualified electricians make electrical repairs.
  • Moisture and electricity never mix. Dry hands and feet offer more resistance to electrical current.
  • Unplug tools immediately after use.
  • Do not use water to put out an electrical fire.
diagram of a plug, power pole with a ground, meter, and 3-way plug
Note to the Trainer: Using the diagram above as a guide, familiarize workers with the difference between 120V and 240V outlets. As an activity, have employees inspect power tools for proper grounding. 

Make sure that electrical power tools have a true ground or are double-insulated. For example, a drill has a third wire which is the ground wire. This means that the current will follow the ground wire—not the operator. If a drill develops a short, have it repaired before using it again.

Check that portable electric hand tools are properly grounded or use an acceptable double-insulated electric power tool. Usually a three-prong plug in a three-hole outlet provides a proper ground.

If an electrical system has only two-prong receptacles, it is not properly grounded. In that case, use only a double-insulated electric power tool. 

Ground-Fault Circuit Interrupter (GFCI)

A ground-fault circuit interrupter (GFCI) is specifically designed to protect people from electrical shock. GFCIs quickly (1/40th of a second) shut off the power in the event of an electrical short or ground fault. GFCI protection can be obtained by using special breakers, hard-wired receptacles, and portable models which can be plugged into any electrical outlet. GFCI protection should always be used when operating electrical devices outside and in wet or damp locations. 

Review the Following Points

  • Electricity always follows the path of least resistance.
  • Use an effective ground.
  • Only electricians should make electrical repairs.

About These Modules

The Ag Tailgate Training Series was developed by members of the Agricultural Safety and Health Program in the Department of Food, Agricultural and Biological Engineering. Revised by Dee Jepsen, State Agricultural Safety Leader, with editing assistance by Lisa Pfeifer and Cody McClain.

True or False Answer Key

  1. T
  2. T
  3. T
  4. T
  5. T
 

Quiz: Grounding Electricity

 

Name____________________________________     

True or False?    

1. Never use a wire attached to a pipe to act as the ground. T F
2. Electricity always follows the path of least resistance. T F
3. If the ground prong is broken off the hand tool plug-in end, it should be taken out of service. T F
4. If your body becomes part of the circuit, electricity will pass through it. T F
5. If a person comes in contact with electricity, then they may become electrocuted. T F