Savannah Valley District

Stay Grounded: Be Safe Around Electrical Systems on the Farm and in the Home

Rebecca H. Davis, Area Water Resources Agent

Summer brings thoughts of vacation, hot days, and afternoon thunderstorms! During storms, the first concern is getting inside to keep dry. However, it is important to keep in mind that electrical storms can cause power surges which can damage equipment and cause personal injury and death by electrocution if systems are not properly grounded. Clemson’s Agricultural Safety Program and the Regional Water Resources Agents are sending voltage testers to farmers to remind them to check irrigation systems before touching any part of it, especially after thunderstorms.  Also, it is crucial to check the ground rods on irrigation systems and grain bins equipped with electronic scales. A National Electric Code (NEC) states that the minimum ground rod length is 8’ and 5/8” in diameter. The rod, generally copper-coated steel, must be totally driven into the ground near the electrical control box. A copper wire connecting the control box to the rod is tightly clamped to the ground rod. This creates a path of least resistance for stray voltage to go into the ground instead of through an individual touching the energized equipment, risking the chance of injury or death.

Over time, the grounding connector which attaches the conducting copper wire to the ground rod can become loose due to freezing and thawing or even disconnected due to damage such as by mowing equipment. Therefore, it is necessary to inspect the connection on a regular basis. Another safety reminder is to always check for the presence of stray voltage by brushing any questionable equipment with the back of your hand. Grabbing a charged object will result in the inability to let go and likely cause death by electrocution.

It is also good to keep in mind that your house should also be grounded in a similar manner.

Figure 1. Copper wire is attached to a ground rod with a grounding connector.
Figure 2. Electrical control box grounding system.
Figure 3. A non-contact voltage tester.











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