Published on 03/27/96

Some Farm Irrigation Systems Shocking

The condition of some farm irrigation systems is shocking.


"We see an average of one death every year caused by electrical problems in irrigation systems," said Kerry Harrison, an engineer with the University of Georgia Extension Service.

"This is one thing farmers need to fix before it's broken," Harrison said.

Most irrigation systems powered by three-phase electrical lines run on 480 volts. But Harrison said it's not the volts, but the amps that present the most danger.

AMilliamps can kill a man," he said. "But some of these larger systems have 30 to 50 amps running through them."

As systems age, the parts wear. Conduits break, and insulators fray or crack and expose the wires. They wear slowly, but they do wear. Eventually they threaten the farmer's safety.

Bitter winter cold this year made conduits and wire insulation brittle and prone to cracking or breaking. If water entered the system, it could have frozen and expanded. This could create more problems by causing shorts in the wiring.

Harrison said farmers should inspect their irrigation electrical systems as a part of their routine maintenance. It's best to inspect in early spring before the season's first use.

A thorough electrical system inspection includes checking for:

* Broken insulation.

* Exposed wiring.

* Wiring run through an inappropriate conduit or not in a conduit.

* Inadequate or no grounding.

"Farmers can do their own inspection if they're confident in their knowledge of electrical systems," he said. "Or they can hire an electrician."

Before inspecting any electrical equipment, check for yourself that it's turned off at the main switch. Harrison also tests metal parts with a small pen-like indicator that lights when electricity is present, just to be sure.

If live exposed wires touch a metal part of the system, it becomes "hot," or electrically charged. If someone touches the "hot" part, he can become the ground.

Most electricians install a wire from the system's metal frame to a metal rod pushed into the soil. That provides a safe route for stray electricity to follow. This simple step can prevent a person from becoming electrocuted.

Other areas to inspect include disconnect switch boxes. "Some systems don't even have disconnect switches in the field. That's dangerous. One needs to be installed immediately."

Many boxes aren't as rodent-proof as they need to be, Harrison said. Birds, rats, squirrels or other small animals may have nested in the box over the winter. If not removed, the nest could catch on fire from live wires, shorting out the system.

Harrison said perils he sees often are wires strung across field surfaces. "I see that too much,"he said. These wires are vulnerable to damage from tractor or implement tires, animals and weather.

Some farmers also burn off fields with exposed wires running through them, burning off protective insulation. Without insulation, the "hot" wire can cause its own fire in dry grass or crop debris.

Most accidents happen during everyday activities. "Farmers get so used to the equipment," Harrison said, "they lose respect for it and the injury it can cause."

Farmers and others need to develop safe habits when working with their equipment, especially irrigation systems powered by generators.

Safe habits include:

* Touching electrically powered equipment with the back of your hand before grasping it.

* Using a volt/ohmmeter to detect electricity where it's not supposed to be.

* Buying a light indicator to test metal equipment for an electrical charge (about $20).

* Regular inspections for blackened areas around switches or outlets, arcing or exposed wires. These point to problems that need immediate repair.

"One death a year from these problems is one too many," Harrison said. "Farmers and operators need to be aware of the threat on their lives. Electricity doesn't give you a second chance."