Farm overhead & underground power lines: Are your poles sagging?

Power lines are used to carry electrical power from the source to the electric equipment load. Typically, lines are mounted at approximately 15 to 18 feet above the ground or buried three feet below the ground. Electrical services lateral to outbuildings and other remote locations are often installed below grade in conduit. Above-ground power lines are easier to install than underground lines. However, above-ground wiring is more often affected by harsh weather or vehicle accidents and can get in the way of large vehicles or equipment.

Are your poles sagging?

Overhead, customer-owned power lines and poles may sag or shift respectively over time. When this occurs, restore the tension and the proper height clearance. It is important to keep areas surrounding power lines clear of foliage or other objects. Trees can damage or knockdown overhead power lines.

Wooden overhead power poles can rot near the pole base and fall over

Regularly inspect poles for rot or insect damage and replacing them before a structural failure occurs. Avoid future pole rotting potential by using pressure-treated poles designed for direct burial. Locate power poles away from farm vehicle traffic routes to prevent gouging of the pole material by vehicle bumpers or tractor implements.

Overhead single conductors can be damaged by high-vehicle impacts

Stop overhead damage from tall vehicles by routing overhead conductors to avoid passing over roadways or tractor paths. Prevent wires from being pulled down by making sure the installed height of the conductors provides adequate clearance for all farm-owned vehicles and attachments. Consider using underground wiring when wires must cross roadways to eliminate impact possibilities. Use signage to mark or identify low overhead conductors for visitor drivers.

Overhead conductors can be damaged by storm-related activity

Prevent tree damage to conductors by inspecting, trimming, or removing nearby tree limbs that could hit conductors if broken during a storm. Stop conductor shorting or grounding by removing any “climbing” vines like Virginia Creeper, Wild Grape, Ivy, etc. that wrap around and climb the pole to contact the conductors. Prevent unexpected power loss by periodically inspecting, tightening, or replacing defective conductor-attaching devices such as insulators, cable clamps, and splices. Wind and ice accumulation can easily pull down weak attachments or loosely spliced cables.

Underground conduits or direct-buried cables can get damaged during digging or site work activities

Avoid nuisance power losses by meeting with digging contractors to define all underground feeder routings and buried utility excavation markings before work begins. Reduce the chance for an outage by always using plastic “buried cable warning” marking tape installed over the buried conductors. Backhoe operators will lift the warning tape before damaging the cable beneath. Prevent accidental underground damage to critical circuits by installing permanent warning markers on posts driven into the ground at regular intervals along the buried conductor route.

Underground electrical systems can become shorted or grounded by infiltration of ground-water

Prevent unexpected cable failures by periodically inspecting cables and splices in underground manholes and junction boxes. Rework any failing splices with modern splicing kits before the failure occurs. Prevent excessive amounts of ground-water from infiltrating manhole vaults by maintaining existing, or installing new sump pumps with automatic level switch activation and pump failure alarms. Test the floats periodically. Proactively replace any underground cable runs with a history of failure due to age-related deterioration. One new cable replacement project will be less costly than repeated repairs with business interruption losses.

Other tips to consider:

  • Never try to move or alter exposed utility power lines on your own. Only qualified utility workers should handle exposed power lines.
  • Customer-owned power lines should be handled by licensed electricians.
  • Always call the digger’s hotline in your area to have the locations of existing utility-owned underground wiring marked out prior to starting any excavation work on your property.
  • Mapping of installed farm-owned underground power lines and referring to it when excavating can help prevent cutting or damaging the lines.

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© 2021 The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. This article is for informational purposes only and is not intended to convey or constitute legal advice. HSB makes no warranties or representations as to the accuracy or completeness of the content herein. Under no circumstances shall HSB or any party involved in creating or delivering this article be liable to you for any loss or damage that results from the use of the information contained herein. Except as otherwise expressly permitted by HSB in writing, no portion of this article may be reproduced, copied, or distributed in any way. This article does not modify or invalidate any of the provisions, exclusions, terms or conditions of the applicable policy and endorsements. For specific terms and conditions, please refer to the applicable endorsement form.

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