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Attachment keeps power flowing — and squirrels going

Why does OPPD use them?

Power outages occur for a variety of reasons: weather, vehicle crashes, trees encroaching into lines and animal interference, among others.

Squirrels spend time on the lines and power poles, as do birds and occasionally raccoons and possums. They can cause problems when they chew through lines or come into contact with equipment.

For animal safety and power reliability, OPPD’s specifications call for installing animal covers, commonly known as squirrel guard attachments, on overhead equipment. Installation of the guards in established areas is based on outage numbers.

What are they?

There are two components to what are referred to as squirrel guards. One component is just what it sounds like, rubber boots or covers that fit over wires, lightning arrestors and other equipment up on the lines near the transformers. Some areas of line that are at odd angles, such as connectors, are covered with special tape to protect against curious animals.

The other component involves installing “cutouts” on the poles. Line technicians install them on small arms near the top of the poles that contain a transformer fuse. These fuses serve as reliability protection for customers by protecting primary feed wires. The transformer fuses will fail if an animal still gets through the other protections on the pole or transformer, but that failure will cause just that transformer fuse to blow. So instead of multiple transformers out and multiple customers without power, the fuses ensure the outage is isolated.

How common are they?

Squirrel guards are on a majority of OPPD’s overhead equipment, especially in older areas of the service territory. These areas have more trees where animals can hang out. Crews continually add the guards to poles as situations arise.