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Insulating Power Lines and Transformers

Insulating Transformers and Power Lines

Take the initiative, be proactive and help us keep our wildlife safe by insulating your transformers and power lines. Remember, there is no company or government agency that monitors power lines and transformers or provides the equipment to ensure the safety of wildlife. It is up to us to keep our wildlife safe!

Send an email to if you would like to isolate your transformer. Our Stop the Shocks team will help you inspect the location, prepare a quote, provide payment details, order/receive products, and liaise with ICE for installation.

How Can You Tell if Your Power Lines are Safe?

Insulated wires are thick and have a black or grey coating. If the cable is not insulated it will be thinner and grey (see image above).

As a general rule, high-voltage power lines have an “insulator” between the cable and to the pole. You can see how dangerous the cables are by looking at the size of the insulator. A clear indicator that there is an extreme amount of electricity emerging from the cable is a large insulator protecting the cable from the pole.

The highest wires in the pole (normally connected to the top of the post) have the most voltage because it is the main distribution line. These cables can be 2,400 volts up to 34,400 volts.

The cables that are just below the transformer barrel are of lower voltage and still deadly if the monkey touches more than one cable or also touches something grounded (tree, pole, transformer).

If there is only one cable under the barrel, it is a one-phase system and this cable does NOT need to be insulated. Wildlife must touch at least two uninsulated electrical wires (or one wire and something grounded) to be electrocuted.

If there are three wires under the barrel, it is a 3 phase system. You can easily identify these wires because they are commonly connected to a bar that separates them. Of these 3 wires at least two (the bottom two) need insulation (the neutral top line does not need to be covered).

The lowest cables in the pole, the closest to the ground, are telephone lines, Cable TV, internet and fiber optic cables. All these are safe for wildlife to travel. You can distinguish these from electric wires because they are almost always black. Monkeys prefer to walk on these cables because they are thicker and more stable.

What Does and Uninsulated Transformer Look Like?

An uninsulated power transformer

Uninsulated electrical transformers have many dangerous components and if any part of them is touched by wildlife, it will be severely electrocuted. The voltage is high towards the top of the post and gradually decreases towards the bottom, but all parts can be fatal. This is an example of just one transformer style, there are many different styles of transformers with different components, but they all contain at least two of these six main components.

  • Stirrup and Hot Clamp
  • Fuse Cutout Switch
  • Primary Bushing Inputs
  • Lightning Arrestor
  • Secondary Outputs
  • Cables from Hot Clamp to Fuse Cutout/Bushing

How Can You Tell is Your Transformer is Safe?

A transformer insulated with wildlife protection equipment

Insulated transformers have grey silicone rubber wildlife protective equipment installed (See attached images). In Nosara, we have several different transformer styles and some require more protective equipment than others. We also have several transformers that are only part insulated which makes it harder to know if the transformer is safe or not. Especially when the protection is the same grey color as the rest of the transformer, it can be difficult to know. If you are not sure, send an email to Refuge for Wildlife at

Below you will find images of the main covers we use to protect our wildlife from electrocutions. With a quick glance, you will be able to see instantly if the transformer has been insulated when looking for these key equipment components for wildlife protection. If you are not sure, please take a photo of your transformer and send it by email – we can gladly confirm the safety of your transformer!

Stirrup Hot Clamp Cover
Fuse Cutout Cover
Primary Input Bushing Cover





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