Utilities have been designing and constructing distribution circuits for nearly a century, utilizing wood, steel, concrete, and composite poles. These poles provide a perch for birds to hunt for prey. These poles support the wires or conductors that distribute the power needed for our everyday lives. When a raptor, or bird, comes in contact with one of these energized wires and ground, or comes in contact with two of these energized wires simultaneously the result is usually fatal to the bird and results in an outage for the utility. The Department of Justice recently ruled that under the Migratory Bird Treaty Act and the Bald and Golden Eagle Protection Act a utility whose equipment electrocutes federally protected birds could face criminal prosecution.
At Eco Electrical Systems we work together with utilities, wildlife biologists, engineers, line personnel, and manufacturers to design products that will help prevent these problems. If you have a product that you would like to see developed or are experiencing any problem we would like to hear from you. We’re here to help.
The conductor guard is manufactured to prevent animals, raptors or other avian species from coming in contact with the energized conductor while landing, taking off, or perching on a supporting structure. It is manufactured of a substrate material of schedule 40, electrical grade PVC designed for indoor or outdoor use. It is designed to be installed with hot sticks or personal protective equipment such as rubber gloves by qualified personnel. It can be removed and reinstalled for maintenance purposes.
Due to the electrical properties of PVC we have added a silicone elastomer coating. This coating will provide hydrophobicity, track resistance, arc resistance, UV resistance, and additional insulation. We feel this is necessary due to the electrical stresses incurred by being either in direct contact with the energized conductor, an electrical insulator or being in the proximity of energized conductors. If your engineering department feels that due to your location, the amount of contaminants in your area, the system voltage, or any other sound engineering principle that you do not need the silicone elastomer compound we can deliver the product without it.
When placing an order for the conductor guard we will need to know the conductor size, the insulator size according to ANSI specifications, and the voltage of the circuit. You can consult with us by phone, or fax Mon-Fri PST in the United States. Consult with an electrical engineer when designing and applying these products for use.
We are currently developing a perching deterrent. This is due to electrical testing performed on various product designs that were tested at a High Voltage Lab. Some electrical concerns were identified regarding clearances, materials, and the various designs we tested. For more information please contact us at 775-828-3301 or by fax at 775-828-3895.
There are no standards or specifications within the IEEE, NEMA, or ANSI regarding testing of these products that we are aware of at the present time. This is not to preclude that there may be a standard or specification written in the future of which we agree should be addressed. There are numerous tests that address the materials used in the manufacturing of products by ANSI and even the Underwriters Laboratories, but none regarding the use for which these are intended. Therefore, we felt that our products should be tested to ensure some type of reliability during operation. During the design of the conductor guard it was and is our opinion that certain parameters should be addressed. It is our opinion that the electrical insulation properties of an insulator should not be compromised or at least kept to a minimum. Insulators are manufactured and designed to have a certain amount of leakage distance, dry and wet flashover values, and other characteristics for the system to which they are being applied. With these considerations in mind we tried to design a product that would not compromise the purpose of the insulator and protect the bird or animal from coming in contact with the energized components.
It should be noted that there are guidelines within the National Electrical Safety Code that still need to be adhered to for the use of products that are attached to the supporting structure or the supporting arm of a structure. These are addressed in Table 235-6 of the NESC. It is our understanding and interpretation of the code that if these products are not manufactured of an insulated material that is currently being used within the industry for the voltage of which they are being subjected or applied that they would be considered to be non-insulated and therefore considered a part of the supporting arm and subject to the clearances under Table 235-6 of the NESC. It should be noted that these clearances are from the conductor or any device in contact with the conductor that would be energized at the system voltage. That would mean tie wires, pre-formed ties, or clamps. Also, careful consideration should be taken regarding the profile of the insulators used. Some insulators have a semi-conductive area around the top of an insulator and should be taken into consideration regarding clearances from the skirt or skirts.
We recently conducted testing at a High Voltage Lab on our products. They were subjected to 15 and 25 k.V. dry and wet flashover tests. The test configuration consisted of a wood pole, an 8 ft. wood crossarm, and a wood brace to support the arm. The insulator pin was grounded during all testing. Different insulators were used according to the voltage. A ground was attached to a hot stick and was used to contact the surface area of the conductor guards to simulate a grounded bird or animal, or a bird coming in contact with two phases simultaneously at various points of the conductor guard.
Reference partial discharge measurements were taken for each hardware configuration prior to testing of the guards with no detectable increase once the guards were installed.
A dry flashover test was conducted according to ANSI C-29.1. An ANSI class 55-5 insulator was flashed three times, and then the conductor guard was installed and subjected to a flashover. It did not alter the dry flashover characteristics of the insulator.
The wet flashover test was modeled according to IEEE 4.
A photo multiplier imaging device was utilized to determine if there was any discharge activity.