HomeMy WebLinkAbout14 Substation mitigation measures Agenda Item #
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TRUCKEE
Public Utility District
Workshop
To: Board of Directors
From: Joe Horvath, District Electrical Engineer
Date: January 31, 2007
Date of Board Meeting: February 7, 2007
Subject: Mititgation of Animal Induced Substation Outages
1. WHY THIS MATTER IS BEFORE THE BOARD
The District has experienced several substation outages over the last few years caused by
squirrels and other vermin. This workshop item is to discuss applied mitigation measures.
2. HISTORY
Substation outages caused by animal contact incidents, even if they do not result in equipment
damage, are very costly to the District and to our customers. These outages are caused when
an animal bridges a high voltage and a grounded surface with their body, resulting in a flow of
short circuit (fault) current and the inevitable outage.
3. NEW INFORMATION
It is almost impossible to prevent animals from entering the substation area, but it is possible to
reduce the available exposed high voltage contact surfaces that are in close proximity to
grounded surfaces, typically at a bushing insulator. The District has installed insulator shields
and bird cage guards to minimize the available contact area at these critical locations. Attached
for your consideration are photographs depicting damage resulting from animal induced outages
and the installed protective devices.
4. RECOMMENDATION
This is a workshop item. No formal Board action is suggested.
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Recloser with Arc Flash Damage at Tahoe Donner Substation
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Missing Bus Insulator at Tahoe Donner Substation
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Bird Cage Guards on a Recloser at Martis Valley Substation
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Insulator Shields installed at Martis Valley Substation