Ice Accretion on Power Grid Sub-Station.
Newfoundland Hydro sub-station, Mt. Scio Rd., St. John's, spring 1995.
A buildup of clear ice ("glaze") on power grid sub-station components occurs
following several hours of rain and/or drizzle with air temperatures just below
0°C. in the near-surface air layer, causing the droplets to freeze on impact.
Accretion will grow faster in freezing rain than in drizzle owing to larger
droplet size. This may lead to failure of conductors or transmission lines if the
situation persists over a lengthy period and is not immediately followed by
thawing, especially if wind speeds are high which would place more load strain on
the equipment.
Reproduced by permission of Colin Banfield. ©1995.
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