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Unformatted text preview: reakers at their outer ends (immediately after the service drop or lateral) they may be installed in
any of the recognized wiring methods. 7.1 Abandoned Lines and/or portions of lines no longer required to provide service shall be
removed. 7.2 Power or communication poles, lines, service drops and other line equipment shall be free
from any attachment for antennas. sings, streamers and the like. 7.3 Metallic sheaths or jackets of overhead power or communication cables shall be grounded
at a point as close as possible to ground level whenever such cables change from
overhead to underground installations. 8. Transformers
8.1 Oil-Insulated Transformers Installed Outdoors.
Combustible material, combustible buildings and parts of buildings, fire escapes, door
and window openings shall be safeguarded from fires originating in oil-insulated
transformers installed on. attached to, or adjacent to a building of combustible material.
space separations, fire-resistant barriers and enclosures which confine the oil of a
ruptured transformer tank are recognized safeguards. One or more of these safeguards
shall be applied according to the degree of hazard involved in cases where the transformer
installation presents a fire hazard. Oil enclosures may consist of fire-resistant dikes,
curbed areas or basins, or trenches filled with coarse, crushed stone. Oil enclosures shall
be provided with trapped drains in cases where the exposure and the quantity of oil
involved are such that removal of oil is important. 8.2 Dry-Type Transformers Installed Indoors.
Transformers rated 112-1/2 KVA or less shall have separation of at least 300 mm from
combustible material unless separated therefrom by a fire-resistant hear-insulating barrier,
or unless of a rating not exceeding 600 volts and completely enclosed except for
ventilating openings. Transformers of more than 112-1/2 KVA rating shall be installed in
a transformer room of fire-resistant construction unless they are constructed with Class B
(80°C rise) or Class H (150°C rise) insulation, and are separated from combustible
material not less than 1.85 M horizontally and 3.7 M vertically or are separated therefrom
by a fire-resistant hear-insulating barrier. Transformers rated more than 35,000 volts
shall be installed in a vault. 8.3 Askarel-Insulated Transformers Installed Indoors.
Askarel-insulated transformers rated in excess of 25 KVA shall be furnished with a
pressure-relief vent. Where installed in a poorly ventilated place they shall be furnished
with a means for absorbing any gases generated by arcing inside the case, or the pressure
relief vent shall be connected to a chimney or flue which will carry such gases outside the
building. Askarel-insulated transformers rated more than 35,000 volts shall be installed
in a vault. 8.4 Oil-Insulated Transformers Installed Indoors. Oil-insulated transformers shall be installed in a vault constructed as specified in this
Section except as follows:
8.4.1 NOT OVER 112-1/2 KVA TOTAL C...
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This note was uploaded on 09/22/2013 for the course ARIDBE AR taught by Professor Any during the Fall '12 term at Mapúa Institute of Technology.
- Fall '12