]2.2.9
Insulated Barriers
Where insulated barriers are required by reference standards, provide
barriers in accordance with NEMA LI 1, Type GPO-3, 6.35 mm 0.25 inch
minimum thickness.
[2.2.10
SF6 Refill Cylinders
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NOTE: Coordinate with activity to determine if
refill cylinders are required. Many activities have
an adequate supply of SF6 gas on hand.
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Provide two SF6 refill cylinders, with a minimum of 2.724 kg 6 pounds of
SF6 in each. Include regulator, valves, and hose for connection to the
fill valve of the switch.
]2.2.11
Corrosion Protection
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NOTE: Choose the level of corrosion protection
required for the specific project location. Use
stainless steel bases for most applications. In
less corrosive environments galvanized steel can be
included as an alternative to stainless steel. In
hostile environments, the additional cost of totally
stainless steel tanks and metering may be justified.
Manufacturer's standard construction material is
acceptable only in noncoastal and noncorrosive
environments.
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Bases frames, and channels of unit substation shall be corrosion resistant
and shall be fabricated of stainless steel[ or galvanized steel]. Base
shall include any part of unit substation that is within 75 mm 3 inches of
concrete pad. Paint unit substation, including bases, light gray No. 61 or
No. 49.[ Paint coating system shall comply with NEMA C57.12.28 regardless
of base and substation material.] The color notation is specified in ASTM
D 1535.
2.2.11.1
Stainless Steel
ASTM A 167, Type 304 or 304L.
[2.2.11.2
Galvanized Steel
ASTM A 123/A 123M, ASTM A 653/A 653M G90 coating, and ASTM A 153/A 153M, as
applicable. Galvanize after fabrication where practicable.
]2.2.12
Terminal Boards
Provide with engraved plastic terminal strips and screw type terminals for
external wiring between components and for internal wiring between
removable assemblies. Terminal boards associated with current transformers
shall be short-circuiting type. Terminate conductors for current
transformers with ring-tongue lugs. Terminal board identification shall be
identical in similar units. External wiring shall be color coded
consistently for similar terminal boards.
SECTION 16361N
Page 34
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