2.6.3.1
Fuse Cutouts
Medium-voltage fuses and cutouts shall comply with NEMA SG 2 and shall be
of the [loadbreak] [nonloadbreak] [enclosed] [open] type construction
[rated [5.2] [7.8] [15] [27] [28] kV and of the [normal] [heavy]
[extra-heavy] [ultra-heavy] -duty type] [ratings and types indicated].
Open-link cutouts are not acceptable. Fuses shall be either indicating or
dropout type. Fuse ratings shall be as indicated. Fuses cutouts shall be
equipped with mounting brackets suitable for the indicated installations.
2.6.3.2
Power Fuses
[Expulsion-type] [Current-limiting] power fuses shall have ratings in
accordance with ANSI C37.46 and as follows:
a.
Nominal voltage....................................[_____]
b.
Rated maximum voltage..............................[_____]
c.
Maximum symmetrical interrupting capacity..........[_____]
d.
Rated continuous current...........................[_____]
e.
BIL................................................[_____]
2.6.3.3
E-Rated, Current-Limiting Power Fuses
E-rated, current-limiting, power fuses shall conform to ANSI C37.46.
2.6.3.4
C-Rated, Current-Limiting Fuses
C-rated, current-limiting, power fuses shall open in 1000 seconds at
currents between 170 and 240 percent of the C rating.
2.6.3.5
R-Rated, Current-Limiting Fuses
R-rated, current-limiting, fuses shall be used with medium-voltage motor
controllers only. R-rated fuses shall conform to ANSI C37.46.
2.7
MOTOR SHORT-CIRCUIT PROTECTOR (MSCP)
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NOTE: MSCPs are components of motor controllers
rather than fuses. MSCPs, therefore, have no ampere
ratings and are identified by letter designations,
A-Y. Due to a limited number of MSCP manufacturers,
MSCPs should be used only as a sole-source item.
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2.7.1
General
Motor short-circuit protectors shall conform to UL 508 and shall be
provided as shown. Protectors shall be used only as part of a combination
motor controller which provides coordinated motor branch-circuit overload
and short-circuit protection, and shall be rated in accordance with the
requirements of NFPA 70.
SECTION 16475A
Page 15
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