S&C PMH, Instructions For Operation Manual

Page: 30 / 35

S&C Source-Transfer PMH Pad-Mounted Gear
With Micro-AT
®
Control
Outdoor Distribution (14.4 kv and 25 kv)
S&C ELECTRIC COMPANY
s
663-503 INSTRUCTION SHEET
Page 30 of 35
August 14, 1995
Ratings for S&C Power Fuses
with Uni-Rupter
Complete ratings and capabilities of S&C Power Fuses
with Uni-Rupter as applied in S&C Source-Transfer PMH
Pad-Mounted Gear are shown in the table below. Uni-
Rupter is also capable of carrying and interrupting load
currents up to and including the emergency peak-load
capabilities of the associated SML Power Fuses, or up to
400 amperes at 14.4 kv and 200 amperes at 25 kv when
used with Fault Fiter Electronic Power Fuses. In addition
to the load-dropping capabilities shown, Uni-Rupter is
capable of interrupting transformer magnetizing currents
associated with the applicable loads, as well as line-charg-
ing and cable-charging currents typical for distribution
systems of these voltage ratings. The duty-cycle fault-clos-
ing capabilities shown for S&C Power Fuses with Uni-
Rupter represent the fault-closing capabilities of the fuse
with Uni-Rupter when the fuse is closed with a purposeful
thrust without hesitation. Following the specified number
of such closings (one or two), Uni-Rupter will remain
operable and able to carry and interrupt rated current.
APPENDIX C — Continued
RATINGS AND CAPABILITIES FOR S&C POWER FUSES WITH UNI-RUPTER
Fuse Type
Ratings Live Switching Capabilities, Amperes, Rms
Kv Amperes, Rms
Load
Dropping
Load Splitting
(Parallel or
Loop Switching)
Duty-Cycle Fault-Closing
(Asym.)
Nom. Max BIL Max
Interrupting
(Sym.)
One-Time
Two-Time
SML-20
14.4 17.0 95
200E or
200K
14 000
200 200
22 400 13 000
25 27 125
200E or
200K
12 500
200 200
20 000 13 000
SML-4Z
14.4 17.0 95 200E 12 500
200 200
20 000 13 000
25 27 125 200E 12 500
f
200 200
20 000 13 000
Fault Fiter
14.4 17.0 95 400 14 000
400 400
22 400 13 000
25 29 125 200 12 500
200 200
20 000 13 000
f
Applicable to solidly grounded-neutral systems only, with fuses con-
nected by single-conductor, concentric-neutral-type cable to a trans-
former or transformers. Rating is 9,400 amperes rms symmetrical for all
other applications.