Proper Application; Application Notes; Ratings - S&C Loadbuster Instruction Sheet

Application Notes

The Loadbuster tool must only be used for specific switching applica tions that are
within the ratings of the tool selected. Loadbuster tool ratings are listed on a ratings
label attached to the chassis of the tool. Ratings are also listed in Specification
Bulletin 811-31.
When used with appropriately designed "hook-equipped" disconnects, cutouts, power
fuses, fuse limiters, and pad-mounted gear, the Loadbuster tool is suitable for these
live-switch ing duties of single- or three-phase overhead distribution circuits through
34.5 kV and underground distribution cir cuits through 25 kV:
• Transformer switching—Transformer load currents up through 600 amperes
nominal, 900 amperes maxi mum, as well as transformer magnetizing currents
associated with the applicable loads
• Line switching—Load-splitting (parallel or loop switching) and load-dropping of
currents up through 600 amperes nominal, 900 amperes maximum; also line dropping
(charging currents typical for distribution systems of these voltage ratings)
• Cable switching—Load-splitting (parallel or loop switching) and load-dropping of
currents up through 600 amperes nominal, 900 amperes maximum; also cable dropping
(charging currents typical for distribu tion systems of these voltage ratings)
• Capacitor bank switching—Switching of single capacitor banks, as shown in Table 2.
Table 1. Ratings
Item
Loadbuster—The S&C Loadbreak Tool, use
with overhead distribution devices
Loadbuster—The S&C Loadbreak Tool, use in
suitably designed pad-mounted gear
Loadbuster—The S&C Loadbreak Tool, use
with overhead distribution devices
Table 2. Capacitor Bank Ratings
Loadbuster
Nominal System
Catalog Voltage, kV,
Number Three-Phase
12 thru 14.4
16
5300R3
20.8 thru 23.9
24.9 and 26
20.8 thru 23.9
24.9 and 26
5400R3
27.6
34.5
Loadbuster tools must not be used for switching parallel ("back-to-back") capacitor banks.
①
Loadbuster tools must not be used for switching ungrounded-wye con nected banks—or grounded-wye
connected banks on ungrounded sys tems—where maximum system operating voltage exceeds 18 kV for
Loadbuster tool catalog number 5300R3 or 29 kV for Loadbuster tool catalog number 5400R3.
WARNING
Rating
kV
Nom. Max
14.4/25 27
14.4/25 27
25/34.5 38
Maximum Capacitor Bank Rating,
kVac, Three Phase
Solidly or Effectively
Grounded System
Single Banks, Single
① ①
Grounded-Wye Ungrounded-Wye
Connected Connected
1800 1800
2400 2400
3000
3600
3000 3000
3600 3600
3600 3600
4800
S&C Instruction Sheet 811-505

Proper Application

Catalog
Amps, Interrupting
Number
Nom. Max
600 900 5300R3
600 900 5300R3-E
600 900 5400R3
Ungrounded System
Single Banks,
①
Banks,
Grounded- or
Ungrounded-Wye
Connected
1800
2400
3000
3600
3600
3