33
BUS CONN
TIE
TIE
MT22-8
BUS CONN
MAIN OR TIE
MT22-1
MAIN
SAMPLE AKD-10 LINE-UP
TRANSFORMER
TRANSITION
TRANSFORMER
TRANSITION
TT22-1
22"
TRANS-
FORMER
TO
BUS CONN
FEEDER
22"
21"
21"
800A
F22-1
22"
21"
21"
800A
21"
21"
2000A
800A
21"
21"
800A
800A
800A
BUSWAY CONN
MAIN OR TIE
ABOVE=FRONT POS'N
INCOMING BUSWAY
FRONT POSITION
BUSWAYS
BUSWAY CONN
FEEDER
ABOVE=REAR POS'N
BUSWAYS
22"
21"
21"
800A
F22-12
22"
21"
21"
FEEDER BUSWAY
REAR POSITION
B/W
ABOVE=FRONT POS'N
FEEDER BUSWAY
FRONT POSITION
BUSWAYS
21"
21"
2000A
800A
800A
21"
800A
21"
800A
B/W
LOWER
SECTION WIDTH
SECTION CODE
SECTION
DESCRIPTION
MT22-7
22"
21"
21"
800A
BUS
BUS LEVEL
21"
800A
21"
MAIN
2000A
B/W
BUS
MID
*
UPPER
BUS
CABLE CONNECTION (OTHER THAN FEEDER BREAKER)
INCOMING
OUTGOING
MID BUS LEVEL IS NOT AVAILABLE AT 5000A
(USE ONLY UPPER OR LOWER BUS LEVELS)
LEGEND & NOTES
*
FEEDER CABLE CONNECTION
BUSWAY CONNECTION
B/W
Switchgear layout and sizing
Rules and examples
Switchgear layout considerations
1. Sections can be bussed together if there are matching bus levels
in the adjacent sections. Refer to the sample AKD-10 line-up below.
2. Any breaker compartment shown on the section drawings can be
made blank to provide additional space for mounting protection,
instrumentation, and control devices.
3. Any blank compartment greater than 7 inches high can be used
for instrumentation (except vent compartments).
4. The ampere ratings shown beside each breaker symbol indicate
the range of frame sizes that are allowed in the particular section
arrangement. This takes into consideration the temperature rise
in the section due to breaker loading. Refer to ANSI C37.20.1-1993
para 7.4.2.3 for cumulative circuit breaker loading guidelines.
5. Devices cannot be mounted on breaker cubicle doors. Refer to
the instrument panel drawings on page 44 for breaker control
device mounting.
6. 3200A, 4000A, and 5000A fuse roll-outs are the same size as
their respective breakers, therefore any compartment shown
with a 3200, 4000 or 5000 amp breaker will also accommodate
a fuse roll-out and vice versa.
7. Front busway connections to a circuit breaker require a blank
compartment above the breaker for busway above or a blank
compartment below the breaker for busway below.
8. Use of fused breakers does not necessarily require 200kA bus
bracing. Bus bracing should be based on the available short
circuit current on the switchgear bus.
9. 200kA bus bracing can limit feeder breaker placement. 200kA
bus bracing does not allow adjacent 22 inch wide sections.
10. Factory review of layout is required for bus bracing greater
than 100kA
11. Some cable entrance designs are not suitable for service
entrance. Consult the factory if service entrance is required for
the incoming cable section.
12. Additional cable and conduit space is available by making
breaker sections wider (22 inch wide to 30 inch wide or 30 inch
wide to 38 inch wide) or by making the line-up deeper (7 or 14
inches). Refer to table 32.1 for switchgear depth options.
13. Maximum shipping section widths are 120 inches for indoor
construction and 96 inches for outdoor construction.
Special considerations for 5000 amp equipment
1.
5000 amp equipment is available in indoor or outdoor walk-in
aisle construction only. 5000 amp breakers are not available in
outdoor NEMA 3R non-walk-in construction.
2.
Minimum depth of a 5000A breaker section is 74 inches.
3.
Upper and lower bus levels are available at 5000 amps. The
center bus level is not available at 5000 amps.
4.
5000 amp bus is available as a bare bus design or with bus
compartment barriers. Insulated/isolated bus design is not
available on 5000 amp equipment.
5.
Sections adjacent to a 5000 amp transformer transition section
must be 38 inches wide, minimum.