ABB MNS-SG - Horizontal Neutral Bus (Optional Feature); Ground Bar

10 MNS-SG Operation and Maintenance | Manual
Bus ratings and sizes
The number of installed bars per phase depends on the
current ratings. Up to five bars per phase may be installed.
Only sections with the same horizontal bus configuration
can be coupled (or spliced) together except for tie main
sections.
Busbars systems are 3-phase 3-wire or 3-phase 4-wire. See
Horizontal Neutral Bus for details.
There is the option of only having 3-phase 4-wire in the
incoming section and the rest of the lineup will be 3-phase
3-wire.
Sections in the same shipping split will be connected at the
factory. For lineups that combine multiple shipping splits,
each shipping split must be connected together during
installation using the splice kits provided on each split. The
splice kits’ bolts must be tightened to the specified torque.
See the Torque Table provided in this manual.
Horizontal bus is available in silver-plated copper or
optional tin-plated copper.
1.7.2. Horizontal neutral bus (optional feature)
When required, a 100% rated neutral horizontal busbar is
provided in the busbar compartment above the lower A-phase
horizontal busbar. For four-wire systems that have no line-to-
neutral load requirements, an incoming neutral connection
point can be provided to facilitate the power system
grounding connection, but without neutral horizontal or
distribution busbars are provided.
1.7.3. Ground bar
A continuous, sectionalized, bare-copper ground bus, rated
1,000A, is provided at the bottom-rear side of each section
running from side-to-side on the cable compartment of all
sections. In the cable compartment, the ground bar is linked
to the ground bar in other sections by a splice link.
Ground bars
The copper bus bars have a size of 9.52 mm (3/8”) of thickness
and a width of 50.80 mm (2”). The ground system can be silver
or tin plated and also bare copper.
The lateral ground bus is machined with a series of holes
spaced 2.0 in (50 mm) apart for attaching ground lugs and
other conductors. Ground the switchgear ground bus using
equipment-grounding conductors sized according to NEC
250-94, or by bonding the ground bus to the raceway
enclosing the main supply conductors according to NEC 250-
92(B).
Bus ratings and sizes
1,600A set
MBB (¼”x5”)
2,000A set
MBB (¼”x4”)
3,200A set
MBB (¼”x5”)
4,000A set
MBB (¼”x5”)
5,000A set
MBB (¼”x5”)
Ground bus