ABB MNS iS design aspects Switchboard construction

Switchboard construction

MNS iS as part of the ABB low voltage switchgear

solution uses the well proven ABB MNS standard

design aspects. MNS aspects described in this

section are fully applicable to MNS iS.

MNS system is a verified low voltage switchgear

design in accordance with IEC 61439 series and IEC 61641.

The consistent application of the modular

principle both in electrical and mechanical design

as well as the use of standardized components

allows its flexible and compact design.

Depending on operating and environmental

conditions different design levels are offered.

Notable system advantages with regard to

design aspects:

• Optimum personal protection

• Design verified by testing

• Arc fault containment acc. criteria 1-7

• High operational reliability and availability

• Earthquake-, vibration- and shock-proof

designs are available

• Maintenance-free busbar construction

• Simple retrofitting procedures

• Compact, space-saving design

• Easy project and detail engineering through

standardised components

The switchboard is divided into vertical and

horizontal compartments thus separating

different functional areas.

As a standard, power cabling and control wiring

are strictly separated within MNS iS. The

switchboard is structured as follows:

1 Equipment compartment

All equipment, including the standard motor

starter modules (MStart) in withdrawable

design, is situated therein. The compartment

can be divided in horizontal and vertical

sub-compartments.

2 Control cable compartment

Contains the motor control devices

(MControl), control cables and terminals.

3 Power cable compartment

Contains power cables and connection units.

4 Busbar compartment

Contains the MNS main busbar system and

distribution bars. The distribution bars are

embedded in the multifunction separation

wall (MFW) which is located between the

equipment compartment and the busbar

compartment.

System highlights

• Functional areas are separated from each other

in accordance with IEC 61439 series.

• Power cables are fully separated from the control

and communication cables, thus avoiding

electromagnetic interferences.

• Different access rights to cable compartments

can be granted using different key locks.

The basic elements of the MNS iS frame

construction are “C” shaped steel profiles with

a 25 mm hole pitch according to DIN 43660.

This 25 mm equals the dimension of 1E used

in MNS to define the area usage within

the switchgear.

Each cubicle is precision constructed by bolting

horizontal and vertical profiles together, to form

a rigid modular structure. The assembly is

maintenance free as a result of the construction

method utilizing a combination of thread locking

ESLOK screws with bolted pressure plates and

thread forming screws.

The profiles are galvanic protected (Zn or AL/Zn)

against corrosion.