Switch cabinet

MDS  type Mw

Switchgear components making up the switchboard are installed in drawers to ensure rapid and dependable

maintenance and servicing. A column maybe equipped with twelve drawers, each three 50mm modules high, given

that four modules are reserved for the horizontal busbars.

Larger components maybe installed in deeper drawers that are 6,9,12 or15 modules high, motor feeders installed in withdrawable drawers may not exceed 250kW.

Parts of a withdrawable unit A  withdrawable functional unit is made up of:   a moving part(chassis) that supports the equipment  a fixed part bearing the positioning elements for the moving  part.   disconnecting contacts for power connections, which clip on to the busbars.   disconnecting contacts for auxiliary connections. Functional units comply with standard IEC 60439-1 and with WWW-type  withdrawability specifications.

Safety

Drawers are built in compliance with international standard IEC 60439-1 which regulates the drawer extraction and locking system.

The connection mechanism is designed to allow the drawer to be set to any of the four positions presented below. The degree of protection of the switchboard is maintained in all positions(connected, test, disconnected and drawer removed) .

This is made possible by the door that can remain closed in these four positions.

1) Connected position

    Power and auxiliary circuits are all connected. This position maybe locked using up to three padlocks.

    A safety system prevents door opening as long as the circuit breaker is closed (ON position) .The interlocking mechanism connects the door handle and the operating shaft on the circuit breaker.

2) Test position      Power circuits are disconnected(upstream and downstream),auxiliary circuits remain connected.      This position maybe used to check auxiliary circuits and may be locked using up to three padlocks. 3) Disconnected position      All circuits are disconnected. This position maybe locked using up to three padlocks. 4) Removed position