Technical Papers: ABB circuit-breakers inside LV switchboards

An electrical switchboard is the combination of more protection and switching devices assembled in one or more adjacent compartments.

A switchboard is formed by the compartment, which the Standards name “enclosure” (with support and mechanical protection functions for the different components enclosed), and the electrical equipment, constituted by the apparatus, the internal connections and the incoming and outgoing terminals for the connection to the installation.

click here to download the guide

This Technical Paper is intended to deal in detail with the equipment in the switchboard, providing the reader with the basic information necessary to choose the circuit breakers to be installed inside low voltage switchboards in the easiest and most correct way, paying particular attention to ABB SACE range of products.

After a quick survey of the main product Standards concerning switchboards and circuit-breakers, IEC 60439-1 and IEC 60947-2 respectively, the main problems which a manufacturer has to face when designing a switchboard are analyzed. 

This Technical Paper is divided into three main parts dealing with the problems of overheating in switchboards, general prescriptions to improve the current carrying capacity of the circuit-breakers inside enclosures and the problems caused by short-circuit in switchboards.