This document provides an overview of general information about low voltage switchgear and controlgear assemblies, including their electrical characteristics, classification, protection levels, and forms of separation. It also discusses the effects of electric arcs on assemblies and human beings, as well as the characteristics of internal arc-proof switchgear and controlgear assemblies.
This manual provides an overview of ABB's arc‑proof low‑voltage switchgear and controlgear assemblies, covering the applicable IEC standards, safety requirements and the definition of assemblies. It explains the importance of arc‑proof design, the effects of internal arcs, and the regulatory background such as the European Directive 2006/95/EC.
The document details constructional types (primary and secondary distribution switchgear, motor control centers, control boards, and construction‑site assemblies), protection classifications (IP codes), and testing procedures. It also distinguishes between Type‑Tested (TTA) and Partially Type‑Tested (PTTA) assemblies and outlines the requirements for each.
| Rated Voltage | ≤ 1000 V AC or 1500 V DC |
|---|---|
| Applicable Standard | IEC 60439‑1 |
| Protection Rating Code | IP (International Protection) code |
| Assembly Types | Type‑Tested Assembly (TTA) and Partially Type‑Tested Assembly (PTTA) |
The assemblies are governed by IEC 60439‑1, which defines construction, safety and maintenance requirements.
The IP code indicates the degree of protection an enclosure provides against solid objects and water ingress, as defined in IEC 60529.
The standard defines Type‑Tested Assemblies (TTA) and Partially Type‑Tested Assemblies (PTTA).
MCCs are intended for the control and centralized protection of motors, providing switching and protection equipment with drawer‑units for each motor.