Power-system switching, protection, control, monitoring and regulation
There has been a significant increase in the global demand for electrical power in recent years. As a result, the need to ensure the reliable operation of power systems is paramount.
Electric switchgear is required at every switching point in a power system. Besides the power network, switchgear is also required in virtually every sphere of our modern society, from manufacturing and processing plants, through to residential homes and remote rural areas. The voltage levels alter dramatically, depending on transmission, distribution and utilisation. This entails the safe control of the differing fault-current levels occurring between the generating stations and final load-centres. Therefore various types and combinations of switchgear-assemblies are required, depending upon the differing voltage levels and functions of the network.
Switchgear, as a generic term entails all devices associated with power-system switching, protection, control, monitoring and regulation. A combination of these devices in a logical manner, in order to safely, reliably and efficiently fulfil these functions, form a manufactured switchgear assembly.
Safety and reliability
International and National standards define the manner in which electric circuits of installations must be safely and reliably realized, and the capabilities and limitations of the various devices which are collectively referred to as switchgear assembly. The main functions entail;
- Full protection of personnel and plant.
- Full isolation, wherever required, in the various sections of the network/s.
- Full control and monitoring of the network.
Low Voltage Switchboards (Pty) Ltd.
Low Voltage Switchboards (Pty)Ltd is entering its 17th year of operation and, in this period, has established itself as a large independent manufacturer of high-quality switchgear assemblies in the low voltage market category ( up to & including 1000Vac). The product range includes Motor Control Centres (Standard and Containerised), Power Distribution Boards, and Sub-Distribution Boards, PLC/Automation Panels, Electronic-Drive Panels (VFI’s and Soft starters), Control Desks and general control panels.
The company benchmarks world standards and are an approved SANS 1973 enterprise, being accredited to the SABS ‘mark of approval’ for all its products. Low Voltage Switchboards (Pty) Ltd has, over these years, forged very strong partnerships with all the reputable switchgear manufacturers. Among these, special mention must be made of the CUBIC System from Denmark, which is exclusively used by Low Voltage Switchboards (Pty) Ltd for its range of switchboards.
This system is franchised and supplied by SABELCO (Pty)Ltd in South Africa, in which CUBIC of Denmark owns a 40% share. CUBIC was founded in 1973, based on a unique idea of a modular system for the construction of electrical switchboards. They manufacture and market a low voltage modular system in mild steel or stainless steel – grades 3CR12, 304 and 316 – for electrical switchgear assemblies in ‘fixed-pattern’ and/or ‘fully-withdrawable pattern’. They are specialists in individually adapted enclosures for Power Distribution Boards, Motor Control Centres, marine, and general control panels. All the products are Type-Tested by KEMA and ASTA and conform fully to IEC 60439 and the latest IEC 61439 specifications. They are also tested and conform fully to UL (USA), Det Norske Veritas and Germanischer Lloyd.
The following are the listed verified tests;
- Temperature-rise limits.
- Dielectric properties.
- Short-circuit withstand strength.
- Effectiveness of the protective circuit.
- Clearance and Creepage distances.
- Mechanical operation.
- Degree of Protection (IP rating/s).
- Vibration and Shock withstands.
- Arcing-fault test.
Low Voltage Switchboards (Pty) Ltd offers comprehensive, integrated switchgear solutions, ranging from ad-hoc installations to full turnkey projects. The company customises solutions to the specific requirements of each individual workplace and client. It services a wide range of industries, including mining, manufacturing, water/waste-water treatment, pulp & paper, food & beverage, agriculture, pumping and cement sectors, and has successfully secured and completed many prestigious projects in South, Southern, Central and West Africa and as far-afield as Chile and Russia.