A low-voltage (LV) switchboard can be defined as equipment consisting of the combination of one or more protection or switching devices, with any control, measurement, signaling, protection, regulation, etc. devices, completely assembled under the responsibility of the manufacturer, with all electrical interconnections and internal mechanics, including structural support elements.
The rated voltage of these switchboards is up to 1000V for alternating current switchboards and 1500V for direct current switchboards.
Low voltage switchboards have the function of providing electrical protection to both the system and the operators, against the thermal and mechanical stresses of short-circuit currents. Specifically, they protect against overload currents, over-circuit currents and insulation faults.
Thanks to low voltage switchboards, it is possible at any time to have an indication of the state of health of the system and to check the processes in place.
The reference standard that regulates low voltage switchboards is CEI EN 61439 1/2/3.
- CEI EN 61439-1 “Assembled protection and switching equipment for low voltage (LV switchboards) – Part 1: General rules”
It establishes general definitions, service conditions, construction requirements, technical characteristics and verification requirements for low voltage switchgear (LV switchgear).
- CEI EN 61439-2 “Assembled protection and switching equipment for low voltage (LV switchboards) – Part 2: Power switchboards”
It defines the specific requirements of protection and power switching equipment.
- CEI EN 61439-3 “Distribution panels for untrained personnel”
Contrary to Part 1 of the legislation, power panels (part 2) are designed to be used by ordinary people, therefore with output circuits equipped with automatic and differential switches for domestic and similar use. These are panels with a rated phase voltage not exceeding 300V AC, rated current of the output circuits limited to 125A and rated current of the panel not exceeding 250A.
TYPES OF LOW VOLTAGE SWITCHBOARDS
The family of low voltage switchboards includes different types of switchboards, according to their function.
C.R. Technology Systems manufactures LV switchboards in compliance with the current regulations and according to the customer needs. The types of switchboard can be:
- MCC (Motor Control Center)
- Euro PC: Power Center
- Euro P&C: Command and control panels
- Euro SDS: distribution panels and auxiliary service panels inside the shelter (switching on lights, sockets, aux medium / low voltage circuits, power supply for fire and intrusion prevention systems,..)
The MCC panel has a modular and compact structure, made up of single units called drawers. It includes modules with fully extractable technology that allows, in the event of a fault, to be replaced quickly, easily and safely.
These sections house control units mounted in the drawer compartments, a common busbar for distributing power to the control units, and a network of conduit and conductor entry areas to accommodate incoming and outgoing load and control cables.
This type of switchboard represents the best technical choice for creating industrial electrical systems in which it is necessary to control from a single control room a complex production process of a large industrial plant, such as chemical industries, refineries, platforms, oil plants, power plants, medium and high voltage substations and plants, etc.
Each MCC drawer has a mechanical system to operate the switching devices contained within it and warning lights to indicate the status of the controlled system.
The safety of the MCC panel is guaranteed thanks to its structure with separate and hermetically insulated compartments.
The Euro PC and Euro P&C panels are command and control panels, for plant protection, equipped with RTU, BCU, transformer and line equipment, which include switches, gateways, computers and industrial servers. All these devices can be connected to the SCADA system, which guarantees the remote control and command of medium voltage switchboards.
Euro P&C is a LV panel designed to house a variety of accessories and equipment for operation, control, signaling and protection. Its robustness makes it ideal for the protection of continuous processes in installations such as refineries, electrical and petrochemical plants.
The Euro PC switchboard is constructed for the distribution of primary LV electricity and is made up of prefabricated modules in steel sheet, suitable for floor installation. The internal sheets are subjected to galvanizing treatment (sendzimir/galvanized) , while the exterior is painted with RAL 7035 epoxy powders.
It has a degree of protection equal to IP55 for outdoor use and IP20 for indoor use.
The Euro SDS switchboard can be divided into two categories: distribution switchboards and auxiliary service switchboards inside the shelters. It is designed for the command and control of small powers: switching on lights, electrical sockets, medium and low voltage auxiliary circuits, power supply for fire and anti-intrusion systems.
Its degree of protection can be from IP31 (open version) to IP55 with blind door or transparent door with toughened glass.
