Low Voltage (LV) Distribution System

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Distribution System

The distribution system is defined as the part of electrical power system which distributes electrical power for local use. On the basis of voltage level a distribution system can be classified in two categories viz.

  • Low Voltage (LV) Distribution System

  • High Voltage (HV) Distribution System

Low Voltage (LV) Distribution System

The distribution system which operates on the voltage levels that are directly utilised without any further reduction. It is also known as low tension (LT) distribution system or secondary distribution system. The low voltage distribution system is the part of electrical power distribution network which carries electrical power from distribution transformer to energy meter of consumer.

The voltage level of LV distribution system is typically equal to the mains voltage of electrical appliances. The LV distribution system is a 3-phase 4-wire distribution network.

Most modern low voltage distribution systems are operated at AC rated voltage of 230/415 V at 50 Hz in India and 120/208 V at 60Hz in USA.

Components of a Low Voltage Distribution System

  • Distribution Transformer – The distribution transformer is a step down transformer which has delta connected primary winding and star connected secondary winding. It sends electrical power to the distributors.

  • Distributor – A distributor is a conductor from which tapings are taken for supply to the consumers. The current throughout the distributor is not constant since tapings are taken at various places along its length.

  • Service Mains – It is a small cable which connects the distributor to the electricity meter of the consumer.

Types of Loads Connected to LV Distribution System

Generally, the low voltage loads are of two types as follows −

Single Phase Loads

The 1-phase loads are operated at 230 V (in India) which are supplied by connecting them between one phase and neutral wire of the supply system (see the figure). The examples are home appliances such as fans, bulbs, TV, 1-phase motors etc.

Three Phase Loads

The three phase loads are operated at 415 V (in India) which are supplied by connecting with three phase wire (delta connected loads) or three phase wires with neural wire (star connected loads). Examples of 3-phase loads are 3-phase induction motors etc. The three phase loads are also two types as −

  • Star Connected 3-Phase Loads

  • Delta Connected 3-Phase Loads

Updated on 05-Jul-2021 07:40:49