HT / LT Electrical Work
High Tension (HT) and Low Tension (LT) electrical systems are essential components of electrical power distribution and management in buildings, industries, and utilities. They handle the transmission and distribution of electrical power at different voltage levels. Here’s an overview of HT and LT electrical systems, their components, functions, and key considerations:.
High Tension (HT) Electrical Systems
HT electrical systems operate at high voltages, typically above 1 kV (1000 volts) up to 33 kV. These systems are used for the transmission of electrical power over long distances.
Key Components:
HT Switchgear:
Circuit Breakers: Protect the electrical network by interrupting fault currents.
Isolators: Ensure that sections of the network can be safely de-energized for maintenance.
Transformers:
Power Transformers: Step down the high voltage from transmission levels to distribution levels (e.g., from 132 kV to 33 kV or 11 kV).
Overhead Lines and Underground Cables:
Used for the transmission of high-voltage power from power plants to substations.
Protective Relays:
Detect faults and initiate the operation of circuit breakers to isolate the affected section.
Capacitor Banks:
Improve power factor and voltage stability in the network.
Functions:
Efficient transmission of electrical power over long distances.
Reduction of power losses during transmission.
Interconnection of power generation sources with substations.
Low Tension (LT) Electrical Systems
LT electrical systems operate at lower voltages, typically up to 1 kV (1000 volts). These systems are used for the distribution of electrical power within buildings, industrial facilities, and local areas.
Key Components:
LT Switchgear:
Distribution Boards (DBs): Distribute electrical power to various circuits within a building.
Circuit Breakers and Fuses: Protect individual circuits from overloads and short circuits.
Transformers:
Distribution Transformers: Step down the voltage from HT levels (e.g., 11 kV) to LT levels (e.g., 415 V or 230 V).
Cables and Busbars:
Carry electrical power from distribution transformers to various loads (e.g., lighting, appliances, machinery).
Meters:
Measure electrical energy consumption for billing and monitoring purposes.
Capacitor Banks:
Improve power factor and reduce reactive power consumption.
Functions:
Distribute electrical power to end-users in residential, commercial, and industrial settings.
Ensure safe and reliable operation of electrical equipment.
Provide protection against electrical faults and hazards.