LV switchgear components include circuit breakers, changeover switches, fuses, overload relays, and disconnectors.
LV switchgears play a critical role in protecting electrical equipment. Their main components are as follows:
LV circuit breakers
Circuit breakers are the switchgear devices used to make and break the circuit. The LV circuit breaker is used in electrical systems with a voltage of less than 600V. Earth Leakage Circuit Breaker ❲ELCB❳, Miniature Circuit Breaker ❲MCB❳, Molded Case Circuit Breaker ❲MCCB❳, and Residual Current Circuit Breaker ❲RCCB❳ are the most common LV circuit breakers.
ELCB
ELCB detects any voltage leakage in equipment and protects the operating personnel from getting an electric shock. It also identifies stray voltages on the casing and body of equipment, and breaks the power to the equipment when the voltage developed is dangerously high.
MCB
MCB is the new replacement to the fuses. It de-energizes the electric circuit to which it is connected under overload and short circuit conditions. This device is installed where low breaking capacity is required.
MCCB
MCCB functions similar to MCB, but can be used in systems requiring both high and low breaking capacity. The current rating can go up to 1600A, and the interrupting range goes from 10 kA to 85k A.
RCCB
This electrical device disconnects the circuit whenever there is a chance of electric shock or unbalanced currents in the conductors. It trips the circuit on detection of leakage current.
Changeover switches
If you are depending on a local generator whenever the utility grid fails, you need a changeover switch. Changeover switches are transfer switches that facilitate the changeover of the power connection from commercial utility to the local generator, and vice versa. When the changeover can be made with the loads on, such switchgear is called on-load changeover switches. When the changeover can only be done under no-load condition, then such a transfer switch is called an off-load changeover switch. It improves the reliability of the power supply by providing uninterruptible electricity to the circuits.
Overload relay
Electric motors are the core elements in any electrical system, whether it is a high or low voltage system. Thermal protection can be offered to electric motors by using overload relays. Heat generated in the motor is detected by a heat-detecting device, and the motor is protected from getting heated above a preset temperature. The thermal overload relay cuts the power supply to the motor when an overcurrent flows to it for a long period. The principle behind the magnetic overload relay is the detection of magnetic field strength due to the motor current and is suitable for systems where temperature rises exponentially compared to the ambient.
Disconnectors
The electrical disconnectors are also called isolators. They are used to break a circuit but under offload conditions. The circuit breaker serves the same function under loaded conditions. The isolators are used to disconnect the faulty sections in a healthy LV power system and isolate the system for maintenance and repair.
Binghalib Group of companies is one of the leading switchgear component distributors in Dubai UAE. Contact us for more details.
