What are Switchgears?

Electrical equipment needs to be protected against a sudden surge in voltage which could damage or destroy them. The tools like switches (circuit protection devices), fuses, relays, circuit breakers function to protect, control and isolate electrical equipment against damage. A combination of these tools is known as Switchgear.

During normal working, switchgear permits switching ON or OFF of distributors, generators, motors, transformers, transmission lines and other electrical equipment. Switchgears effectively disconnect the power supply, thereby preventing damage to the electrical appliance and the person handling it. Protection is provided against electrical surges, faulty earthing and short circuits. Switchgears also provide protection against overheating beyond the specified range.

Switchgear Types

Low Voltage (LV) Switchgears have a rating capacity of up to 1KV. Typically Earth Leakage Circuit Breakers, HRC fuses, Offload Isolators, Moulded Case Circuit Breakers (MCCB) and Miniature Circuit Breakers (MCB) fall into this category.

Medium Voltage (MV) Switchgears have a rating capacity between 3KV and 36KV. These have different types including metal-enclosed indoor or outdoor switchgear, gas-insulated switchgear, metal-clad switchgear, and others.

High Voltage (HV) Switchgears have a rating capacity above 36KV. Due to high voltage, the arcing produced in course of transition is also high. For this reason, HV switchgear has determined attributes for dependable and safe functioning.

Circuit Breakers

MCB- Miniature Circuit Breakers

MCB’s are electromechanical tools that provide protection and measurement up to 125 A. They sense a surge in current usually caused because of short circuit and automatically trip to disconnect the power supply. MCB’s have a simple working mechanism with two contacts points; one fixed and one movable. The movable point disconnects making the circuit open to trip the power supply.

MCCB- Molded Case Circuit Breaker

MCCB’s are protection devices for requirements up to 1600 A. MCCBs come with a manual switch for physical operation. These are best suited for protection against overload in the circuit. MCCBs have bimetallic contact and protect against excess heating and excess current.

ACB- Air Circuit Breaker

ACB’s are tools providing safety against short-circuits and excess current. They are usually installed in LV circuits for the protection of industrial plants and electrical machines such as capacitors, generators, and transformers for measurements ranging from 630 A to 6300 A.

Selection of Switchgear – Points to consider

The work of the switchgear or feeder – Depending on what the device is being used for is important. Whether for overload protection, installation protection, group- protection or motor safety? An appropriate protection device should be selected based on these factors.
Current Range – The operating current range for the equipment should be considered while choosing the desired protective switchgear. The requirements for the specific work should be taken care of in the setting range of the switchgear. One current setting may be overlapped by more than one capacity range of switchgear. (eg. 100 A or 125 A CB rating can cover the 80 A range).
Operational Voltage – The making/breaking capacity of the protective switchgear is important for the protection of the electrical equipment. The making/breaking capacity of the switchgear should be equal to or greater than the capacity of the current at the point of installation.
Specific Considerations – Reduction factors, like surrounding ambient air temperature and altitude of installation, should be taken into account. These factors will help in choosing the right type of protective switchgear for optimum performance.
Type of Co-ordination – The downstream contactor is chosen in consideration with the type of co-ordination, Type-1 or 2.
Method of Mounting – Mounting method is a decisive aspect for the adapter plates of the Modular mounting system. One should consider whether the switchgear of choice can be installed with the chosen method of mounting.
Connecting Wires or Cables – Wires/cables should be chosen per the current capacity/thermal overload of the switchgear. The optimum length of the connecting cable is required to prevent shock hazards caused by touch potential due to short-circuit.

Pankaj Electricals provides a range of safety Switchgears from the renowned brand Legrand, for various domestic, industrial and commercial applications. The wide range of MCB’s, MCCB’s, ACB’s, Controlgears, Modular Devices conforms to ISI and CE standards. Legrand products are of impeccable quality that ensures maximum safety and offer the latest design and high performance. We offer switchgear that boosts output, provide better voltage regulation, and improve system capacity. They help in reducing electricity bills and overall system losses. All these switchgear from Legrand are easy to install in the environment chosen. Visit Pankaj Electricals to learn more about the products and services we offer.

At Pankaj Electricals, we ensure customer satisfaction.