Medium Voltage Switchgear Guide: A Beginner’s Guide

What is Medium Voltage Switchgear?

Medium voltage switchgear, or MV switchgear, is switchgear with a voltage range of 3 KV to 36 KV. There are several types of this switchgear. These might come from manufacturers of enclosures and be classified as metal-enclosed indoor switchgear, metal-enclosed outdoor switchgear, or outdoor switchgear without a metal enclosure.

Type of Medium Voltage Switchgear

Medium voltage switchgear comes in a variety of forms, each having special qualities and uses.

Appliances with Air Insulation (AIS)

The most popular kind, known as AIS, uses air as its insulating medium. It is a well-liked option for several applications because to its reputation for dependability and simplicity.

Switchgear with Gas Insulation (GIS)

Sulfur hexafluoride (SF6) gas is used as insulation in GIS. This kind is perfect for high-demand situations and metropolitan settings since it is small and extremely dependable.

Switchgear Clad in Metal

Metal-clad switchgear has a metal casing that offers strong defense and adaptability. It is extensively utilized in commercial structures and industrial facilities.

Hybrid Switchgear

Hybrid switchgear offers flexibility and cost-effectiveness by combining the advantages of AIS and GIS. It is an adaptable solution for a range of uses.

Medium Voltage Switchgear Components

Medium Voltage Switchgear include switches, circuit breakers, contactors, fuses with switch units, and HRC fuses. All these devices or equipment are connected in a logical manner which ultimately creates switchgear. 

Circuit Breaker

Circuit breakers are a form of switchgear that is intended to break an electric circuit in the case of a fault. Faults are undesirable electrical occurrences that occur when an electrical circuit does not operate within its set limitations. Short circuits are examples of faults, which occur when a foreign item comes into contact with a live wire and the ground plane. These generate large currents to flow across the circuit, which the circuit breaker may detect and terminate, preventing more equipment damage.

The “secondary system” monitors currents at medium and high voltage and checks to see whether they are above the safe limit. The secondary system is a low voltage control circuit made up of sensors and a “relay” that analyzes the current and orders the circuit breaker to trip if it exceeds a certain limit.

Read More：Circuit Breaker vs. Switchgear: What’s the Difference?

Fuses

Fuses are one of the basic forms of electrical circuit protection. They are a designed weak spot in the electrical circuit that melts when the rate of electricity flow (current) exceeds the fuse’s rating. Unlike circuit breakers, which may be reset, fuses consume and burn throughout operation.

Recloser

Reclosers are circuit breakers that meet IEEE and IEC standards 62271-111. This circuit breaker is intended to be opened and closed quickly in order to restore power for temporary failures.

Switches

Switchgear switches are electrical devices that generate, carry, and break currents under normal circuit circumstances while also meeting the stated criteria when creating, carrying, and breaking specified abnormal circuit conditions.

Relays

A switchgear relay is an electrically controlled switch. During an electrical problem, its contacts close and transmit a signal to the circuit breaker. The signal instructs the breaker to interrupt power transmission to a circuit or load. As such, it is commonly referred to as a protective relay.

Application of Medium Voltage Switchgear

The Distribution and Control Switchgear can be used in a wide range of applications in medium voltage systems, the main ones being:

• Substations of utility companies
• Protection and main disconnection of manufacturing plants and industrial installations
• Pumping stations
• Thermal and hydroelectric plants for power generation
• Start of medium-voltage motors
• Unitary substations
• Load switchboard panels

Medium Voltage Switchgear FAQs

What are the standards for medium voltage switchgear?

ANSI and IEEE standards define voltage classifications as follows: Low-voltage: up to 600V. Medium-voltage: between 600V and 69 kV. High-voltage: between 69 kV and 230 kV.

Why do we need MV switchgear?

MV Following Tedaş MYD and the IEC 62271-200 standard, switchgear is designed, produced, and tested for switching, protection, and control functions in alternating current systems from 1 kV to 52 kV. Furthermore, medium voltage switchgear offers energy control and utilization.

What is the difference between MV and LV switchgear?

LV switchgear usually consists of fuses, contactors, relays, and circuit breakers. Switchgear classified as medium voltage (MV) is intended for systems with voltage ratings ranging from 1kV to 36kV. They are often utilized in commercial and industrial settings, including data centers, hospitals, and industries.

How do I choose a medium voltage switchgear?

Line structure, line protection, tripping timings and selectivity, reserves/availability, switchover time, operating procedures, in-plant generation, emergency supplies, or power quality (unstable loads) are important influencing variables for choosing the appropriate MV switchgear.

What two main types of switchgear are used in an electrical system?

• Switchgear with low voltage. Low voltage switchgear, or just LV switchgear for short, is made for systems that handle less than 1000 volts of power.
• Intermediate Voltage Switchgear.
• Switchgear with High Voltage.

What is the basic knowledge of switchgear?

Electrical disconnect switches, fuses, and circuit breakers are examples of switchgear in an electric power system, which is used to isolate, regulate, and safeguard electrical equipment. Switchgear is used to both remove faults downstream and de-energize equipment to allow maintenance to be done.

Conclusion

Industrial applications for medium voltage switchgear are many. They are essential to maintaining the electric system’s electrical safety. In order to guarantee the safety and security of your system, get in touch with us at ElectricalCabinet for premium Mv supplies.