All You Need to Know About Switchgear – What Is It, How Does It Work and Types

The combination of circuit or fuses, electrical disconnects switches or breakers used to isolate, protect and control electrical equipment or gears from the defective condition are usually called switchgear.

Listed below are some examples of switchgear:

  • Fuses,
  • Switches
  • Relays
  • Isolator
  • Circuit Breaker
  • Potential and Current Transformer
  • Indicating Device
  • Lightning Arresters

Let us discuss what switchgear is, how does it work, and what are its types.

What Is Switchgear?

The switchgear systems are connected to the electric supply system.

It’s placed in both the low and high voltage of the power transformer. It’s used for de-energising the equipment for maintenance and testing to eradicate the defect. Each time ant defect or failure (for example, short circuit) takes place on the power system, a heavy current run through the electric equipment, enormous damage to the apparatus and disruption of supply to the user.

In the course of standard operation, switchgear allows the switch to on or off distributors, transmission lines, generators and some other electric powered equipment.

How Does Switchgear Work?

The automated protective switchgear primarily includes the circuit breaker and relay.

The relay comes into action when a fault occurs, and it usually closes the trip circuit which automatically disconnects the faulty line. After that, the operative and healthy section runs the normal and required supply load. And therefore, there’s no damage to apparatus and no disruption of supply.

While the occurrence of any fault or defect in the power system, all electric apparatuses are vulnerable to have a heavy current which means the apparatus could get damaged and the supply also gets disrupted.

Types of Switchgear

HV: High Voltage Switchgear

The power system controls voltage over 36KV, which is known as high voltage.

As the voltage is usually high, the arcing generated during transitioning operation is also high.

Therefore, additional care is taken during manufacturing of high voltage switchgear. A high voltage circuit breaker is actually the major part of HV switchgear, that’s why high voltage circuit breaker needs to have specific features for reliable and safe operations.

LV: Low Voltage Switchgear

In most cases switchgear which is rated up to 1 KV is usually called low voltage switchgear.

The term LV Switchgear consists of low voltage switches, earth leakage circuit breaker, HRC fuses, offload electrical isolators, moulded case circuit breakers (MCCB) and miniature circuit breakers (MCB).

MV: Medium Voltage Switchgear

From three KV to thirty-six KV switchgear systems are sorted as MV switchgear or medium voltage switchgear.

Most of these switchgears are of several types. They are usually metal enclosed outdoor type, metal enclosed indoor type, indoor or outdoor type without the metal enclosure, and so forth.

The interruption channel of this particular switchgear is a vacuum, SF and oil. The primary responsibility of the MV power system is to disrupt heavy current during defective situation no matter what type of CB is being used in the medium voltage switchgear system.

Contacts for all Energy Suppliers

If you want to contact energy suppliers directly, here are their contact details:


The Big 6

British Gas/Scottish Gas

New and existing customers: 0800 048 0202


Existing customers (monthly direct debit): 0845 070 4851
Existing customers (bill and quarterly direct debit): 0845 070 4850
New customers: 0800 073 3000


New customers to Eon: 0345 301 4905
Existing customers (for moving home): 0345 303 3020
Existing customers (to query a bill): 0345 052 0000
Existing customers (for prepayment): 0345 303 3010

Scottish Power

New and existing customers (online): 0845 270 6543
New and existing customers (domestic): 0845 270 0700


New and existing customers: 0800 975 0485

Including Swalec
Existing customers (electricity): 0800 052 5252
Existing customers (gas): 0800 052 0567
New customers: 0800 028 3028

Including Scottish Hydro Electric
New and existing customers: 0800 980 9628

Including Southern Electric
New and existing customers: 0800 980 9651

Including Atlantic
Existing Customers: 0800 980 8437

EDF Energy

Existing customers: 0800 096 9000
New customers: 0800 056 5927

The Others

Co-operative Energy

New and existing customers: 0800 954 0693


Existing customers: 0800 096 6344
New customers: 0800 458 7689 and 01993 608404


New and existing customers: 0800 0302 302

EDF Energy

Existing customers: 0800 096 9000
New customers: 0800 056 5927

First Utility

New and existing customers: 01926 320 700

Flow Energy

New and existing customers: 0800 092 0202

Good Energy

Existing customers: 0845 601 1410
New customers: 0845 456 1640

Green Energy UK

Existing customers: 0800 783 8851
New customers: 0800 954 0675

Green Star Energy

New and existing customers: 0800 012 4510


New and existing customers: 0845 074 3601


Customer services are only available online. Switching queries ought to be sent via their online contact form and existing customers can get in contact by logging in to their online account.


New and existing customers: 0800 5999 440

Spark Energy

New and existing customers: 0845 869 4002

The Utility Warehouse

Existing customers: 0844 815 7777
New customers: 0800 131 3000


New customers: 0845 8830146

Prepayment customers: 0845 4504357

Direct debit customers: 0845 3311499