What is a switching surge?

A switching surges is a short duration transient voltage produced in the system due to a sudden opening or closing of a switch or circuit breaker or due to an arcing at a fault in the system. Thus, switching surges contain larger energy than the lightning impulse voltages.

What is switching surge overvoltage?

Switching surges are of short duration, of irregular or impulse form and highly damped. A typical switching impulse standard form is the 250/2,500 microsecond, time-to-crest/time-to-half value wave. Overvoltages due to switching phenomena become important at the higher transmission voltage levels (above 245 kV).

What is temporary over voltage?

A transient over-voltage or spike is an electrical impulse of short duration but high energy that is induced onto an electrical or electronic circuit from external sources; these may be repetitive or random.

What are the different types of surges?

There are three different types of Surge Protective Devices:

• Type 1 SPD installed at the origin, e.g. main distribution board.
• Type 2 SPD installed at sub-distribution boards. (Combined Type 1 & 2 SPDs are available and are usually installed in consumer units).
• Type 3 SPD installed close to the protected load.

What are the switching over voltages?

Apart from being caused by dielectric faults or flashover, switching overvoltages appear in the power systems due to switching of load and/or fault currents, and they cannot be avoided. Switching overvoltages are the primary dimensioning parameter for air-clearances in EHV and UHV systems.

What causes overvoltage surges in a power system?

The main cause of these voltage surges in power system are due to lightning impulses and switching impulses of the system. But over voltage in the power system may also be caused by, insulation failure, arcing ground and resonance etc.

What are the types of over voltage?

Over voltage stressing a power system can be classified into two main types: 1-External overvoltage: generated by atmospheric disturbances of these disturbances, lightning is the most common and the most severe. 2. Internal overvoltages: generated by changes in the operating conditions of the network.

What are the causes of over voltage?

What is a Type 3 SPD?

Type 3 Surge protector device (SPD) Type-3 SPD is characterized by a combination of voltage waves (1.2/50 µs) and current waves (8/20 µs). • Its main function is to limit low level surges which can damage sensitive electronic circuits in TVs, PCs and electric appliances.

What is Type 2 surge protection?

The Type 2 Surge Protection Devices are the main protection system for all low voltage electrical installations. Installed in each electrical switchboard, it prevents the spread of any overvoltages in the electrical installations and protects the loads. Type 2 SPD is characterized by an 8/20 µs current wave.