Various types of Surge Protective Device (SPD) are used in the electrical field to prevent transient surge voltage.In this article describes in detail the selection and classification of Surge Protective Device (SPD).
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| Surge Protective Device (SPD) Selection and Classification |
What is Transient Surge Voltage
Let us first describe what a transient surge voltage is but things will get much easier. The transient surge volts are often only temporary high volts that generate lightning and switching sources within microseconds (μs).
Switching surges occur when the power is turned on or off at the transformer and power station. Voltage fluctuations like this sometimes occur when large machines are turned on or off in industrial areas. This can often cause damage to electrical and electronic equipment.
Therefore, it is very important to protect our electrical and electronics equipment from this transient surge. SPD is a device built for this.
The Surge Protective
Device (SPD) helps to protect valuable electrical and electronic equipment from transient surge voltages generated by lightning and switching sources.
These transient surge voltages can cause premature aging of the equipment, logic failures, or complete destruction or damage of the equipment throughout the electrical installation.
Products such as LCD
and LED screens, data servers, computer, industrial equipment and PLC are
critical to commercial and domestic operations. SPD may now be required to
protect these devices.
Surge protection
devices (SPD) are classified according to their electrical current discharge
standard.
Surge Protective Devices (SPD) Selection and Classification
Type 1 - SPD (Surge
Protective Devices) is the type in which partial lightning current can be discharged. Its typical wavelength is 10/350μs (micro seconds). Type 1 SPD is the spark gap technology commonly used by .
Type 2 - SPD is
connected to electrical installations to prevent excessive voltage transmission and to protect equipment. It usually uses a metal oxide variator (MOV). This technology has a current wavelength of 8/20 μs (micro seconds).
Selection Criteria, Differences and uses of SPDs
Provides further guidance on the differentiation and design of different types of SPD applications.
A Type 1 or Type 2
SPD may be used at the time of origin. Additionally, it may use a combination of both Type 1 + 2 SPD. At the point of origin, the starting point of the power supply to the dB may be connected in parallel to the isolator.
Both Type 2 and Type 3 devices are designed to be located close to the devices to be protected.
Type 3 - These SPDs
have a very low discharge capacity. Therefore they should only be installed in addition to the Type 2 SPD and in the vicinity of sensitive loads. Type 3 SPDs feature a combination of current voltage waves (1.2 / 50 μs) and Type 2 SPD voltage waves (8/20 μs).
Therefore, Type 3 SPD should only be installed after the Type 2 SPD has been installed. As mentioned above, it is designed to be attached to the closest of the sensitive devices. For example, coaxial cable, RF cable connector and low power AC & DC etc ...
Related Abbreviations of SPD
Iimp - The impulse current of 10/350 μs waveform is related to type 1 SPD
In - Surge current of 8/20 μs waveform is related to type 2 SPD
Up - the residual voltage measured across the related terminal is applies
UC - Maximum voltage that can be applied continuously to the SPD without ground / earth.
Conclusion
I hope you have learned from this article what is Surge Protective Device (SPD) Selection and Classification. Thanks for reading this article to understand Surge Protective Device.
