What is a Surge Protection Device?

Figure 1: Electrical equipment.

Surge protection device, also known as SPD, is an electronic equipment that provides safety protection for various electronic equipment, instruments and communication lines. When the electrical circuit or communication line suddenly generates peak current or voltage due to external interference, the surge protection device can conduct shunt in a very short time to avoid the damage of surge to other equipment in the circuit.

1. Features

1. It has large protective flow, low residual voltage and fast response time;

2. It adopts the latest arc extinguishing technology to avoid fire;

3. It adopts temperature control protection circuit and built-in thermal protection;

4. It has power status indication to indicate the working status;

5.It has rigorous structure and stable and reliable operation.

2. Working Principle

Figure 2: A surge protection device.

SPD can prevent damage caused by sudden surge. Its working principle is to pull the current out of a socket and transfer it to the equipment inserted into the surge protector. The SPD includes a metal oxide varistor (MOV) which can transfer any additional voltage to ensure that the equipment obtains a consistent power level.

The type and structure of SPD are different according to different purposes, but it should contain at least one nonlinear voltage limiting element. The basic components used for it include: discharge gap, inflatable discharge tube, varistor (MOV), suppression diode and choke coil.

3. Function

When the electrical circuit or communication line suddenly generates peak current or voltage due to external interference, the SPD can conduct shunt in a very short time, so as to avoid the damage of surge to other equipment in the circuit.

SPD can quickly discharge lightning surge current into the earth to protect electrical equipment from lightning. Products with SPD can effectively absorb sudden huge energy to protect the connected equipment from damage.

It is applicable to the power supply system with AC 50 / 60Hz and rated voltage of 220V / 380V to protect the surge affected by indirect lightning and direct lightning or other instantaneous overvoltage. It is applicable to the requirements of SPD in family residence, tertiary industry and industrial field.

4. Tips of Selecting Surge Protection Device

Figure 3: Selecting appropriate SPD.

Now you have known what surge protector is and how it works. To make sure you know what to look for when buying surge suppressors for your electronics. The following are important things to consider:

1. Think about what you want to protect.

2. Obtain the correct number of ports or sockets.

3. Make sure it has UL seal and is a transient voltage surge protector.

4. Check clamping voltage and energy absorption rating.

5. Look for warranty.

6. Make sure it has an indicator light.

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