Surge Protector SPD Selection Criteria

The surge protector is divided into three levels according to the area that needs to be protected. The first level surge protector can be applied to the main power distribution cabinet in the building, and can release the direct lightning current. The maximum discharge current is 80KA~200KA ;The second-level surge protector is used in the branch distribution cabinet of the building. It is a protection device for the participating voltage of the front-level lightning arrester and the induced lightning strike in the area. The maximum discharge current is about 40KA; the third-level surge protector is about 40KA. The surge protector is applied to the front end of important equipment and is the final means of protecting the equipment. It is protected by the residual lightning strike energy of the second-level lightning arrester, and the maximum discharge current is about 20kA.

Ⅱ. Look at the price of surge protectors

Don't be greedy when buying a surge protector. There are many low-priced surge protectors on the market, and it is best not to use them. These units are rather limited in capacity and will not be useful for larger surges or spikes. It is easy to overheat, which in turn can cause the entire surge protector to catch fire.

Ⅲ. See if the surge protector has a safety mark

If you want to know the quality of the SPD surge protection device, you also need to see whether it has a lightning protection center test report or product safety certification. If the protector, like tv antenna surge protector, does not have a safety inspection mark, it is likely to be an inferior product, and its safety cannot be guaranteed. Even the high price does not mean the quality is good.

Ⅳ. See the strength of the energy absorption capacity of the surge protector

The higher its energy absorption capacity, the better the protection performance. The value of the protector you buy should be at least 200 to 400 joules. For better protection, protectors with values above 600 joules are the best.

Ⅴ. Look at the response speed and clamping voltage of the surge protector

1. Look at the response speed of the surge protector

SPD devices, such as cctv lightning surge protectors, do not disconnect immediately, they respond to surges with a slight delay. The longer the response time, the longer the computer (or other device) will experience the surge. So buy a surge protector with a response time of less than a nanosecond.

2. Look at the clamping voltage of the surge protector

The lower the clamping voltage (a protection voltage measured after the lightning protection discharges energy or current), the better the protection performance is. It has three protection levels of 300 volts, 400 volts and 500 volts, usually clamped Voltages over 400 volts are very high. Therefore, it is necessary to observe the value of its clamping voltage to ensure safe use.

When choosing to install a surge protector, consider the design of the grid. The installation position of the SPD equipment should also be considered, and the distance between its placement position and the protected equipment should be appropriate. If the surge protector is placed too far from the protected device, it cannot ensure that the protected device is effectively protected; if it is too close, an oscillation wave will be generated between the device and the surge protector, and in this way, even if the device is considered to be protected, a large overvoltage will be generated on the protected equipment.