Use, Installation and Configuration of Surge Protectors

1. Parameters selected by SPD of surge protector at all level

1. SPD-1

If the first-level surge protector SPD1 is installed in the general power distribution room of a building, three switch-type surge protectors can meet the system requirements. The current power supply mode even if the entire power supply system adopts TN-S mode, and N and PE in the main power distribution room are a grounding point, so installing three-piece switch-type SPD in the main power distribution cabinet in the power distribution room can play a role. It is not necessary to add between N and ground. The recommended parameters for SPD-1 surge protector selection are as follows:

(1) Maximum continuous operating voltage: Uc=440V

(2) Maximum discharge current: generally calculated and designed according to the requirements of the specification or the requirements in the reference standard

(3) Protection level: Up≤2.5K

(4) Response time: tA≤100ns

2. SPD-2

The second-level power surge protector, like aerial surge protector, is the most widely used product. There are few cases where the lightning electromagnetic pulse can generate a lightning current of more than 20KA for the intrusion of the power line in the LPZ1 area. Therefore, the second-level SPD is rated as a voltage-limiting surge protector. The flux In is positioned at 20-40KA. SPD-2 recommends the selection of technical parameters as follows:

(1) Maximum continuous operating voltage: Uc=260～320V

(2) Rated discharge current (8/20μs) In=20KA

(3) Maximum discharge current (8/20μs) Imax=40KA

(4) Protection level: Up≤1.5KV

(5) Response time: tA≤25ns

3. SPD-3

The third-level power surge protector is generally installed at the front end of important equipment, so-called fine protection. SPD-3 recommends the selection of technical parameters as follows:

(1) Maximum continuous operating voltage: Uc=255V

(2) Nominal discharge current (8/20μs): In L→N 3KA N→PE 5KA

(3) Voltage protection level Up: L→N≤1.25KV L→PE≤1.5KV

(4) Response time: tA≤25ns

Ⅱ. The use and installation of surge protector SPD

Three-phase basic requirements for using and installing surge protectors:

(1) After installing the SPD, the SPD should not affect the normal operation of the electrical (electronic) system when no power surge occurs.

(2) After installing the SPD, in the event of a surge, the SPD can withstand the expected lightning current without damage, and can clamp the surge voltage and divide the surge current.

(3) After the surge current passes, the SPD should quickly restore the high resistance state and cut off the power frequency current.

As a prominent surge protection supplier, Techwin specializes in cutting-edge technologies, including lightning protection boxes, leakage protectors, SPD (Surge Protective Device) for telecom, and Ethernet SPD.