3 phase spd connection diagram।

A surge protective device SPD is a protective device for limiting transient voltages by diverting or limiting surge current and is capable of repeating these functions as specified SPDs were previously known as Transient Voltage Surge Suppressors TVSS or secondary surge arrestors SSA.
what is a 3 phase line
Three phase power is a three wire ac power circuit with each phase ac signal 120 electrical degrees apart. residential homes are usually served by a single phase power supply, while commercial and industrial facilities usually use a three-phase supply.
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