Single-Phase Distribution-Board Surge Protector, 2-Pole 20 kA

PF-SPD-AC-1PH is a surge protector for a single-phase distribution board: a 2-pole module that clips onto the DIN rail beside the breakers and connects across live and neutral to the earth bar. A surge arriving on the mains from a lightning strike on the power lines is diverted to earth at the board, before it reaches the computers, switches, TVs and chargers on every circuit behind it.

It is rated for a 220 V supply with 10 kA nominal and 20 kA maximum discharge current (8/20 µs) and a 1.2 kV voltage protection level, as printed on the module (model KHYS220-20KA/2). A window on each pole shows green while it is working and red when it has absorbed a large surge and needs replacing; the modules plug out of the base, so replacing them does not need rewiring. Installation in a distribution board must be done by a qualified electrician, with a breaker in front of the protector as the board's design requires.

Made by a Shenzhen surge-protection factory that offers custom production; the photo shows the factory's standard label. The factory sells from two units, so the minimum order is 2. Price includes delivery within Thailand. Warranty is 1 year and does not cover a module used up by a surge, which is what it is for.