Low-voltage surge protective devices: Part 11 AC power systems, Part 21 telecommunications and signalling networks, Part 31 PV installations; TS 61643-06 (draft) SSD disconnectors.
Parts declared by products:
Part 11 covers surge protective devices (SPD) for AC power systems up to 1000 V RMS, 50/60 Hz, limiting overvoltages and diverting surge currents caused by lightning and switching surges; the 2025 edition clarified dielectric, short-circuit and clearance tests.
Part 21 covers SPDs for telecommunications and signalling networks with system voltage up to 1000 V AC / 1500 V DC. Part 31 covers SPDs on the DC side of PV installations up to 1500 V DC, permanently connected; it excludes systems with energy storage and two-port SPDs.
IEC TS 61643-06 (under development) is intended to cover stand-alone disconnectors for SPDs that disconnect the protective device from systems up to 1000 V AC / 1500 V DC at end of life (leakage current, short-circuit current, temperature) and must withstand the SPD’s rated impulse.
A 61643-11/-21/-31 declaration confirms the test class (T1/T2/T3), Up, In/Iimp and end-of-life behavior of SPDs for power, signal and PV circuits in trackside facilities; an SSD disconnector according to TS 61643-06 completes the SPD short-circuit coordination, but until the TS is published the manufacturer may refer only to the draft.
Part 11 - SPDs for AC power systems up to 1000 V; Part 21 - for telecommunications and signalling networks; Part 31 - for the DC side of PV installations up to 1500 V. Test class T1/T2/T3 indicates surge-current withstand capability.
A draft technical specification for disconnectors dedicated to surge protective devices (SSD), which disconnect the SPD at end of life and must withstand its rated impulse. Until publication, the manufacturer may refer only to the draft.
