IEC 63445 Ed. 1.0 b:2025
IEC 63445 Ed. 1.0 b:2025 System referencing conductor switching device
standard byInternational Electrotechnical Commission , 09/01/2025
standard byInternational Electrotechnical Commission , 09/01/2025
IEC 63445:2025 applies to system referencing conductor switching devices (3.3) (SRCSD) for
household and similar uses within a Prosumer’s electrical installations (PEI (3.1)).
The SRCSD (3.3) provides functions as described in IEC 60364-8-82:2022 [2], 82.8.2.2.4.
PEI (3.1) intended for operating by either being connected to a distribution network or
disconnected from the distribution network is an islandable PEI (3.7).
Intentional disconnection from and connection to the distribution network relies on the local
earthing system being switched by the SRCSD (3.3). In addition, unintentional loss of
distribution network is covered.
The SRCSD (3.3) is a single pole device intended to connect one live conductor of the power
system to an earthing arrangement.
In general the neutral conductor is earthed.
Switching the SRCSD (3.3) can change the local type of system earthing if types of system
earthing are different in island and grid connected modes.
The system referencing conductor switching device (3.3) (SRCSD) is interlocked with the
switching device for islanding (3.4) (SDFI) of a Prosumer electrical installation.
SRCSD (3.3) can be integrated in a device with other functions e.g.. with a SDFI (3.4).
NOTE 1 See also IEC 60364-8-82 [1].
This document applies to SRCSD (3.3) for rated voltages not exceeding 440 V AC with rated
frequencies of 50 Hz, 60 Hz or 50/60 Hz.
NOTE 2 SRCSD (3.3) for DC operations is under consideration.