WG 3 - TC 122/WG 3

IEC TS 63042-301:2026, which is a technical specification, applies to on-site acceptance tests of electrical equipment with the highest voltages of AC transmission system exceeding 800 kV and its protection and control system.
The electrical equipment exceeding 800 kV includes the following items:
- power transformers;
- circuit-breakers;
- gas insulated switchgear (GIS);
- gas insulated transmission line (GIL);
- surge arresters;
- voltage and current transformers;
- shunt reactors;
- series compensators;
- insulators;
- disconnectors and earthing switches;
- high-speed earthing switches (HSES).
This second edition cancels and replaces the first edition published in 2018. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) new subclause with measurement of short-circuit impedance and load loss for on-site assembly transformer has been added;
b) new subclause with measurement of no-load loss and current for on-site assembly transformer has been added;
c) on-site acceptance test requirement for GIL has been added;
d) new clause with protection and control system on-site acceptance tests has been added.

IEC TS 63042-302:2021(E) applies to the commissioning of UHV AC transmission systems.
It mainly specifies the test purposes, test items, test preconditions, test methods and test acceptance criteria during pre-commissioning and system commissioning. Also, the measurement requirements for system commissioning are specified.

IEC TR 63042-303:2021(E) specifies measurement methods of UHV AC transmission line power frequency parameters. These measured parameters mainly include sequence parameters, mutual parameters between double-circuit lines, phase parameters and some other related parameters.

IEC TS 63042-301:2018(E) applies to on-site acceptance tests of electrical equipment with the highest voltages of AC transmission system exceeding 800 kV.