IEC 60196:2009 specifies the standard frequencies. The standard frequencies are the frequencies to be adopted for single-phase and three-phase a.c. systems, for installations in ships, for a.c. traction systems, for tools and for aircraft. This standardization is limited to frequencies up to 10 000 Hz. This second edition cancels and replaces the first edition published in 1965. It constitutes a technical revision. The main change is the removal of the standard frequencies for the rayon industry. It has the status of a horizontal standard in accordance with IEC Guide 108.