IEC 61140:2016

Applies to the protection of persons and animals against electric shock. It is intended to give fundamental principles and requirements which are common to electrical installations, systems and equipment or necessary for their co-ordination. Prepared for installations, systems and equipment without a voltage limit. NOTE - There are some clauses in this standard which refer to low-voltage and high-voltage systems, installations and equipment. For the purpose of this standard, low -voltage is any rated voltage up to and including 1 000 V a.c. or 1 500 V d.c. High voltage is any rated voltage exceeding 1 000 V a.c. or 1 500 V d.c. The requirements of this standard apply only if they are incorporated, or are referred to, in the relevant standards. It is not intended to be used as a stand-alone standard. Has the status of a basic safety publication in accordance with IEC Guide 104.

Applies to a.c. electrical installations of buildings supplied at a frequency not exceeding 60 Hz and at a nominal voltage up to and including 1 000 V. Defines two voltage bands: Band I covers the installations where protection against shock is provided under certain conditions by the value of voltage and the installations where the voltage is limited for operational reasons (e.g. telecommunications, signalling, bell, control and alarm installation). Band II contains the voltage for supplies to household, commercial and industrial installations. This band contains all the voltage of public distribution systems in the various countries. Note: The voltage bands defined are intended mainly for use in connection with installation rules (see IEC 60364), but may also be used when preparing requirements for electrical equipment.

Classification of d.c. installations according to their nominal voltage. As for a.c. a distinction has been made between two bands when the lower band relates mainly to installations whose voltages are restricted for safety reasons. Covers all voltages from zero up to and including 120 V ripple-free d.c.