IEC 61557-1:2019 pdf download

IEC 61557-1:2019 pdf download.Electrical safety in low voltage distribution systems up to 1 000 V a.c. and 1 500 V d.c.
1 Scope
This part of IEC 61 557 specifies the general requirements applicable to measuring and monitoring equipment for testing the electrical safety in low-voltage distribution systems with nominal voltages up to 1 000 V AC and 1 500 V DC. When measuring equipment or measuring installations involve measurement tasks of various measuring equipment covered by this series of standards, then the part of this series relevant to each of the measurement tasks is applicable. NOTE The term “measuring equipment” will hereafter be used to designate “testing, measuring and monitoring equipment”. Other parts of IEC 61 557 can specify additional requirements or deviations. This document does not cover functional safety or cybersecurity.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: • IEC Electropedia: available at http://www.electropedia.org/ • ISO Online browsing platform: available at http://www.iso.org/obp 3.1 nominal system voltage U n value of the voltage by which the distribution system is designated and to which certain characteristics are assigned 3.2 voltage against earth U o <in distribution systems with an earthed neutral point> voltage between a phase conductor and the earthed neutral point 3.3 voltage against earth U o <in all other distribution systems> voltage present between the remaining phase conductors and earth when one of the phase conductors is short-circuited to earth 3.4 fault voltage U f voltage between a given point of fault and reference earth resulting from an insulation fault [SOURCE: IEC 60050-826:2004, 826-1 1 -02, modified – The symbol has been added.]3.5 effective touch voltage U t voltage between conductive parts when touched simultaneously by a person or an animal Note 1 to entry: The value of the effective touch voltage may be appreciably influenced by the impedance of the person or the animal in electric contact with these conductive parts. [SOURCE: IEC 60050-1 95:1 998, 1 95-05-1 1 , modified – The symbol has been added.] 3.6 conventional touch voltage limit U L maximum value of the touch voltage which is permitted to be maintained indefinitely in specified conditions of external influences and is usually equal to 50 V AC, RMS or 1 20 V ripple free DC [SOURCE: IEC 60050-826:2004, 826-1 1 -04, modified – “prospective” has been omitted from the term and from the definition and values for the limit have been added to the definition; the symbol has been added.] 3.7 supply voltage voltage that is used to power the measurement equipment Note 1 to entry: If a supply voltage is specified, for instance in the supply contract, then it is called “declared supply voltage”. 3.8 rated supply voltage U S value of the supply voltage at a point where the measuring equipment does or can accept electric energy as a supply 3.9 output voltage U a voltage across the measuring equipment terminals where this equipment does or can output electric energy 3.1 0 open-circuit voltage U q voltage present across unloaded terminals on the measuring equipment 3.1 1 rated voltage U N voltage value assigned by a manufacturer or other entity for a specified operating condition of the measuring equipment Note 1 to entry: The value for the rated voltage of low-voltage equipment is generally assigned from the list of nominal voltages in IEC 60038:2009, Tables 1 and 6. Note 2 to entry: Equipment may have more than one rated voltage value or may have a rated voltage range. [SOURCE: IEC 60050-61 4:201 6, 61 4-03-09, modified – The domain <of equipment> and Note 1 have been omitted; the symbol has been added; 3.1 2 extraneous voltage external voltage to which the measuring equipment can be subjected during measurement 3.1 3 rated current I N current assigned by the manufacturer for the specified operating condition of the measuring equipment Note 1 to entry: The specified operating condition is a value (or values) within the rated operating conditions that are designated by the manufacturer. [SOURCE: IEC 60050-442:1 998, 442-01 -02, modified – “for accessories” has been deleted from the term and Note 1 has been added; the definition has been adapted for application to measuring equipment.] 3.1 4 short-circuit current over-current resulting from a short circuit due to a fault on the terminals or within the measuring equipment