IEC 62440 pdf – Electric cables with a rated voltage not exceeding 450/750 V – Guide to use

IEC 62440 pdf – Electric cables with a rated voltage not exceeding 450/750 V – Guide to use
1scope
This International Standard provides general guidance for the safe use of electric cables with arated voltage not exceeding 450/750 v. lt is applicable to those cables that are specified inIEC 60227 and lEC 60245.
The guidance given in this standard can also be applicable to low-voltage cables of a similartype to those specified in lEC 60227 and lEC 60245 but not specifically mentioned in thosestandards. In such cases, it is advisable to seek additional advice from the cable manufacturer.
NOTE Whilst this International Standard, which offers guidelines to the user, is a voluntary standard, those whochoose to use it, or who claim conformance to it, must follow the advice contained therein, e.g. with regard tocertain bending radii or certain clip spacings，etc. Notwithstanding this，national laws and regulations (especiallythose relating to selection and installation of cables via lEC 60364), will always take priority.
2Normative references
The following referenced documents are indispensable for the application of this document.Fordated references,only the edition cited applies.For undated references，the latest edition ofthe referenced document (including any amendments) applies.
IEC 60050-461, International Electrotechnical Vocabulary – Part 461:Electric cables
IEC 60245-6,Rubber insulated cables – Rated voltages up to and including 450/750 v- Part 6:Arc welding electrode cables
IEC 60287(all parts),Electric cables – Calculation of the current rating
IEC 60335-1，Household and similar electrical appliances – Safety – Part 1: Generalrequirements
lEC 60364 (all parts),Low-voltage electrical installations
lEC 60364-5-52，Electrical installations of buildings – Part 5-52: Selection and erection ofelectrical equipment – Wiring systems
3Terms and definitions
For the purposes of this document, the terms and definitions given in lEC 60050-461 and in thelEC 60364 series, as well as the following, apply.
3.1
internal wiring
wiring mechanically protected by being enclosed within a casing of equipment or by otherequivalent means
4 Safety
4.1 General
Safety of a cable means that the product does not present an unacceptable risk of danger tolife or property whilst being used in its intended manner.
The duration of acceptable performance of a particular type of cable depends upon:- the type of use,
– installation, or
– electrical apparatus,
and on the particular combination of influences that the above might incur. For example,theduration of acceptable performance considered as reasonable for a cable used in a fixedinstallation for the distribution of electricity in a building is more than that for a flexible cord.
Cables shall not be buried directly in the ground， and unless otherwise stated, shall not beused for any purpose other than the transmission and distribution of electricity.
The test methods and test parameters described in the lEC standards referred to in Clause 1are only for the purposes of checking design with respect to safety and quality assurance.Theydo not necessarily indicate that the cables are suitable for service under conditions equivalentto the test conditions.
4.2selection and installation
4.2.1 All conductors and cables shall be selected so as to be suitable for the voltages andcurrents likely to occur，and under all conditions which are anticipated in the equipment orinstallations or for the part in which they are to be used.
4.2.2 Cables shall be so constructed, installed, protected, used and maintained as to preventdanger so far as it is reasonably practicable.
4.2.3 Cables shall be selected so that they are suitable for the intended operating conditionsand equipment classification.Examples of operation conditions include:
a) voltage;
b) current;
c) protective measures;d) grouping of cables;e) method of installation;f)accessibility.
4.2.4 Cables shall be selected so that they are suitable for any external influences whichmight exist.Cables should not be installed under any of these conditions unless they are of atype specifically designed to withstand such conditions. Examples of external influencesinclude:
a) ambient temperature;
b) presence of rain,steam or accumulation of water;
c) presence of corrosive, chemical or polluting substances;