Grados De Protección

n° 166
photographie

enclosures and degrees of protection

Jean Pasteau Graduated in physics sciences in 1959, he joined Merlin Gerin in 1962 in the air-blast circuitbreaker design-office where he was mainly in charge of the preparation and follow-up of the technical part of contracts. Since 1983 he has been Technical Delegate for Merlin Gerin in standardization bodies (IEC, UTE,CENELEC,...) That led to him becoming in particular: s chairman of the French Committee 70 in charge of the preparation of standards for «Degrees of protection provided by enclosures» in 1987, s convenor of the BTTF 68-3 in charge of the preparation of the European standard for the IK Code in 1991.

E/CT 166, first issued 1993, january

Cahier Technique Merlin Gerin n° 166 / p.2

enclosures anddegrees of protection

summary
1. Introduction 2. General p. 4 p. 5 p. 6 p. 7 p. 7 p. 8 p. 9 p. 9 p. 9 p. 10 p. 11 p. 11 p. 12 p. 12 p. 12

Definitions Uses of a code system 3. The IP Code General First numeral Second numeral Additional letter Supplementary letter 4. The IK Code Introduction Degrees of protection 5. Application to the design of electrical equipment 6. Conclusion Appendix 1:correspondence between the IP code and water-tests of IEC 68-2-18 Appendix 2: equivalence between the old third numerals of the french IP code and IK code Appendix 3: bibliography

The protection of persons against direct contacts is required by certain regulations (in France the Decret of the 14th of November 1988), and specified by electrical installation standards, such as IEC 364. On the otherhand, types of external stresses likely to influence the behaviour of equipment are described in IEC 721-2. The protection against some of these influences is often specified in product standards. Therefore, to explain the degrees of protection that enclosures can provide, and how standards codify them, constitutes an essential information for all, prescribers, installers, operators and inspectingorganizations, the purpose of this «Cahier Technique». It replaces «Cahier Technique» No 6 written in 1982, made obsolete by the revision of IEC 529.

Cahier Technique Merlin Gerin n° 166 / p.3

1. introduction

It is not sufficient that a piece of equipment fulfils the functional requirements assigned to it. It also has to be protected against possible adverse external influences, andlikewise to ensure that it is not harmful to the user or to the environment. Different means can be used alone or combined to comply with this last requirement. All of them derive from one of the following methods: s placing out of reach vertically or horizontally, for instance by means of an obstacle, s total solid insulation as used particularly for cables, but which is not easily applicable whenmoving parts are involved, s putting into an enclosure, which is the object of this «Cahier Technique». This last method has the advantage of providing an easy solution to the other requirement, i.e. the protection of equipment against certain influences such as:

s the

ingress of foreign bodies which could disturb the mechanical or electrical operation. They comprise not only sand and dust butalso small animals and flying or creeping insects, s water and other liquids which could alter the insulation and generate degradation, s mechanical impacts which might deform or break brittle parts, s corrosive gas from the environment, s radiated electromagnetic fields, s various radiations including light. Constituting a supporting structure, the enclosure also allows for the building ofassemblies of complementary and coordinated apparatus. Therefore it is the most common method of protection. It is used for electronic or information technology equipment as well as for domestic appliances or for high or low voltage equipment, or for rotating machines. The enclosure may be built into the equipment or manufactured separately and sold empty to an

assembly-maker. It can be made of...