外壳防护等级(IP)仪表外壳防护等级(IP)代码(BS EN60529;1992),由字母IP 和后续的两位特征数字表示。

例：IP65 即要求具有尘密及对喷水的外壳防护功能附加数字：防机械冲击第三位特征数字（至ＥＮ标准中不包括），适合在某些欧洲国家中通用（参阅法国标准ＮF Ｃ２０-０１０）：IP 外壳防护等级"接近等于NEMA 防护等级：IP codesDegrees of Protection Provided by EnclosuresThis standard describes a system for classifying the degrees of protection provided by the enclosures of electrical equipment. Developed by the European Committee for Electrotechnical Standardization (CENELEC), these standards are designed to numerically rate an electrical product on the level of protection its enclosure provides. By assigning different number codes, the product's degree of protection can be identified quickly and easily. In the code IP 54, for example, IP identifies this standard, the 5 describes the level of protection from solid objects, and 4 describes the level of protection from liquids.Second Characteristic Numeral DEGREE OF PROTECTION (Second Number in Code)Brief DescriptionDefinition0 Not protected __1 Protected against vertically falling water drops.Vertically falling drops shall have no harmful effects.2Protected against vertically falling water drops when enclosure is titled up to 15 °.Vertically falling drops have no harmful effects when the enclosure is tilted at any angle up to 15° on either side of the vertical. 3 Protected against spraying water. Water sprayed at an angle up to 60° degrees on either side of the vertical shall have no harmful effects. 4 Protected against splashing water.Water splashed against the enclosure from any direction shall have no harmful effects. 5 Protected against water jets. Water projected in jets against the enclosure from any directionshall have no harmful effects.6 Protected against powerful water jets.Water projected in powerful jets against the enclosure from any direction shall have no harmful effects.7Protected against the effects of temporary immersion in water.Ingress of water in quantities causing harmful effects shall not be possible when the enclosure is temporarily immersed 1 meter in water under standardized conditions of pressure and time.8Protected against the effects of continuous immersion in water.Ingress of water in quantities causing harmful effects shall not be possible when the enclosure is continuously immersed in water under conditions which shall be agreed between manufacturer and the user, but are more severe than for number 7.International Protection (IP) RatingsThe IP rating system classifies the degree of protection from solid objects and liquids afforded by electrical equipment and enclosures. Recognized in most European countries and meets a number of British and European standards, this rating system includes: Classification of Degrees of Protection Provided by Enclosures, BS (British Standards) 5490:1977; IEC (International Electrotechnical Commission) 529:1976.Specifications for Degrees of Protection of Enclosures of Switchgear and Control Gear for voltages up to and including 1000 VAC and 1200 VDC, BS 5420:1977; and IEC 144:1963.First NumberProtection against solid objectsSecond Number Protection against liquids0 no protection1 protected against solid objects up to 50 mm (e.g. accidental touch by hands)2 protected against solid objects up to 12 mm (e.g. fingers)3 protected against solid objects over 2.5 mm (e.g. tools and wires)4 protected against solid objects over 1 mm (e.g. tools and small wires)5 protected against dust-limited to ingress (no harmful deposits)6 totally protected against dust 0 no protection1 protected against vertically falling drops of water (e.g. condensation)2 protected against vertically falling drops of water up to 15° from the vertical4 protected against water sprayed from all directions limited ingress permitted6 protected against strong jets of water—limited ingress permitted (e.g. for use on ship decks)7 protected against the effects of temporary immersion between 15 cm and 1 mNEMA/IEC Enclosure RatingsNEMA/IEC Enclosure Ratings Conversion of NEMA type classifications to IEC classification designation (IP ratings). Note: NEMA standards meet or exceed IEC standards; therefore, the conversion does not work in the opposite direction.NEMAenclosure type no.NEMA definitionIECenclosureclass1General-purpose. Protects against dust, light, and indirect splashing but is not dust-tight; primarily prevents contact withlive parts; used indoors and under normal atmospheric conditions.IP102Drip-tight. Similar to Type 1 but with addition of drip shields;used where condensation may be severe (as in coolingrooms and laundries).IP113 and 3S Weather-resistant. Protects against weather hazards such asrain and sleet; used outdoors on ship docks, in constructionwork, and in tunnels and subways.IP543R Intended for outdoor use. Provides a degree of protectionagainst falling rain and ice formation. Meets rod entry, rain, external icing, and rust-resistance design tests.IP144 and 4X Watertight (weatherproof). Must exclude at least 65 GPM ofwater from 1-in. nozzle delivered from a distance not lessthan 10 ft for 5 min. Used outdoors on ship docks, in dairies,and in breweries.IP565Dust-tight. Provided with gaskets or equivalent to excludedust; used in steel mills and cement plants.IP526 and 6P Submersible. Design depends on specified conditions of pressure and time; submersible in water; used in quarries, mines, and manholes.IP677Hazardous. For indoor use in Class I, Groups A, B, C, and D environments as defined in the NEC.—8Hazardous. For indoor and outdoor use in locations classified as Class I, Groups A, B, C, and D as defined in the NEC.—9Hazardous. For indoor and outdoor use in locations classified as Class II, Groups E, F, or G as defined in the NEC.—10MSHA. Meets the requirements of the Mine Safety and Health Administration, 30 CFR Part 18 (1978).—11General-purpose. Protects against the corrosive effects of liquids and gases. Meets drip and corrosion-resistance tests.—13General-purpose. Primarily used to provide protectionagainst dust, spraying of water, oil, and noncorrosive coolants. Meets oil exclusion and rust resistance designtests.IP54National Electric Code (NEC) RatingsHazardous Classifications:Class I: Areas in which flammable gases of vapors may be present in the air in sufficient quantities to be explosive.Group A: Atmospheres containing acetyleneGroup B: Atmospheres such as butadiene, ethylene oxide,propylene oxide, acrolein, or hydrogen (or gases or vaporsequivalent in hazard to hydrogen, such as manufactured gas)Group C: Atmospheres such as cyclopropane, ethyl ether,ethylene, or gas or vapors of equivalent hazardGroup D: Atmospheres such as acetone, alcohol, ammonia,benzene, benzol, butane, gasoline, hexane, lacquer solventvapors, naphtha, natural gas, propane, or gas or vapors ofequivalent hazardCLASS II: Areas made hazardous by the presence of combustible dustGroup E: Atmospheres containing combustible1.metal dusts, regardless of resistivity2.dust of similarly hazardous characteristics having a resistivity lessthan 100 k½-cm3.electrically conductive dustsGroup F: Atmospheres containing combustible1.carbon black, charcoal, or coke dusts having more than 8% totalvolatile material2.dusts so sensitized that they present an explosion hazard, and dustshaving a resistivity greater than 100 ½-cm but less than or equal to1 x 108 ½-cmGroup G: Atmospheres containing combustible1.dust having resistivity equal to or greater than 100 k½-cm2.electrically nonconductive dustsCLASS III: Areas made hazardous by the presence of easily ignitable fibers or dust, but which are not likely to be in suspension in the air in quantities that are sufficient to igniteDivision 1: Atmospheres where hazardous concentrations existcontinuously, intermittently, or periodically under normaloperating conditionsDivision 2: Atmospheres where hazardous concentrations existonly in case of accidental rupture or breakdown of equipmentExplosion-proof: Enclosures or housings are designed to withstand internal explosions and prevent the spread of fire to the outside.Intrinsically-safe: Systems designed in which electrical energy in the circuits is not present at levels that would ignite a flammable mixture of a gas and air.The IP Code SymbolsThe chart at the right illustrates the use of special symbols in the IP classification system. In the "1st digit" column, not the grid-like symbols net to numbers 5 and 6. In the "2nd digit" column numbers 3-8 are symbolised by teardrop shaped symbols, sometimes enclosed in a box or a triangle, sometimes unenclosed (#7-8). These symbols can be placed on equipment to illustrate the IP protection provided.。