The enclosure of any equipment serves to keep out dirt , dust , moisture and prying finges . This is a separate matter from protetion against explosion ; a piece of electrical equipment may have to be mounted outdoors and be protected against the weather where there is no risk of explosion , or it may be indoors in a particularly dusty but non-flammabe atmosphere .
An internationnaly agreed system has been developed to designate the degree of protection afforded by an enclosure , it consist of the letters Ip followed by two digits. The letters stand for International protection and the digits indicate the degree of protection . The first digit , which may be from 0-6 , describes the protection against ingress of liquids . In both cases , the higher the numeral the greater the degree of protection . The definitions of the levels of protection are given in tables 1.3a and 1.3 b which are based on BS En 60529 . Specification for degrees of protection provided by enclosures ( IP code ) .
This method of classification can be aplied to all the equipment described in this chapter and the distribution equipment and luminaires discussed
No comments:
Post a Comment