ICI's Actuator & Valve Industry Blog

Knowing Nema

Posted on Fri, Jun 07, 2013

Nema, actuators, electric actuators

When looking at valve automation solutions it always important to know what type of environment the application calls for purchasing an actuator without this knowledge is like driving with your convertible top down in a hail storm or lighting bottle rockets at a gas station. Knowing what you need and how to order it are too important to over look.Your most common Nema ratings in the valve automation world are Nema 4, 4x, 6 & 7 & 4x\7.

 

Nema 4 Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt, rain, sleet, snow, windblown dust, splashing water, and hose directed water; and that will be undamaged by the external formation of ice on the enclosure.

 

NEMA 4X enclosure constructed for indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (windblown dust); to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, snow, hose directed water); provides an additional level of protection against corrosion and that will be undamaged by the external formation of ice on the enclosure

 

Nema 6 Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt; against hose directed water and the entry of water during occasional temporary submersion at a limited depth; and that will be undamaged by the external formation of ice on the enclosure.

 

Nema 7 for indoor use in locations classified as Class I, Groups A, B, C, or D, as defined in the National Electrical Code. Type 7 enclosures shall be capable of withstanding the pressures resulting from an internal explosion of specified gases, and contain such an explosion sufficiently that an explosive gas-air mixture existing in the atmosphere surrounding the enclosure will not be ignited. Enclosed heat generating devices shall not cause external surfaces to reach temperatures capable of igniting explosive gas-air mixtures in the surrounding atmosphere. Enclosures shall meet explosion, hydro-static, and temperature design tests