NEMA Enclosure Ratings Overview

Introduction

The National Electrical Manufacturers Association (NEMA) provides a rating system to classify industrial enclosures based on their ability to protect users from internal electronics and internal electronics from the external environment.

HIS provides Industrial Monitors and accessories in five different NEMA ratings: NEMA 1, 2, 4, 4X, and 12.

NEMA 1

Enclosures are constructed for indoor use to provide a degree of protection to personnel against access to hazardous parts and to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt).

NEMA 2

Enclosures are constructed for indoor 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 (falling dirt); and to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (dripping and light splashing).

NEMA 12

Enclosures constructed (without knockouts) for indoor 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 (falling dirt and circulating dust, lint, fibers, and flyings); and to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (dripping and light splashing).

NEMA 4

Enclosures constructed for either 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 (falling dirt and 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, splashing water, and hose directed water); and that will be undamaged by the external formation of ice on the enclosure.

NEMA 4X

Enclosure constructed with all of the protection of the NEMA 4 rating plus protection against corrosion of the enclosure. HIS products with this rating are typically constructed of Stainless Steel or Polycarbonate.

Protection against:	1	2	12	4	4X
Access to hazardous parts
Ingress of solid foreign objects (falling dirt)
Ingress of water (dripping or light splashing)
Ingress of solid foreign objects (windblown dust, lint, fibers, and flyings)
Ingress of water (rain, snow, and sleet)
Ingress of water (hose down)
Corrosive agents