In this article:
- Ratings Overview and Comparison
- Self-Certifying or Outside Testing and Certification?
- Selecting an Industrial Enclosure Rating
- In-Depth: NEMA Ratings
- In-Depth: IP Ratings
Ratings Overview and Comparison
Hope Industrial Systems uses two standards for rating the ability of industrial displays and accessories to withstand harsh industrial environments: IP ratings and NEMA ratings. Ingress Protection (IP) ratings were developed in Europe and are used internationally. NEMA ratings (also called NEMA Type ratings) were developed by the U.S.-based National Electrical Manufacturers Association. Hope Industrial tests and rates products to both standards and uses additional outside testing to certify to the NEMA standard.
While NEMA and IP ratings are not identical, they are very similar and can often be used interchangeably for the purpose of rating enclosures for industrial environments. IP ratings specify standards primarily for protection against ingress of solid foreign objects or liquids, while NEMA ratings also specify protection against other conditions, such as the presence of corrosive agents. This chart gives an approximate comparison of the NEMA and IP ratings used by Hope Industrial:
NEMA Rating (U.S.) | IP Rating (International) | |
1 | = | IP20 |
2 | = | IP22 |
12 | = | IP54 |
4 | = | IP65 / IP66 |
4X | = | IP65 ⁄ IP66 |
Self-Certifying or Outside Testing and Certification?
When evaluating products for use in industrial environments, it is important to determine whether the manufacturer is "self-certifying" or whether the products have undergone outside testing and certification.
Both NEMA and IP ratings are "self-certifying," meaning that manufacturers can simply design a product to meet the standard, then specify that rating without any approval or certification of any outside agency. This method is used by many manufacturers of industrial displays and often leads to products being placed on the market that do not actually meet the ratings.
Hope Industrial goes a step further to meet these industrial ratings by certifying products through Underwriters Laboratories, who puts Hope Industrial products through rigorous environmental tests before certifying that they meet these industrial standards (see UL 50E for more information).
Selecting an Industrial Enclosure Rating
For a full comparison of the various ratings, see the "In-Depth: NEMA Ratings" section below. To simplify selection of the proper industrial enclosure, consider the following questions:
- Will the monitor experience prolonged exposure to liquids or corrosive chemicals during normal operation or cleaning? Select a NEMA 4X display: these models are IP65/IP66 sealed for wash-down or wet environments and constructed of anti-corrosive stainless steel.
- Will the monitor be exposed to a dusty or dirty environment, with a chance of prolonged exposure to liquids? Select a NEMA 4 (or 4X) display: these models are IP65/IP66 sealed to protect against dust, dirt, and liquids.
- Will the monitor be exposed to a dusty or dirty environment, with only moderate exposure to liquids? Select a NEMA 12 (or 4/4X) display: these models are IP54 sealed against dust and dirt and can handle some light splashing of liquids.
- Will the monitor be exposed to an environment not suitable for office-grade equipment, with potential exposure to falling dust, dirt, and light splashing of liquids? Select a NEMA 2 (or 12, 4, or 4X) display: these models are housed in rugged IP22 sealed enclosures that can handle a variety of industrial environments.
In-Depth: NEMA Ratings
The U.S.-based 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. NEMA ratings only apply to products going to North America.
Hope Industrial Systems provides industrial monitors and accessories in five different NEMA ratings: NEMA 1, 2, 12, 4, and 4X.
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) or oil and coolant seepage.
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. Note: if using a Hope Industrial monitor outdoors, the brightness of the monitor may be insufficient for clear viewing when exposed to direct sunlight.
NEMA 4X
Enclosure constructed with all of the protection of the NEMA 4 rating plus protection against corrosion of the enclosure. Hope Industrial Systems products with this rating are typically constructed of stainless steel or polyester.
NEMA Ratings; Protection Against: | 1 | 2 | 12 | 4 | 4X |
Access to hazardous parts | X | X | X | X | X |
Ingress of solid foreign objects (falling dirt) | X | X | X | X | X |
Ingress of water (dripping or light splashing) | X | X | X | X | |
Ingress of solid foreign objects (windblown dust, lint, fibers, and flyings) | X | X | X | ||
Ingress of water (rain, snow, and sleet) | X | X | |||
Ingress of water (hose down) | X | X | |||
Corrosive agents | X |
In-Depth: IP Ratings
Ingress Protection (IP) ratings are standards for the degree of protection an electrical enclosure provides for users from internal electronics and for the electrical components inside against the ingress of foreign objects and water.
IP ratings have two numbers: the first digit in the rating indicates the enclosure's ability to protect against the ingress of foreign solid objects, such as dust; the second digit indicates the level of protection against the ingress of water or other liquids.
Hope Industrial Systems provides industrial monitors and accessories in four different IP ratings: IP20, IP22, IP54, and IP65/IP66.
First Digit:
Protection against foreign objects: | Number |
Solid objects > 12.5 mm | 2 |
Dust protected, limited ingress | 5 |
Dustproof, no ingress | 6 |
Second Digit:
Protection against water: | Number |
No protection | 0 |
Water sprayed up to 15° from vertical | 2 |
Water sprayed, any direction | 4 |
Water projected by low pressure water jets, any direction | 5 |
Water projected by high pressure water jets, any direction | 6 |