Feedback: Enclosure standards don't correlate

The table "NEMA and IEC enclosure comparison" shown in "Enclose as Needed" (CE, p. 58, March 2006; www.controleng.com/archive) could be construed by readers as a direct one-to-one correlation and interchangeability from IEC IP [ingress protection] Code-rated enclosures to NEMA Type-rated enclosures. No such direct conversion is possible.

06/01/2006


The table "NEMA and IEC enclosure comparison" shown in "Enclose as Needed" ( CE , p. 58, March 2006; www.controleng.com/archive ) could be construed by readers as a direct one-to-one correlation and interchangeability from IEC IP [ingress protection] Code-rated enclosures to NEMA Type-rated enclosures. No such direct conversion is possible. Many electrical inspectors in the U.S. who apply the National Electrical Code (NEC) will not approve installations where an enclosure has only an IP Code rating with no NEMA Type rating.

IEC IP Code only addresses requirements for protection of people, ingress of solid objects, and ingress of water. Many other requirements covered by NEMA Type standards that are not covered in the IEC IP Code, include construction requirements; door and cover securement; corrosion resistance; effects of icing; gasket aging and oil resistance; and coolant effects.

NEMA Type designation specifies requirements for these additional performance protections. For this reason, the IEC enclosure IP Code designations cannot be converted to NEMA enclosure Type numbers.

NEMA Standards Publication, "A Brief Comparison of NEMA 250 and IEC 60529," provides additional information and is available for free download from NEMA at www.nema.org .

James R. Reizner is with Corporate Engineering; Power, Controls and Information Systems, The Procter & Gamble Co., www.pg.com





No comments
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by...
The System Integrator Giants program lists the top 100 system integrators among companies listed in CFE Media's Global System Integrator Database.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
This eGuide illustrates solutions, applications and benefits of machine vision systems.
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
This eGuide contains a series of articles and videos that considers theoretical and practical; immediate needs and a look into the future.
Intelligent, efficient PLC programming: Cost-saving programming languages are available now; Automation system upgrades; Help from the cloud; Improving flow control; System integration tips
Smarter machines require smarter systems; Fixing PID, part 3; Process safety; Hardware and software integration; Legalities: Integrated lean project delivery
Choosing controllers: PLCs, PACs, IPCs, DCS? What's best for your application?; Wireless trends; Design, integration; Manufacturing Day; Product Exclusive
PLCs, robots, and the quest for a single controller; how OEE is key to automation solutions.
This article collection contains several articles on improving the use of PID.
Learn how Industry 4.0 adds supply chain efficiency, optimizes pricing, improves quality, and more.

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

Special report: U.S. natural gas; LNG transport technologies evolve to meet market demand; Understanding new methane regulations; Predictive maintenance for gas pipeline compressors
Cyber security cost-efficient for industrial control systems; Extracting full value from operational data; Managing cyber security risks
Drilling for Big Data: Managing the flow of information; Big data drilldown series: Challenge and opportunity; OT to IT: Creating a circle of improvement; Industry loses best workers, again