Saving energy with NEMA enclosures

A member of the Control Engineering Automation & Control Facebook site highlights energy considerations related to NEMA cabinets.

02/17/2009


Editor’s note: Discussions on Control Engineering’ s Automation & Control ” group on Facebook, recently led to a posting about energy saving considerations related to NEMA enclosures. The posting, by David Marin from Noren Products , appears below, along with a link to additional tips.
Over the past few decades, the use of electronics for automation, process controls, drives, and PLCs have become more commonly installed in NEMA enclosures (cabinets used to protect electronic devices from the harsh environments encountered in many industries, both indoor and outdoors). Though most electronics can handle temperatures between 40 and 50 degrees C, it’s always a good idea to check with the manufacturer regarding the heat load specifications of the device being used; this will help in making the correct thermal decision for your applications.
Enclosure tips: Correct size, fan filter, cooling
Following is a rundown of the most important issues to consider when investigating the thermal management capabilities of electronic enclosures.

  • Purchasing a cabinet large enough so that natural convection can be used to remove the waste heat through the cabinet. Though this is sometimes a preferred cooling method, be sure to investigate that this approach will not actually cost more money than installing cooling capabilities, due to the cost of the larger metal cabinet.

  • Pay close attention to the fan and filter. This option is the most economical of all, but is not preferred in dirty environments. The extra maintenance needed to clean the electronics within the cabinet defeats the cost savings and puts expensive electronics at risk.

  • Check out the cabinet’s thermoelectric device. A cabinet’s solid state air conditioner can provide cooling, but uses one watt of energy to remove one watt of heat. These devices are typically used in small cabinets and are not very efficient.

  • Investigate the air compressor coolers, which use plant air to create a “cyclone” effect that cools the inside of the cabinet. The cost of plant air should be considered, as well as whether or not the air used is clean. Unclean air can produce an oil mist inside the cabinet.

  • Consider the panel air conditioner. When electronics first came into the plant, air conditioners were used because of the thermal thresholds of the electronics required that the temperatures be below ambient conditions. Now, however, the components are made to withstand more heat. Air conditioner units cost more to install and maintain and use more energy than most other options. Thermostats are a common option to regulate the operation of air conditioners in certain cabinet conditions.

  • Study the heat exchangers or cabinet coolers. These devices are being used more and more because of energy savings and low maintenance. Most heat exchangers are designed to be sealed from dust in the air and some can protect against moisture and corrosion. They are generally easy to install and very reliable. They also can be used with thermostats. Air to water heat exchangers can be used for high ambient applications were water is available.

  • For all outdoor applications, sun load should be a consideration and most enclosure companies or thermal management companies can help with this calculation. Generally it’s a good idea to consider a sun shield.

Also read:
- Enclosures: Improve NEMA designs, enclose wireless equipment, keep cabinets cool .
- Proud of your control panel design? Share your knowledge .

– Edited by David Greenfield , editorial director

Control Engineering News Desk

Register here .





No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2013 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
The Leaders Under 40 program features outstanding young people who are making a difference in manufacturing. View the 2013 Leaders here.
The new control room: It's got all the bells and whistles - and alarms, too; Remote maintenance; Specifying VFDs
2014 forecast issue: To serve and to manufacture - Veterans will bring skill and discipline to the plant floor if we can find a way to get them there.
2013 Top Plant: Lincoln Electric Company, Cleveland, Ohio
Case Study Database

Case Study Database

Get more exposure for your case study by uploading it to the Plant Engineering case study database, where end-users can identify relevant solutions and explore what the experts are doing to effectively implement a variety of technology and productivity related projects.

These case studies provide examples of how knowledgeable solution providers have used technology, processes and people to create effective and successful implementations in real-world situations. Case studies can be completed by filling out a simple online form where you can outline the project title, abstract, and full story in 1500 words or less; upload photos, videos and a logo.

Click here to visit the Case Study Database and upload your case study.

Bring focus to PLC programming: 5 things to avoid in putting your system together; Managing the DCS upgrade; PLM upgrade: a step-by-step approach
Balancing the bagging triangle; PID tuning improves process efficiency; Standardizing control room HMIs
Commissioning electrical systems in mission critical facilities; Anticipating the Smart Grid; Mitigating arc flash hazards in medium-voltage switchgear; Comparing generator sizing software

Annual Salary Survey

Participate in the 2013 Salary Survey

In a year when manufacturing continued to lead the economic rebound, it makes sense that plant manager bonuses rebounded. Plant Engineering’s annual Salary Survey shows both wages and bonuses rose in 2012 after a retreat the year before.

Average salary across all job titles for plant floor management rose 3.5% to $95,446, and bonus compensation jumped to $15,162, a 4.2% increase from the 2010 level and double the 2011 total, which showed a sharp drop in bonus.

2012 Salary Survey Analysis

2012 Salary Survey Results

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.