NFPA-79 is the electrical standard that has been developed by the National Fire Protection Association (NFPA) and is "intended to minimize the potential hazard of electrical shock and electrical fire hazards of industrial metalworking machine tools, woodworking machinery, plastics machinery and mass produced equipment, not portable by hand."
The National Fire Protection Association is also responsible for the National Electric Code (NEC)/ (NFPA-70).
The scope of NFPA-79 is summarized as follows: "The standard shall apply to the electrical/electronic equipment, apparatus, or systems of industrial machines operating from a nominal voltage of 600 volts or less, and commencing at the point of connection of the supply to the electrical equipment to the machine."
One of the focuses of the latest edition is to improve product safety by ensuring that appropriate types of wire and cable are used in the application with regard to current carrying capacity, temperature rating, or flammability.
As such, the guidelines for NFPA-79 compliant products are more stringent than those cables allowed by past editions.
The NFPA-79 provisions make specific reference to only two types of cable.
This whitepaper is the first in a series on the security of OPC (OLE for Process Control) and focuses on providing an overview of the widely-used industrial communication standard and how it is actually used in industry.
British Columbia Institute of Technology (BCIT), Digital Bond and Byres Research
Selecting the appropriate Surge Protective Devices (SPD) can seem like a daunting task with all of the different types on the market today. The surge rating or kA rating of an SPD is one of the most misunderstood ratings. Customers commonly ask for an SPD to protect their 200A panel and there is a tendency to think that the larger the panel, the larger the kA device rating needs to be for protection As we will explore in this paper, this is a common misunderstanding.
When a surge enters a panel, it does not care or know the size of the panel. So how do you know if you should use a 50kA, 100kA or 200kA SPD? Realistically, the largest surge that can enter a building's wiring is 10kA, as explained in the IEEE C62.41 standard. So why would you ever need a SPD rated for 200kA? Simply stated - for longevity.
So one may think: if 200kA is good, then 600kA must be three times better, right? Not necessarily. At some point, the rating diminishes its return, only adding extra cost and no substantial benefit. Since most SPDs on the market use a metal oxide varistor (MOV) as the main limiting device, we can explore how/why higher kA ratings are achieved. If an MOV is rated for 10kA and sees a 10kA surge, it would use 100% of its capacity. This can be viewed somewhat like a gas tank, where the surge will degrade the MOV a little bit (no longer is it 100% full). Now if the SPD has two 10kA MOVs in parallel, it would be rated for 20kA. Theoretically, the MOVs will evenly split the 10kA surge, so each would take 5kA. In this case, each MOV have only used 50% of their capacity which degrades the MOV much less (leaving more left in the tank for future surges).
Does this translate into surge "stopping power?" No, just because an SPD has 2 or 20 MOVs in parallel it does not mean it will limit the 10kA surge any better then a single SPD (of the same rating). The main objective of having MOVs in parallel is to increase the longevity of the SPD. Again, keep in mind that it is subjective and at some point you are only adding cost by incorporating more MOVs and receiving little benefit.
As mentioned before, panel size does not really play a role in the selection of a kA rating. The location of the panel within the facility is much more important. IEEE C62.41.2 defines the types of expected surges within a facility as:
Category C: Service Entrance, more severe environment: 10kV, 10kA surge
Category B: Downstream, greater than 30' from category C, less severe environment: 6kV, 3kA surge
Category A: Further downstream, greater than 60' from category C, least severe environment: 6kV, 0.5kA surge
How do you know what kA rating to use? The IEEE categories provide a good base for selecting kA ratings. There are many "right" sizes for each category but there needs to be a balance between redundancy and added cost. Qualified judgment should always be used when selecting the appropriate kA rating for an SPD.
Registration Evaluation Authorization and Restriction of Chemical Substances
It is certainly no secret to anyone that the past decade has placed a renewed focus on the environment and how all members of the world community, to include business organizations, affect it. Concerns about protecting the world in which we live have been the impetus behind such worldwide movements as recycling and renewable energy. From a manufacturing standpoint, RoHS (Reduction of Hazardous Substances) has impacted businesses as well as REACH, a more recent set of regulations that are becoming more significant to North American based manufacturing operations that are part of a supply chain that directly or indirectly supplies products into the European Union.
As with any new regulatory requirements, the initial exposure to the documentation can create a degree of uncertainty among those who will be asked to comply. From this perspective, REACH is no different from any of its predecessors. In an attempt to offer some understanding of the REACH regulations and some clarification of the requirements it places on manufacturers, C&M Corporation gathered Michael Karg, Director of Product Development, along with Randy Elliott, Regulatory Compliance Engineer, and Ariann Griffin, Regulatory Compliance Technician, to discuss some of the particulars of REACH and respond to some of the questions C&M has been discussing with members of its client base.
What is the purpose of REACH?
Mike Levesque, Randy Elliott, Ariann Griffin and Michael Karg, C&M Corporation
This ebook describes the main elements of RS-422 and RS-485 data communications systems. The authors have provided enough technical details so that personnel can be successful in designing, modifying or troubleshooting an RS-422 or RS-485 data communications system.
The date of January 1, 2005 sits vividly in the minds of manufacturers within the industrial control panel field. That's because that's the day when the National Fire Protection Association's (NFPA) National Electrical Code (NEC) 2005 Article 409 officially went into effect. The code required that short circuit current rating be clearly marked on the industrial control panels in order to be inspected and approved. The markings made it easier to verify proper over-current protection against hazards such as fires and shocks on components or equipment, whether it be for initial installation or relocation. It was the beginning of an era when things would become a little more complicated, but for all the right reasons of ensuring more safety within the industrial world.
The main vision of the NFPA is to reduce or limit the burden of fire and other hazards on the quality of life by providing and advocating scientifically based consensus codes and standards, research, training and education. These codes and standards were established to minimize the possibility of and effects of fire and other risks. Due to misinterpretations, inconsistencies and advancements in technology over the years, they have had to update their codes with consistency in order to comply with existing standards.
Therefore, the focus of this paper will look at the changes that occurred due to Article 409, the impacts that it had, who was affected by the code and how to comply with the code. Precautions like this article had been enforced in the past, but they were too vague, so people found ways to get around them.
The biggest change that took place within the article was the new requirements adopted for industrial machinery electrical panels, industrial control panels, some HVAC equipment, meter disconnect switches and various motor controllers. For the purpose of this paper, we will be concentrating on industrial control panels which are specified as assemblies rated for 600V or less and intended for general use. All in all, it states that the above products must feature a safe design and be clearly marked with specific information concerning Short Circuit Current Rating (SCCR) in efforts of aiding with the designing, building, installation and inspection of the control panels. This way, the above users can both reference and apply all the needed requirements for all new products and installations as well as for modifying existing ones.
When it comes to accurately measuring the flow of liquid or gas, your flowmeter is only as accurate as the equipment it is calibrated on. And in the age of ISO 9001, ISO/IEC 17025, ANSI Z540 and other strict quality standards, this fact is becoming increasingly important.
Test and measurement applications depend on repeatable flow measurements, which provide performance criteria of the instrument being tested.
These devices often play a critical role on aircraft, placing greater demand on accurate flow test measurement for fuel consumption or hydraulic actuator controls.
Industrial operations live and die by the repeatability of process conditions. It is not enough for an individual flow-metering instrument to perform in a consistent manner, day in and day out; measurements must also be replicated. Multiple devices running on the same process-in different physical locations-must perform the same under identical conditions. This is only achieved through repeatable calibration equipment traceability to government metrology laboratories such as NIST.
For industrial operations, inaccurate flowmeter calibrations can have a serious impact on plant performance, ultimately resulting in poor yields or compromised quality. Therefore, periodic flowmeter calibration must be part of the user's quality process.
Mubeen Almoustafa, Calibration Application Engineer, Flow Dynamics. Inc.
Across various industries, the performance of a flow measurement device is ultimately dependent upon the proper functioning of its sensors or other signal producing elements, which have an active relationship with the flowing fluid.
In this PC Automation white paper, we discuss getting data from manual processes. Download this white paper to learn more about how hidden data is becoming more important in the manufacturing industry.
Every manufacturing industry is experiencing an increasing speed of business in several areas including changing schedules, customer needs, costs of materials, business models, and technologies. At the same time, many manufacturing sites - particularly in the discrete industries - have growing complexity in their operations which makes it more difficult to adapt. There are more SKUs and data to keep track of due to product proliferation, smaller lot sizes and compliance to government regulations.
The demands for improved speed and agility conflict with the plants' ability to respond. Visibility into current operations, including the control system, is the primary reason manufacturers buy Manufacturing Execution Systems (MES). This visibility provides the information necessary for informed decision making in real-time by all levels of personnel - plant floor to the executives.
MES applications contain the critical business processes for executing a production schedule. These systems perform the production-centric functions of planning, controlling, operating and informing. Control systems execute these functions to produce the goods needed to fulfill customer orders. By integrating MES with control systems, manufacturing becomes more agile for responding to change in this increasingly dynamic business environment. Integrating the control system with the MES allows for more effective and broader set of production management functions to improve operational performance.
To improve their response to operational issues, managers look to technology for connecting plant floor and business systems for automated business processes. Some manufacturers have implemented point solutions on a case-by-case basis. Because of the higher development costs and support issues, this approach is not acceptable. An integration platform is needed.
Industrial application developers have had two main options for interacting with production processes via programmable logic controllers (PLCs): they can buy a preprogrammed monolithic, shrink-wrapped human machine interface (HMI), complete and ready to go or they can customize their own solutions.
Shrink-wrapped HMI software packages are appealing because many complex tasks are hidden from you. Purchase the development software from an authorized distributor, load it into your development PC and then configure, debug and test. Then, just deploy the necessary runtime applications, data servers and configuration files on to your target PC or PCs. What could be easier?
But cookie-cutter HMI software solutions might not necessarily be the best or most practical approach for your specific industrial applications.
For one thing, while the shrink-wrapped HMI software packages enable connections to other vendors' devices, software, and systems via OPC or other standards, such connectivity is seldom adequate for high security or real-time control. And no matter how advanced the integration technology the package uses, you will end up lagging behind the technology curve. For example, if you had bought a package using the distributed common object model (DCOM) and wanted to benefit from advances in security and robustness that Microsoft had made since you bought the package, you would have to buy a new package. Moreover, the monolithic nature of the shrink-wrapped offerings often makes it difficult to embed third-party capabilities directly into your solution, thus limiting your options further.
Then there's training. Because the development environment and behavior of each HMI vendor's software varies, you'll need to acquire specialized skills to accomplish similar tasks. Training courses, material costs and schedules also vary by HMI publisher and many times are offered only through exclusive distributor channels. You could consider hiring outside help, but because of the specialized training and experience, the talent pool can be relatively shallow and therefore proportionately expensive.
And for many, cost of multiple deployments is an even bigger issue. Before you can actually deploy your solution to PCs, portable devices, or Web servers, you must typically have to pay for additional runtime software licenses. If you have more than a couple of users, this could amount to a considerable expense, often making this approach cost-prohibitive, especially if you are paying for more functionality than you actually never need.
Finally, there are the intangibles. As well-designed and flexible as these shrinkwrapped solutions might be, they almost always force compromises that would not be necessary if the solution were custom built for your specific applications. Whether that is a matter of function or just pride, it can be significant determining your satisfaction with the resulting interface.
This paper demonstrates how field device tool (FDT) technology standardizes the communication interface between field devices and systems, while complementing EDDL from design, installation and commissioning, to operation and maintenance, and eventual asset replacement.
Sensing options enable users to choose the sensor most appropriate per application. However, making this choice is not often easy. This paper helps unravel the complexities and differences between sensor types and applications in which they are used.
Plant managers are increasingly forced to maintain aging control systems while meeting management calls for improved productivity and quality. If you're ready for a change, this new paper was developed to help you select your best option. The paper covers: How to determine what is "end of life"; The pros and cons of different upgrade options - total system replacement, "gateway" options, I/O replacement; and the relative costs for each approach.
As the next generation of distributed control systems (DCS) becomes firmly established in the marketplace, each manufacturer must face the issue of upgrading. DCS vendors already have plans to phase out support of many current platforms, so it's critical that you develop your own plan for moving forward. The most proactive plants already have a plan in place, while others might continue scavenging for spare parts to keep their existing controllers alive for as long as possible. Of course, every control system has a limited lifespan and must be upgraded eventually. The big question is when. Download this white paper to learn when you should upgrade your DCS.
Genentech Inc.s bulk manufacturing facility in Vacaville, CA has been in production for the past two years. Application of S88 design concepts has provided the needed flexibility for multi-product manufacturing. Furthermore, the DCS has provided the integrated manufacturing environment necessary to trace and track the multitude of process activities required for the production of a single batch.
To meet increasing manufacturing capacity requirements, there is an effort underway to maximize yield and plant throughput. There is an increasing recognition that these goals may be realized by decreasing the time for postproduction analysis of batch production data and the generation of a Batch Assay History Report prior to its market release. Yields may be maximized by real time preemption of deviations in batch quality while the batch is in production. Such time demanding requirements are met by using the Web to deploy raw data and processed information to fulfill users data needs; when, where and how they need it. This paper discusses benefits realized through the use of Web technologies for supervisory batch control, batch production data analysis and batch report generation.
Chinmoy Roy, Manager- Automation Engineering, Genentech Inc.; Leonard Johnson, DCS System Administrator, Genentech Inc.
Although modern fieldbus transmitters have been improved compared to older transmitter models, that does not eliminate the need for calibration. Learn more about how a multi-functional calibrator can reduce time and money spent during commissioning and maintenance in a fieldbus installation.