How To Protect Wired Equipment From Lightning Strikes

There are methods to protect process control
equipment from lightning strikes

Lightning, though visually and audibly fascinating, is a high risk environmental factor for process measurement and control equipment. Recent advancements in the study of this natural occurrence have significantly increased general understanding of the source and path of a lighting strike, granting some additional insight into mitigating the risk to electronic equipment associated with lightning activity.

The abstract included below provides a useful synopsis of grounding, surge protection, and other methods for providing levels of protection from lightning strikes. Of particular interest is the concept of lightning ground potential rise (L-GPR) and how it can be used to predict an impending lighting event.

The predictive technology, combined with automated disconnection of the protected equipment from the AC power service can provide superior protection against damage caused by lighting strikes. Browse the paper below, as it is concise, illustrated, and will improve your understanding of lightning and how it impacts industrial process control equipment.

More information and consultation on enhancing your level of lightning protection is available from Analynk Wireless.

Lightning Protection Considerations for Wired Systems from Analynk Wireless, LLC

Practical Considerations for Wireless Transmission of Industrial Process Control Signals

Industrial process signal transmitter

Rigging up the proper gear to establish wireless transmission of process measurement signals is generally a straight forward task. There are, however, a vastly different set of considerations than those for a wired transmission of the same signal. In order to select the right equipment for the job, some general comprehension of radio signals can be useful.

Radio wave frequencies are below the infrared range on the electromagnetic spectrum, thus their wavelengths are comparatively long. Three things can happen to electromagnetic radiation (radio waves) when encountering a barrier. 

• Reflectance: The wave bounces off the barrier.
• Transmittance: The wave passes through the barrier.
• Absorbance: The wave is stopped.

Which of the three possibilities will occur depends upon a number of factors relating to the signal and the barrier, some of which include:

• The wavelength of the radiation
• The intensity of the radiation hitting the barrier
• The chemical composition of the barrier
• The physical microstructure of the barrier
• The thickness of the barrier

Here is a conglomeration of knowledge items pulled together from a number of public sources that can be applied when considering a wireless installation.

Milliwatts (mW) are the common measurement unit of radio frequency (RF) power. A logarithmic scale of decibels, referencing 1 mW as the zero point, provides a useful way to express the comparative strength of RF signals. Using decibels, a signal strength of 1 mW is registered as 0 dBm. RF power attenuates according to a logarithmic function, so the dBm method of expressing RF power enjoys widespread use.

Industrial wireless communications applications in North America predominantly operate in either the 2.4 GHz or 900 MHz frequency range. Higher frequency will provide more bandwidth, but at the cost of reduced transmission distance and obstacle penetration. Lower frequency can require a larger antenna to attain the same signal gain.

Transmission power is not the only solution for delivering a signal. Low power signals can be successfully received by sensitive radio equipment. Reducing the data transmission rate can increase the functional sensitivity of the receiving equipment, too.

Be mindful of the existence or potential for RF background noise in your communications environment. A higher level of background noise can hamper the effectiveness of your equipment. The "noise floor" varies throughout the frequency spectrum and is generally below the sensitivity level of most equipment. Industrial environments can sometimes provide unusual conditions which may warrant a site survey to determine the actual noise floor throughout the communications area.

Weather conditions can impact signal transmission

Radio transmission is susceptible to environmental elements on a variable basis. Since the environment can change without notice, it is useful to know the fade margin of a wireless installation. Fade margin expresses the difference between the current signal strength and the level at which the installation no longer provides adequate performance. One recommendation is to configure the installation to provide a minimum of 10dB of fade margin in good weather conditions. This level can provide sufficient excess signal strength to overcome the diminishing effects of most weather, solar, and interference conditions.

There are a number of simple methods to determine whether an installation has at least a 10 dB fade margin. Temporarily installing a 10dB attenuator on the system antenna, or installing a length of antenna cable that yields 10dB of attenuation will allow you to determine if the installation can accommodate 10dB of environmental impact on the signal. If the system operates suitably with the attenuation installed, you have at least that much fade margin.

RF signals attenuate with the square of the distance traveled, so if transmission distance is to be doubled, then the signal power must increase fourfold. 

True “line of sight” signal paths are found in a limited number of installations. The number, type, and location of obstacles in the signal path can have a significant impact on the signal and contribute to what is referred to as path loss. Probably the simplest way to reduce the impact of obstacles is to elevate the antennas above them.  Obstacles, in almost every case, are affixed to the earth, so their interference is reduced by elevating antennas to “see” over the obstacles.  

Wooded areas can be a significant barrier

When the signal path extends through an outdoor area, weather conditions have an impact on the path loss, with higher moisture levels increasing the loss. Large plants, most notably heavily wooded areas, can impose substantial reduction on RF signals and may require elevating antennas above the trees or using repeaters to route the signal around a forested area.

Industrial installations routinely present many reflective obstacles in the signal path. The transmitted signal may reflect off several obstacles and still reach the receiving antenna. The received signal strength will be the vector sum of all the paths reaching the antenna. The phase of each signal reaching the antenna can impact the total signal strength in a positive or negative way. Sometimes relocating the antenna by even a small amount can significantly change the strength of the received signal.

Antenna cable 

Antenna cable contributes to signal attenuation. Use high quality cable of the shortest length possible to minimize the impact on performance.

Analynk Wireless has the equipment and expertise to help you deliver wireless process signals across the room, across the street, or across the globe.

Protect Electrical Equipment From Lightning Strikes - Demonstration Video

Lightning strike damage to electrical equipment
can be prevented

Equipment damage from lightning is estimated to cause $5+ billion dollars of equipment damage in the USA annually; This in spite of grounding and various surge suppression systems.   Existing protection is focused on presenting convenient conductive paths to coax the sky's energy away from, or around, facilities and equipment. However, existing technologies cannot protect from L-GPR (Lightning Ground Potential Rise) which is estimated to be responsible for >80% of all lightning damage. This literally is lightning surge “entering” you system through ground!

LightningShield^TM manufactured by Alokin Industries employs a patented technology that PREDICTS an impending lightning event, then isolates equipment from the damaging L-GPR PRIOR to and during the lightning event. For full protection:  Grounding, Surge Suppression and L-GPR protection are all required. The video below of the LightningShield^TM demonstrates how the technology works.  

This is why we say, LightningShield^TM is

LightningShield^TM protection from the ground up.^TM

Analynk is a distributor for LightningShield^TM.  We provide application support, system configuration for your specific system.  More details, including case studies, IEEE white papers are available by contacting Analynk Wireless. 

New Explosion Proof Antenna for Iridium Satellite Industrial Communications

Analynk antennas expanded capability includes
Iridium satellite based communications

Analynk Wireless has expanded its hazardous area antenna line with a new series designed for communication across the Iridium satellite network. The Iridium network provides worldwide process data transmission access for industrial operations of all types. The explosion proof antennas can be utilized with Analynk equipment, or that of other manufacturers, to provide wireless connection between a central control or monitoring facility and mobile or remotely located process measurement and control equipment.

There are two basic models, differing only in manner in which a connection is made to a suitable enclosure. The CTM model is provided with the M20 connection. The CTX model has a 3/4" NPT connector. Both models carry the same array of approvals for use in hazardous locations. The same construction that enables installation in a hazardous area also makes these units a good choice for any location requiring rugged construction.

A data sheet is provided below with details on approvals and specifications. Contact Analynk directly for any assistance you may need in meeting your wireless communication challenges. The company's extensive product offering is directed at the needs of the process control field.

Hazardous Area Antenna - Iridium Satellite Communication from Analynk Wireless, LLC

Analynk Wireless and the Offshore Technology Conference 2016

Offshore Technology Conference 2016 brings together
participants in all sectors of the energy sector

Analynk Wireless will be exhibiting their full line of products May 2-5 2016 at the Offshore Technology Conference in Houston, Texas USA. OTC 2016 brings together professionals and vendors from all sectors of the energy industry, providing attendees access to leading-edge technical information, the industry’s largest equipment exhibition, and unrivaled opportunities for networking and the exchange of ideas and opinions. Analynk will be showcasing their wireless communication products that enable connections across the room or across the globe. Be sure and stop at their exhibit in booth 9056 and see how simply and effectively your wireless industrial process control and monitoring connections can be put into operation.

Learn more about the conference and register at the event website. 

Analynk Wireless is an innovative designer and supplier of wireless instrumentation for the process control industry, with products suitable for hazardous and non-hazardous locations. Transmitters, repeaters, receivers, and hazardous area antennas are available for 900 MHz, 2.4 GHz, cellular, GLONASS, GPS, and Iridium based communication of process signals.

Developing a Useful Alarm Strategy

Industrial process at pharmaceutical plant

Industrial process control operators and designers have the capability to measure many aspects of machine operation and process performance. Determining the elements to measure, method of measurement, and how to handle and process the derived information can be challenging, but can also impact the security, performance, and safety of an operation. A plan for monitoring, reporting, and responding to abnormal process conditions, if properly developed and executed, can yield real benefits to a process operator. A protocol that is not well conceived may produce a negative operational impact by creating events that unnecessarily draw resources away from productive endeavor. That protocol, or plan, is often referred to as an alarm plan.

There are numerous forces that can influence the development and implementation of an alarm plan. Each operation must incorporate its own set of external regulatory requirements, internal procedures and policies into a complete alarm protocol. Distilling that macro description down to a workable set of procedures and response tasks is where the real work begins. There is, however, a basic framework that can help organize your thinking and focus on what is most important.

• What parameters define the process or operation?
  Produce a schedule of every non-human element that is required to make the process function. This will require drilling down through every machine and material that is part of the operation. Expect the schedule to be extensive, even huge. If it is not, consider that your analysis may not be reaching deep enough. The goal here is to create an overview of what makes the process work and provide a tool for systematically studying the process elements and gleaning possible commonalities or relationships among them. Consider disregarding things that cannot be measured, since that prevents the derivation of data for evaluation. Review the completed schedule and decide which parameters shall be measured and evaluated for proper performance.
• What level of measurement is needed for each monitored parameter?
  An assessment of the needed accuracy, frequency, and resolution for parameter measurement will help define the requirements for instrumentation or other devices used to monitor a particular item. The goal is to make sure the monitoring device is capable of detecting and delivering information of sufficient quality to make decisions.
• Define the limits of acceptability for each monitored parameter.
  Until the endpoint of the process or operation, each step is likely dependent in some way on previous steps. The output of each step becomes the input of the next. While this, in many cases, may be an oversimplification, it is important to consider the relationships between the

  

  High speed filling operation

  tasks and operations that comprise the process. Monitored parameters should relate to the successful completion of a process step, though not necessarily be a direct indicator of success. The maintenance of the parameter within certain bounds may be used as an indicator that a component of successful completion was properly attained. Defining limits of acceptability may involve an element of subjectivity and will likely be customized to accommodate the process. Each organization shall evaluate their operation and determine limits based upon intimate process knowledge and experience.
• Define abnormal operation for each monitored parameter.
  Abnormal operation may not necessarily be any value not within what is considered acceptable. Consider abnormal to be the range of values that would be cause for notification of the operator, or even automated or human intervention. Note that the definition of unacceptable or abnormal operation might appropriately include filters or defined relationships with other parameters. An example of a simple filter is a time delay. If the measured variable exceeds the specified limit for 2 seconds, it make not be significant. If the threshold is exceeded for 2 minutes, it may be cause to take action. As with the limits of acceptability, developing the definition of abnormal operation for each parameter will be customized for each process.
• Provide a defined response for every alarm occurrence.
  If it is important to monitor something, then it is likely important to do something when things get out of hand. Human executed alarm response should be concise and uncomplicated, to reduce the probability of error. Automated response should be designed in a manner that provides for functional testing on a regular basis. The scope of the response will be specific for each process, with the level of response depending upon factors determined by the process operators. Response can be as simple as annunciating the condition at a monitoring station, or as dire as shutting down part or all of the process operation.
• Review every alarm occurrence
  Each alarm event should be logged and reviewed. Consider whether the event detection and response was adequate and beneficial. If the results were less than expected or desired, assess whether changes can be made to provide improved results in the future. The alarm plan is unlikely to be perfect in its first incarnation. Be prepared to reevaluate and make changes to improve performance.

The exercise of developing a comprehensive alarm plan will help to build understanding of process operation for all involved parties. This article is but a brief synopsis of the subject, intended to get the reader on the path of developing a useful alarm plan. Your alarm plan should an extension of process operation decision making, and have a goal of enhancing safety and reducing loss.   

Product Update - RoHS Compliant Hazardous Area Antenna

Model CTX Antenna
All Analynk hazardous area antennas are
now RoHS compliant

Analynk Wireless announces that the company's entire line of hazardous area antenna products are RoHS compliant. These rugged antennas are intended for global application in the industrial process control field. Analynk hazardous area antennas are UL listed for Class 1, Groups C & D and have ATEX/IECEx Certification. A range of frequencies are available: 900MHz, 2.4GHz, Cellular, GPS, GLONASS, Iridium and dual bands. Ideal for dual band access points.

More information is available by reaching out directly to the product specialists at Analynk. Share your industrial wireless challenges with them and work toward a good solution.