Improper relay logic threatens your electrical assets and investments

Four programmable relay logic settings that will improve protection and add value

05/06/2014


In the event of an electrical system fault, the protective relay system isolates the affected components while maintaining stability within the rest of the grid distribution system. Many utilities and industrial facilities are replacing aging electromechanical and solid-state relays with new generation microprocessor-based relays that deliver many benefits including self-testing and diagnosis, reduced maintenance, simplified regulatory compliance, arc flash mitigation, event recording and reporting capabilities, and improved protection.

While microprocessor-based relays have vast potential functionality, many of the relays’ capabilities and advantages often go unrealized. This happens for a number of reasons, including:

  • Lack of owner awareness: Custom relay configuration has only recently become an option.
  • Simple oversight: Owners may overlook the need for relay customization and programming during the estimating, bidding, and specification processes.
  • Lack of knowledge and expertise: Engineers may not have the skill levels needed to program relays, or the designers and installing electricians may be unfamiliar with the relay’s capabilities.
  • Complexity issues: Custom programming can sometimes cause the system design to become overly complex. For simple applications, the effort needed to configure all the available features would not be worthwhile.

Unfortunately, relay capabilities have outpaced industry skill levels. Often a relay is installed as a direct replacement for aged or defective equipment and the subsequent logic programming is performed by personnel unfamiliar with the new equipment. Improperly programmed relay logic can lead to a wide range of protection system problems. For example, inappropriate logic settings can lead to repeated system misoperation, nuisance tripping, unplanned shutdowns, and production interruptions becoming a source of frustration for asset and facility managers. In these cases, managers often revert to the default logic settings just to keep the system running. While this is a tempting quick fix to a frustrating situation, this practice can ultimately result in even greater costs if the equipment is not adequately protected.

The key to leveraging the full range of microprocessor-based relay capabilities and optimizing system protection is to work with integration engineers that have the expertise to properly configure each relay to meet the utility or facility’s unique objectives. They consider the many differing needs of owners, engineers, utilities, and equipment manufacturers and then balance those with the requirements of local jurisdictions and industry standards (JCAHO, MSHA, NERC, FERC).

Within this framework, integration engineers begin to apply power system studies, such as short circuit, coordination, arc flash hazard, motor starting, and load flow analysis, to customize protection for each application. Ultimately, the relay system is easy to use, reliable, and only as complex as needed.

While project requirements will obviously be unique for each facility or utility that upgrades to microprocessor-based relays, there are at least four programmable relay settings that every facility should consider to improve their protection scheme and add value to the system.

1. Self-monitoring and diagnostics

Simplification of the control system through the reduction of necessary components and single points of failure is a tremendous benefit which can be further compounded by adding real-time monitoring and failure alert functionality. However, these benefits can only be realized if custom logic has been programmed and tested.

The reduction of necessary hardware components can be accomplished when previously installed hardware (e.g., 86 lockouts or 62 auxiliary timing relays) is emulated with customized logic programmed in the relay. For example, an 86 lockout relay previously installed as hardware can now perform the exact same functionality through operator interaction with the front panel display of the protective relay. Through the reduction of separate hardware components, the number of single point failures decreases, thereby increasing the robustness and reliability of the electrical system.


<< First < Previous 1 2 3 Next > Last >>

No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2015 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
World-class maintenance: The three keys to success - Deploy people, process and technology; 2016 Lubrication Guide; Why hydraulic systems get hot
Your leaks start here: Take a disciplined approach with your hydraulic system; U.S. presence at Hannover Messe a rousing success
Hannover Messe 2016: Taking hold of the future - Partner Country status spotlights U.S. manufacturing; Honoring manufacturing excellence: The 2015 Product of the Year Winners
The digital oilfield: Utilizing Big Data can yield big savings; Virtualization a real solution; Tracking SIS performance
Getting to the bottom of subsea repairs: Older pipelines need more attention, and operators need a repair strategy; OTC preview; Offshore production difficult - and crucial
Digital oilfields: Integrated HMI/SCADA systems enable smarter data acquisition; Real-world impact of simulation; Electric actuator technology prospers in production fields
Improving flowmeter calibration; Selecting flowmeters for natural gas; Case study: Streamlining assembly systems using PC-based control; CLPM: Improving process efficiency, throughput
Putting COPS into context; Designing medium-voltage electrical systems; Planning and designing resilient, efficient data centers; The nine steps of designing generator fuel systems
Warehouse winter comfort: The HTHV solution; Cooling with natural gas; Plastics industry booming

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

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.
This article collection contains several articles on the vital role that compressed air plays in manufacturing plants.
This article collection contains several articles on the Industrial Internet of Things (IIoT) and how it is transforming manufacturing.
This article collection contains several articles on strategic maintenance and understanding all the parts of your plant.
click me