Prelude and Overview The electrical power services market should see tremendous growth over the next five years. The legal and regulatory requirements, the need for qualified electrical workers, and the requirement that the workers are properly trained and educated are paramount. When it comes to electrical safe work practices, the use of NFPA 70E as a roadmap to success is …
Demystifying Off-Line PD Testing for an Effective CBM Strategy
Off-line partial discharge (PD) testing has emerged as a valuable diagnostic tool for assessing the insulation health of power cables, accessories, and switchgear. By detecting and measuring PD activity, this technique provides insights into the presence of insulation defects, which can lead to premature insulation failure if left undiagnosed. Off-line PD testing is particularly useful in creating a condition-based monitoring …
AC/DC Cable and Splicing Test Standards for Solar
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Circuit Breaker Timing And Time Travel Analysis Testing: the What, How, When, Why, AND Where
Circuit breakers are a critical component for protection against overloaded electrical and short circuits in our electrical infrastructure. When circuit breakers fail to perform their duties as designed and specified per application, the results can be catastrophic, expensive, and life-threatening. Every technician from a NETA Level 1 Trainee to a Level 4 Senior Technician understands the importance of testing circuit …
Electrical Signature Analysis of Oil- and Dry-Type Transformers
Periodic and continuous electrical signature analysis can be used to evaluate the general condition and power quality that affects oil- and dry-type transformers. This article discusses how conditions such as loose connections, resonance, component looseness, and failing electrical components can be detected. Case studies from several applications including wind power, solar, and industrial dry- and oil-type transformers are presented. ELECTRICAL …
A Review of Current Protection Testing Practices
Current protection testing practice is the result of history, custom, and seemingly conflicting motivations. Despite dramatic advances in protection system technology, protection testing philosophy and practice have not kept pace. This article reviews past and present protection testing practices and explores ways the industry could evolve to meet current and future challenges. As it was in the very beginning, the …
From Should to Shall: NFPA 70B Becomes a Standard
In today’s rapidly evolving industrial landscape, ensuring the reliable operation and safety of electrical systems is crucial. More than ever, facility managers and businesses must prioritize regular maintenance, testing, and repairs to prevent hazards to equipment and personnel as well as costly downtime. Over the years, convincing clients of the importance of these electrical maintenance services has met various challenges, …
Relay Testing in the Digital Substation
IEC 61850-based protection, automation, and control (PAC) brings a lot of advantages. Therefore, the adoption of the standard has been consistently increasing. IEC 61850 defines much more than just protocols; it defines a data model to represent information in the power grid. It also defines services for communicating data and a system configuration language (SCL) that allows configuration data to …
Substation Communications — A Primer
In the early days of protective relaying, it was recognized that communications between substations could improve relaying performance. Schemes such as power line telephony (1920s) and pilot wire relaying (1930s) evolved into digital time division multiplexers (TDMs) (invented in 1960s and used for power system communications in 1970s). TDM allowed audio teleprotection, audio-based relaying, SCADA, and telephony to share a single link …
Insulation Assessment Using Non-Invasive Techniques
The status of the insulation in a rotating machine can be evaluated using various testing techniques. Static tests are performed while the motor is disconnected from the system, typically during manufacturing, commissioning, maintenance, or repairs. The goal of a static test is to provide an accurate picture of the machine’s electrical characteristics. Static tests can often be performed from the …