The Finepoint Conference is pleased to offer a “Circuit Breaker Timing and Analysis” seminar that includes details about both traditional timing and travel-motion testing and energized first trip testing. The seminar is being jointly presented by Kelman North America, leaders in first trip testing, and Vanguard Instruments, leaders in timing and travel-motion testing, on Oct. 5. Timing and travel-motion testing of circuit breakers has been around for over 60 years, while first trip testing is a relatively recent enhancement. Both techniques have their unique benefits and the purpose of the seminar is to thoroughly cover all aspects of circuit breaker timing and analysis.

Part 1: Kelman North America

Kelman will take the stage first with its focus on the value of capturing the first trip on any circuit breaker while the circuit breaker is being removed from service or tied to another breaker and comparing that data to an immediate second trip.

Randy Cox, sales and support manager for Kelman, North America, will lead the presentation and discussion. His current duties include the sale and technical support of Kelman’s PROFILE P2 operator analyzer.

“We will discuss why first trip testing is important and necessary to finding the issues that lay hidden within each circuit breaker,” Cox said. “Due to past maintenance practices, and a reduction in overall personnel, the utility is now experiencing problems that are not easily detected. Utilizing the correct tools to locate these problems is imperative to the utility’s overall success.”

As part of this discussion, Kelman will discuss the importance of measuring and evaluating the operating coil’s current signature. When called upon to operate, the circuit breaker’s operating coils will produce a specific current profile, which can then be evaluated in detail with the appropriate software. When the breaker’s operator is functioning as designed, the current profile of the breaker’s operating coils will be repeatable. As problems develop with the operator, these current profiles will change, alerting the user to a developing problem.

Finding Problems

As utilities and industrial companies have extended maintenance intervals on their circuit breakers in an effort to conserve costs, many of these entities are now beginning to experience problems that cannot be easily explained.

There are unique and innovative means to finding problems that have been plaguing utilities for many years. As transformer outages due to feeder faults and high-voltage breaker over-trips increase, a seemingly endless array of reasons have been sought and developed to explain this phenomena while the problem sits undetected by traditional diagnostic methods. The problems are not limited to these events, but extend to other issues such as failed trip and close coils. In many cases the end user will find one of these coils in a failed position and think that this is the problem, when in reality it is only a symptom of a greater problem.

One Solution

Kelman will cover how the PROFILE P2 breaker operator analyzer can perform the first trip testing and present past experiences with the analyzer.

“The Profile P2 revolutionized my business when I was employed by the utility. For years I could not figure out why my transformers were coming out of service on associated feeder faults. Each time the dispatcher called me with an outage, I would ask my Patrolman what flags we had, and he would tell me (for example) that we had a C phase over-current on feeder breaker #2. Then he proceeded to tell me that the transformer flags were also C phase over-current. Each time I would place the unit back and send the diagnostic technicians out the next day to time the breaker. Each time the breaker timed flawlessly,” Cox said.

“We were all truly trying our best to find out why this was happening. Finally one day a guy called me out of the blue asking me if this sort of thing was happening to me (I thought he had been eavesdropping on us),” Cox said. “He explained why we were unable to find the slow breaker that we ultimately were sure we had. He explained that once that breaker tripped under fault conditions, the valuable information had been lost.

“For years we had been spraying the operators down with penetrants. These penetrants were separating the oil from the soap (grease) in the operator bearings, particularly trip latches since they were the easiest to get to. As a result of this, the bearings were sticky and unable to move when called upon to do so. This caused many slow breaker operations. We were replacing trip coils that were also failing thinking that the trip coils were just faulty, when in reality they had been energized for a longer period of time than they were designed to be, causing heating in the coil until ultimately they failed. Imagine, failed trip coils due to slow operators with grease problems. We were unable to find these issues with traditional timers until it was too late.

“The reason is that you have to trip the breaker and take it out of service to perform that test, thereby losing the information that you need. Once the breaker operates, any oil properties still in the soap would be redistributed thereby providing enough lubrication to mask the problem. Within a short period of time the breaker operator would be in the same shape that it was when it took the transformer out the first time, and inevitably the problem would repeat itself,” Cox said.

Past Experiences

Dale Rogers with Progress Energy located in Raleigh, North Carolina, will be presenting several case studies using the P2 technology. The case studies will include breakers Progress Energy has found to be on their way to problems. His section will discuss how the program was implemented, what they found, how they prioritized the work and the overall success of the program. Rogers is in the Transmission Component Engineering group and oversees this process for many areas of his company.

Part 2: Vanguard Instruments

The second part of this in-depth seminar will feature Hai Nguyen from Vanguard Instruments covering circuit breaker timing. Substation maintenance departments have always been faced with high-voltage circuit breakers failing to operate properly due to a fault situation. “Are my breakers in good condition to perform properly?” is the question that has plagued the utility industry for many years.

The Cincinnati Timer, manufactured by Cincinnati Clock and Instruments Company since 1940, was the first diagnostic instrument to answer that question. The advancement of electronics and microprocessor technology has dramatically improved circuit breaker testing and recording procedures over the last 15 to 20 years. Hai Nguyen was involved with development of the first digital circuit breaker analyzer in the United States in 1987. Since joining Vanguard Instruments Company in 1991, he helped developed several generations of microprocessor-based circuit breaker analyzers. These state-of-the-art microprocessor based instruments removed the doubt and apprehension of the operating condition of circuit breakers.

Since Vanguard supplies circuit breaker analyzers to meet the needs of utilities around the world, Nguyen will bring a great deal of information to the conference. One of the greatest attributes or qualities Nguyen provides is his hands-on approach to the industry. He is consistently in the field, both in the United States and internationally, observing and assessing Vanguard’s products’ performance as well as its competition.

In this session, Hai will introduce to the audience all the circuit breaker analyzers available in the U.S. market. The main presentation emphasis is the detailed information on the graph and tabular record generated by an electronic analyzer. There will be ample time allocated for questions and answers as well.