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December 2011

Client Committees

Doble Client Committees are the lifeblood of the client conference. These nine different technical committees are made up of clients who not only decide on what papers will be presented at the March conference, but also discuss different apparatus issues in their respective sections.

Committee discussions are the proving ground for new diagnostic methods used throughout the industry. These disucssions often become technical papers at future conferences. Read some items of note from our recent committee meetings held in San Diego, California, USA.

Arresters, Capacitors, Cables, & Accessories (ACCA)

One client reported arrester failures that were caused by the improper voltage arresters being installed. He stated that field personnel were going by the physical size of the arresters and that the same size polymer housing may be used for arresters ranging from 3 kV to 30 kV. It appears that construction personnel are not paying attention to the voltage class. In this instance, a 15 kV arrester was installed on a 35 kV system. The arrester exploded when the circuit was placed into service. It was stressed that field personnel must pay attention to what is being installed. Many clients offered their experiences and most agreed that they see and pay attention to this issue.

Asset & Maintenance Management (AMM)

The committee reviewed the final stages of their project for a guide for minimum or recommended maintenance practices. This guide will be utilized to help utilities justify best practices when preparing for a regulatory audit or for general maintenance and testing references. Currently, utility best practices are often used but regulators are starting to question how they are derived. Regulating agencies aren’t prescriptive in telling the utilities what should be done and how often, but it is possible that once audits are completed and the information is gathered, standards may be introduced by these agencies.

In a proposed paper, one client continues to experience significant growth of its substations. This growth, coupled with aging infrastructure, increasing regulatory requirements and customers’ increasing reliability expectations creates the need to do a better job at substation maintenance. Traditional maintenance program execution cannot keep up with what needs to be done, even with a robust replacement program. As a result of these operating environment pressures, the client is proactively redesigning its substation maintenance practices to optimize maintenance to ensure crews perform the right work, on the right piece of equipment, at the right time.

Bushings, Insulators, & Instrument Transformers (BIIT)

The BIIT committee recently undertook a project to change some of the information in their existing Bushing Guide. One section that was of particular interest was the need to fill the tap chamber with insulating material. Several different manufacturers were surveyed on their recommendations and now have been consolidated into the guide with updated language on the section. Many opinions and experiences, as well as cautions, were discussed in a lively conversation.

Circuit Breakers (CB)

While presenting a proposed paper, a client stated that they have recently installed 4 bays of breakers and a half layout of GIS. The manufacturer informed them that some of the test data they requested was not available because they do not test the breakers in the same manner. The client was told that motion perspective is not useable information and they do not recommend performing these tests, however the client was given all of the timing data. The client believes that motion perspective is a valid diagnostic and needs to develop test plans for their new apparatus. The paper will describe the successful implementation of their testing strategy.

Protection, Automation, Controls, and Communications (PACC)

NERC PRC-005 continues to be a very interesting discussion topic within the PACC committee. In this session, a discussion of compliance, audits and the interpretation of the standard took place. Questions were brought up on the following topics: what and how substation communication components are tested, standards for maintenance testing and how to handle an audit. An additional point brought up was that test equipment calibration is not mentioned. There are still a large number of unknowns in the area of requirements and compliance continues to be a big topic of interest.

Transformers

In another proposed paper, a presentation on the new method for OLTC diagnostics using the dynamic resistance recording (an off-line, dc current, non-destructive test, through all tap changer positions) and evaluation of different features, like ripple, transition time, graph signatures, and motor current. Experiences from transformers tested at three different clients are showing this simple methodology to be a powerful diagnostic tool. The successful paper will be presented in March by the three clients involved. 
 

2012 International Conference of Doble Clients
March 25 - March 30, 2012
Westin Hotel Copley Place
Boston, MA, USA