ArresterNEWS is a totally independent monthly e-journal dealing with system reliability and arresters. |
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Arrester of the Future May be Here Now!!
For several years, I have watched a development in the IEC TC37 Maintenance Team 4 (MT4) unfold with interest. The Japanese National committee brought a new work item to the table regarding an arrester that has been available from  several manufacturers in Japan and France for years but did not have an IEC standard associated with it. After numerous taskforce meetings and several subtle battles between team members about the content of a draft standard, a Committee Draft has been circulated regarding this arrester type.
MT4 members have coined the name of this arrester as the "Externally Gapped Line Arrester" (EGLA). I do not have any real problem with the name because it describes the arrester precisely, but the acronym (pronounced egg-la) is a bit unappealing. The primary application for this arrester is to mitigate the effect of lightning on transmission and distribution lines.
An interesting aspect of this arrester design is the fact that it uses the oldest arrester component (an air gap) with the newest arrester component (metal oxide disks) to produce a device that has much of what the industry is looking for in the arrester of the future. However, because it has a gap in its design it has been shunned by the industry. Yes, can you believe it, shunned. The pundits in the industry cannot believe that a superior technology could contain an antiquated gap.
When the MOV arresters were first introduced in the early 80's one of the selling features of the new technology was the fact that series gaps were no longer needed and all the gap issues would be gone. The entire industry jumped on the anti-gap bandwagon. Millions of dollars were spent convincing the users of arresters that gaps were outdated and undesirable.
Enter EGLA. Because the gap is in series with a metal oxide varistor and not a silicon carbide varistor, nearly all the negative characteristics of the gap are gone. The benefits of this arrester for line protection are impressive. In particular, its fail open feature makes it highly desirable for applications were outages are a major issue. This could be the arrester of the future for line protection if we can get over the negative bias toward series gaps.
For more information on this arrester type see
ArresterFacts 004a Externally Gapped Line Arrester (EGLA). |
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Arrester Standards Update Both IEEE and IEC standards writing groups are actively working on upcoming changes.
IEC
TC 37 MT4
This is the group responsible for 60099-4, 60099-6 and the upcoming 60099-8.
60099-4 has a substantive change in the works. It is related to mechanical testing of arresters. This is an area of the 99-4 standard that has been in need of improvement for quite a while.
60099-6 has no changes in the works.
60099-8 is a new standard that will cover the testing of the externally gapped line arrester.
TC 37 MT10
This group is responsible for the arrester application guide 60099-5. They are drafting a new edition at this moment. The target publish date is 2010.
IEEE
SPD WG 3.3.11
This group has just completed an update in the short circuit test requirements for all arresters. The IEEE and IEC tests are now quite well aligned.
Task Force 14 of this group is working on writing the rationale of all C62.11 tests. They are also making recommendations on tests that are outdated.
SPD WG 3.4.14
This group is about to publish a major update to the application guide. C62.22. Watch for it.
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Surge Protection Hall of Fame
François Martzloff has more than 50 years experience in engineering with 40 of it in the surge protection industry. He is perhaps the most prolific author in this industry for the past 40 years, and perhaps for all 150 years of this business. There was a rumor a few years back that said François had retired, but it is not obvious by his action. Even as I was gathering this information from him, he was in the middle of an email-flurry on a surge subject with colleagues from the Surge Protective Devices Committee (SPD).
When asked to offer words of wisdom for those that follow us in this business, he offered these:
Guidance #1
After concluding your own experiment, or reading someone's else, before drawing any conclusion, always apply the criterion: "Does it really make sense?
Guidance #2
Never, never -- or hardly ever, -- take NO! for an answer, even the second time. However, be aware that the world has two different definitions when reviewing the same initiative: if finally accepted, you have been perseverant; if still rejected, you are merely obstinate, period.
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Arrester History Photo of the Month
1928 Expulsion Arrester
This was the first arrester produced by the Line Material Company (One predecessor to Cooper Power Systems.) It was manufactured in Milwaukee WI during the 30's
Key Benefits of this arrester per its brochure were
1. It need not be inspected every day
and
2. Leakage current was very low, less than .5 amps.
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Distribution System
Overvoltage Protection Course Now Available
As of this month, ArresterWorks is now available to visit your site to present 4-8 hour seminars on the protection of Distribution System Overvoltage Protection Seminars as well as Substation and Transmission Line
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