From: Ryan, Paul [mailto:Paul.Ryan@hitmet.com]  

Sent: Thursday, October 20, 2011 9:53 AM

To: Brian Coffey

Subject: RE: Amorphous Core Experience at BGE

Hi Brian,

Good question.  The epoxy serves two primary purposes, 1) to provide mechanical

stability to move the core around (e.g. shipping and production) and 2) provide a

barrier to possible metallic flakes.

The joint opening is "encapsulated" by various means (depends on mfg.) during the

core coil assembly process.  I quote encapsulation as this is the common term

used in the industry.  A common method of joint opening encapsulation is the use

of a box formed from insulation paper.  The joint opening is completely sealed

off (encapsulated) by the box; thus, not allowing any possible flakes to escape.

I hope this helps to clarify.  Please don't hesitate to ask if you have any other

questions.

Sincerely,

Paul C. Ryan

paul.ryan@hitmet.com

Product Group Head

Hitachi Metals America ‐ Metglas Inc.

Tel: +760‐720‐0408

Mobile: +760‐415‐3469

Fax: +760‐720‐0626

‐‐‐‐‐Original Message‐‐‐‐‐ 

From: Brian Coffey [mailto:brian.coffey@navigant.com]

Sent: Thursday, October 20, 2011 6:42 AM

To: Ryan, Paul

Subject: RE: Amorphous Core Experience at BGE

Paul,

This is more a curiosity than a concern, but it's not obvious to my untrained eye

that the top portion of the transformer would be protected to the same degree as

the epoxied section. The epoxy is there to prevent little amorphous flakes from

circulating in the oil and carving up the insulation, right? Is there a different

way of protecting the top portion? Or does it not need protection for some

reason? Clearly, you guys have worked it out if you're not having field failures.

Thanks,

Brian  

______________________________________________________________

Brian Coffey | Senior Consultant | Energy | Navigant Consulting, Inc.

1801 K Street NW | Suite 500 | Washington, DC 20006
+1.202.481.7521 Office

‐‐‐‐‐Original Message‐‐‐‐‐ 

From: Ryan, Paul [mailto:Paul.Ryan@hitmet.com]

Sent: Thursday, October 20, 2011 8:49 AM

To: Phil Hopkinson; Hirsch, Bruce R; Richard Parker; Alex Hofmann; Andrew

Delaski; Aris Marantan; Art Rosenfeld; Bob Saint; Brian Coffey; Bruce Smith;

Caitlin Johnson; Carlos Gaytan; Caskey, John; Charlie Drexler; Charlie Stevens;

Chris Bolduc; Clark Silcox; Creevy, Jim; Dan Cohen; Daniel Young; Eric Peterson;

Freeman, Jeremiah; Gary Fernstrom; Greg Coulter; Greg Rosenquist; James Lass;

Jennifer Tiedeman; Jerry Corkran; Jerry Hodge; Jerry Schoen; Joanna Mauer; John

Cymbalsky; John Rossetti; Katie Coughlin; Ken Winder; Mahesh P. Sampat; Matt

Miller; Matthew Nardotti; Meg Waltner; Meyers, Aaron; Michael Hyland; Michael

Rivest; Millure, Dave; Phil Harter; Polinski, Raymond; Puesh Kumar; Rick

Anderson; Rob Greeson; Robert Berman; Robert van Buskirk; Robin Roy; Scott Beck;

Simmons, Chuck; Steve Nadel; Steve Rosenstock; Tim Ballo; Tom Eckman; Wes

Patterson; Zhimei Luo; maxinesavitz@aol.com

Subject: RE: Amorphous Core Experience at BGE

Dear all,

  

As the saying goes, a picture is worth a 1,000 words.  I'm attaching a few slides

showing that amorphous cores can easily be opened and closed multiple times;

thereby allowing repair of a transformer by coil replacement.  In other words,

epoxy does not prevent disassembly as noted below.   

Additionally, considerable advances in amorphous core transformer techniques and

manufacturing practices have been implemented since the commercial launch of the

product in the 1980's.  An estimated 2.3M amorphous core transformers have been

produced worldwide with no reported core failures.   

Lastly, the wind farm incident described below was related to imported

transformers from Asia which had some manufacturing issues that have since been

reported to be corrected by the OEM.  

I hope this helps.

Sincerely,

Paul C. Ryan

paul.ryan@hitmet.com

Product Group Head

Hitachi Metals America ‐ Metglas Inc.

Tel: +760‐720‐0408

Mobile: +760‐415‐3469

Fax: +760‐720‐0626

________________________________________

From: Phil Hopkinson [mailto:phopkinson@hvolt.com]

Sent: Friday, October 14, 2011 6:25 PM

To: Hirsch, Bruce R; 'Richard Parker'; Alex Hofmann; Andrew Delaski; Aris

Marantan; Art Rosenfeld; Bob Saint; Brian Coffey; Bruce Smith; Caitlin Johnson;

Carlos Gaytan; Caskey, John; Charlie Drexler; Charlie Stevens; Chris Bolduc;
Clark Silcox; Creevy, Jim; Dan Cohen; Daniel Young; Eric Peterson; Freeman,

Jeremiah; Gary Fernstrom; Greg Coulter; Greg Rosenquist; James Lass; Jennifer

Tiedeman; Jerry Corkran; Jerry Hodge; Jerry Schoen; Joanna Mauer; John Cymbalsky;

John Rossetti; Katie Coughlin; Ken Winder; Mahesh P. Sampat; Matt Miller; Matthew

Nardotti; Meg Waltner; Meyers, Aaron; Michael Hyland; Michael Rivest; Millure,

Dave; Phil Harter; Polinski, Raymond; Puesh Kumar; Rick Anderson; Rob Greeson;

Robert Berman; Robert van Buskirk; Robin Roy; Ryan, Paul; Scott Beck; Simmons,

Chuck; Steve Nadel; Steve Rosenstock; Tim Ballo; Tom Eckman; Wes Patterson;

Zhimei Luo

Subject: RE: Amorphous Core Experience at BGE

Hi all:

I have had considerable experience with amorphous cores and they can be made to

work.  However, the process is not forgiving because the material is britle after

anneal and flakes off and breaks into tiny shards that remain loose and

undisciplined in the laced up core.  Some manufacturers have learned to contain

the shards.  It is relatively easy in small single phase transformers.  It is

more difficult in three phase cores.  It is extremely difficult for large three

phase cores that require two or more cores wide to be packaged together.  This

leaves blind locations where containment is not very easy.  Some have tried

sealing with epoxy but this prevents disassembly if a winding failure occurs.  

Some have tried pressboard boxes with cotton tape wrappers.  However, the cores

have greater magnetostriction than silicon iron and vibrate with greater

amplitude, and if not well contained may pump the shards of metal out of the

containment and into the windings where catastrophic failures have occurred.  I

investigated a wind farm in 2008‐9 where all 200 transformers had to be removed

from service, scrapped and rebuilt with silicon iron.  Not all manufacturers have

had such negative experience, but a few incidents can destroy a business.

This experience suggests that limitations should be anticipated in the use of

amorphous.  I certainly salute all who are successful because it can be made to

work.  I continue to believe that amorphous should not be the basis of a minimum

national standard for energy efficiency.   It is something that I recommend is

for applications where customers have needs for extremely low core loss and where

the manufacturers have a proven track record of design and application.

All the best,

Phil

Philip J Hopkinson, PE

President & CEO HVOLT Inc.

3704 High Ridge Rd.

Charlotte, NC 28270

phopkinson@hvolt.com

Ph     704‐846‐3290

Fx     704‐845‐2520

Cell   704‐236‐3320

www.hvolt.com

From: Hirsch, Bruce R [mailto:Bruce.R.Hirsch@bge.com]
Sent: Friday, October 14, 2011 12:16 PM

To: 'Richard Parker'; Alex Hofmann; Andrew Delaski; Aris Marantan; Art Rosenfeld;

Bob Saint; Brian Coffey; Bruce Smith; Caitlin Johnson; Carlos Gaytan; Caskey,

John; Charlie Drexler; Charlie Stevens; Chris Bolduc; Clark Silcox; Creevy, Jim;

Dan Cohen; Daniel Young; Eric Peterson; Freeman, Jeremiah; Gary Fernstrom; Greg

Coulter; Greg Rosenquist; James Lass; Jennifer Tiedeman; Jerry Corkran; Jerry

Hodge; Jerry Schoen; Joanna Mauer; John Cymbalsky; John Rossetti; Katie Coughlin;

Ken Winder; Mahesh P. Sampat; Matt Miller; Matthew Nardotti; Meg Waltner; Meyers,

Aaron; Michael Hyland; Michael Rivest; Millure, Dave; Phil Harter; Phil

Hopkinson; Polinski, Raymond; Puesh Kumar; Rick Anderson; Rob Greeson; Robert

Berman; Robert van Buskirk; Robin Roy; Ryan, Paul; Scott Beck; Simmons, Chuck;

Steve Nadel; Steve Rosenstock; Tim Ballo; Tom Eckman; Wes Patterson; Zhimei Luo

Cc: Hirsch, Bruce R

Subject: RE:Amorphous Core Experience at BGE

Importance: High

This is just a single Company's experience with amorphous core transformers.

Please note that based on this data we have NOT ruled out using amorphous steel

in our transformers, however, the numbers are troubling.  

BGE owns 2,770 transformers with amorphous steel cores. Most are three phase

units purchased in the mid to late 80's.

Of that number, 201 have failed in service. The cause of failure is not known but

to be considered a failure the probability is that either the core or coil

failed. This represents an 7% failure rate.  

The average age of the failed amorphous core transformers is 10.97 years.

The average age of failed transformers for BGE's entire fleet is 29.4 years.  

BGE has over 216,000 transformers in the fleet, thus the quantity of amorphous

core transformers represents 1.4% of the total.

While we could debate the cause of failure for any particular class or design of

transformer, the average age to failure date is a good apples to apples

comparison of the performance of the transformers since the exact same criteria

was used across the board.   

Hope this information, along with other user responses is helpful in the decision

making process.  

                                                                              

      Bruce

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