From: Millure, Dave [mailto:Dave.Millure@metglas.com] 

Sent: Wednesday, October 26, 2011 2:33 PM 

To: Corkran, Jerry L; Ryan, Paul; 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 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; 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; Trujillo, Antonio; Marusinec, Richard M; Meyers, Aaron 

Subject: RE: Amorphous Core Experience at BGE 

Dear Mr. Corkran and committee members, 

 

Metglas amorphous core material for the US market is and will be produced in Conway, Horry County, 

South Carolina, U.S.A. so import of billions of dollars worth of foreign material would not occur if 

amorphous gained in popularity. We welcome committee members to arrange for a visit our facility. 

Metglas amorphous core material was invented in the US with support from EPRI, and thus was partially 

funded by US utilities as an extremely successful industry sponsored energy conservation initiative. 

In General:

  

 First and foremost, the charter of the committee and DOE is to establish a national 

standard which serves the purpose of energy conservation and appropriately considers 

environmental considerations and costs. The objective is not to select specific material 

types or a particular technology; but rather, review viable means and technologies of 

meeting the energy conservation objective. 

 The committee has already established a preference in choosing a standard which allows 

competition among a range of core materials such as M3, M2, ZDMH, HiB, MOH and 

amorphous In the same fashion, encouraging competition requires that no particular 

material such as M3 be chosen as the base line or guaranteed a minimum market share. 

 Like other high efficiency materials, amorphous metal is a quality material that offers 

superior energy efficient properties. It is a technologically and commercially proven 

material which has been adopted throughout the world for more than 30 years to meet 

energy conservation objectives. It is a part of the product portfolio of most major 

transformer manufacturers. 

 Throughout this negotiating process, Metglas Inc. has never encouraged a standard which 

would be based solely on amorphous metal. Rather, we share the opinion of the 

committee that a standard should be chosen which allows a range of core materials to be 

competitive while meeting the objective of energy conservation. As we all know, more 

choices mean a more competitive and fruitful marketplace for the end consumer. 

Competition promotes lower prices for consumers and demands continued improvement 

and innovation on the part of producers. 

Specific to Mr. Corkran’s bullet points and the Lot 2 report created for the European Commission by

Veto NV and Bio IS:
 We object to use of definitive statements such as (I added bolding) “The added 

movement of the coils and the amorphous cores also results in a pumping action to force 

any debris from the cores out into the transformer coils increasing the risk of field 

failures. Movement within the coils will result in more abrasion of the conductor 

insulation leading to dielectric breakdowns.” Such statements must be backed by 

actual studies of amorphous DTs that include silicon steel DT’s for valid comparison. 

 As for the Lot 2 report, please be advised that much of the referenced section on 

amorphous itself references a CIRED paper authored by an EU transformer manufacturer 

that had, to the best of our knowledge, at the time of publication, built only two (2) 

amorphous transformers with little dialogue/direction from Metglas. In fact, with the 

exception of some work in Europe in the mid 1990’s, Metglas’s business development in 

Europe began only about five (5) years ago with participation in the SEEDT EU effort. 

Europe is in its infancy with respect to adoption of amorphous, but is moving toward 

amorphous in a deliberate manner. 

 Please note that the Lot 2 report found that, given a few years to develop EU supply chain 

for amorphous transformers (AMT), that amorphous-based distribution transformers are 

the lowest life cycle cost (LLCC) and is the Best Available Technology (BAT) for a 

number of transformer classifications: 

 
SEEDT Definition:

 Finally, to demonstrate commitment by major EU utilities to fully evaluate amorphous 

transformers, please see attached paper by EDF R&D et.al. The issues raised in Mr. Corkran’s email have done nothing to deter adoption of amorphous transformers in Europe even with their 

long stacked-core history.

Excerpt from attached paper:
Best regards

Dave Millure and Paul Ryan 

USA 

From: Corkran, Jerry L [mailto:Jerry.Corkran@CooperIndustries.com] 

Sent: Saturday, October 22, 2011 2:05 PM 

To: Ryan, Paul; 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 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; Trujillo, 
Antonio; Marusinec, Richard M; Meyers, Aaron 

Subject: RE: Amorphous Core Experience at BGE 

To Paul Ryan and the DOE working group, I have listed some technical reasons

below why amorphous core material is the wrong choice for a minimum US national

energy standard for transformers, but it is also the wrong choice from a national

interest, because it would force many billions of US dollars to be spent to

import a foreign material.   

   

•     The amorphous core material has some very low losses but the technical

concerns with it being considered for a national minimum efficiency standard for

transformers are explained to a great degree in the report supplied by Wes

Patterson to the WG titled Eup Lot 2 Transformers Final Report.  This report has

a detailed summary about what problems occur when amorphous core steel is used in

Distribution transformers. If any of those copied lack this report, please let me

know and I will send a copy.

•     What becomes apparent when the report is reviewed, is that the material

requires a new transformer design that does not allow any stress on the fragile

amorphous material. Even the weight of the amorphous cores may damage the cores

and result is shards breaking away from the main core loops. With silicon core

transformer designs, it is typical to assume the distribution transformer may

receive shipping jolts of up to three G in vertical forces.  

•     In silicon steel transformers, the core is the supporting part to hold the

coils.  The coils on larger 3 phase transformers exert short circuit forces

between phases and against the core clamp depending on the KVA rating and the

transformer impedance of 200 PSI to about 800 PSI during the initial transformer

fault.   

•     When the short circuit forces are applied to the 0.001 thick amorphous

material, it will compress.  This movement results in the risk of damage to the

cores and metal fragments coming off the cores during the short circuit.  The

added compressibility of the many layers of 0.001" thickness material in the

amorphous cores will result in more movement inside the transformer coils than a

similar design using silicon steel. The added movement of the coils and the

amorphous cores also results in a pumping action to force any debris from the

cores out into the transformer coils increasing the risk of field failures.

Movement within the coils will result in more abrasion of the conductor

insulation leading to dielectric breakdowns. This is a good reason for users to

require short circuit certification of testing performed on amorphous core

transformers before accepting delivery of amorphous core transformers just as

they have required short circuit certification testing for silicon core

transformers for many years.    

Part of the section on amorphous core transformers starting on page 225 of the

report Eup Lot 2 Transformers Final Report is copied below with underlining and

bold added to emphasize key points in the summary.

Main technical differences of amorphous core transformers compared to silicon

steel:  
A larger core cross‐section means more winding conductor length, with an increase

in resistance and hence an increase in the load losses (Pk).

Amorphous metal cores have a lower saturation magnetic flux density than the

silicon steel transformer cores. Lower flux density in amorphous metal cores

means that to achieve similar levels of total core flux, as in normal

transformers, the amorphous core must have a larger cross‐section.  

A design induction of 1.35T allows 110% overvoltage without saturation. At 85C

core temperature (hotter than cores get in normal operation), 110% overvoltage is

7 VA/kg.  

The AMT core space factor should be 84%. The AMT core material density is 7,200

kg/m3. The cores should be supported from the coils.  

Because of the rather specialized process needed to manufacture the amorphous

metal (an extremely rapid cooling of molten metal is required) it can only be

produced in very thin and long strips. The material is relatively brittle and

cannot easily be cut to shape. During the process, due to the brittleness, there

are some risks of particles inside the active part of the transformers that could

lead to dielectric breakdown.  

Amorphous ribbon is typically available in widths of 142, 170 and 213.3 mm,

multiple widths can be stacked side by side; It requires  ̳Wound core‘ technology

and therefore relies on the use of only one strip width. This results in a

rectangular cross section of the core (Figure 5 8). This rectangular core cross‐

section means more winding conductor loss (see also section 5.1.2.2); Another

difference between oval shaped and rectangular coils are the forces during short

circuit testing. However the unbalanced axial forces are nearly eliminated by

using a sheet or foil wound low voltage coil. Use of sheet wound LV coils is an

almost universal technique (see section 5.1.1.1). The low voltage coil then

balances its current distribution to match the high voltage coil current

distribution eliminating most of the axial force. This might also explain why

until now no power transformers were developed based on amorphous material. With

proper engineering transformers can pass the short circuit qualification tests of

European Utilities120.;

References: 120 B. JARRY (2009), P. LAUZEVIS P. LAGACHE M. SACOTTE,  ̳AMORPHOUS

SHEET CORE TRANSFORMERS UNDER EXPERIMENTATION ON THE ERDF NETWORK‘, CIRED

conference paper, 20th International Conference on Electricity Distribution

Prague, 8‐11 June 2009.

226

Both 3‐phase 3‐limb and 3‐phase 5‐limb core forms can be constructed. See section

5.1.3.3 for technical differences; Due to their bigger size and construction as

well as to the higher magnetostriction value of AM compared to GO these

transformers tend to have higher noise levels when constructed without additional

sound level reducing measures. According to T&D Europe, European manufacturers

have the feeling that the difference of noise is probably around 10db (A) between

amorphous transformers and the better level of losses with standard magnetic

steels transformers (400KVA);  
The magnetization requirement of these transformers is generally lower compared

to silicon121 due to the higher magnetic permeability, at least if one stays away

from magnetic saturation. AMT requires typically 0.5 VA/kg (1.3 T) while silicon

0.7 VA/kg; The higher magnetic permeability compared to silicon steel contribute

to reducing stray losses; Corner losses due to flux deviation are absent (see

section 5.1.1.3); These transformers are less subjective to harmonic currents

(see chapter 3) compared to silicon steel (see 5.1.1.2), The core losses of

material 2605SA1 are proportional to frequency and maximum flux density:

(equation 5.6) where,f is the frequency [kHz] Bmax is the maximum flux density

[T]  

The amorphous metal core must be conditioned prior to its installation in

transformers and the application of the windings (Figure 5‐9). The metal has to

be heated above its Curie temperature and then cooled slowly over some hours in

the presence of a conditioning DC magnetic field. This then orientates the

magnetic domains in the amorphous material. This procedure adds to the cost of

manufacturing such transformers.  

The  ̳wound core‘ technology in case of the amorphous material needs field anneal

in order to come to maximum performance. Therefore the cores will undergo heat

treatment at 340‐360°C. The cycle consists in a heat up phase, soak time (1 hour)

and cooling phase (no forced cooling) that can take up to 5 or 6 hours (according

to core size and oven load).; Low resistance to external stresses.  

In silicon sheet technology, once the magnetic circuit has been installed, it is

rigid, and acts as a mechanical support on which all the transformer elements

rest. In amorphous technology, the circuit elements are closed at the bottom‐end.

This is a fragile area, which must not be subjected to any stress. The impact of

own weight on stress in the core has also to be avoided122.

Amorphous transformers are significantly larger in size and inevitably have a

higher purchase price.

Potential barriers for up‐take:

No production capacity is available in Europe so far for material production and

transformer manufacturers need to adapt their production prices.

Technical development are necessary in most of European company to fulfill

completely European standard and IEC standard regarding ability to withstand

short circuit tests (According to T&D Europe at stakeholder meeting).

References: 121 M.J. Heathcote (2007):  ̳J&P Transformer Book‘, p. 50, ISBN 978‐

0‐7506‐8164‐3

122 CIRED (2009‐1): Bertrand JARRY, Patrick LAUZEVIS, Pierre LAGACHE, Michel

SACOTTE  ̳AMORPHOUS SHEET CORE TRANSFORMERS UNDER EXPERIMENTATION ON THE ERDF

NETWORK‘, CIRED 2009 conference proceedings.

227

According to T&D Europe at stakeholder meeting (May 2010), European manufacturers

face difficulties to produce compliant transformers above 1 MVA rated power. ).

Industrial end users might hesitate procuring these transformers as long as this

uncertainty exists and/or is communicated by trusted European brands.
In Asia however larger (1000‐2000 kVA) dry‐type and liquid‐immersed transformers

are produced that passed the short circuit test with similar standards.

One local Amorphous Metal Dry‐type Transformer (AMDRT) manufacturer obtained

national patent in China (patent No. 99225846.4).

Long time reliability for three phase transformers as demanded by European

utilities is not demonstrated on European networks(According to T&D Europe at

stakeholder meeting).

Although amorphous transformers are on the market since the early 90ies (see

2.2.6.9). For amorphous transformers still some new patents are filed. A search

for European Patents related to  ̳amorphous transformers‘ results in 36

patents123. In the period 2005‐2009 still four relevant patents for liquid‐filled

and/or dry type transformers were filed. This shows that the R&D to cover above

mentioned problems is still active.

Quantitative performance data used in this study:

AMT transformers can surpass class A0 no‐load requirements at least by up to 60

%, e.g. 195 Watt compared to 430 Watt class A0 requirement for a 400 kVA

transformer124. Especially at low load factors this is an advantage to increase

transformer efficiency, see Figure 5‐11.

Regards,

        Jerry Corkran

‐‐‐‐‐Original Message‐‐‐‐‐ 

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

Sent: Thursday, October 20, 2011 7:49 AM

To: Phi

‐‐‐‐‐Original Message‐‐‐‐‐ 

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

Sent: Thursday, October 20, 2011 7:49 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; Corkran, Jerry L; 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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