new iec 60296 ed 4 from a transformer oil manufactures perspective 2013-09-01
TRANSCRIPT
TLM 2013, Transformer Life Management, Hannover / Dubai
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New IEC 60296 (ed. 4)
From a Transformer Oil Manufacturer’s Perspective
Nils Herlenius Ergon Europe MEA Inc.
Drève Richelle 161, Building C B‐1410 Waterloo, Belgium
Jimmy Rasco and Edward Casserly
Ergon, Inc. Jackson, Mississippi 39215‐1639, USA
ABSTRACT This paper highlights some of the major updates in the new IEC 60296 (ed. 4, published in 2012), “Fluids for electrotechnical applications – Unused mineral transformer oils for transformers and switchgear” [1], and some of the considerations a transformer oil manufacturer needs to take in order to fully meet the new IEC 60296 standard.
1. INTRODUCTION The IEC 60296 (ed. 4) published in February 2012 replaces the IEC 60296 (ed.3) from 2003 [2]. Since 2003, various findings made an update of the IEC 60296 necessary. Few of them mentioned below: In 2005, Doble conducted testing for presence of corrosive sulphur in some 500 un‐used transformer oils. The tests showed that more than 40 percent of the oils were corrosive as per ASTM 1275A [3] which was the existing test method for corrosive sulphur. In 2006, the laboratory of Sea Marconi Technologies and the Italian utility Terna, together with Italian and US Universities, identified a single compound, suspected to been added to the oil as an antioxidant, in declared un‐inhibited transformer oils [4]. In 2009 Cigre published a report on the copper corrosion problem “Copper sulphide in transformer insulation” [5] and IEC published the new corrosive test method IEC 62535 [6], complimenting the already existing corrosive tests DIN 51353 [7] and ASTM 1275B [8]. In 2010 Cigre started the new working group A2‐40, “Copper sulphide long‐term mitigation and risk assessment” [9], and IEC initiated work to establish an official IEC method of detecting Dibenzyl Disulfide [10]. Professor Kapila from the University of Missouri – Rolla presented at the My Transfo 2010 the detection of an
undeclared metal deactivator in transformer oils in his presentation “Rapid and Specific Determination of Additives, Contaminants and By‐products in Transformer Mineral Oils with Electrospray – Mass Spectrometry and Tandem Mass Spectrometry” [11] In 2011, the Belgian laboratory Laborelec [15] presented a paper on its discovery of an undeclared metal deactivator in transformer oils.
2. Major change of IEC 60296 (ed. 4) versus IEC 60296 (ed. 3)
New interpretation of “un‐inhibited”
and “inhibited” transformer oil
Metal passivators / deactivators
Dibenzyl disulfide
Other additives
Corrosive sulfur test
2.1 New interpretation of “un‐inhibited” and “inhibited” transformer oil
In the previous IEC 60296 (ed. 3) inhibitors improving the oxidation stability of the transformer oil were strictly limited to those described in the IEC 60666 “Detection and
TLM 2013, Transformer Life Management, Hannover / Dubai
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determination of specified additives in mineral transformer oils” [13]. No other additives improving the result the oxidation stability were allowed as per the IEC 60296 (ed. 3). If any of the antioxidant of the IEC 60666 were added, the oil should have been declared as either “trace inhibited” or “inhibited” transformer oil depending on the amount of inhibitor used. In the new IEC 60296 (ed.4), the definition of “un‐inhibited” and “inhibited” transformer oils is only linked to the antioxidants of the IEC 60666. As before, if any of the antioxidant described in the IEC 60666 are added ‐ the transformer oil should be declared as either “trace inhibited” or “inhibited”. Furthermore, in the new IEC 60296 (ed. 4) any additives may be used, including those which as per IEC 60296 definition are defined as an antioxidants. The choice of antioxidants is no longer limited to those described in the IEC 60666. As a consequence, the transformer oil manufacture can add any antioxidant additive that is not described in the IEC 60666 and declare the oil as “un‐inhibited”, even though the transformer oil contains a synthetic antioxidant.
2.2 Metal Deactivators
The discovery of metal deactivators in some transformer oils on the market [11 and 12] raised concerns. These types of additives could hide potentially corrosive oil and give so called “false negative” results on corrosion tests. These additives additionally sabotage the oxidation test and do not give a fully representative result of the oxidation test, though the known metal deactivators are consumed quickly in service. The use of such additives without declaration and agreement with the buyer of the transformer oil – is a violation of both the previous IEC 60296 (ed. 3) and the new IEC 60296 (ed.4). Chemical literature classifies metal deactivators into two major groups as per their functioning mechanism, which either can be of chelant or of passivating type [19]. The new IEC 60296 (ed. 4) describes both “metal deactivators” and “metal passivators” as examples of “antioxidant additive”, but it is important to note that the IEC 60666 can only detects metal passivators, i.e. not metal deactivator of the chelant type. As per the new IEC 60296 (ed.4) the oil shall be tested for “metal passivator additives of IEC 60666”. Some of the other metal deactivators found declared or un‐declared in transformer oils and that is not described in the IEC 60666, can be detected by independent laboratories such as: Sea Marconi [14] and Laborelec [15].
2.3 Dibenzyl Disulfide Detection
Method for detection of dibenzyl disulfide as per IEC 62535 [6] is added as a compulsory requirement. For more information regarding this additive, see: [4], [16] and [17].
2.4 Other Additives
Known by few and used by even less, in the previous IEC 60296 (ed.3), article 5.4C gave the buyer an option to request the supplier to declare all additives in the oil. In the new IEC 60296 (ed.4) all additives shall be declared. An transformer oil that fully complies with the new IEC 60296 (ed.4) shall include the following information on additives in the Product Data Sheet (PDS):
Antioxidant additives, as per the IEC 60666
Metal Passivators, as per the IEC 60666
Dibenzyl disulfide as per the IEC 62535
Other Additives – shall be declared It is important to note that as per the new IEC 60296 (ed.4), if any additives are added that improve the oxidation stability, i.e. not only those described in the IEC 60666, the transformer oil shall be subject to the 500 hours oxidation test as per IEC 61125 C [18]. Example: any oil containing a metal deactivator, passivating or chelant type.
2.5 Corrosive Sulfur Test
Additionally to the corrosive sulphur test DIN 51353, the IEC 62535 [6] test on “potentially corrosive sulphur” is included in the new IEC 60296 (ed. 4). An informative annex has also been added with information on “potentially corrosive sulfur”. The annex includes useful information on how to “detect corrosive sulphur compounds in oil containing a metal passivator additive (declared or suspected),” [1]
3. Manufacturing of Transformer Oil Meeting the IEC 60296 (ed.4)
For a mineral transformer oil to meet the new IEC 60296 (ed.4) standard: crude oil selection and correct oil fractionation by distillation are important to meet the requested viscosity at 40 and ‐30 degree Celsius (ISO 3104), sufficient amount of polycyclic aromatic compounds must be removed in order to pass the health requirements (IP 346), corrosive sulphur has to be removed in order to pass the “not corrosive” requirements tested as per IEC 62535
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Reference Fluids for electroils for transforIEC 60296 (ed. 4 Fluids for electroils for transforIEC 60296 (ed. 3 Standard Test Oils ASTM D1275‐0 Riccardo MaVander TumiattDibenzyl disulfiin used and unu[A]Sea Marconi
Venezia – Italydegli Studi di Ro “Dibenzyl disuand unused mForce A2‐32.01, CIGRE WG A2‐3Report, 2009, Bhttp://a2.cigre.Accessed: Octo Insulating liquidcorrosive sulphIEC 62535 (ed.1 Testing of insulatest, DIN 51353 Standard Test Oils, ASTM D12 CIGRE WG A2‐4Copper sulphidURL: http://a2term‐mitigationAccessed: Octo
] Test methods focompounds in umethod for quaIEC 62697‐1 (ed
] R. SeemamahanV.Tumiatti(2), CMaina(2), RapContaminants Electrospray – MPresented at M
] A. Schaut, S. Auas Additive in TVol. 19, No. 1, F
] Detection and insulating oils, I
es
rotechnical applicarmers and switchg4), IEC, 2012
rotechnical applicarmers and switchg3), IEC, 2003
Method for Corro
03, ASTM Interna
ina[A], Fabio
ti[A], Michela Tumi
de (DBDS) as corroused mineral transTechnologies, Co
y, [C]University of
oma “La Sapienza”lfide (DBDS) as coineral insulating o, Paris, France, 200
32, Copper sulphidBrochure 378, URLorg/cigre_search/ber 30, 2012
ds – Test method fur in used and unu1), IEC, 2008
ating oils; detectio3:1985, 1985
Method for Corro75‐06, ASTM Inter
40 e long‐term mitiga.cigre.org/WG‐Aren‐and‐risk‐assessmber 30, 2012
or quantitative deunused and used iantitative determind. 1), 2012
nnop(1), Kyle AndeCarlo Roggero(2), pid and Specifand By‐products Mass Spectrometry Transfo 2010, Tu
utru, A. De Rop, S.Transformer Oil,”February, 2012, p.
determination EC 60666 (ed.2), I
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ations ‐ Unused mear
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e in transformer i: /result/%28Search
for detection of poused insulating oil
on of corrosive sul
osive Sulfur in Elrnational, 2006
ation and risk asseea/WG‐A2.40‐coppment
termination of cornsulating liquids –nation of dibenzyl
erson(1) and S. KaMichela Tumiattic Determinatioin Transformer M
ry and Tandem Maurin, Italy
Eeckhoudt, “Effec IEEE Trans. Diele175.
of specified addEC, 2010
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ineral insulating
ineral insulating
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ubhen Kapila[C]
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Sea Marconi Techvia Ungheria 20, 1Tel +39 011 234.34Fax +39 011 234.3E‐mail info@seamURL: www.seamarAccessed: October
Laborelec Rodestraat 125, 16Tel +32 (0)2 382 0Fax +32 (0)2 382 0E‐mail: info@laboURL: www.laborelAccessed: October C. Qiu, S. Han, X. CDetermining the abomb oxidation calorimetry, Therm
S. Plaza, B. MazurkThermal decompomechanism, Wear
Unused hydrocarevaluating the oxi
J. Dong, C. MigChemistry and ApTaylor & Francis G
NilsChe(KTHUnivknoOEMbus
r of technical papnical & Marketing onate musician and
JimmservedRefiniLaboraalso sRefini
henic and paraffng for 38 years in urrently has globafinic and naphthenn State University.
Edwa B.Ain Hfromin R&prodscien
ts. He is currently
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nologies sas 10093 Collegno (TO4.34 34.35 marconi.it rconi.com r 30, 2012
630 Linkebeek 2 11 02 41 relec.com lec.com/ r 30, 2012
Cheng and T. Ren antioxidant activit
test and premochimica Acta, V
kiewicz and R. Gruosition of dibenzyr, Vol. 174, 1994, p
bon based insuladation stability, IE
gdal, “Antioxidanpplications,” L. RuGroup, USA, 2009,
s Herlenius was bemical EngineeringH) in Stockholm aversity of Strathcwn speaker andMS with nearly 2iness. Active mepers and reviewingDirector for Ergod a private pilot.
my M. Rasco was bd as Manager ong, Inc, Vicksburatory and Technicserved as Vice Prng, Inc responsiblfinic base oils. Jithe area of Qualital responsibility fnic products. He h
ard Casserly was A. in Chemistry frouston, Texas an
m Rice University in&D and technical ducts for over 28 ntific publicationsy Director – Refine
O), Italia
ties of organic suessurized differeVol. 447, 2006, pag
uzinski yl disulfide and itpages 209‐216
ating liquids ‐ TesEC 61125, IEC, 199
ts”, in “Lubricanudnick, ed., 2nd pages 3 – 50.
born in Sweden. g from Royal Techand an Executive clyde in Glasgow adviser at man20 years in the tember of both Cg author for IEEE.on Europe MEA In
born in the United of Technical Servrg Refinery respocal Services for 1resident‐Product e for quality and dmmy has workedty Control and Tecor base oil technas a BS degree in
born in the Unitedrom the Universitynd a Ph.D. in Orgn Houston. He hasupport for specyears. He has c
s and is co‐inveery R&D for Ergon
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lfides by rotary ntial scanning ges 36‐40
ts load carrying
st methods for 2
nt Additives – Ed., CRC Press,
He has a MSc. hnical University MBA from the . He is a well‐ny utilities and transformer oil CIGRE and IEC, He is currently nc. He is also a
States. vice for Ergon onsible for the 15 years. Jimmy Services, Ergon development of d in petroleum chnical support. nology for both Chemistry from
d States. He has y of St. Thomas ganic Chemistry s been involved ialty petroleum co‐authored 18 entor on 7 US Refining.