Asian experience with rtv silicone coatings - Presentation by Project Sales at INMR

Asian Experience with RTV Silicone Coatings

for Insulators

Asian Experience with RTV Silicone Coatings

for Insulators

Case Histories

Paper Presented at INMR Hongkong 2005 by Project Sales Corp. mailto:[email protected]

AbstractReview RTV silicone coating experiences for high voltage

porcelain insulators in Asian countries such as Korea, China, Taiwan, Thailand and India.

Focus on case histories of field application of RTV Silicone Coatings in these countries.


The Flashover Process

Accumulation of Contaminants(Salt particles from coastal environment/ industrial pollution)

+Water Filming

(light rain, dew, heavy fog)

Leakage Currents

Dry-band Arcing & Flashover


Cost of FlashoversLoss of revenueDisruption of businessDisruption of serviceInconvenience to consumersPoor service provider image


Flashover Protection MethodsCleaning

Manual wiping or energized washing with high pressure systems. Repetitive short-term solution. Cleaning must be repeated at a rate that will stay ahead of the contamination in order to be effective


Flashover Protection MethodsDesign

Extended creepage distance insulators/ Units designed for a high voltage class.When pollution problem is known before equipment is specified. More often pollution levels are not known or pollution comes after the construction of the utility system.


Flashover Protection MethodsSurface Modification

Modify the surface properties of the insulator with the use of silicone greases and coatings. Silicones imparts hydrophobicity to the insulator surface that prevents a conductive film to be formed, thereby limiting and managing surface leakage currents. Additives used in the formulation suppress arc and control surface temperatures.


RTV Silicone CoatingDeveloped by Dow Corning between 1970-74 as a response

to industry’s need for a maintenance free solution.

Extensively tested at various utilities across the United States between 1974-84.

Commercially available since 1984 as Sylgard® HVIC.

Global Applications across United States, Europe, Middle East and Asia in voltage ranging from 11kV to 500 kV DC.


How RTV Silicone Coating Works ?Imparts hydrophobicity and prevents wetting of contaminants

and formation of an ionisable solution that can lead to increased leakage, dry band arcing and eventual flashovers.

Low molecular weight silicone molecules encapsulate contaminants and neutralize them.

In extreme weather events, arc resistance fillers, ATH releases H2O and resists degradative effects of high temperatures.


Review Of Silicone RTV Coating Installations

Across Asia

Review Of Silicone RTV Coating Installations

Across Asia

Few Case Studies


Sylgard HVIC at 400 kvSS in India

Customer:State Power Utility

Location:South India

Pollution:Salt particles from cooling tower of a thermal power plant. Veryfrequent flashovers

Solution:Sylgard® HVIC applied in 2004 on all equipments in one bay at the 400 kvSS



All equipments in one bay of the 400 kVSS, incl. CTs, CBs, Pilots, Suspension, Pantograph Isolators, Supports, etc coated with Sylgard HVIC
















Sylgard HVIC Applied to Transformer Bushings at Taiwan Power Company

Customer:Taiwan Power Company Din - Hu Substation

Location:LinCo, Taipei County, North West Region of Taiwan

Pollution:Saline, smog, industrial and chemical pollution

Solution:Sylgard® HVIC applied in 1993 continues to perform until 1999


Sylgard HVIC Applied to Transformer Bushings atTaiwan Power Company

Substation started operation in 1988Situated near the coast exposed to saline environments as well as industrial and chemical pollutants.Weekly washing in the first few years of operation.Applied Silicone Grease in 1992.

Substation wanted a long-term maintenance free solution.Sylgard HVIC applied on 345 kV transformer bushings in 1993.Washed them in 1996 during third year inspection.Continued to perform until 1998. Recoated with Sylgard HVIC 0.25mm thick in 1999.


Sylgard HVIC at Hsinchu Industrial Park 68 kV Substation

Customer:Taiwanese Power Utility – Hsinchu Industrial Park Substation

Location:Hsinchu Industrial Park, Taiwan

Pollution:Dust, salt deposits and chemical pollution

Solution:Sylgard® HVIC applied in 1993 continues to perform.


Sylgard HVIC at Hsinchu Industrial Park 68 kV Substation

Substation located 10 km from ocean.Serves Industrial customers including large manufacturing plants. Used Silicone Compound but found shutdown for repetitive application difficult.Started energized washing weekly but experienced flashovers during and between washing.

Entire substation coated including support and suspension insulators, bushings, etc with Sylgard HVIC in 1993.Sylgard HVIC sprayed over a week in two stages – 8 hours each.No flashovers since 1993. SylgardHVIC continues to perform.


Shanghai Extra High Voltage Power Transmission Company

500kV Nanqiao HVDC Converter station, wall bushings coated with Sylgard HVIC.

This line links central and eastern network (Yangtze to Shanghai).

HVDC creates special problem. Contaminated particles get polarized and attract to the insulators.

Converter stations are located at each end of the line. Light industrial and river pollution necessitated continual hand cleaning of the HV DC insulators until the application of Sylgard® HVIC coating in 1991


Bhutan Power Station 220/132 kVSSCustomer:Pashaka Substation 220/132 kVSS

Location:Bhutan

Pollution:Slurry from land slides, carbide dust from carbide plant, cement dust from cement plant

Problem:Frequent tripping and repeated shutdowns to clean 220 kv support insulators and isolator switches.

Solution:Sylgard® HVIC applied in 2000


Cement Plant, North India 132/33 kVSS

Customer:Gujarat Ambuja Cement 132/33 kV SS

Location:North India

Pollution:Captive Dust; Fly Ash from adjacent thermal plant

Problem:Frequent tripping and shutdowns to clean insulators

Solution:Sylgard® HVIC applied in 2004


Gujarat, West India, Petrochemicals Complex 220kv SS

Customer:Reliance Petrochemicals

Location:Gujarat, West India

Pollution:Iron Ore Dust from a neighboring steel plant, captive dust and saline environment

Problem:Shutdowns to regularly clean insulators was difficult; CT Failure

Solution:Sylgard® HVIC applied in 2000 on CTs and other critical equipment


What kind of approach would you use ?








Trend Towards RTV Coating in Power Utilities Utilities gradually moving from water washing and greasing

to one time application of Silicone RTV Coating for installed equipments.

Silicone RTV coating has proven as a very cost-effective protection method.

Internal study of 132 kv SSs in a state utility in India –(i) The cumulative revenue losses from outages over a period 3 years is almost equal to the investment in Sylgard HVIC coating. (ii) It also works to approx. 1% of annual revenue of the sub-station. With better reliability vis-à-vis other methods.


Salt161 kVShen-au Power Plant1994

Salt345 kVTaichung Power Plant1993

Salt345 kVLin-Co Substation1993

Salt69 kVHseih-ho Power Plant1993

Salt, Industrial69 kVChung-Mei-Ho Power Plant (petrochemical)1992

Salt345 kVTaichung Transmission Lines1991

Salt69 kVFang-San Substation1991

Salt69 kVFang-Liau Substation1991

Salt, industrial69 kVTaiwan Glass1991

Industrial, dust69 kVTaiwan Styrene-Petrochemical Plant1991

Industrial, dust69 kVSang-Yang Motor Company1991

Salt, Industrial161 kVSang-Min Power Plant1990

Salt, Industrial161 kVTa-Lin Power Plant1990

Salt 69 kVMai-Laio Transmission line1990

Salt, dust69 kVHsin- Tao Substation1990

Salt, dust161 kVNan-Pu Power Plant1989

Industrial pollution500 kV DCGe Zhou Ba Power Plant1989

ContaminantVoltageCustomerYear

RTV Silicone Coating in Taiwan and China


Salt, industrial230 kVEgat CC&CC Block 1 & 21996

Salt, industrial115 kVEgat Substation1996




Lignite, Chemical115 kVThai Caprolactam Public Co Ltd1996

Industrial pollution22 kVKR Precision Public Co Ltd1996

Salt, industrial230 kVEgat ( Switchyard Bay 7 - 10 )1995

Industrial pollution22 kVSiam Tire cord Co Ltd1995

Industrial pollution22 kVMagtric Co Ltd1995



Salt, industrial230 kVPhadaeng Industry Public Co1995

Pollution115 kvNakornluang Cement1994

Industrial pollution22 kVCharernsawat CoLtd1994

Industrial pollution22 kVNagyang Factory Co Ltd1994

Phosphate/others69 kVThai Central Chemical1994

Sodium hydroxide/others69 kVThai Asahe1994

Pollution69 kVMEA Transmission Line1993

Industrial pollution11 kVTPI Petrochemical Public co. Ltd1993


RTV Silicone Coating in Thailand


Salt345 kVDongseo Power plant (Dangjin petro)2005

Salt345 kVWolsung Nuclear Power Plant2004

Salt345 kVGori Nuclear Power Plant2004

Salt345 kVKEPCO (Suwon Power Station)2004

Salt345 kVUljin Nuclear Power Plant2003

Salt, Industrial154 kVSeobu Power Plant (Pyungtaeck)2003

Salt154 kVNambu Power Plant (Youngnam petro)2003

Salt345 kVKEPCO (Sin-Goyang)2003

Salt345 kVKEPCO (Sin-Ulsan)2003

Salt, industrial154 kVKumho Power Plant2002

Salt, dust345 kVYoungkwang Nuclear Plant2002

Dust345 kVNambu Power Plant (Hadong petro)2002

Salt, Industrial345 kVKEPCP (Jinju Power Station)2001

Industrial154 kVKERI2001

Salt, dust154 kVHyundai Mipo (Ship building Co.)2000

Salt, dust345 kVDongseo Power plant (Ulsan petro)1998

Salt, dust345 kVNamdong Power plant (Samcheonpo)1997

Industrial154 kV KEPCO (Suncheon Power Station)1995


RTV Silicone Coating in Korea


To ConcludeAfter its commercial introduction in 1984, hundreds of

installations have been successfully coated in Asia and worldwide with Sylgard® HVIC, the brand from Dow Corning.

In particular, Asian installations now have a proven alternative to mitigating contamination related flashovers.

Sylgard® HVIC has successfully avoided flashovers in most kinds of pollution and weather environments.

Sylgard® HVIC is a cost-effective method to prevent contamination induced flashovers..


Special ThanksMr. Venkatraman Sundaramoorthy, Sales Manager, EEI,

Dow Corning India (P) Limited, India

Mr. Nitin Kamat, Industry Sales Manager, HVIC, Dow Corning India (P) Limited, India


Thank you


Business

Asian experience with rtv silicone coatings - Presentation by Project Sales at INMR