Fuji "MOLTRA" Cast-Resin Dry Type Transformers

Fuji Cast Resin Transformers

Our company

  • ・Fuji Electric developed our first cast-resin transformers in Japan in 1974.
  • ・Third party certification of IEC60076-11 was obtained in 2006
  • ・Secured top market share in Japan for 22 consecutive years in 2010

Standard Specifications

・Standard design

  • ・Rated voltage; up to 36kV, Rated power; up to 24,000kVA
  • ・Insulation system temperature; 155℃(F)
  • ・Type of cooling; AN (Naturally-Cooled), AF (Forced-air-Cooled)
  • ・Maximum ambient temperature; 40℃, yearly average temperature; 20℃
  • ・Utilizing aluminum for winding and copper for terminal
  • ・Climatic, environmental and fire behavior classes C2, E2 and F1.

・Optional design

  • ・Insulation system temperature; 180℃(H)
  • ・High & Super-high efficiency type
  • ・Low noise type
  • ・Maximum ambient temperature 50℃
  • ・Rectifier transformer (provision for harmonics)
  • ・In-rush current reduced design to standard value 15~20 times
  • ・Winding temperature rise reduced design for higher ambient temperature site


・Transformer Applications Designs

Fuji Cast-Resin Transformer can be applied to power transformers, distribution tansformers, transformers for static converter (such as VSD : variable-speed drive ).

・High-Rise Building Applications Designs

Japan's largest capacity cast resign transformer at 17MVA, the units are installed on the 13th floor of a 41story building using the site-reassemble method. This technique allows for product installation in applications with size and weight restrictions.

Technical data
3-phase 60Hz 13MVA(AN)/17MVA(AF) 22.0/6.6kV
Insulation class H

Deployment of Cast Resin Transformers
2008 - 3 units deployed to a high-rise building the city of Osaka, Japan.

・Wind Turbine Applications Designs

Optimum design results in compact size and lightweight transformers

Compact and light : Space saving with slip-on cable joint ⇒ Possible to install inside the shaft
High efficiency : 99.2% or more at rated power
Salt resistance : (*)ESDD 0.06mg/cm2
Vibration resistance : acceleration 0.5G (max.3G for TR body)
Able to withstand AC 77kV Separate-source test voltage for 2000m above sea level site

Technical data
3-phase 60Hz 2700kVA 0.69/34.5kV Insulation class H

Delivery Record
Approximately 500units delivered since 2007

・Railway Applications Designs

Withstand cyclic load; excellent overload capability
Provision for harmonics of rectifier
; taking into account of the additional losses
Withstand 170kV Lightning impulse test voltage
refer to IEC60076-11

Technical data
3-phase 50Hz 2700kVA 33.0/2x0.59kV
Insulation class H
With protection enclosure IP21

Delivery Record
Approximately 170units delivered to the railway substations in the Middle East in 2009

Product Features


Our product is manufactured with vacuum casting method using a premium metal pattern, resulting in a thick resin layer with a smooth surface

Fire Resistant

Epoxy resin possesses self-extinguishing and fire resistant properties, making it safe in flammable environments
Fuji Electric's cast resin transformer successfully completed and passed all tests of IEC 60076-11 in 2006.

Partial Discharge Free

Void-less : Excellent partial discharge characteristics.
In order to maintain superior quality, Fuji Electric voluntarily adopted the following stricter standard:

All units are subjected to partial discharge test.
Voltage that is twice that of the operating system is applied to ensure safety
Partial discharge is less than 10 pC (Pico-coulombs intensity)

Cast resin transformers are also coated in high-vacuum chambers to reduce air and other gases in the resin that could produce partial earth discharges. In effect, they hermetically seal the transformer's core.

Shop Test Items

・Routine test

Measurement of insulation resistance
Measurement of winding resistance
Measurement of voltage ratio and phase displacement check
Measurement of short-circuit impedance and load loss
Measurement of no-load loss and current
Separate-source AC withstand voltage test
Induced AC withstand voltage test
Partial discharge measurement

・Type test (Optional)

Lightning impulse test
Temperature-rise test
Measurement of sound level

Applied standards

  • ・IEC60076-11
  • ・ANSI/IEEE C57.12.01
  • ・GB6450, GB/T10228
  • ・JEC-2200 etc.

Third Party Certification of IEC60076-11

Fuji cast resin transformers were officially certified after successful completion of all test items under IEC60076-11
This includes special test items and type test items by KEMA and CESI.

Certificate organization KEMA(Netherlands), CESI(Italy)

Japan's first manufacturer to obtain IEC60076-11 certification
Third party certification ensures objective confirmation of product compliance
Special test certification; climatic class C2 (crack resistance)
; environmental class E2 (moisture resistance)
; fire behavior class F1 (fire resistance)
; short-circuit test

Production Bases

Fuji Electric Corporation has two cast resin transformer production bases:
Chiba Factory in Japan, and Fuji Tusco Co.,Ltd in Thailand


/Philippines/Sri Lanka,
Fuji Electric Asia Pacific Pte. Ltd.
Address : 151 Lorong Chuan #03-01/01A, New Tech Park, SINGAPORE 556741
Tel : +65-6533-0014
URL : http://www.sg.fujielectric.com/
Email : x-fap-sales@fujielectric.com
Indonesia PT Fuji Electric Indonesia
Address : Gedung Sucaco 2nd Floor, Kebon Sirih Raya No.71 PO Box 4872,
Kebon Sirih, Jakarta Pusat, 10340, INDONESIA
Tel : +62 21 398-43211
Email : kukita-tetsuya@jkt.fujielectric.com
Fuji Electric (Thailand) Co., Ltd.
Address : 43 Thai CC Tower, 11F, Room No. 114-9 South Sathorn Rd,
Yannawa, Sathorn, Bangkok 10120, THAILAND
Tel : +66-2-210-0615
Email : matsuyama-akira@fujielectric.com
Vietnam Fuji Electric Vietnam Co.,Ltd
Address : Room 401, 4thfloor, Corner Stone Building, 16Phan Chu Trinh,
Hoan Kiem, Ha Noi, VIETNAM
Tel : +84-4-3935-1593
Email : nt-thong@fujielectric.com
Middle East
(Saudi Arabia, UAE,
Oman, Bahrain, etc.)
Fuji Electric Middle East Branch Office
Address : 71, Bldg 892, Road 3618, Block 436, Seef, Manama, KINGDOM OF
Tel : +973-17 564 569
Email : alan.grant@fujielectric.com

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