Transformer manufacturing workshop

Dry-type
Transformadores

Cast-resin and amorphous-core designs
for indoor power distribution.

Taller de fabricación de transformadores.

Dry-type
serie de transformadores

SCB cast-resin designs for 6–10 kV, 20 kV and 35 kV systems, alongside the SCBH amorphous-core family.

6–10 kV Cast-resin Transformers

30–4000 kVA at 10 kV · SCB12 / SCB14 / SCB18

Three-phase cast-resin distribution transformers with SCB12, SCB14 and SCB18 rating schedules.

20 kV Cast-resin Transformers

30–4000 kVA at 20 kV · SCB Series

Cast-resin distribution transformers with 20, 22 and 24 kV primary-voltage options.

35 kV Cast-resin Transformers

35 kV · SCB series

Three-phase resin-insulated construction for 35 kV indoor distribution and infrastructure installations.

Amorphous-core Transformers

30–4000 kVA at 10 kV · SCBH15 / SCBH17 / SCBH19

Amorphous-core distribution transformers with separate SCBH15, SCBH17 and SCBH19 loss schedules.

SCB and SCBH distribution ranges

The dry-type range includes cast-resin SCB transformers in the 6–10 kV, 20 kV and 35 kV families, together with SCBH amorphous-alloy transformers for the 6–10 kV family. These three-phase designs serve buildings, industrial facilities and indoor distribution installations where the transformer arrangement, cooling air and enclosure must fit the room.

Rated capacity is 30–4000 kVA for 10 kV SCB and SCBH transformers and 20 kV SCB transformers. The reference schedules show loss and impedance data for the ratings listed.

Electrical scope by dry-type family
familiaCapacity coverageOpciones de voltaje primariovoltaje secundarioDetailed schedule
SCB 6–10 kVOpciones de voltaje primario6 / 6.3 / 6.6 / 10 / 10.5 / 11 kVvoltaje secundario0.4 kVCapacity coverage30–4000 kVA at 10 kVDetailed schedule19 entries; SCB12, SCB14 and SCB18 loss columns
SCB 20 kVOpciones de voltaje primario20 / 22 / 24 kVvoltaje secundario0.4 kVCapacity coverage30–4000 kVA at 20 kVDetailed schedule17 entries; B/F/H load-loss conditions
SCB 35 kVOpciones de voltaje primarioClase 35 kVvoltaje secundarioEspecificado por proyectoCapacity coverageEspecificado por proyectoDetailed scheduleSCB10 · 35/0.4 kV reference examples; AN/AF and enclosure options by design
SCBH amorphous alloyOpciones de voltaje primario6 / 6.3 / 6.6 / 10 / 10.5 / 11 kVvoltaje secundario0.4 kVCapacity coverage30–4000 kVA at 10 kVDetailed schedule19 entries; SCBH15, SCBH17 and SCBH19 loss columns

Voltage options describe winding configurations within a family. The selected voltage, capacity and impedance form one specified transformer rating.

Reading SCB and SCBH model codes

SCB identifies a three-phase resin-insulated transformer with the low-voltage foil-winding designation. The number that follows identifies its performance series; the capacity and high-voltage class follow in the remaining model fields. The SCB family descriptions list SCB10, SCB11, SCB12, SCB13, SCB14 and SCB18.

The H in SCBH identifies an amorphous-alloy core. SCBH15, SCBH17 and SCBH19 have separate loss columns in the amorphous-family schedule. This H belongs to the core designation and should not be confused with thermal insulation class H.

The rating table determines which numerical loss values are available for each series. A full model designation should be read together with the voltage ratio, vector group, impedance, cooling method and insulation specification.

Dry-type model fields
campoSignificado
Strifásico
CResin insulation / epoxy-resin cast construction
BLow-voltage foil-winding designation
H in SCBHAmorphous-alloy core
12 / 14 / 18 in SCBPerformance-series code in the 6–10 kV loss schedule
15 / 17 / 19 in SCBHPerformance-series code in the amorphous loss schedule
Campo de capacidadRated capacity in kVA
Campo de tensión después de /Clase de alto voltaje en kV

Cast-resin winding construction

Cast-resin winding construction
SCB cast-resin winding assembly

The 6–10 kV SCB construction uses copper-wire high-voltage windings and copper-wire or copper-foil low-voltage windings. Glass-fibre reinforcement surrounds the winding assembly before vacuum casting with epoxy resin. Curing forms an integrated cylindrical winding structure.

The resin insulation and reinforcement provide the mechanical and dielectric structure around the winding. The described coil design uses thin resin layers on the inner and outer surfaces to support heat transfer to the surrounding air. The complete transformer remains an air-cooled assembly, so the room and any enclosure must allow heat to leave the winding area.

The 20–35 kV SCB family also uses epoxy-resin cast, oil-free construction. Its insulation arrangement is specified for the selected voltage class. Winding geometry, clearances and test requirements are reviewed for that configuration rather than being inferred from a lower-voltage model.

HV winding
Copper-wire windingForms the high-voltage winding circuit
LV winding
Copper-wire or copper-foil windingForms the low-voltage winding circuit
Reinforcement
Glass-fibre wrapping and fillingSupports the cast winding structure
Casting process
Epoxy-resin casting under vacuumForms the winding insulation system
Cured winding
Integrated cylindrical structureCombines insulation and mechanical support

Cooling, monitoring and enclosure design

Air cooling and temperature monitoring

Natural and forced air

AN cooling uses natural air circulation around the transformer. AF cooling adds forced airflow from fans. The SCB family describes AN as the standard cooling method, with AF available as a selected arrangement. The specified output must be associated with the cooling method used to achieve it.

Thermal duty

A fan arrangement can support a different thermal duty, but it does not establish a universal overload allowance. The fan configuration, operating duty, room ventilation and winding-temperature limits must be considered together. Any required output in AF operation belongs in the transformer specification.

Monitoring and control

Temperature monitoring is a configuration topic for the dry-type range. Define the indication, alarm, trip and fan-control functions needed by the installation. The controller and its interfaces should be coordinated with the enclosure location, auxiliary supply and building or station control scheme.

AN
Air naturalMaintain airflow around the core-and-coil assembly
AF
Air forcedDefine the fan arrangement and the required operating duty
Temperature indication
Local indication as specifiedChoose an accessible viewing and service location
Alarm / trip functions
Interfaces defined in the control scheduleCoordinate with the upstream protection and control system
Fan control
Selected with the AF arrangementCoordinate control logic and auxiliary supply

Enclosure protection and cooling space

SCB enclosure options include stainless steel and aluminium alloy. IP20 and IP23 protection options are described for the family. The enclosure material, protection degree and ventilation layout are separate choices: specifying one of them does not establish all the others.

An enclosure affects both access protection and heat removal. Its openings, internal clearances and position in the transformer room influence airflow. The transformer output and temperature-rise requirements therefore need to be reviewed with the selected enclosure in place.

For installations exposed to water, dust or corrosive contamination, describe the actual exposure and location. The IP designation by itself does not specify corrosion resistance, the room environment or suitability for every outdoor location. Use the project conditions to define the complete enclosure arrangement.

Enclosure protection and cooling space
Aluminium-alloy enclosure option
Enclosure specification fields
campoAvailable family informationWhat the project defines
MaterialStainless steel or aluminium alloyMaterial selection and environmental exposure
Protection degreeIP20 or IP23 optionsRequired protection for the installation position
VentilationAir-cooled transformer inside the enclosureAir entry/exit paths and available room ventilation
AccessEnclosed core-and-coil assemblyDoor arrangement and service access
ConnectionsDefined for the selected installationCable or busbar approach and termination space

Electrical performance and construction choices

Thermal class and load-loss reference temperature

Loss reference temperature

The 20 kV SCB electrical schedule separates load loss into three thermal-class columns. The class and the reference temperature printed beside it must remain with the loss figure. A numerical load-loss value without this condition is incomplete for specification or comparison.

Insulation class and temperature rise

Thermal insulation class, winding temperature rise and the temperature used to state load loss are different quantities. The thermal class describes the insulation system; the loss reference temperature is the condition used for the electrical-loss value. Neither should be read as the permitted ambient temperature.

Keep each schedule intact

The 6–10 kV SCB and SCBH loss tables use watts and do not state the same B/F/H reference-temperature columns. Their values remain in their own schedules. The 20 kV values are expressed in kilowatts, including the separate impedance variants at 2000 and 2500 kVA.

20 kV SCB load-loss conditions
ColumnThermal-class designationLoad-loss reference temperatureLoss unit
B130 °C (B)100 °CkW
F155 °C (F)120 °CkW
H180 °C (H)145 °CkW

These are the conditions printed with the electrical schedule. They are not ambient-temperature ratings or interchangeable loss values.

Impedance variants and network interfaces

6–10 kV impedance variants

The 6–10 kV SCB and SCBH schedules each contain two 630 kVA entries: one at 4% impedance and one at 6%. These are distinct electrical ratings. Their loss figures must stay with the corresponding impedance entry when preparing the specification.

20 kV network interfaces

The 20 kV SCB reference schedule lists 6% impedance for ratings from 50 to 2500 kVA, with separate 8% entries at 2000 and 2500 kVA. Dyn11 and Yyn0 are listed vector-group options. Select the impedance and vector group with the network fault-level, neutral and protection design.

Parallel operation

For an installation with parallel transformers, include the existing unit data in the review. Ratio, vector group, tap position and impedance need to work together. Terminal approach, phase identification and the neutral connection are then fixed on the electrical and arrangement drawings.

Separate impedance entries in the electrical schedules
familiaCapacityImpedance variants
SCB 6–10 kV630 kVA4% and 6%
SCBH 6–10 kV630 kVA4% and 6%
SCB 20 kV2000 kVA6% and 8%
SCB 20 kV2500 kVA6% and 8%

Each variant retains its own load-loss entry. Matching capacity does not make the variants interchangeable.

SCBH amorphous-alloy core construction
SCBH amorphous-alloy transformer construction

SCBH amorphous-alloy core construction

The SCBH family uses an amorphous-alloy core with a cast-resin dry-type winding arrangement. SCBH15, SCBH17 and SCBH19 are identified separately, and the electrical schedule provides both no-load and load losses for each series.

No-load loss is especially relevant when a transformer remains energized for long periods at light load. Load loss becomes more significant as operating current increases. Use the expected energization hours and load profile with the actual SCBH rating row to evaluate operating energy; a single saving percentage cannot describe every installation.

Primary-voltage options are 6, 6.3, 6.6, 10, 10.5 and 11 kV, with a 0.4 kV secondary. The SCBH technical data lists losses for reference ratings from 30 to 2500 kVA, including the separate 630 kVA impedance variants.

SCBH family information
CharacteristicSpecification scope
Core materialAmorphous alloy
Construction familyCast-resin dry-type
Performance seriesSCBH15 / SCBH17 / SCBH19
Rated capacity at 10 kV30–4000 kVA
voltaje secundario0.4 kV
Loss presentationSeparate no-load and load-loss columns for each performance series, in W
Impedance variants4% and 6% groups; two separate 630 kVA entries

35 kV distribution duty

The 35 kV SCB branch brings the incoming medium-voltage supply into a dry-type indoor installation. Specify the secondary voltage and required output together; the voltage class alone does not define the winding ratio or thermal duty.

The SCB10 · 35/0.4 kV reference configuration uses 6% impedance, Dyn11 or Yyn0 connection options and off-circuit HV tapping. Its technical details contain seven rating examples, with load loss stated for F-class insulation at 120 °C.

For the project specification, keep the performance-series code, frequency, cooling duty and loss reference condition together. Ratings from a different SCB performance series or secondary-voltage arrangement should not be substituted for the selected configuration.

35 kV distribution duty
35 kV SCB family construction

Aplicaciones

SCB dry-type transformers serve urban distribution, high-rise buildings, commercial centres, hospitals, hotels, tunnels, rail facilities, ports and airports. The preliminary dry-type guide also identifies data centres and indoor industrial rooms. These application names describe installation contexts; the actual room, load and protection requirements determine the transformer configuration.

Illustrative commercial-building electrical room with an enclosed cast-resin dry-type transformer

Commercial buildings

Indoor building distribution brings the transformer, switchgear and ventilation into one coordinated electrical-room layout. Access and cooling space are part of the installation design.

Illustrative manufacturing-plant distribution room separated from the production hall

Instalaciones de fabricación

Dedicated electrical rooms supply production equipment through the plant distribution network. Loading, ventilation and the surrounding industrial environment guide the transformer configuration.

Illustrative infrastructure power room with enclosed dry-type transformers and organized cable routes

Infrastructure power rooms

Infrastructure power rooms coordinate transformers with switchgear, cable routes and maintenance access. The electrical schedule defines the required duty for each transformer.

Entornos de aplicación ilustrativos.

Dry-type transformer buying questions

Which site conditions should be defined before selection?

The indoor layout must provide adequate cooling air, electrical clearances and access for inspection. Ambient temperature, altitude, dust and condensation conditions belong in the design review. An enclosed unit still requires a heat-removal path from the transformer, through the enclosure and out of the room.

For noise-sensitive rooms, specify the measurement requirement and the installation constraints. For loads supplied through power electronics, include the load characteristics in the enquiry. These requirements help define the design review without assuming a universal noise limit, harmonic rating or overload capability.

What does an indoor distribution room need?

Indoor distribution room

Room layout, ventilation and equipment access

Revisión de diseñoCooling arrangement and enclosure position

What should a building project specify?

Building or public facility

Noise requirement and local fire-safety criteria

Revisión de diseñoAcoustic and insulation-system review

What load information is needed?

Industrial load

Load profile and major connected equipment

Revisión de diseñoCapacity and thermal-duty review

Which environmental conditions affect selection?

Environmental exposure

Altitude, temperature, dust and condensation

Revisión de diseñoInsulation, cooling and enclosure review

What is needed for a replacement transformer?

Replacement installation

Existing nameplate, connections and dimensions

Revisión de diseñoElectrical and mechanical compatibility

Which technical documents and configuration records are available?

The product details contain 55 dry-type rating entries: 19 for SCB 6–10 kV, 17 for SCB 20 kV and 19 for SCBH. The schedules retain the separate model loss columns, temperature conditions and repeated capacities with different impedance values. A separate seven-row SCB10/35 reference schedule provides preliminary 35 kV loss and impedance values.

Dry-Type Transformers — Selection GuideSubian · Edición preliminar · Páginas de 2 · Aplicaciones y temas de configuraciónAbrir PDF
SCB Series 6–10 kV Cast-resin TransformerThree-phase cast-resin distribution transformers with SCB12, SCB14 and SCB18 rating schedules.
SCB Series 20 kV Cast-resin TransformerReference ratings from 50 to 2500 kVA with 20, 22 and 24 kV primary-voltage options and load-loss data by thermal class.
SCB Series 35 kV Cast-resin TransformerThree-phase resin-insulated construction for 35 kV indoor distribution and infrastructure installations.
SCBH Series Amorphous-alloy Dry-type TransformerAmorphous-core distribution transformers with separate SCBH15, SCBH17 and SCBH19 loss schedules.
SCB18-2000/10-NX1 — Published Verification Copy by SubianOne-page Test Verification of Conformity, CN26I11C 001, dated 30 March 2026; names JIANGSU SUBIAN POWER EQUIPMENT CO., LTD. and the SCB18-2000/10-NX1 specimen.View document
Document scope and configuration notes

A publicly available Test Verification of Conformity identifies SCB18-2000/10-NX1 as a 2000 kVA, 50 Hz, three-phase dry-type transformer with 10 (±2 × 2.5%) / 0.4 kV rated voltage. The published copy names JIANGSU SUBIAN POWER EQUIPMENT CO., LTD. as applicant and manufacturer. Its configuration details and download are included under the SCB 6–10 kV product.

That document addresses the named specimen and Tier 2 maximum no-load and load losses. It does not state the numerical loss values, assess ongoing production or authorize use of a TÜV Rheinland conformity mark. The two-page Subian Dry-Type Transformers guide is a separate preliminary overview of applications and configuration topics.

Available technical information
Document or scheduleScope
SCB 6–10 kV electrical scheduleSCB12 / SCB14 / SCB18; 19 ratings; losses in W
SCB 20 kV electrical schedule17 ratings; B/F/H load-loss conditions in kW
SCBH electrical scheduleSCBH15 / SCBH17 / SCBH19; 19 ratings; losses in W
SCB10 · 35/0.4 kV reference scheduleSeven rating examples; F-class load loss at120 °C; published manufacturer reference
SCB18-2000/10-NX1 verification copyNamed 2000 kVA configuration; document dated 30 March 2026
Subian Dry-Type Transformers — Selection Guide / Preliminary EditionTwo-page family introduction and configuration topics

Dry-type Transformer Technical Guides

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