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Distribution Transformers

SGB Series Non-Encapsulated Dry-Type Transformer

Product Overview

SGB11/12/13/14/18 Series

Product Overview
The SGB non-encapsulated dry-type transformer leverages NOMEX® insulation technology to deliver exceptional operational safety and reliability. Its innovative open-ventilated design achieves superior energy efficiency while inherently eliminating fire and explosion hazards, significantly reducing long-term maintenance requirements. Engineered with precision-balanced electromagnetic structures and corrosion-resistant components, the unit demonstrates exceptional robustness in challenging environments.
Performance validation confirms key metrics surpass domestic standards, with optimized thermal management systems enabling stable operation in tropical climates exceeding 95% humidity. The transformer’s modular construction facilitates swift on-site servicing, further reinforcing lifecycle cost advantages. These technical attributes make it the preferred solution for critical installations including offshore platforms, chemical processing plants, and high-rise commercial complexes where uncompromising fire safety and moisture resistance are paramount.

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Model Definition

Features

● Voltage level: 10~35/0.4kV.
● Capacity: 30~3150kVA. 
● Core Technology:
Employs high-permeability laminated silicon steel cores with optimized stacking factor and step-lap joint design to eliminate third-harmonic flux paths. This advanced magnetic circuit configuration minimizes core losses and delivers substantial energy savings across varying load profiles.
● Insulation System:
Features an H-class insulation system reinforced with C-class NOMEX® aramid paper as the primary dielectric barrier. This dual-rated insulation structure provides exceptional thermal stability, chemical resistance, and dielectric strength under extreme operating conditions.
● Winding Design:
High-voltage pancake windings with interleaved layers and low-voltage foil conductors with uniform current density distribution ensure low leakage reactance and enhanced short-circuit withstand capability. The compact, rigid structure minimizes mechanical stresses during fault conditions.
● Thermal & Mechanical Performance:
Integrates low-loss materials and an optimized cooling path to minimize heat generation, while the finned radiator design facilitates efficient natural convection cooling. The high-temperature insulation system supports continuous operation at elevated loads without compromising safety margins.
● Manufacturing Process:
Undergoes a precision-controlled secondary vacuum pressure impregnation (VPI) process, which fully encapsulates the core and windings in a moisture-resistant epoxy resin matrix. This treatment ensures long-term protection against environmental contaminants and reduces partial discharge activity to negligible levels.
● Environmental Friendliness:
Designed for end-of-life disassembly and material recovery, with separable components and recyclable materials throughout. The transformer utilizes non-toxic, non-hazardous materials that comply with global environmental standards, supporting sustainable lifecycle management practices.

Range of application

High-rise buildings, densely populated residential areas, key government institutions, airports, subways, railway stations, ports, petrochemical plants, metallurgical and mining sites, nuclear power plants, nuclear submarines, light rail systems, power plants, and locations requiring fire and explosion protection.

Technical specifications

Rated capacity
(kVA)

Rated voltage

Vector group

No-load loss
(W)

Load loss
(W)

No-load current
(%)

Impedance voltage
(%)

HV
(kV)

Tapping range (%)

LV
(kV)

11#

12#

13,14#

18#

10#

11#

12#

13#

14#

18#

120℃

120℃

120℃

145℃

100

6
6.3
6.6
10
10.5
11

±5

Or

±2
X
2.5

0.4

Dyn11

or

Yyn0

400

360

320

290

270

230

1570

1415

1520

0.7

4

4

125

470

420

375

340

320

270

1850

1665

1780

0.7

160

540

480

430

385

365

310

2130

1915

2050

0.7

200

620

550

495

445

420

360

2530

2275

2440

0.6

250

720

640

575

515

490

415

2760

2485

2665

0.5

315

880

790

705

635

600

510

3470

3125

3355

0.5

400

980

880

785

705

665

570

3990

3590

3850

0.5

500

1160

1040

930

835

791

670

4880

4390

4705

0.4

630

1340

1200

1070

965

910

775

5880

5290

5660

0.4

630

1300

1170

1040

935

885

750

5960

5365

5760

0.35

6

6

800

1520

1360

1215

1095

1035

875

6960

6265

6715

0.35

1000

1770

1590

1415

1275

1205

1020

8130

7315

7885

0.3

1250

2090

1880

1670

1505

1420

1205

9690

8720

9335

0.3

1600

2450

2200

1960

1765

1665

1415

11730

10555

11320

0.25

2000

3050

2740

2440

2195

2075

1760

14450

13005

14005

0.2

2500

3600

3240

2880

2590

2450

2080

17170

15445

16605

0.2

1600

2450

2200

1765

12960

11660

0.2

8

8

2000

3050

2740

2195

15960

14360

0.2

2500

3600

3240

2590

18890

17000

0.2

Note: The above data is subject to change due to technical improvement.

Additional Product Overview

SGB11/12/13/14/18 Series

Product Overview

The SGB series focuses on non-encapsulated dry-type transformers, a high-end power transmission and distribution equipment integrating safety, efficiency, low interference, and eco-friendliness. Its core function is to deliver reliable power solutions for complex scenarios like industrial production, urban infrastructure, and high-end commerce.

It uses an H-class insulation system with Nomex paper and solvent-free impregnating resin, offering long-term temperature resistance up to 180°C .The non-encapsulated open structure paired with VPI technology balances insulation stability and easy maintenance. Performance breakthroughs include 120% long-term/150% short-term overload capacity for load fluctuations, and operating noise below 42dB for noise-sensitive environments. It also adopts high-permeability silicon steel sheets and optimized electromagnetic design, cutting power loss by 10%-20% vs. ordinary models. With eco-friendly materials throughout, VOC emissions are nearly zero, meeting green standards like EU RoHS.

Model Definition

Features

² Voltage level: 10~35/0.4kV.

² Capacity: 30~3150kVA.

² Safety Protection Features:
Adopts an H-class insulation system combined with NOMEX® paper as the core material, boasting a long-term temperature resistance of 180°C and complying with the UL94V-0 flame-retardant standard, fundamentally eliminating fire hazards. The non-encapsulated open structure and oil-free design completely eradicate explosion risks, meeting the safety requirements of crowded and high-risk scenarios.

² High Efficiency and Energy-Saving Features:

Utilizes high-permeability silicon steel sheets and optimized electromagnetic circuit design, reducing power loss by 10%-20% compared to ordinary models. Both no-load loss and load loss reach industry-leading levels. With 120% long-term and 150% short-term overload capacity, it maintains efficient operation even under load fluctuations, minimizing energy waste.

² Low Noise and Quiet Operation Features:

Achieves operating noise below 42dB (far lower than the industry average) through optimized core lamination technology and winding structure layout. The design avoids mechanical vibration amplification and is paired with a quiet heat dissipation structure, making it directly applicable to noise-sensitive environments such as data centers and medical facilities.

² Environmental Adaptability Features:

The optimized thermal management system enables stable operation in tropical climates with humidity exceeding 95%. Corrosion-resistant components and sealing design enhance durability in harsh environments. Environmentally friendly materials are used throughout the entire process, with VOC emissions nearly zero, complying with green standards such as the EU RoHS and adapting to scenarios with strict environmental requirements.

² Easy Maintenance Features:

The non-encapsulated open structure combined with VPI (Vacuum Pressure Impregnation) technology allows daily inspection and maintenance without complex disassembly. The modular design simplifies component replacement, reduces downtime for maintenance, and lowers long-term operation and maintenance costs as well as labor input.

² Structural Reliability Features:

Features interleaved laminated high-voltage pancake windings and low-voltage foil conductors with uniform current density distribution, ensuring low leakage reactance and enhanced short-circuit withstand capacity. The precision-balanced electromagnetic structure paired with high-strength fixing components can resist mechanical stress during transportation and operation, extending the equipment’s service life.

² Application Adaptability Features:

Compact in size and flexible in installation, it is suitable for diverse scenarios such as high-rise buildings, chemical parks, and urban power grid upgrades. It not only meets the high-quality power supply needs of precision equipment but also maintains continuous operation of the power system under complex working conditions, offering strong versatility.

Range of application

Applicable to industrial production, high-rise buildings, transportation hubs, data centers, new energy projects and urban power distribution networks. Suitable for factories, hospitals, subways, communication base stations and other venues requiring stable power supply and environmental adaptability.

Technical specifications

Rated capacity
(kVA)

Rated voltage

Vector group

No-load loss
(W)

Load loss
(W)

No-load current
(%)

Impedance voltage
(%)

HV
(kV)

Tapping range (%)

LV
(kV)

11#

12#

13,14#

18#

10#

11#

12#

13#

14#

18#

120℃

120℃

120℃

145℃

100

6
6.3
6.6
10
10.5
11

±5

Or

±2
X
2.5

0.4

Dyn11

or

Yyn0

400

360

320

290

270

230

1570

1415

1520

0.7

4

4

125

470

420

375

340

320

270

1850

1665

1780

0.7

160

540

480

430

385

365

310

2130

1915

2050

0.7

200

620

550

495

445

420

360

2530

2275

2440

0.6

250

720

640

575

515

490

415

2760

2485

2665

0.5

315

880

790

705

635

600

510

3470

3125

3355

0.5

400

980

880

785

705

665

570

3990

3590

3850

0.5

500

1160

1040

930

835

791

670

4880

4390

4705

0.4

630

1340

1200

1070

965

910

775

5880

5290

5660

0.4

630

1300

1170

1040

935

885

750

5960

5365

5760

0.35

6

6

800

1520

1360

1215

1095

1035

875

6960

6265

6715

0.35

1000

1770

1590

1415

1275

1205

1020

8130

7315

7885

0.3

1250

2090

1880

1670

1505

1420

1205

9690

8720

9335

0.3

1600

2450

2200

1960

1765

1665

1415

11730

10555

11320

0.25

2000

3050

2740

2440

2195

2075

1760

14450

13005

14005

0.2

2500

3600

3240

2880

2590

2450

2080

17170

15445

16605

0.2

1600

2450

2200

1765

12960

11660

0.2

8

8

2000

3050

2740

2195

15960

14360

0.2

2500

3600

3240

2590

18890

17000

0.2

Note: The above data is subject to change due to technical improvement.

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