Efficient 2100 kVA dry type distribution transformer with superior insulation and smart protection
01 General
1.1 Project Description
Manufactured for a South African customer in 2024, this 2100 kVA dry type distribution transformer features windings fully encapsulated in epoxy resin. Being oil-free, it lowers the risk of fire and environmental pollution. With Class F insulation rated for operating temperatures up to 155°C.
The transformer is rated at 2100 kVA, with a primary voltage of 13.8 kV and a secondary voltage of 0.468 kV (468 V). It is ideal for powering mine hoists and heavy processing equipment that operate at 468 V.
Its vector group is D(+15°)d0, where the high-voltage side features a +15° phase shift. This design meets system phase requirements and helps reduce harmonics and circulating currents during parallel operation.
The core is made of grain oriented silicon steel, which provides low losses and high magnetic flux density, contributing to a low no-load loss of 3.2 kW.
Equipped with a temperature controller and a current transformer (5000/1 CT), the transformer supports winding temperature monitoring and protection, as well as current measurement, facilitating integration into protection and monitoring systems.
1.2 Technical Specification
2100kVA Resin cast dry type transformer specification and data sheet
| Delivered to | South Africa |
| Year | 2024 |
| Type | Resin cast dry type transformer |
| Core material | Grain oriented silicon steel sheet |
| Standard | IEC60076 |
| Rated Power | 2100kVA |
| Frequency | 60HZ |
| Phase | Three |
| Vector group | D(+15°)d0 |
| Cooling Type | AN |
| Primary Voltage | 13.8 KV |
| Secondary Voltage | 0.468 kV |
| Winding Material | AL |
| Impedance | 7.5% |
| Tap Changer | / |
| Tapping Range | / |
| No Load Loss | 3.2 kW |
| On Load Loss | 15.6 kW |
| Insulation level | F |
| Accessories | Temperature controller, CT（5000/1） |
1.3 Drawings
2100kVA Resin cast dry type transformer dimensions and weight details
02 Manufacturing
2.1 Core
The 2100 kVA dry type distribution transformer core uses grain-oriented silicon steel sheets with high magnetic permeability, improving electromagnetic efficiency and reducing core losses. These sheets have strong mechanical properties to endure processing and long-term stress. SCOTECH ensures burrs ≤ 0.02mm and no defects. The stacked core is coated with moisture-proof epoxy resin for added durability and humidity protection. |  |
2.2 Winding
 | The dry type distribution transformer features two windings, both constructed with durable aluminum conductors to ensure excellent performance and long service life. All windings are insulated with Class F insulation materials, and the entire coil is vacuum impregnated with Class F epoxy resin, forming a solid, moisture-resistant and thermally stable insulating system. |
2.3 Final Assembly
| The fabricated core and winding components are assembled, during which electrical connections, insulation, and structural fixation are performed. Under vacuum, epoxy resin is poured between the windings and the core, forming a solid, cured structure. After assembly and curing, a series of electrical and mechanical tests are performed to ensure the transformer meets design and safety standards. |  |
03 Testing
Routine Test
- Measurement of winding resistance
- Measurement of voltage ratio and check of phase displacement
- Measurement of short-circuit impedance and load loss
- Measurement of no-load loss and current
- Applied voltage test
- Induced voltage withstand test
- Partial discharge test
- Oil dielectric test
Test Results
| No. | Test Item | Unit | Acceptance Values | Measured Values | Conclusion | |
| 1 | Measurement of winding resistance | / | Maximum resistance unbalance rate Line resistance:≤2% | HV (line) | LV (line) | Pass |
| 0.18% | 1.61% | |||||
| 2 | Measurement of voltage ratio and check of phase displacement | / | The tolerance of voltage ratio on the principal tapping: ±1/10 Connection symbol: D(+15°）d0 | -0.18% ~ -0.07% D(+15°）d0 | Pass | |
| 3 | Measurement of Short-circuit Impedance and Load Loss | / kW kW | t:120℃ Z%: measured value Pk: measured value Pt: measured value | 8.13% 12.662 16.261 | Pass | |
| 4 | Measurement of No-load Loss and Current at 90% and 110% of rated voltage | / kW | I0 :: provide measured value P0: provide measured value | 90% Ur | 110% Ur | Pass |
| 0.162% | 0.198% | |||||
| 2.3265 | 2.8435 | |||||
| 5 | Applied Voltage Test | / | HV: 38kV 60s LV: 3kV 60s | No collapse of the test voltage occurs | Pass | |
| 6 | Induced Voltage Withstand Test | / | Applied voltage (KV): 2 Ur Induced voltage (KV): 0.936 Duration(s):40 Frequency (HZ): 150 | No collapse of the test voltage occurs | Pass | |
| 7 | Partial Discharge Test | pC | The maximum level of partial discharges shall be 10 pC | ＜10 | Pass | |
04 Packing and Shipping
05 Site And Summary
This 2100 kVA dry type distribution transformer is specially designed for a South African customer. This transformer is especially suitable for heavy-duty machinery, large motors, and processing equipment in mining and industrial applications requiring high load capacity. SCOTECH is ready to provide professional customization and quality service to meet your demands.
As a professional dry type transformer manufacturer, SCOTECH offers products compliant with international standards such as IEC, ANSI/IEEE, NEMA, CSA, and BS. Our resin cast dry type transformers cover rated powers from 50 kVA up to 15 MVA, with high voltages up to 36 kV. Both 50 Hz and 60 Hz frequencies are available, with delta or star connections. Medium voltage windings are encapsulated in epoxy resin, with insulation classes ranging from A, E, B, F to H, and protection levels customizable from IP 2X to IP 4X.
Cooling options include natural air cooling (ONAN) and forced air cooling (ONAF), equipped with multiple temperature sensors and thermal relays for reliable thermal protection. We also provide accessories such as wheels, current transformers, on-load tap changers (OLTC), and marshalling boxes to meet diverse customer needs.
