Innovative Designs for a Greener Future: Choose Resin Cast Dry-Type Transformers!
01 General
1.1 Project Description
The 630 kVA resin cast dry type transformer was delivered to South Africa in 2024; the rated power of the transformer is 630 kVA. The high voltage of this dry type transformer is 6.6 kV, and the low voltage is 0.55 kV. This high voltage dry type transformer is equipped with a no load tap changer, the tapping range is ±2*2.5% at the primary side. The cooling is KNAF, they formed a vector group of Dyn11.
Resin cast dry-type transformers lead the way in transformer design, providing an optimal blend of electrical and mechanical performance. Their durable construction, achieved by encasing windings in epoxy resin, offers unmatched mechanical strength and safety, essential for meeting environmental and sustainability goals.
Designed for harsh environments, these eco-friendly transformers feature a low-maintenance, oil-free design that reduces operational costs. Their flame-retardant, self-extinguishing insulation ensures high safety standards, while the compact design saves valuable installation space.
By utilizing high-quality insulation materials and robust coil structures, our resin cast dry-type transformers deliver excellent reliability and durability. Choose our transformers for efficient, safe, and sustainable power solutions that give you a competitive edge in modern power systems.
1.2 Technical Specification
630 kVA resin cast dry type transformer specification and data sheet
| Delivered to | Georgia |
| Year | 2024 |
| Type | Resin cast dry type transformer |
| Core material | Grain oriented silicon steel sheet |
| Standard | IEC60076 |
| Rated Power | 630kVA |
| Frequency | 50HZ |
| Vector group | Dyn11 |
| Phase | 3 |
| Cooling Type | KNAN/KNAF |
| Primary Voltage | 6.6 kV |
| Secondary Voltage | 0.55 kV |
| Winding Material | Aluminum |
| Impedance | 4.5% |
| Tap Changer | NLTC |
| Tapping Range | ±2*2.5%@primary voltage |
| No Load Loss | 1.3KW |
| On Load Loss | 5.96KW |
| Insulation level | H |
1.3 Drawings
630 kVA resin cast dry type transformer diagram drawing and size.
02 Manufacturing
2.1 Core
| The transformer core is built from high-quality, cold-rolled, grain-oriented silicon steel with step-lap joints to reduce energy loss. It features three legs arranged in a single plane and interconnected by a sturdy yoke. Each leg is circular and interlaced with yokes, while the core is mitred at a 45-degree angle to minimize noise and losses. It is insulated and protected from corrosion with a resin coating. The frame consists of upper and lower steel channels holding the core and coils together, with all steel parts coated in corrosion-resistant epoxy paint for enhanced durability. This design ensures efficient operation and reliability in various conditions. |  |
2.2 Winding
 | Winding construction features high-grade insulated conductors arranged in multiple sections and layers to reduce transient maximum voltages. High-voltage windings are cast in vacuum molds using an advanced computer-controlled process, ensuring no voids in the coils. The windings are further reinforced with fiberglass to enhance mechanical strength. After assembly, all high-voltage coils undergo partial discharge testing to verify void-free conditions and ensure high-quality performance. This meticulous design guarantees durability and reliability in demanding environments. |
2.3 Final Assembly
| Coil Installation: The tested resin-cast windings are carefully placed within the transformer frame, ensuring precise alignment. Core Integration: The windings are securely mounted to the core to minimize stress and ensure stability. Electrical Connections: The electrical connections are established with precision, linking the windings to the transformer terminals and ensuring proper integration with the electrical system. Resin Pouring: High-quality epoxy resin is poured over the assembly, providing protection from moisture and enhancing insulation. Curing Process: The transformer is cured to harden the resin, ensuring desired mechanical and electrical properties. |  |
03 Testing
| 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 |
| 0.41% | 0.44% | |||||
| 2 | Measurement of voltage ratio and check of phase displacement | / | The tolerance of voltage ratio on the principal tapping: ±1/10 Connection symbol: Dyn11 | -0.14% ~ 0.07% Dyn11 | Pass | |
| 3 | Measurement of Short-circuit Impedance and Load Loss | / kW kW | t:120℃ Z%: measured value Pk: measured value Pt: measured value | 4.5% 3.98 5.456 | 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 | 0.477 1.029 | Pass |
| 100% Ur | 0.53 1.144 | |||||
| 110% Ur | 0.583 1.258 | |||||
| 5 | Applied Voltage Test | / | HV: 20kV 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): 1.1 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
Our resin cast dry type transformer is an efficient and reliable power solution designed to meet the high-performance demands of industrial and commercial applications. Made with high-grade epoxy resin and utilizing a meticulous casting process, each transformer undergoes rigorous testing to ensure exceptional electrical insulation and moisture resistance. Our transformers feature excellent thermal management characteristics, enabling stable operation in various environmental conditions while reducing maintenance costs and extending equipment lifespan. The compact design and superior protective performance of the resin cast dry type transformer make it an ideal choice for modern power systems, ensuring safe and efficient energy transmission. Choose our transformers to guarantee the continuous and efficient operation of your power system.
