Stable energy for every application - choose scotech cast coil transformers
01 General
1.1 Project Description
Our 650 kVA Cast Resin Dry-Type Transformer (CRT) provides stable power for medium-voltage to low-voltage distribution. Follow IEC standards. Featuring an input voltage of 11kV and an output voltage of 0.34 kV, with a power rating of 650 kVA. Featuring a grain-oriented silicon steel core and copper windings, the transformer operates safely while ensuring long service life. The Yd11 vector group gives a stable neutral point and balanced three-phase output, supporting a consistent voltage supply.
The 650 kVA cast coil transformers manufacturers, suppliers and factory – Scotech uses AN/AF cooling and F-class insulation, allowing it to operate safely under varying loads. Its no-load loss is 1.25 kW and load loss is 7.3 kW, which helps reduce energy consumption. The NLTC (No-Load Tap Changer) with ±2×2.5% adjustment keeps the output voltage steady.
1.2 Technical Specification
650kVA Resin cast dry type transformer specification and data sheet
| Delivered to | United Arab Emirates |
| Year | 2025 |
| Type | Resin cast dry type transformer |
| Core material | Grain oriented silicon steel sheet |
| Standard | IEC |
| Rated Power | 650kVA |
| Frequency | 50HZ |
| Phase | Three |
| Vector group | Yd11 |
| Cooling Type | AN/AF |
| Primary Voltage | 11KV |
| Secondary Voltage | 0.34 kV |
| Winding Material | Copper |
| Impedance | 6% |
| Tap Changer | NLTC |
| Tapping Range | ±2*2.5%@primary voltage |
| No Load Loss | 1.25 kW |
| On Load Loss | 7.3 kW |
| Insulation level | F |
| Accessories | Temperature controller, Cooling fans, Enclosure |
1.3 Drawings
650kVA Resin cast dry type transformer drawing and weight details
02 Manufacturing
2.1 Core
The core of our dry-type transformer is made with grain-oriented silicon steel sheets. It uses a step-lap joint design with 45° mitred, hole-free laminations. This design lowers no-load losses and also reduces noise. The transformer runs in a stable and quiet way.
2.2 Winding
 | The 650 kVA cast coil transformers coils are made of high-conductivity copper, providing high mechanical strength and short-circuit resistance. The windings utilize Class F (155°C) insulation and are epoxy-casted for reliable protection against moisture, dust, and short circuits, ensuring long-term safe and stable operation. |
2.3 IP20 Enclosure
Our indoor dry-type transformers feature an IP20-rated protective enclosure, providing comprehensive protection: preventing accidental contact with high-voltage components, isolating dust and foreign objects, and extending the transformer’s service life. The enclosed enclosure also reduces operating noise and enhances indoor working comfort. Its aesthetically pleasing design and compact structure provide customers with a safe, reliable, and easy-to-maintain power distribution solution. |  |
2.4 Final Assembly
 | During assembly, each dry-type transformer is equipped with a temperature controller and PT100 temperature probes built into the three-phase windings. These monitor winding temperatures in real time and display them on a digital display. Six high-efficiency cooling fans optimize heat dissipation and ensure long-term stable operation. Each product undergoes multiple rigorous inspections and tests during the manufacturing process and is thoroughly inspected again before shipment. We are committed to providing customers with a reliable, safe, and high-performance dry-type transformer experience. |
03 Testing
Testing Standard and Routine Test
IEC 60076-1-2011 Power Transformers – Part 1: General
IEC 60076-3-2013 Power Transformers – Part 3: Insulation levels, dielectric tests and external clearances in air
IEC 60076-11-2018 RLV Power Transformers – Part 11: Dry type transformer
- 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
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
|
| 0.19% | 0.84% | |||||
| 2 | Measurement of voltage ratio and check of phase displacement | / | The tolerance of voltage ratio on the principal tapping: ±1/10 Connection symbol: Yd11 | 0.02% ~ 0.17% Yd11 | Pass
| |
| 3 | Measurement of Short-circuit Impedance and Load Loss | / kW kW | t:120℃ Z%: measured value Pk: measured value Pt: measured value | 6.09% 5.857 7.338 | 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 | 0.44 1.000 | Pass
|
| 100% Ur | 0.49 1.112 | |||||
| 110% Ur | 0.53 1.223 | |||||
| 5 | Applied Voltage Test | / | HV: 35kV 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): 0.68 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
The Scotech 650 kVA Cast Resin Dry-Type Transformer delivers safe and stable power for industrial and commercial applications. It has a silicon steel core and copper windings fully covered in epoxy resin, allowing long-term operation without oil.
The 650 kVA cast coil transformer has a Yd11 vector group and a No-Load Tap Changer (NLTC) to keep voltage steady under changing loads. AN/AF cooling and Class F insulation allow it to run safely at high temperatures. Low no-load and load losses help reduce energy use.
The IP20 enclosure keeps people safe and stops dust and objects from entering. Built-in temperature sensors and cooling fans help the transformer run reliably.
