Reliable power in compact form - your trusted dry distribution transformer
01 General
1.1 Project Description
This 12 kVA Cast Resin Dry-Type Transformer (CRT) is a compact and reliable solution for low-capacity three-phase power distribution. Designed according to IEC standards, it features a grain-oriented silicon steel core and copper windings, with natural air cooling (AN), a primary voltage of 11 kV and a secondary voltage of 0.22 kV.
Equipped with a Dy11 vector group and a No-Load Tap Changer (NLTC) with ±2×2.5% adjustment, this 12 kva dry distribution transformer features low no-load and load losses of 0.09 kW and 0.39 kW. Class B insulation ensures reliable and safe operation under normal conditions.
A Cast Resin Transformer (CRT), also called an Epoxy Cast Resin Dry-Type Transformer, is a dry-type transformer. The windings are fully covered with epoxy resin. It does not use oil or other liquids for insulation. Air is used to cool and insulate the core and windings.
The epoxy resin gives strong insulation and stops the transformer from absorbing moisture. This lets it work well in humid, dusty, or harsh environments. The resin is poured under vacuum. This makes sure the coils are completely sealed and protected. This dry transformer has a 12 kVA capacity and an 11 kV/0.22 kV voltage rating. It provides a stable solution for medium-to-low voltage distribution.
1.2 Technical Specification
12 kVA 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 | 12 kVA |
| Frequency | 50HZ |
| Phase | Three |
| Vector group | Dy11 |
| Cooling Type | AN |
| Primary Voltage | 11KV |
| Secondary Voltage | 0.22 kV |
| Winding Material | Copper |
| Impedance | 4% |
| Tap Changer | NLTC |
| Tapping Range | ±2*2.5%@primary voltage |
| No Load Loss | 0.09 kW |
| On Load Loss | 0.39kW |
| Insulation level | B |
| Accessories | Temperature controller, Enclosure |
1.3 Drawings
12kVA Resin cast dry type transformer dimensions and weight details
02 Manufacturing
2.1 Core
The silicon steel has about 3% silicon. It has good magnetic performance and low loss. This helps reduce eddy currents and works well at higher frequencies. Laminated sheets of premium silicon steel minimize eddy current losses and magnetic hysteresis, enhancing energy efficiency.
2.2 Winding
 | This 12 kVA dry distribution transformer utilizes high-performance copper conductors for high strength and short-circuit resistance. The low-voltage winding utilizes a foil design to ensure uniform current distribution. The transformer utilizes Class B (130°C) insulation and epoxy resin casting technology for excellent moisture and dust resistance, while also providing reliable short-circuit protection. |
2.3 IP20 Enclosure
This indoor dry-type transformer features an IP20-rated protective enclosure, effectively preventing direct contact between fingers and solid foreign objects and live components, ensuring operator safety. The enclosure also prevents dust, metal shavings, and other debris from entering the transformer, reducing the risk of insulation breakdown and localized overheating. Furthermore, the enclosure reduces operating noise and optimizes the indoor environment. |  |
2.4 Final Assembly
 | The fabricated core and winding components are assembled, during which electrical connections, insulation, and structural fixation are performed. |
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
|
| 0.68% | 0.53% | |||||
| 2 | Measurement of voltage ratio and check of phase displacement | / | The tolerance of voltage ratio on the principal tapping: ±1/10 Connection symbol: Dy11 | 0.01% ~ 0.12% Dy11 | Pass
| |
| 3 | Measurement of Short-circuit Impedance and Load Loss | / kW kW | t:100℃ Z%: measured value Pk: measured value Pt: measured value | 3.64% 0.259 0.317 | 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 | 2.88 0.083 | Pass
|
| 100% Ur | 3.21 0.093 | |||||
| 110% Ur | 3.53 0.102 | |||||
| 5 | Applied Voltage Test | / | HV: 28kV 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): 0.44 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
In industrial and commercial buildings, a stable power supply is very important. The Scotech 12 kva dry distribution transformer gives safe and efficient medium- to low-voltage power.
It has a copper winding and a silicon steel core. The windings are fully covered in epoxy resin and air-cooled, so no oil is needed. The resin protects against moisture and dust, allowing long-term use in harsh environments.
It has a Dy11 vector group and a No-Load Tap Changer (NLTC) for flexible voltage adjustment. Low no-load and load losses make it efficient. The IP20 enclosure keeps people safe and stops dust from entering, while also reducing noise indoors.
