Introduction
SCOTECH resin cast dry-type transformers represent the pinnacle of safe, reliable, and eco-friendly power distribution solutions. Designed for demanding applications where fire safety, environmental sustainability, and maintenance-free operation are critical, these transformers use advanced epoxy resin encapsulation technology to provide superior protection against moisture, dust, and harsh environmental conditions.
With no flammable oil, they are ideal for indoor installations in high-risk areas such as hospitals, data centers, commercial buildings, and industrial plants. Their robust construction ensures excellent thermal stability, low noise levels, and high resistance to short circuits and overloads. Additionally, SCOTECH’s dry-type transformers comply with international standards (IEC, IEEE, and CSA) and offer customizable designs to meet specific voltage, power rating, and environmental requirements.
Engineered for efficiency and longevity, these transformers deliver maintenance-free operation while supporting smart grid integration with optional IoT monitoring. Whether for renewable energy systems, urban infrastructure, or critical facilities, SCOTECH resin cast dry-type transformers provide a safe, sustainable, and high-performance power solution.
Construction
Example Drawings
2500kVA resin cast dry type transformer diagram drawing and size.
Manufacturing
Steel – plate: Made from cold – rolled steel, surface treated for corrosion resistance. Advantages like good look, ventilation, easy install/transport. Assembled, high strength, with access doors. Color customizable.
Aluminum – alloy: From polished alloy plates, good appearance and corrosion resistance. Easy assembly, access doors. Provides IP20/23+ protection, suitable for outdoor (blocks impurities/water).
NEMA 1: Indoor, shields from dust/debris, reduces personnel contact risk.
NEMA 12: Indoor, like NEMA 1 but better against dust/drips, passes resistance tests.
NEMA 3R: Indoor/outdoor, resists dirt, dust, weather (rain/snow/ice).
NEMA 4/4X: Indoor/outdoor, watertight (blocks high – pressure water). Used in harsh areas. “X” adds corrosion resistance (not submersible).
Components
Function: Measures current for protection, metering, or monitoring.
Installation: Typically embedded in HV or LV bushings or mounted separately.
Output: Provides standardized signals (e.g., 1A or 5A) to relays or meters.
Function: Monitors the ambient temperature inside the transformer enclosure.
Features:
Alarms or trips if overheating occurs due to poor ventilation or overloading.
Often includes Pt100/Pt1000 sensors for accurate readings.
Function: Protects the transformer from dust, moisture, and mechanical damage.
Materials:
IP20: Basic protection against touch (indoor use).
IP23: Weatherproof for limited outdoor exposure.
Ventilation: Louvers or mesh panels for natural cooling; may include forced-air fans.
Function: Enhances heat dissipation under high load conditions (AN/AF cooling).
Control: Automatically activated by temperature sensors (e.g., >80°C).
Placement: Mounted on the enclosure walls or near windings.
Function: Connects the HV winding to external circuits.
Insulation: Reinforced with resin or silicone sleeves for creepage protection.
Function: Termination point for HV incoming cables.
Types:
Cable lugs for direct connection.
Busbar terminals for switchgear integration.
Construction: Encased in epoxy resin for mechanical strength and moisture resistance.
Material: Aluminum or copper conductors with class F/H insulation.
Function: Isolates the transformer core/tank from the enclosure to prevent grounding faults.
Material: High-grade composite or rubber with high dielectric strength.
Function: Facilitates safe handling during installation/maintenance.
Design: Stainless steel lugs rated for the transformer’s total weight.
Function: Termination point for low-voltage output cables.
Options:
Bolt-on terminals for rigid busbars.
Cable glands for flexible connections.
Construction: Resin-encapsulated for thermal and electrical stability.
Taps: May include no-load tap changers for voltage adjustment.
Displays critical transformer specifications (e.g., rated capacity, voltage class, impedance, weight) for maintenance and compliance checks.
Function: Automates tap position monitoring and alerts for manual adjustment.
Features:
Remote status indication via SCADA.
Prevents operation under load (mechanical interlock).
Function: Designated side for LV cable exits, often with gland plates or bushing cutouts.
function：Designed to facilitate transformer movement and positioning during installation or maintenance, typically used with pulling equipment for safe relocation.
Featuring excellent arc resistance and mechanical strength.These insulators effectively prevent surface discharge and pollution flashover, ensuring safe operation in harsh environments like humidity and contamination. The specially designed shed configuration further enhances anti-pollution performance.
Actions:
Alarm at 130°C (Class F) or 150°C (Class H).
Trip at 155°C (F) or 180°C (H).
Function: Enables mobility for floor-mounted units.
Types:
Fixed or swivel casters with brakes.
Rated for 1.5× transformer weight.
Tests
Routine test
1.measurement of winding resistance
2.measurement of voltage ratio and check of phase displacement
3.measurement of short-circuit impedance and load loss
4.measurement of no load loss and current
5.applied voltage
6.induced voltage withstand test
7.partial discharge test
Type test
1.Full wave lightning impulse test (LI)
2.temperature rise test
Special test
1. Short circuit test certified by KERI and PT&T
2. Noise test according to IEC 60076-10, using a Pressure Level (Lp)
Applications
Ideal for critical operations such as nuclear power plants, semiconductor manufacturing facilities, automotive production lines, petrochemical industries, offshore drilling platforms, dock cranes, rolling mills, international airports, thermal power stations, and transformer substations.
Designed to meet the power demands of complex structures including skyscrapers, multifunctional buildings, and residential apartments.
Suitably deployed in locations that require protection against environmental hazards, such as water treatment plants and hydroelectric power stations, ensuring operational integrity despite adverse conditions.
Optimally utilized in sustainable energy projects, including solar photovoltaic systems and wind power installations, supporting the shift to greener energy solutions.
Recommended for public infrastructures where fire safety is paramount, including underground shopping centers, subway systems, hotels, and hospitals, ensuring robust protection and reliable power delivery.
Perfect for data centers requiring stable, continuous power. With many servers and network equipment relying on steady power, resin cast dry type transformers deliver stable output, suit high-density use, and support operations reliably with strong safety and durability.
Our advantages
Oil-free design: Eliminates the risk of oil leaks and fires, making them suitable for indoor, high-rise buildings, subways, hospitals, and other fire-sensitive locations.
Self-extinguishing material: Epoxy resin is flame-retardant, preventing combustion even under high heat or short-circuit conditions (compliant with UL, IEC standards).
No pollution: No insulating oil means no toxic emissions, complying with RoHS and REACH environmental regulations.
Zero maintenance: Resin encapsulation resists moisture and dust, eliminating the need for oil changes or filter replacements.
High insulation strength: Uniform resin casting ensures excellent partial discharge resistance, extending lifespan.
Strong short-circuit resistance: Resin-reinforced windings withstand high current surges, reducing failure risks.
Moisture & corrosion-proof: Resin protects windings from humidity, salt spray, chemicals, and dust, ideal for mines, ships, and industrial plants.
Wide temperature range: Operates reliably from -25°C to +50°C (with optional forced-air cooling for overload capacity).
Quiet operation: <55dB noise due to vibration-dampening resin, suitable for schools and residential areas.
High efficiency: Low no-load/loss performance (meets IE3/IE4 standards) with premium silicon steel cores.
Supports PT100 sensors and IoT integration for real-time temperature/load tracking, enabling smart grid management.
Available ratings
Table1.Torque values for connecting with low voltage terminals
| Bolt | M8 | M10 | M12 | M16 |
| Torque | 125 | 250 | 405 | 1500 |
Table2. Cast Resin Transformer Basic Impulse Level (BIL)
| Highest voltage (kV) | BIL (kV) | Minimum clearance (mm) | |
| Active – Earthed | Surface of epoxy Resin– Earthed | ||
| ≤1.1 | 10 | ||
| 3.6 | 40 | 60 | 50 |
| 7.7 | 60 | 90 | 50 |
| 12 | 75 | 120 | 75 |
| 17.5 | 95 | 160 | 100 |
| 24 | 125 | 250 | 150 |
| 36 | 170 | 350 | 200 |
Table3. Typical Cast Resin Transformer Impedance Ranges
| Voltage | ＜2000kVA | ＞2000kVA |
| 4.16 kV | 4.0-6.0% | 6.0-7.0% |
| 8.8 kV | 4.5-6.5% | 6.0-8.0% |
| 15 kV | 5.5-7.0% | 6.5-8.0% |
| 27 kV | 6.5-7.5% | 7.0-8.5% |
| 38 kV | 6.5-7.5% | 7.0-8.5% |
