Dry Type Distribution Transformers (SCB / SC(B) / SGB Series)
XBRELE supplies a full range of dry type transformers based on cast resin and epoxy resin technology, designed for indoor substations, commercial buildings and projects with strict fire-safety requirements. The SCB, SC(B) and SGB series cover 6–35 kV classes with low loss, reliable insulation performance and easy maintenance.
Fire-Safe Dry Type Transformers for Indoor Power Distribution
Dry type transformers use cast resin or epoxy resin insulation instead of oil, making them ideal for indoor substations and buildings with strict fire-safety requirements. XBRELE dry type distribution transformers are designed for 6–35 kV networks, with low loss, low noise and easy maintenance for long-term operation.
Based on SCB, SC(B) and SGB series designs, these cast resin transformers and epoxy resin transformers provide reliable performance in high-rise buildings, hospitals, metro stations, commercial complexes and other densely populated areas where oil-filled units are not preferred.
XBRELE products are developed with reference to international standards such as IEC 60076-11 dry-type power transformers , ensuring consistent insulation levels and temperature-rise performance.
For a complete view of our power distribution transformer portfolio, including oil-immersed and 11 kV dry type transformer options, visit the Power Distribution Transformers pillar page .
Dry Type Transformer Data by Series
Switch between SCB10 / SCB11, SCB13, SCB11-35kV and SG(B)10 eco-friendly dry type transformers to review rated capacities, voltage combinations and key loss parameters for indoor, fire resistant applications.
SCB10 / SCB11 Epoxy Cast Dry-Type Distribution Transformers
SCB10 and SCB11 dry-type transformers adopt vacuum cast epoxy resin technology with F or H class insulation, low partial discharge and excellent fire resistance. They are widely used in high-rise buildings, commercial complexes, hospitals, schools, subways and indoor substations where strict fire-safety requirements apply.
Main Technical Parameters — SCB10 6/10kV 30–2500kVA Dry-Type Voltage Regulation Distribution Transformer
| Rated capacity (kVA) | No-load loss (kW) | Load loss 130°C (kW) | Load loss 155°C (kW) | Load loss 180°C (kW) | No-load current (%) | Short-circuit impedance (%) |
|---|---|---|---|---|---|---|
| 30 | 0.19 | 0.67 | 0.71 | 0.76 | 2 | 4.0 |
| 50 | 0.27 | 0.94 | 1 | 1.07 | 2 | 4.0 |
| 80 | 0.37 | 1.29 | 1.38 | 1.48 | 1.5 | 4.0 |
| 100 | 0.40 | 1.48 | 1.57 | 1.69 | 1.5 | 4.0 |
| 125 | 0.47 | 1.74 | 2.85 | 1.98 | 1.3 | 4.0 |
| 160 | 0.54 | 2.00 | 2.13 | 2.28 | 1.3 | 4.0 |
| 200 | 0.52 | 2.37 | 2.53 | 2.71 | 1.1 | 4.0 |
| 250 | 0.72 | 2.59 | 2.26 | 2.96 | 1.1 | 4.0 |
| 315 | 0.88 | 3.27 | 3.47 | 3.73 | 1.0 | 4.0 |
| 400 | 0.98 | 3.75 | 3.99 | 4.28 | 1.0 | 4.0 |
| 500 | 1.16 | 4.59 | 4.88 | 5.23 | 1.0 | 4.0 |
| 630 | 1.34 | 6.53 | 5.88 | 5.29 | 0.85 | 6.0 |
| 630 (20/24kV) | 1.30 | 5.61 | 5.96 | 6.40 | 0.85 | 6.0 |
| 800 | 1.52 | 6.55 | 6.96 | 7.46 | 0.85 | 6.0 |
| 1000 | 1.77 | 7.65 | 8.13 | 8.76 | 0.85 | 6.0 |
| 1250 | 2.09 | 9.10 | 9.69 | 10.3 | 0.85 | 6.0 |
| 1600 | 2.45 | 11.0 | 11.7 | 12.5 | 0.85 | 6.0 |
| 2000 | 3.05 | 13.6 | 14.4 | 15.5 | 0.70 | 6.0 |
| 2500 | 3.60 | 16.1 | 17.1 | 18.4 | 0.70 | 6.0 |
| 1600 (20/24kV) | 2.45 | 12.2 | 12.9 | 13.9 | 0.85 | 8.0 |
| 2000 (20/24kV) | 3.05 | 15.0 | 15.9 | 17.1 | 0.70 | 8.0 |
| 2500 (20/24kV) | 3.60 | 17.7 | 18.8 | 20.2 | 0.70 | 8.0 |
Note: 6kV / 10kV high-voltage windings with tap ranges ±2.5% / ±5% (and ±2×2.5% for part of the ratings). 20/22/24kV versions are marked in brackets. Data come directly from the SCB10 manufacturer catalogue.
Main Technical Parameters — SCB10 20kV 30–2500kVA Dry-Type Distribution Transformer
| Rated capacity (kVA) | No-load loss (W) | Load loss (W) | No-load current (%) | Short-circuit impedance (%) |
|---|---|---|---|---|
| 30 | 33 | 630 / 600 | 1.50 | 4.0 |
| 50 | 43 | 910 / 870 | 1.20 | 4.0 |
| 63 | 50 | 1090 / 1040 | 1.10 | 4.0 |
| 80 | 80 | 1310 / 1250 | 1.00 | 4.0 |
| 100 | 75 | 1580 / 1500 | 0.90 | 4.0 |
| 125 | 85 | 1890 / 1800 | 0.80 | 4.0 |
| 160 | 100 | 2310 / 2200 | 0.60 | 4.0 |
| 200 | 120 | 2730 / 2600 | 0.60 | 4.0 |
| 250 | 140 | 3200 / 3050 | 0.60 | 4.0 |
| 315 | 170 | 3830 / 3650 | 0.50 | 4.0 |
| 400 | 200 | 4520 / 4300 | 0.50 | 4.0 |
| 500 | 240 | 5410 / 5150 | 0.50 | 4.0 |
| 630 | 320 | 6200 | 0.30 | 4.5 |
| 800 | 380 | 7500 | 0.30 | 4.5 |
| 1000 | 450 | 10300 | 0.30 | 4.5 |
| 1250 | 530 | 12000 | 0.20 | 4.5 |
| 1600 | 630 | 14500 | 0.20 | 5.0 |
| 2000 | 750 | 18300 | 0.20 | 5.0 |
| 2500 | 900 | 21200 | 0.20 | 5.0 |
Note: 20kV SCB10 series uses high-voltage windings of 6 / 6.3 / 10 / 10.5 / 11kV on the low-voltage side, with tap ranges ±2×2.5% / ±5%. All data originate from the SCB10 20kV manufacturer catalogue.
SC(B)13-10kV Series Resin Insulation Dry-Type Transformer
Scope of Application: Especially suitable for places with high fire protection requirements, such as mines, oil fields, subways, power plants, schools, hospitals, commercial centers, and high-rise buildings.
Structural Features:
- Foil Coil: Low voltage winding uses whole copper foil winding to solve low voltage/high current problems.
- Core Iron: 45° fully oblique step joint with high magnetic permeability silicon steel sheet.
- Temp Control: BWDK series signal thermometer buried in the LV coil.
- Moisture Proof: Can operate normally under 100% humidity without pre-drying.
| Rated Capacity (kVA) | No-load Loss (kW) | Load Loss 130°C (kW) | Load Loss 155°C (kW) | Load Loss 180°C (kW) | Imp. (%) |
|---|---|---|---|---|---|
| 30 | 0.135 | 0.605 | 0.640 | 0.685 | 4.0 |
| 50 | 0.195 | 0.845 | 0.900 | 0.965 | 4.0 |
| 80 | 0.265 | 1.16 | 1.40 | 1.33 | 4.0 |
| 100 | 0.290 | 1.33 | 1.41 | 1.52 | 4.0 |
| 125 | 0.340 | 1.56 | 1.66 | 1.78 | 4.0 |
| 160 | 0.385 | 1.80 | 1.91 | 2.02 | 4.0 |
| 200 | 0.445 | 2.13 | 2.27 | 2.44 | 4.0 |
| 250 | 0.515 | 2.33 | 2.48 | 2.66 | 4.0 |
| 315 | 0.635 | 2.94 | 3.12 | 3.35 | 4.0 |
| 400 | 0.705 | 3.37 | 3.59 | 3.85 | 4.0 |
| 500 | 0.835 | 4.13 | 4.39 | 4.70 | 4.0 |
| 630 (Type A) | 0.965 | 4.97 | 5.29 | 5.66 | 4.0 |
| 630 (Type B) | 0.935 | 5.05 | 5.36 | 5.76 | 6.0 |
| 800 | 1.09 | 5.89 | 6.26 | 6.71 | 6.0 |
| 1000 | 1.27 | 6.88 | 7.31 | 7.88 | 6.0 |
| 1200 | 1.50 | 8.19 | 8.72 | 9.33 | 6.0 |
| 1600 | 1.76 | 9.94 | 10.5 | 11.3 | 6.0 |
| 2000 | 2.19 | 12.2 | 13.0 | 14.0 | 6.0 |
| 2500 | 2.59 | 14.5 | 15.4 | 16.6 | 6.0 |
| 1600 (High Imp) | 1.76 | 11.0 | 11.6 | 12.5 | 8.0 |
| 2000 (High Imp) | 2.19 | 13.5 | 14.3 | 15.4 | 8.0 |
| 2500 (High Imp) | 2.59 | 15.9 | 17.0 | 18.2 | 8.0 |
Note: Data derived from SCB13 6kV/10kV Class 13 dry-type non-excitation voltage regulation distribution transformer technical parameters.
SCB11-35kV Dry Type Power Transformers
Product Overview: The SCB11-35kV series utilizes three-phase solid molding (epoxy vacuum casting) and low-voltage foil coil technology. It offers high mechanical strength, short-circuit resistance, and is maintenance-free.
Key Specifications:
- Voltage: HV 35kV (35, 36, 37, 38.5) / LV 0.4kV
- Insulation Level: LI170AC70 / AC5
- Join Groups: Dyn11, Yyn0
- Tapping Range: ±2×2.5% or ±5%
| Rated Capacity (kVA) | No-load Loss (kW) | Load Loss 130°C (kW) | Load Loss 155°C (kW) | Load Loss 180°C (kW) | No-load Current (%) | Imp. (%) |
|---|---|---|---|---|---|---|
| 50 | 0.450 | 1.34 | 1.42 | 1.52 | 2.3 | 6.0 |
| 100 | 0.630 | 1.97 | 2.09 | 2.23 | 2.0 | 6.0 |
| 160 | 0.790 | 2.65 | 2.81 | 3.00 | 1.5 | 6.0 |
| 200 | 0.880 | 3.13 | 3.32 | 3.55 | 1.5 | 6.0 |
| 250 | 0.990 | 3.58 | 3.80 | 4.06 | 1.3 | 6.0 |
| 315 | 1.17 | 4.25 | 4.51 | 4.82 | 1.3 | 6.0 |
| 400 | 1.37 | 5.10 | 5.41 | 5.79 | 1.1 | 6.0 |
| 500 | 1.52 | 6.27 | 6.65 | 7.11 | 1.1 | 6.0 |
| 630 | 1.86 | 7.25 | 7.69 | 8.23 | 1.0 | 6.0 |
| 800 | 2.16 | 8.60 | 9.12 | 9.76 | 1.0 | 6.0 |
| 1000 | 2.43 | 9.86 | 10.4 | 11.1 | 0.75 | 6.0 |
| 1250 | 2.83 | 12.0 | 12.7 | 13.6 | 0.75 | 6.0 |
| 1600 | 3.24 | 14.6 | 15.4 | 16.5 | 0.75 | 6.0 |
| 2000 | 3.82 | 17.2 | 18.2 | 19.5 | 0.75 | 6.0 |
| 2500 | 4.45 | 20.3 | 21.8 | 23.3 | 0.75 | 6.0 |
Note: HV rated voltages: 35kV, 36kV, 37kV, 38.5kV. Tapping range: ±2×2.5% or ±5%.
Load losses listed correspond to different insulation system temperatures (B=100K rise/130°C, F=120K rise/155°C, H=145K rise/180°C) per GB1094.11.
SG(B)10 Eco-friendly Dry Type Transformers
Product Features: The product uses DuPont new materials with insulation heat resistance grades reaching Class H (180°C) and key parts reaching Class C (220°C).
Safety & Reliability:
- Safe: Non-combustible, self-extinguishing, and non-toxic. No toxic smoke at 800°C. Ideal for subways, ships, and chemical plants.
- Reliable: NOMEX-based insulation system withstands thermal shock and has no partial discharge. Excellent resistance to moisture, mold, and smoke.
| Temperature Grade | Grade B | Grade F | Grade H | Grade C |
|---|---|---|---|---|
| Average Temperature Rise (°C) | 80 | 100 | 125 | 150 |
| Maximum Ambient Temperature (°C) | 40 | 40 | 40 | 40 |
| Hot Spot Temperature Tolerance (°C) | 10 | 15 | 20 | 30 |
| Maximum Temperature (°C) | 130 | 155 | 180 | 220 |
Note: Data reference for SG(B)10 type dry transformer insulation heat resistance grades.
Key Features of XBRELE Dry Type Transformers
XBRELE dry type transformers adopt cast resin and epoxy resin insulation with Class B, F, H and C systems, offering high fire safety, low loss and reliable performance for indoor power distribution in high-rise buildings, tunnels, commercial centers and public facilities.
Non-Combustible Insulation System
SCB and SC(B) series use flame-retardant resin systems with very low smoke emission, making them suitable for critical locations where oil-filled transformers are restricted.
- Self-extinguishing resin: Non-combustible insulation with low smoke and toxicity.
- Indoor transformer design: Ideal for metro, hospitals, schools and commercial buildings.
- Fire resistant transformer choice: Helps meet modern building fire-safety codes.
Cast Resin & Epoxy Resin Technology
High-voltage windings are vacuum cast with epoxy resin or cast resin, ensuring excellent dielectric strength, moisture resistance and stable temperature rise under different insulation classes.
- Insulation classes: Class B, F, H and C with reference hot-spot temperatures up to 220 °C.
- Optimised loss values: No-load and load losses aligned with GB1094 and IEC 60076-11.
- Stable performance: Suitable for 6–35 kV dry type distribution transformer projects.
Robust Core & Foil Winding Structure
The core adopts high-grade oriented silicon steel with step-lap joints, while the low-voltage winding uses foil or multi-layer copper conductors for strong short-circuit withstand capability.
- Low partial discharge: Careful processing and vacuum casting reduce PD levels.
- Short-circuit strength: Compact winding structure improves mechanical reliability.
- Easy maintenance: Dry type design avoids oil treatment and simplifies routine inspection.
Manufacturing & Testing of Dry Type Transformers
XBRELE dry type transformers follow IEC 60076-11 and GB/T 10228 requirements for insulation, temperature rise, short-circuit strength and partial discharge levels—ensuring safe indoor operation for 6–35 kV networks.
Controlled Manufacturing Process
SCB / SC(B) / SGB series transformers are cast in controlled environments with vacuum drying, resin casting and precision coil winding to guarantee stable dielectric performance and low partial discharge.
- 01
Core Processing
High-grade oriented silicon steel is cut using CNC shearing and stacked with step-lap joints to reduce no-load loss.
- 02
Foil & Layer Winding
Low-voltage foil windings and high-voltage multi-layer coils are wound under tension for strong short-circuit withstand capability.
- 03
Vacuum Drying
Coils are vacuum-dried to eliminate moisture, improving insulation resistance and long-term stability.
- 04
Resin Casting / Epoxy Casting
High-voltage windings are cast with epoxy resin or cast resin under vacuum to reduce voids and partial discharge (PD).
- 05
Final Assembly & Temperature-Rise Run
Transformers undergo assembly, terminal installation and simulated load temperature-rise tests before inspection.
Routine & Type Tests
All tests comply with IEC 60076-11 and GB/T 10228 standards for cast-resin dry-type transformers.
Electrical Tests
- Ratio & polarity tests for all tapping positions.
- Load loss & impedance measured at reference temperature.
- No-load loss aligned with SCB / SC(B) / SGB energy levels.
- Applied & induced voltage tests on HV/LV windings.
Insulation & PD
- Insulation resistance and tan δ measurements.
- Partial discharge: Must be <10 pC (dry type standard).
- Resin curing quality and thermal stability checks.
Mechanical & Appearance
- Verification of short-circuit withstand capability.
- Inspection of coil bonding, casting quality and support structures.
- Final check of terminals, mounting frames and enclosure options.
Reliable Supply Chain for Dry Type Transformers
From standard 11 kV dry type transformers to customised SCB / SC(B) / SGB solutions, XBRELE coordinates production, packing and logistics so your dry type distribution transformers arrive on time and ready for indoor installation.
Flexible Production for SCB / SC(B) / SGB
Our dry type transformer lines support both standard catalogue ratings and project-based designs, helping EPCs and end users meet substation and building schedules.
- Standard dry type transformers: Typical lead time around 30–45 days for common 6–11 kV ratings.
- Special voltage / enclosure options: Approx. 45–60 days depending on insulation class and protection degree.
- Project batches: Coordinated production for multi-set deliveries on large building or metro projects.
- Spare units: Recommended safety stock schemes for key dry type distribution transformer sizes.
Protection for Indoor Equipment
Although dry type transformers are oil-free, they still require robust protection during transport, especially for cast resin windings, terminals and enclosures.
- Export wooden pallets / crates: Fumigated and reinforced for transformer weight and dimensions.
- Moisture control: Film wrapping and desiccant bags to protect core and coils during sea shipment.
- Shock protection: Extra padding around HV/LV terminals and epoxy resin coils.
- Clear identification: Nameplate, rating and dry type transformer model labels for easy site handling.
Installation & Commissioning Assistance
XBRELE provides technical support for installing and operating dry type transformers in indoor substations, commercial buildings and infrastructure projects.
- Installation guidelines: Recommendations on clearances, ventilation and enclosure selection for SCB / SC(B) / SGB units.
- Commissioning support: Guidance on insulation resistance, ratio and partial discharge checks before energising.
- Maintenance advice: Periodic inspection procedures for resin surfaces, terminals and cooling air paths.
- Remote & document support: Drawings, test reports and Q&A support for consultants and EPC contractors.
Common Questions About Dry Type Transformers
These are the most frequent questions about Dry Type Transformers, including performance, safety, applications, and international standards.
What is a Dry Type Transformer?
What are the advantages of Dry Type Transformers?
Where are Dry Type Transformers typically used?
How long is the lifespan of a Dry Type Transformer?
Do Dry Type Transformers require maintenance?
- Cleaning the windings and enclosure
- Checking temperature rise and ventilation
- Inspecting terminals and tightening connections
- Infrared thermal scanning for hotspots