HUARUI 
SCB10-2500KVA-35/0.4kV Maintenance-Free Three-Phase Dry-Type Transformer
A 35kV energy-saving dry-type transformer is a three-phase power transformer with a rated high-voltage side of 35kV, in which the core and windings are not immersed in any insulating liquid. It uses air as the cooling medium and solid materials such as epoxy resin casting or NOMEX insulation paper as the main insulation. Based on the principle of electromagnetic induction, this product steps down the 35kV grid voltage to the user-side low voltage (typically 0.4kV or 10kV), achieving power conversion and transmission.
Uses solid insulation materials such as epoxy resin casting or NOMEX paper, completely avoiding the use of flammable insulating oil, eliminating leakage and fire hazards, and producing no toxic smoke during operation, complying with fire protection and environmental requirements.
Adopts a vacuum-cast solid insulation structure with high dielectric strength of the insulating material. There is no liquid medium between windings or between windings and the core, eliminating the risk of insulation failure caused by oil leakage.
Eliminates the need for regular maintenance work such as oil sampling, oil filtration, and oil regeneration. The windings and core are completely encapsulated by solid insulation materials, isolating them from external dust and moisture. There is no need to replace the insulating medium during operation, significantly reducing operation and maintenance costs and workload.
Utilizes Air Natural (AN) or Air Forced (AF) cooling, requiring no auxiliary components such as radiators or oil conservators, resulting in a simple structure.
Compact in size and relatively lightweight, it can be placed directly at the load center (such as floor distribution rooms, subway platforms, data centers).
Solid insulation materials age slowly under normal operating conditions, maintaining stable performance throughout their service life. The overall design life can reach 20-30 years.
|
Parameter |
Specification |
|
Rated Capacity |
1250kVA (customization supported) |
|
High Voltage Rating |
10kV (customizable voltage levels) |
|
Low Voltage Rating |
400V (customizable as required) |
|
Cooling Method |
Air Natural (AN), Air Forced (AF) |
|
Insulation Class |
Class F (155℃), Class H (180℃) — for special applications |
|
Impedance Voltage |
4% ~ 10% (depending on capacity and voltage level) |
|
Losses |
Compliant with GB 20052, UL, CSA, IEC, DOE2016, IEEE, ANSI, EN60076, etc.; low-loss optimization available |
|
Connection Group |
Dyn11, Yyn0, YNd11, Yy0, etc. (optional) |
|
Number of Phases |
Three-phase |
|
Rated Frequency |
50Hz / 60Hz |
|
Protection Level |
IP21 |
|
Temperature Rise Limit |
Winding maximum temperature rise ≤ 100K |
|
Ambient Temperature |
Maximum: +40℃; Minimum: Indoor -5℃, Outdoor -25℃ (typically requires special design or additional enclosure) |
Core
Made of grain-oriented silicon steel sheets laminated together to form the main magnetic circuit. Stepped lap or mitered joint processes effectively reduce eddy current losses and hysteresis losses, improving equipment operation efficiency. The core surface is coated with anti-rust insulating varnish, and the grounding plate is reliably led out.
High and Low Voltage Windings
Wound with high-quality copper conductors or aluminum conductors (foil), divided into high voltage winding and low voltage winding. Solid insulation structure is adopted, using epoxy resin vacuum casting (encapsulated type) or NOMEX paper/glass fiber (non-encapsulated type).
High Voltage/Low Voltage Terminal Leads
Using copper busbars, copper terminals, or cable junction boxes to achieve internal and external electrical connections. Closed busway interfaces, cable plug-in connectors, or terminal boxes can be selected according to customer requirements. Dry-type transformers for American-style substations are often configured with side outlet or bottom outlet methods.
Cooling Components
Including cooling fans (axial or centrifugal fans), air deflectors, etc. Cooling methods AN (Air Natural) or AF (Air Forced) are adapted according to power specifications.
Protective Enclosure (Optional)
Made of stainless steel, aluminum alloy, or galvanized steel sheet, providing different protection levels from IP20 to IP65.
1. Core Product Advantages
① Excellent Safety and Environmental Protection: Completely oil-free design eliminates the risk of oil leakage and fire hazards, and no toxic smoke is produced during operation.
②Convenient Installation and Space Saving: Compact in size and relatively lightweight, significantly saving floor space and civil construction investment, with short installation cycle and flexible positioning.
③Maintenance-Free Operation: Eliminates the need for regular maintenance work such as oil sampling, oil filtration, and oil regeneration.
④ Strong Environmental Adaptability: Protection levels (IP20 to IP65) and climate/environmental classes (C2/C3, E2/E3) can be selected according to the application scenario. With the addition of a protective enclosure, it can operate reliably outdoors or in highly polluted environments, adapting to special environmental requirements such as high altitude, salt spray, and humidity.
2. Service Life
Under standard operating conditions and proper usage, the overall design service life of the dry-type transformer can reach 20 to 30 years. The solid insulation materials used, such as epoxy resin casting or NOMEX paper, age slowly when operating below the rated temperature. Moreover, there are no mechanical wearing parts; the magnetic performance of the core silicon steel sheets decays extremely slowly, and the copper/aluminum conductors of the windings are not subject to chemical corrosion. The structural life far exceeds 30 years.
1. Daily Maintenance
① Clean dust from the core and winding surfaces (using a vacuum cleaner or dry compressed air).
② Check whether fasteners and connection terminals are loose.
③ Test whether the temperature controller and fan functions are operating normally.
④ Monitor insulation resistance and partial discharge level trends.
2. Safety Regulations
① Operation Safety: During equipment maintenance, power must be cut off, voltage must be verified, and grounding must be applied. It is strictly prohibited to open the enclosure or touch internal components while the equipment is live. Operators must hold valid certificates and wear insulated protective equipment.
② Fire and Explosion Prevention: The installation site must ensure good ventilation. It is strictly prohibited to store flammable materials around the equipment, and fire escape routes must be kept clear.
③ Dust and Moisture Management: The installation site shall be kept dry and clean. Dust accumulated on winding surfaces shall be cleaned regularly.
④ Fault Handling Procedures: In the event of abnormal sounds, alarms, visible smoke, or arcing, the equipment must be immediately powered off and shut down. Operation may only be resumed after the fault cause has been identified and resolved. Forced operation under fault conditions is strictly prohibited. If cracks, carbonization marks, or discoloration appear on the winding surface, insulation testing and evaluation must be performed.
⑤ Maintenance Access and Safety Clearances: Maintenance access shall be reserved at the front and rear of the equipment (generally no less than 1.2m at the front and no less than 0.8m at the rear). The high-voltage and low-voltage sides must comply with safety clearance requirements for live parts to ground and between phases (determined according to voltage level). For transformers with IP-rated protective enclosures, the maintenance door shall open outward and be equipped with a safety lock to prevent unauthorized personnel from entering live compartments.
1. Power System Substations: Main transformers (step-up/step-down) and distribution transformers.
2. Industrial Manufacturing Plants: Power distribution for industries such as automotive, steel, chemical, and textile.
3. New Energy Power Generation: Step-up grid connection for wind turbines and photovoltaic step-up substations.
4. Mining and Metallurgy: Power supply for high-power crushers, electric furnaces, rolling mills, and other impact loads.
5. Rail Transit: Traction substations for subways and light rails, supplying power to overhead contact lines or third rails.
6. Data Centers and Infrastructure: Main incoming power distribution for large industrial parks, serving as a critical link in backup power systems.
7. Commercial and Civil Use: Power distribution systems for large commercial complexes, industrial parks, residential communities, and township centralized power supply.
1. Environmental Risks
1. Dust Contamination Risk: The winding surface of a dry-type transformer is exposed. In a high-dust environment over a long period, heat dissipation efficiency will decrease and creepage distance will be shortened, which may cause surface flashover or intensified partial discharge.
2. Moisture and Condensation Risk: In a high-humidity environment for a long time or in places with large temperature differences between day and night, the surface of solid insulation easily absorbs moisture and forms condensation, resulting in a significant decrease in insulation resistance and a reduction in the partial discharge inception voltage.
3. High-Temperature Overheating Risk: When a dry-type transformer is installed in poorly ventilated enclosed spaces, basements, or near heat sources, the winding temperature rise will exceed the standard, accelerating the thermal aging of insulation materials.
4. Noise and Vibration Impact: The magnetostriction of the iron core generates electromagnetic noise of 100Hz~400Hz, which may exceed the standard (e.g., ≤45~50dB at night) in quiet places such as residential areas, hospitals, and data centers.
2. Installation Restrictions
1. Indoor Installation: Suitable for high-rise buildings, basements, and densely populated areas. No dedicated oil pit is required.
2. Space Clearance: Distance from wall ≥0.8m, distance from passageway ≥1.2m, clearance between two units ≥1.0m.
3. Ventilation Requirements: Air convection must be ensured. It is strictly prohibited to block air inlets and outlets.
4. Fire Protection Requirements: The dry-type transformer itself is non-combustible. No flammable materials shall be stored around it. Standard fire extinguishers are sufficient.
5. Ambient Temperature: Indoor -5℃ ~ +40℃, outdoor -30℃ ~ +40℃. Special design is required if outside this range.
6. Maintenance Access: Reserve ≥1.2m at the front and ≥0.8m at the rear.
This product supports full-dimensional personalized customization, enabling precise adaptation based on project operating conditions, environmental factors, industry standards, and customer requirements. The customization scope is as follows, with the main dimensions listed below:
|
Dimension |
Available Range / Description |
|
Capacity & Voltage |
30 kVA ~ 10,000 kVA, 6kV ~ 11kV |
|
Connection Group |
Dyn11, Yyn0, YNd11, Yy0, ZNyn11, etc. |
|
Tap-Changer Type |
Off-circuit (No-load) (±2×2.5% or ±5%) / On-load (±8×1.25%, etc.) |
|
Cooling Method |
AN, AF, etc. |
|
Winding Material |
All-copper, all-aluminum, high-voltage aluminum / low-voltage copper, copper-aluminum composite, etc. |
|
Protection & Anti-Corrosion |
IP00 ~ IP40 |
|
Installation Environment |
Dry-type transformers shall be installed indoors in a well-ventilated, dry, clean environment, with ambient temperature -5℃ ~ +40℃, altitude ≤1000m, free from conductive dust, corrosive gases, and explosion hazards, with surrounding clearance reserved for heat dissipation and maintenance. |
|
Accessory Configuration |
Optional add-ons: intelligent temperature controller (winding temperature monitoring), partial discharge online monitoring, remote data transmission, over-temperature alarm/trip, automatic fan start/stop control, intelligent protective enclosure (with electromagnetic lock), temperature & humidity controller (anti-condensation), etc., adaptable to unattended intelligent power distribution systems and smart substations. |
|
Applicable Standards |
UL / EN 60076 / GB 1094 / IEC 60076 / ANSI C57.12 / CSA / DOE Energy Efficiency Levels |
|
Marking / Labeling |
Chinese/English or bilingual nameplate and warning labels |
