Quality standards of product

 

1.Quality management system GB/T 19001-2016 ISO 9001: 2015

The operation of the whole ZHENGRUI system is strictly controlled and managed. This ensures the quality of products and material in all stages, from receiving customer requests to design, materials, production, installation, testing, packaging, delivery, after-sales, all of which operate under strict and logically linked processes.

2.Accreditation certificate CE

LOW VOLTAGE DIRECTIVE,ELECTROMAGNETIC COMPATIBILITY DIRECTIVE ATTESTATION OF CONFORMITY
GENERAL PRODUCT SAFETY REGULATION ATTESTATION OF CONFORMITY

confirms that ZHENGRUI technical quality meets the requirements of all specific international standards for testing and calibration laboratories. All ZHENGRUI products are fully tested in a qualified testing room before leaving the factory, ensuring stable quality and providing absolute peace of mind for customers.

 

Products Description

Dry-type transformers are a specialized type of electrical transformer in which the core and windings are not immersed in insulating liquid, such as oil. Instead, they rely on air or other solid materials for insulation and cooling. These transformers are widely recognized for their safety, efficiency, and environmental friendliness, making them a preferred choice in numerous applications, including industrial, commercial, and renewable energy sectors.

Cooling Methods

Dry-type transformers primarily use air or gas (such as SF6) for cooling. Natural air circulation is sufficient for smaller units, while larger transformers may require forced air cooling systems with fans to enhance heat dissipation. The incorporation of fans improves cooling efficiency, ensuring the transformer operates within the desired temperature range and extends its service life.

Insulation System

Dry-type transformers employ advanced insulation materials to ensure optimal performance and longevity. Typical insulation materials include:

  • High-temperature-resistant resin
  • Special insulating varnishes
  • Insulating papers with high dielectric strength

The windings are often subjected to Vacuum Pressure Impregnation (VPI) or epoxy resin encapsulation, both of which enhance the transformer’s resistance to moisture, dust, and environmental pollutants. VPI transformers provide a balance between cost-effectiveness, durability, and thermal endurance, while cast resin transformers offer superior protection against humidity and corrosive conditions.

Advanced Temperature Control System

To maintain operational reliability and prevent overheating, dry-type transformers are equipped with an intelligent temperature monitoring system. Key features include:

  • Built-in PT100 thermal sensors in the three-phase windings for real-time temperature detection.
  • Digital display screen that cycles through temperature readings.
  • Multi-stage automatic protection mechanisms:
    1. Cooling fans activate automatically upon reaching a preset temperature.
    2. High-temperature alarm alerts the operator of potential overheating.
    3. Over-temperature trip function shuts down the transformer to prevent thermal damage.
  • Manual and automatic fan control options, including timer-based operation for optimized energy consumption.
  • Historical data recording to track operational trends.
  • 4-20mA current output for external monitoring integration.
  • RS485 Modbus communication protocol for seamless connectivity with automation and control systems.
  • Environmental temperature measurement to adjust cooling parameters accordingly.
  • Core temperature monitoring for additional safety assurance.

Applications of Dry-Type Transformers

Due to their fire-resistant, oil-free design, dry-type transformers are ideal for a wide range of applications, including:

  1. Indoor Installations

    • Commonly used in high-occupancy buildings such as office complexes, shopping malls, hospitals, schools, and residential buildings, where fire safety is a primary concern.
    • No risk of oil leaks, making them compliant with strict environmental and safety regulations.

  2. Industrial Facilities

    • Preferred in factories, chemical plants, and manufacturing facilities where oil-filled transformers pose a contamination risk.
    • Can withstand harsh industrial environments with dust, humidity, and temperature fluctuations.

  3. Renewable Energy Systems

    • Extensively used in wind farms and solar power plants due to their high reliability and environmental safety.
    • Designed to operate efficiently in remote and outdoor settings with extreme temperature variations.

  4. Infrastructure & Transportation

    • Utilized in airports, railway stations, and tunnels where low maintenance and fire safety are critical.
    • Ensures a stable power supply to essential systems.

  5. Data Centers and IT Facilities

    • Dry-type transformers provide consistent voltage regulation for data centers and server rooms.
    • Minimize the risk of fire hazards in sensitive IT environments.

Types of Dry-Type Transformers

1. Cast Resin Transformers

  • Windings are fully encapsulated in epoxy resin, offering excellent protection against dust, moisture, and environmental contaminants.
  • Suitable for high-humidity locations and corrosive atmospheres.
  • Minimal maintenance required due to sealed insulation structure.

2. VPI (Vacuum Pressure Impregnated) Transformers

  • Windings are treated with a high-temperature varnish using vacuum pressure impregnation technology.
  • Provide a cost-effective balance between performance, protection, and durability.
  • Suitable for applications requiring moderate environmental protection and high thermal endurance.

Advantages and Disadvantages

Advantages:

✔ Enhanced Safety – No risk of fire or explosion due to the absence of flammable oil.
✔ Environmentally Friendly – Oil-free design eliminates risks of leaks and contamination.
✔ Lower Maintenance – No need for oil changes, reducing operational costs.
✔ Compact Design – Can be installed closer to load centers, reducing power losses.
✔ Durability – Designed to withstand harsh environmental conditions with minimal degradation.

Disadvantages:

✖ Larger and Heavier – Dry-type transformers tend to be bulkier than their oil-filled counterparts.
✖ Higher Initial Cost – Typically more expensive due to advanced insulation materials and safety features.
✖ Potential Noise Levels – May produce more noise, especially in high-power applications, requiring soundproofing solutions in noise-sensitive environments.