ISO 9001 : 2015 Certified  |  CE Certified  |  SGS Audited Special Transformer Production Base in China

Dry-Type Power Transformer

Class H dry-type power transformer with resin insulation

Dry-Type Power Transformer

Class H insulation series · Fire-safe · Low noise · Low loss

Our H-class insulation dry-type transformers are designed for installations where fire safety, environmental protection and low maintenance are essential. The core uses high-permeability premium grain-oriented cold-rolled silicon steel sheet with 45° fully mitered step-lap joints, effectively reducing no-load loss, no-load current and core noise.

  • Low no-load loss, low no-load current, low core noise
  • Special square-tube pulling-plate core clamping structure
  • Core limbs bound with insulating tape for rigidity
  • Special resin coating on the core surface for moisture and rust protection
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Product Overview

Dry-type transformers transfer electrical energy without liquid insulation, making them the preferred choice inside commercial and industrial buildings, basements, high-rise structures and other places where fire and explosion safety are required. Boyuan's H-class insulation series uses a vacuum pressure impregnation (VPI) process with temperature-resistant insulation materials, giving the windings excellent dielectric strength, thermal endurance and moisture resistance even in demanding indoor environments.

Construction Highlights

  • Core material: high-permeability premium grain-oriented cold-rolled silicon steel sheet.
  • Core joints: 45° fully mitered step-lap (stepped) joints reduce the air-gap effect at lamination corners, cutting excitation current and noise.
  • Core clamping: special square-tube pulling-plate structure keeps the core bundle uniformly compressed and vibration-free.
  • Core limbs: bound with insulating tape to maintain compactness and reduce magnetostriction noise.
  • Core surface: coated with special resin for moisture-proofing and rust prevention.
  • Insulation class: Class H (180°C) insulation system, impregnated under vacuum pressure.

Typical Applications

  • Commercial complexes, high-rise buildings, basements and rooftops
  • Box-type (compact) substations
  • Hospitals, airports, metros and other crowded public facilities requiring fire safety
  • Industrial plants supplying dry-type rectifier transformers for monocrystal silicon furnaces

Technical Parameters (Typical Range)

Insulation classClass H (180°C thermal class)
CoolingAN (natural air) / AF (forced air with fans for larger capacities)
CoreHigh-permeability grain-oriented cold-rolled silicon steel, 45° step-lap joints
Surface protectionSpecial resin coating — moisture-proof and rust-proof
Typical usesIndoor distribution, box substations, fire-sensitive locations
StandardsISO 9001:2015 quality system; CE certified

Note: capacity and voltage ratings can be configured to your project's requirements. For operation in humid, hot regions, we recommend the AF forced-air cooling option — see our FAQ for the dry-type vs. oil-immersed comparison.

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