Non-Encapsulated Ventilated Dry-Type Power Transformer CPH2 Class H 1500kVA (75~5000kVA Customizable) 副标题：

Non-Encapsulated Ventilated Dry-Type Power Transformer (Open Wound)

The non-encapsulated ventilated dry-type transformer (open-wound dry-type) is an outdoor-capable distribution product developed for the North American market. HV and LV windings are treated with CPH2-class vacuum pressure impregnated (VPI) weatherproof coating, and the open ventilated structure provides efficient natural-convection cooling with strong short-time overload capability. Compliant with IEEE C57.12.01 and NEMA ST-20, it is a cost-effective replacement for oil-immersed and cast-resin units of the same rating, widely used in commercial buildings, industrial facilities, data centers and renewable energy projects.

Product Overview

This is a three-phase ventilated (non-encapsulated) dry-type transformer. The core is built from premium cold-rolled grain-oriented silicon steel with 45° fully-mitred joints. Windings are made of copper conductors, impregnated and cured with CPH2-class moisture-resistant varnish to form a weatherproof, flame-retardant protective surface. The open ventilated design ensures uniform winding cooling with large thermal margins — significantly better short-time overload performance than cast-resin units. Oil-free and maintenance-free, with a NEMA 3R outdoor enclosure it can operate outdoors year-round, making it an economical solution for outdoor distribution, PV/wind step-up and step-down, and industrial power supply.

Highlights at a Glance

• CPH2-class coated windings — moisture, salt-fog and pollution resistant, outdoor ready;
• Class H insulation system (220℃), typical temperature rise 150K (115K/80K low-loss versions optional);
• Open ventilated structure — high cooling efficiency, strong short-time overload, long thermal life;
• Non-encapsulated, inspectable and repairable windings — easy field maintenance, lower life-cycle cost;
• Oil-free design — no fire or leakage risk, flame-retardant and eco-friendly;
• NEMA 3R outdoor enclosure, wildlife guards, arresters and LV switchgear available as options;
• CE, IEEE and ISO certified, full quality traceability.

Core Advantages

• Superior Cooling & Overload: Windings are directly exposed to ventilation ducts for full convection cooling; emergency overload capability exceeds cast-resin units — ideal for fluctuating loads;
• Repairable, Long Service Life: Non-encapsulated windings can be opened for inspection and partial repair instead of total scrapping — significantly lower life-cycle cost;
• Weatherproof & Moisture-Proof: CPH2 coating withstands outdoor sunlight, rain, fog and salt fog; with an outdoor enclosure it operates reliably all year;
• Safe & Eco-Friendly: Oil-free, no combustible liquids, no leakage pollution, flame-retardant and self-extinguishing;
• Low Noise: Fully-mitred core joints and flexible clamping — quieter than comparable encapsulated units;
• Flexible Delivery: Voltage, impedance, taps and enclosure protection all customizable per order; OEM/ODM supported.

Technical Parameters (typical configuration; final values per order technical agreement)

Standards Compliance

IEEE C57.12.01NEMA ST-20UL 1561 (optional)IEC 60076-11CE / ISO 9001

Applications

Commercial and industrial building distribution, data centers, renewable energy (PV / wind farm step-up and step-down), mining and metallurgy, utility grids, ports and oil & gas sites — indoor and outdoor systems, especially for North American and other ANSI/IEEE markets.

Note: Parameters are typical industry configurations; please verify against your actual product technical documents before publishing.

Contact us for a quotation and customized solution.