A comprehensive guide to the selection and technical parameters of dry-type transformers: 10 key points that engineers and procurement are most likely to overlook

In practical projects, the problem of selecting the wrong model for transformadores tipo seco is very common.

The capacity is sufficient, but the temperature rise exceeds the standard;
Voltage matching, but noise is not qualified;
Parameter compliance, but overseas acceptance failed.

This article will delve into the most critical but easily overlooked technical details of dry-type transformers from the perspective of engineering selection.

1.Capacity selection: You cannot just look at kVA

1.1 Continuous load and intermittent load

Dry-type transformers are highly sensitive to ambient temperature and require appropriate derating in the following scenarios:

• high altitude
• high temperature environment
• Closed computer room

1.2 Overload Capacity Assessment

The short-term overload capacity of epoxy cast transformadores tipo seco is significantly weaker than that of oil immersed transformers, and the load curve needs to be evaluated in advance.

2.Voltage level and wiring group

Common combinations:

• 10kV / 0.4kV
• 20kV / 0.4kV

The wiring group should match the system protection logic, such as:

• Dyn11
• Yyn0

3.Insulation level and temperature rise design

When choosing, consider long-term operating temperature rather than short-term limits.

4.Selection of cooling method

UN: Enfriamiento natural, bajo ruido
DE: Forced air cooling, capacity can be increased by 30-40%

But the reliability and maintenance of the fan also need to be taken into consideration.

5.Partial discharge level

High quality dry-type transformers typically require:

• Partial discharge ≤ 10 pC

This is one of the core indicators for overseas project acceptance.

6.Noise control

Noise often becomes a veto in data center and commercial building projects.
Attention should be paid to:

• core structure
• Shock absorption design
• Installation foundation

7.Protection level and environmental adaptability

Common levels:

• IP00 (indoor)
• IP23/IP31 (anti drip, anti foreign object)

8.Energy efficiency and loss indicators

Critical loss parameters:

• pérdida sin carga
• pérdida de carga

The EU and North American markets have particularly strict requirements for this.

9.Standards, certifications, and documents

Common requirements:

• CEI / IEEE
• CE
• ISO system documents

10Hidden risks of export projects

Wooden crate packaging standard
Shipping moisture prevention
Technical document language

Dry-type transformers are not necessarily “the better the parameter table, the safer it is”, but rather highly coupled system equipment with application scenarios.
The truly professional selection is a comprehensive reflection of technical understanding, engineering experience, and standard awareness.

Tecnología de energía Co. de Luoyang Datang., Limitado. es una empresa de alta tecnología que integra R&D, Fabricación y suministro de equipos eléctricos como transformadores., nuevos componentes energéticos, armarios de distribución e inversores. Con la innovación tecnológica como eje, Nos enfocamos en crear soluciones de energía de alta confiabilidad y alto rendimiento para servir a clientes globales.. Con un estricto sistema de control de calidad y certificación de estándares internacionales., Continuamos produciendo productos excelentes y permitimos a los clientes construir sistemas de energía seguros y estables..