Selection and Procurement Guide for Oil Immersed Transformers: Technical Parameters, Loss Standards, and Export Points

1.Why is selection more important than price?

In international projects, Oil Immersed Transformers failures are often not due to price, but rather:

• Parameter selection mismatch
• Standard understanding deviation
• Insufficient consideration of usage environment

Correct selection=Reduce Total Cost of Ownership (TCO) throughout the entire lifecycle

2.Analysis of core technical parameters

Parameter	Description	Impact
Rated Capacity (kVA)	Maximum output power	Determines load limit
Voltage Rating	HV / LV levels	System compatibility
Frequency	50Hz / 60Hz	Regional compliance
Impedance	Percentage impedance	Short-circuit current
Insulation Class	A / F / H	Temperature rise and lifespan

3.Copper winding vs aluminum winding (hot spot for procurement)

Item	Copper Winding	Aluminum Winding
Conductivity	High	Moderate
Initial Cost	Higher	Lower
Weight	Heavy	Lightweight
Service Life	Longer	Slightly shorter
Market Acceptance	Very high	Medium

Suggestion:

• Europe/Middle East project → Priority copper winding
• Africa/South Asia → Aluminum winding offers higher cost-effectiveness

4.Loss standards and compliance requirements

Standard	Region
IEC 60076	Global
DOE	United States
EU Ecodesign	European Union
AS/NZS	Australia & New Zealand
GOST	CIS countries

Note:
Many bidding documents explicitly require a loss limit table, which must be confirmed during the quotation stage.

5.The impact of usage environment on design

Site Condition	Design Consideration
High ambient temperature	Derating or enhanced cooling
High altitude	Improved insulation and cooling
High humidity	Sealed tank design
Desert environment	Dust-proof radiator and coatings

6.Common technical risks in export projects

• Ignore the local voltage fluctuation range
• Improper selection of cooling method
• Incomplete certification documents
• Insufficient packaging and transportation standards

7.5 common questions asked by buyers

• Should we use mineral oil or eco-friendly oil?
• Does it support customized loss?
• Is a type test report provided?
• Does it support third-party inspection?
• How about delivery time and spare parts support?

Oil immersed transformers are not standard products, but engineering products.
A truly professional supplier is reflected in:

Technical comprehension ability
Standard adaptation capability
export experience

Luoyang Datang Energy Technology Co., Ltd. is a high-tech enterprise integrating R&D, manufacturing and supply of power equipment such as transformers, new energy components, distribution cabinets and inverters. With technological innovation as the core, we focus on creating high-reliability and high-performance power solutions to serve global customers. With a strict quality control system and international standard certification, we continue to output excellent products and enable customers to build safe and stable power systems.