How Much Copper Is In A Power Line Transformer?

The copper content of power line transformers varies according to their power capacity. Generally speaking, the larger the capacity, the higher the copper content, which is determined by the working principle of the transformer. (Click to learn about the working principle of the transformer)

Generally speaking, a 630kVA transformer contains about 120 kg of copper. A 40,000kVA transformer contains about 250 kg of copper.

Typical Range:

Full copper winding (copper for both HV & LV): 120–150 kg (most common reference value from Chinese and international manufacturers).

Example: One reliable source states a standard 630 kVA transformer contains about 120 kg of copper (for reference, not exact for all models).

Some designs (e.g., optimized low-loss or foil-wound): 100–130 kg.

Higher-end or larger physical sizes: Up to 150 kg or slightly more.

Why it Varies:

Winding material - Pure copper windings use more copper than aluminum (aluminum versions have ~40–60% less weight but lower conductivity).

Design type - Oil-immersed (ONAN) vs dry-type (cast resin): Dry-type often uses more copper for better heat dissipation.

Manufacturer & standards - IEC/GB compliant Chinese models (e.g., S11/S13 series) usually around 120 kg for copper; some eco/low-loss designs reduce it slightly.

Total transformer weight for 630 kVA (copper version): Often 2000–3000 kg (including oil ~300–500 kg, core, tank, etc.), so copper is roughly 4–7% of total weight.

Union Transformer (copper winding): Total weight ~2080 kg, oil 390 kg → Copper estimated ~120–140 kg.

Schneider / similar: Total ~3000–3650 kg → Copper in similar range.

General industry reference: For 630 kVA, ~120 kg copper is a frequently cited average for full copper models.

If it's a dry-type (cast resin), copper content is often similar or slightly higher (~130–160 kg) due to insulation needs.

Note: Exact copper weight is not always published (it's proprietary), but these figures are from manufacturer data, recycling estimates, and technical references. For precise value, check the specific model's datasheet (e.g., from S11/S13 series or your supplier).

However, we need to note that the above values are the copper content of general transformers, for reference only. Not all transformers of the same power and capacity contain the same amount of copper. Because the design (model), manufacturing process (whether foil wound) and materials used (copper or aluminum) of the transformer may affect its copper content.

In order to obtain accurate copper content, we can use the product specifications or technical data sheets provided by the transformer manufacturer (Yawei Transformer will protect your after-sales product rights), which usually provide detailed information about the materials used.

Of course, if you are not sure about the quality of the product and want to conduct copper content testing yourself, you can also physically disassemble the transformer to test it on the spot, but this method may damage the equipment, so we do not recommend doing so. In addition, it is also a good way to observe whether the transformer is of qualified quality by its working performance (experimental data). Because the copper content is unqualified, the transformer is working under the corresponding load conditions (click to learn how to test the transformer)