Bare Copper Conductor

CHARACTERISTICS

Basic Structure

1. Electrical Performance

1. Highest conductivity among common overhead conductors

   Copper boasts excellent electrical conductivity (approx. 100% IACS), far better than aluminum, aluminum alloy, steel-aluminum composite conductors. Same cross-section delivers much larger ampacity and significantly lower power loss.

2. Stable AC resistance with no magnetic loss

   Non-ferromagnetic copper generates zero hysteresis or eddy current loss under alternating current, ideal for low-loss power transmission and earthing circuits.

3. Superior overload & heat resistance

   Continuous operating temperature up to 90°C; short-time emergency temperature reaches 150°C, outstanding thermal stability against sudden overload.

2. Mechanical Properties

1. Good ductility & flexible structure

   Stranded design offers great flexibility, easy bending, cutting and terminal crimping; soft copper type is widely used for movable connections.

2. Higher tensile strength than pure aluminum wire

   Copper has higher mechanical strength than AAC, better sag control under tension.

3. Heavy self-weight

   Copper density is much higher than aluminum. Under equal cross-section, bare copper strand weighs far more, which limits its application for long-span overhead power lines.

4. Moderate anti-creep performance

   Hard-drawn copper resists plastic deformation better than soft aluminum, with slow sag growth under long-term tension.

3. Corrosion Resistance

1. Oxidation under open-air exposure

   Copper will slowly oxidize and form dark patina in atmospheric environment; patina can slow further internal corrosion but increases contact resistance at clamps and joints.

2. Vulnerable to corrosive surroundings

   In coastal salt fog, acid rain and chemical industrial zones, copper suffers accelerated corrosion, resulting in higher resistance and potential breakage risk.

3. Galvanic corrosion risk when connected with aluminum/steel

   Direct contact between copper and aluminum or galvanized steel creates potential difference, causing severe electrochemical corrosion. Bi-metal transition fittings must be adopted for mixed metal connection.

4. Installation & Application Advantages

Merits

• Extremely low line loss, perfect for short-distance high-current transmission, substation busbars, grounding grids, electrical equipment internal wiring.
• Excellent conductive contact performance, stable resistance for earthing and lightning protection circuits.
• Mature matching copper hardware, stable crimp connection effect.

Drawbacks

• High raw material cost, much more expensive than all aluminum series conductors.
• Excessive weight restricts long-distance overhead transmission use; mostly applied in short spans or indoor/substation occasions.
• Needs regular maintenance in polluted areas to clean oxide layer on connection points.

Typical Application Scenarios