CuNi20 Sheet (UNS C71000) for LV Circuit Breakers Shunt Resistor Grade

CuNi20 Sheet (UNS C71000) for LV Circuit Breakers Shunt Resistor Grade

CuNi20 Sheet (UNS C71000) for LV Circuit Breakers Shunt Resistor Grade

CuNi20 Sheet (UNS C71000) for Low-Voltage Circuit Breakers | ±30ppm TCR | 100kA Interrupt | IEC 60947/ASTM B122 Applications: Molded Case Breakers • EV Charging Contacts • Shunt Resistors • Busbar Terminals

MATERIAL TECHNOLOGY

Alloy Composition (ASTM B122):

• Cu 79-81% | Ni 18-20% | Fe 0.5-1.0% | Mn 0.3-0.8%
• Density: 8.94 g/cm³ | Melting Range: 1100-1150°C Critical Properties:
• Resistivity: 34 μΩ·cm at 20°C
• TCR: ±30 ppm/°C (0-150°C)
• Thermal Conductivity: 29 W/m·K
• Sulfide Resistance: Zero tarnishing at 150°C/1000hr

CERTIFIED PERFORMANCE

ELECTRICAL RELIABILITY

• Contact Resistance: <15 μΩ·cm² (IEC 60413)
• Arc Erosion Rate: 0.08 mm/1,000 ops at 1kV/10kA (IEC 60947)
• Resistance Stability: ΔR/R <0.05% after 50,000 interruptions

MECHANICAL DURABILITY

• Hardness: 110-140 HV (Hard Temper)
• Fatigue Strength: 180 MPa at 10^(7) cycles (ISO 1099)
• Thermal Shock: -40°C↔150°C × 500 cycles

DIMENSIONAL SPECIFICATIONS

Standard Sheet (ISO 9444):

• Thickness: 0.5–12.0 mm (±0. %)
• Width: 100–600 mm (±0.1 mm)
• Length: 500–2500 mm (±1 mm/m) Surface Treatments:
• Mill Finish (Ra 1.6 μm)
• Passivated (Cr^(3+) oxide layer)
• Tin/Silver Plated (IEC 60413 compliant)

BREAKER-SPECIFIC ENGINEERING

Contact Performance:

• Welding Resistance: ≥800 N/mm² (UL 489)
• Arc Mobility: 20% faster than pure copper
• Current Density: 100 A/mm² continuous Shunt Resistor Capability:
• Voltage Drop: 3.4 mV/A·m
• Thermal Derating: 0.4%/°C above 100°C
• Self-Inductance: <5 nH/cm

INDUSTRIAL VALIDATION

ELECTRIC VEHICLES:

• DC Fast Charger Breakers: 1,500V/20kA clearance
• 0% contact welding at -40°C cold switching INDUSTRIAL AUTOMATION:
• MCCB Contacts: 100kA interrupt at 440V AC (IEC 60947-2)
• Short-Circuit Withstand: 100kA/100ms (IEC 60898) RENEWABLE ENERGY:
• Solar Combiner Boxes: 85% humidity endurance (IEC 61730)
• Wind Farm Switchgear: 15G vibration resistance

Normal composition%

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