Aluminum Vs Copper Contact Arms？ How To Select For 630A & 1250A?

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 High-voltage circuit breaker contact arms on the mainstream market are mostly fabricated from high-purity aluminum alloys (e.g., 6061-T6), with silver plating to boost electrical conductivity and oxidation resistance. Compared with copper counterparts, aluminum contact arms feature lighter weight and lower material cost for mass production, yet the machining finish of mating contact surfaces requires strict control.

Core Parameter Comparison

 630A Contact Arm: Designed for regular-load circuits including outgoing cabinets in compact substations and power distribution rooms; rated at 630A with a 1s short-time withstand current of approx. 20kA.

1250A Contact Arm: Deployed for main incoming cabinets or heavy-duty industrial applications, boasting short-time withstand current exceeding 31.5kA for high-load operating conditions.

Selection Guidelines

✔️ Choose 630A aluminum contact arms where system rated current ≤630A;

✔️ Opt for 1250A-rated specifications when rated current ≥1250A or circuits feed frequently started heavy loads;

✔️ Verify compliance certification to GB/T 11022 (Common Specifications for High-Voltage Switchgear and Controlgear) to guarantee operational safety and regulatory conformity.

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