Gb/t 14315 Guide: Fixed Installation Conditions For Bimetallic Terminal Blocks
Fixed Installation Requirements for Bimetallic Terminal Blocks
The GB/T 14315 standard specifies that bimetallic terminal blocks require fixed installation when connecting aluminum conductors to copper busbars to prevent galvanic corrosion. Fixed installation conditions demand a stable ambient temperature between -40°C and 120°C, strict torque control according to bolt size, and adequate mechanical support to eliminate vibration stress on the joint.
Standard-compliant connection factors
Environmental and Material Compatibility
Selecting the correct bi metallic cable lugs depends heavily on the operational environment. Standard compliance ensures the friction-welded joint between copper and aluminum withstands thermal expansion. Exposure to high humidity or corrosive atmospheres requires additional protective sealing to preserve the integrity of the bimetal cable lug connection over its full operational lifespan.
Mechanical Stress and Torque Specifications
Secure fastening prevents loose connections that cause overheating. Applying a precise torque of 45 Nm for M10 bolts or 85 Nm for M12 bolts ensures the bimetal terminal lug remains stable. Fixed installation structures must absorb external tension so that the heavy conductor does not transfer structural pull directly onto the electrical termination point.
Standard Installations
The following matrix outlines the performance boundaries mandated by national design criteria for transition connections:
| Conductor Material | Termination Method | Max Temperature | Applicable Voltage |
|---|---|---|---|
| Aluminum to Copper | Hexagonal Crimping | 120°C | Up to 35 kV |
| Aluminum to Copper | Indent Crimping | 120°C | Up to 10 kV |
Installation Process
Adhering to standardized mechanical procedures guarantees long-term safety and high electrical efficiency. Every Compression Cable Lug must be integrated into the distribution system using systematic deployment methods that align with national regulatory frameworks. Following these four chronological steps ensures a highly reliable setup for industrial power distribution networks without failure:
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Strip the cable insulation cleanly without nicking the internal aluminum strands.
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Clean the conductor surface thoroughly to remove non-conductive aluminum oxide layers.
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Insert the conductor fully into the barrel of the bimetallic terminal blocks.
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Apply the recommended crimping pressure using a calibrated hydraulic tool.
