Terminating Aluminium Cables
Author: Amplex Group
With the recent increases in commodity materials prices, such as copper, aluminium cables are becoming a more attractive option for major electrical projects.Compared to copper, aluminium conductors have advantages in commercial considerations and engineering properties. Aluminium is around 70% cheaper, only 40% less conductive and 70% lighter.
However, terminating Aluminium cables takes care and consideration. Aluminium is more prone to thermal expansion under load, and it is also more prone to corrosion. In addition, copper and aluminium used together create galvanic corrosion problems due to their difference in reactivity; this is worse if a catalyst such as salt water is present.
Amplex recommends the following precautions be taken to ensure the success of your aluminium cable terminations:
• Ensure ends of stored aluminium cables are sealed against moisture
• Only aluminium crimps can be used on aluminium cable
• Ensure flexible aluminium cables are terminated only with appropriately specified flexible aluminium lugs
• Be careful not to nick the conductor when stripping the insulation
• Ensure you consider the difference of reactivity of metals when making terminations; use bimetal or tinned aluminium lugs when terminating onto the copper busbar
• Ensure the aluminium conductor is clean and free of oxidisation before terminating; use an aluminium or stainless-steel wire brush to remove if present
• Use anticorrosive paste in crimp barrels and between contact surfaces to preclude moisture
Bimetal lugs are aluminium barrels joined to a copper palm by a fusion weld process that excludes oxygen and moisture thus preventing galvanic corrosion. Tinned aluminium lugs have an electro-plated coating of tin that can be joined to a similarly tinned surface of copper or aluminium.
Amplex stocks the following terminations for aluminium cable terminations:
• Bimetal lugs in a single hole and long palm dual hole
• Tinned aluminium lugs single hole and long palm dual hole
• Tinned Aluminium lugs for flexible conductors
Talk to us about your aluminium termination challenges.
