Terminals must ensure good connections without damaging the conductors. Terminals and splicing devices suitable for both copper and aluminum must be marked as CU/AL or CO/ALR. All aluminum conductors require wire-brushing immediately prior to assembly.Ĭopper and aluminum conductors must not make contact with each other in a terminal or splicing device not specifically listed and identified for the purpose. Split-bolt lugs listed for aluminum-to-aluminum come with detailed instructions that vary among lug designs. Terminals listed for aluminum typically have an antioxidant to reduce aluminum oxide, which reduces the conductor/terminal contact resistance. Terminals and splicing devices suitable only for aluminum must be marked AL.

In 404.14(C) and 406.2(C), the Code requires you to use terminals and splicing devices identified for use with the conductor material. If it states “Suitable for 18-2 AWG,” you can use either solid or stranded conductors with the terminating device. If it states “Suitable for 18-2 AWG Solid,” you can use only solid conductors with it. For example, if the labeling on a terminal device states “Suitable for 18-2 AWG Stranded,” you can use only stranded conductors with that device. The Code requires you to follow manufacturer's instructions when installing electrical equipment (110.3), and this applies to terminal devices. They may seem like just the finishing touches, but splices and terminations are critical components of any electrical system.

Wire splice connector without solder