110.14 Electrical connections
Termination devices must be identified and used for the conductor material. Copper and aluminum are not automatically interchangeable at terminals. Conductors also cannot be mixed where dissimilar metals could cause problems unless the device is identified for that use.
110.14(A) Terminals
Connections must be mechanically secure and electrically reliable without damaging the conductor. Terminals used for more than one conductor must be identified for that purpose. One lug does not automatically mean two conductors are allowed.
110.14(B) Splices
Splices must use devices or methods identified for the conductor material and application. They must be mechanically and electrically secure and properly insulated.
110.14(C) Temperature limitations
Conductor ampacity must be coordinated with the temperature rating of the equipment, terminals, and conductors. A conductor may have 90°C insulation, but that does not automatically mean you can size it using the 90°C ampacity column. For many terminations, ampacity is governed by the 60°C or 75°C terminal rating. The lowest applicable temperature rating controls.
110.14(D) Terminal connection torque
Terminals must be tightened to the torque value indicated by the manufacturer or installation instructions. Too loose can cause overheating. Too tight can damage the terminal or conductor.
Field tip
When reviewing equipment connections, verify: conductor material? Terminal rating? Number of conductors permitted? Temperature rating? Required torque? Hub: 110.14 hub. Next: 110.15–110.16.
Code basis
NEC 2026 Article 110.14 education from the owner-provided Daily Code Talk. Confirm adopted edition and equipment markings. Not a conductor-sizing calculation. Working-space dimensions from 110.26 are not published here.