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Monday, January 18, 2021
Question:
Hello Code Question of the Day. I read this every morning. As an inspector, I recently came across an installation of conductors (300 kcmil aluminum) terminated in a 200-ampere, 3-phase disconnect switch. The conductors did not fit in the lug so the installer trimmed the outside strands on each conductor so that they would fit into the terminals of the switch. Is there a specific Code rule that applies to this situation other than Section 110.14? Doesn't seem very professional to me.
Thanks in advance.
Mark Hammer
A
Answer:
Hi Mark,
Good to hear from you again. Thanks for the nice comments. This situation is covered generally in Section 110.14(A) as you indicated, but many AHJs would also cite Section 110.12 for not installing in a neat and workmanlike manner. This is a workmanship issue. Terminating these aluminum conductors in the fashion described also has an impact on conductor ampacity. Section 110.14(A) clearly indicates that "Connection of conductors to terminal parts shall ensure a thoroughly good connection without damaging the conductors and shall be made by means of pressure connectors (including set-screw type), solder lugs, or splices to flexible leads..." There are adaptors or other termination methods that can be used to accomplish the connections without causing damage to the conductors.