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Tuesday, June 7, 2016
Question:
How much copper can I have showing on a 600mcm conductor before it enters a lug on a breaker?
Doug Henderson
A
Answer:
Hey Doug thanks for your question. Splices, joints and the free ends of conductors must be covered with an insulation equivalent to that of the conductors or with an identified insulating device as stated in 110.14(A)(B). A specific dimension for how much of the conductor can be uninsulated at terminations is not provided. Many manufacturers provide instructions and strip length gages for how much insulation to strip from the end of an insulated conductor.
NECA 1 - 2015 Standard for Good Workmanship in Electrical Construction in 9.o states that "Terminations of insulated conductors shall be made so that the stripped length of bare conductor is not longer than required for the equipment terminal, lug or connector. The conductor insulation shall bear against the terminal or connector shoulder but not extend into the terminator point." This standard, and many others, can be purchased by calling (301) 215-4505 or in pdf format at http://www.neca-neis.org/the-standards/general