?
Thursday, October 27, 2022
Question:
Dear CQD, 480-volt MCC's have side compartments for conductors and the conductors are terminated in each cubicle. Are the compartments considered a wire compartment, gutter, wireway, etc.? Are the compartments subjected to the NEC requirements for conductor fill? Thank you, John Bayduss
A
Answer:
Hi John, great question! Yes, the NEC does provide requirements for conductor installation in MCC gutter space. The scope of NEC Article 430 includes Motor Control Centers. Specifically, Part VIII of Article 430 provides us with guidance on MCC's. Section 430.97(A)-(E) provide the rules for Support and Phase Arrangement, Wire Bending Space, Spacing from Terminals, and Barriers. Section 430.97(C) requires the use of Article 312 to determine wire-bending space, and gutter space in MCCs. Additionally, the MCC manufacturer’s installation instructions will most likely provide guidance on the maximum conductor fill, and wire-bending space.