National Electrical Installation Standards

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Revision of NECA 121-201X, Standard for Installing Nonmetallic-Sheathed Cable (Type NM-B)and Underground and Branch Circuit Cable (TypeUF)

Revision of NECA 303-201X, Standard for Installing and Maintaining Closed-Circuit Television (CCTV) Systems


Revision of NECA 413-201X, Standard for Installing and Maintaining Electric Vehicle Supply Equipment (EVSE)



All NEIS Currently Available for Public Review

Featured Standards


NECA 416-2016 Recommended Practice for Installing Energy Storage Systems

This standard describes methods and procedures used for installing multiple types energy storage systems. It also includes information about controlling and managing energy storage systems, in addition to commissioning and maintaining energy storage systems.
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NECA/FOA 301-2016 Standard for Installing and Testing Fiber Optics

This standard describes installation and test procedures for fiber optic cabling networks. This standard applies fiber optic cabling installed indoors (premises installations) and outside plant (OSP) applications.
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State Regulationsusa country shape

Find the major provisions of electrical code, enforcement, and contractor/electrician licensing requirements for each state in the U.S.

US Electrical Codes & Regulations by State »
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NEC Adoption by State

Building Codes Assistance Project Energy Code Adoption

Code Question of the Daytextbook

  • Friday, January 19, 2018
    CQD: 1/19/2018

    Hi Charlie,

    We have a customer who is feeding an 800 Amp 208/120 V panel with two 400 Amp fused disconnects. The switches are in the same panel, but separate buckets and each is feeding a set of 500 kcmil. This appears to be a violation of 240.8 because the fused disconnect switches are not factory assembled in parallel and listed as a unit. My question is, was this ever legal under an older code? Thanks for your time and for this service you provide.

    Regards, Edward M. Barr, P.E.

  • Thursday, January 18, 2018
    CQD: 1/18/2018
    View Question and Answer

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