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Thursday, September 15, 2022
Question:
Top of The Morning Charlie, thank you for the daily read and your daily work in educating us further your input is always appreciated. When installing or replacing the screws for a load center cover, if the screws become stripped out in older existing installations when doing service work or have been lost, is it a code violation to install a sheet metal screw or a thread forming screw to get the cover installed? The instructions that I have read (SQ D QO) say to install the cover with the screws provided. Most load centers and covers are entirely painted surfaces but it appears the screws that come with the cover might have some bonding capabilities that a substituted screw might not have. 110.3(B) requires following manufacturer's instructions, 250.4(B)(4) would require bonding of the cover. 250.8(A)(5)&(6) mention the screw thread requirements, 250.12 discusses clean surfaces.
Kindest Regards,
Brian Frion
A
Answer:
Brian, thanks for the question, you are definitely on the right track with your thoughts here. Section 110.2 of the 2017 NEC requires electrical equipment to be approved. The approval of said equipment is the responsibility of the AHJ. The AHJ is given guidance in judging the acceptability of electrical equipment in Sections 110.3(A)-(C). Often the AHJ will base their approval of equipment on the equipment being listed. When a Nationally Recognized Testing Lab lists a manufacturer's product, the installation instructions are part of that listing. The listing of that product essentially becomes contingent on that product being installed in accordance with installation instructions. If the installation instructions require the use of the provided screws for attaching the cover, then those are the screws that must be used to maintain the products listing.