Electrical Equipment Modification

[bflaaen]

I am working on a project where we are adding some lugs to the load side of the main breaker of an existing MCC to subfeed a new MCC adjacent to it. A situation has come up where it is being claimed that the NEC requires manufacturer approval before this modification can occur.

Is this true?

Can anyone tell me the location in the NEC which calls this out?

Thanks.

 

[haskindm]

If you modify equipment "in the field" then it is no longer in the condition that was existing when the equipment was listed with whatever testing agency (if any) listed it, therfore that listing is no longer valid. Usually it is the responsibility of the AHJ (Authority Having Jurisdiction) to approve equipment. They will usually base their approval on the listing of the equipment. Now that you have negated the listing by modifying the equipment the AHJ will need to determine if they will still approve the equipment as installed. Some will and some won't, it depends on the person and the extent of the modification. By modifying the equipment, you have probably eliminated any warranty on that equipment unless the manufacturer approves the modification. Field modification may be done, but it opens up another level in the approval process and exposes the installer to increased liability.

 

[George Stolz]

A situation has come up where it is being claimed that the NEC requires manufacturer approval before this modification can occur.

Is this true?

No, the NEC is just a book. It can't approve anything.

Can anyone tell me the location in the NEC which calls this out?

90.4 Enforcement. This Code is intended to be suitable for mandatory application by governmental bodies that exercise legal jurisdiction over electrical installations, including signaling and communications systems, and for use by insurance inspectors. The authority having jurisdiction for enforcement of the Code has the responsibility for making interpretations of the rules, for deciding on the approval of equipment and materials, and for granting the special permission contemplated in a number of the rules.
By special permission, the authority having jurisdiction may waive specific requirements in this Code or permit alternative methods where it is assured that equivalent objectives can be achieved by establishing and maintaining
effective safety.
This Code may require new products, constructions, or materials that may not yet be available at the time the Code is adopted. In such event, the authority having jurisdiction may permit the use of the products, constructions, or materials that comply with the most recent previous edition of this Code adopted by the jurisdiction.

 

[celtic]

Let's not forget:

110.3(B)
Installation and Use
Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

 

[dcl34769]

if the lugs are listed for use with the breaker then there should be no problem with swapping out the lugs.