The Orange County Building Official, Christ Sanidas, is having concerns with the 1999 NEC Article 90-7, regarding listing. Someone has told him, supposedly with UL, that if all the electrical components that are installed to make up a piece of equipment are listed, then that equipment would not be required to be listed as a system. I do not know if system is the correct verbage.
I have been enforcing article 90-7, listing, in requiring field evaluations for well over 10 years by an NRTL when any equipment is installed. There are some instances when listing cannot be done, but they are far and few between.
The Building Official, as an alternate method, is looking into possibly accepting a report from the engineer who designed the equipment instead of requiring a field evaluation to be done. In acceptance of an engineer's report, there would be no testing by any third party to verify that the applicable standards and wiring installed were in compliance.
I am asking for some assistance from engineers and other Jurisdictions. Do you feel in accepting an engineer's report is meeting the intent of the code or should a field evaluation by a NRTL be required?. I am asking for your assistance, please respond with your comments by either fax or email.
Send comments to my email at Ed.Fox@co.orange.fl.us or fax 407-836-5545.

Thank You.

Ed Fox,
Orange County Chief Electrical Inspector

[ October 10, 2001: Message edited by: Edward Fox ]

Ed, in general I feel it is a very good idea to request all equipment to be “Listed”. Unfortionly the NEC does not require listing for everything. NEC 110-2 only requires equipment to be “Approved”. Approval is up to the AHJ. There are many references in the NEC when it requires something to be “Listed”. When the code does not require something to be listed then the AHJ is left to “Approve” it. Listing is one way the AHJ can use to approve equipment or they may still not approve it even if it is Listed. Having a real Electrical Engineer certify a piece of equipment is another way. Should an engineer certify a piece of equipment I would ask them to base their evaluation on the NEC and any other recognized standard such as a UL standard.