Does pluggable type B equipment with an Ethernet port need to be provided with a permanently connected protective earthing conductor to comply with the requirements in Clause 5.6.7?
More specifically you asked: In clause 5.6.7, whether pluggable equipment type B is considered to have reliable earthing seems to depend on if it connects to external circuits ID 1 to 5. Would pluggable type B equipment with an Ethernet port need to have provision for a permanently connected protective earthing conductor to comply ? Is it of any significance if (1) the Ethernet connector shield is or is not connected to earth in the equipment?; (2) the equipment does or does not have varistors connected directly between mains and earth?; the Ethernet, or other external circuits ID 1 to 5, do or don't extend outside the building?
The intention of sub-clause 5.6.7 is that it only is to be considered when other sub-clauses in 62368-1 require reliable earthing and reference 5.6.7 for requirements. Sub-clause 5.6.7 does not establish when reliable earthing is required since that determination is made by other sub-clauses which reference 5.6.7. Therefore whether AV/ICT with an Ethernet port requires reliable earthing is not based on sub-clause 5.6.7, but by other sub-clauses.
If another sub-clause requires reliable earthing and references 5.6.7, and the subject equipment is Pluggable Type B (or A) with circuits considered Table 13, ID numbers 1, 2, 3, 4 or 5, then 5.6.7 requires a permanently connected Protective Earthing Conductor (separate from the earthing associated with the plug), with instructions for the installation of that separate conductor to the building earth by a Skilled Person. However, please also note that most Ethernet ports with paired conductor cabling are not considered IDs 1 or 2 (per Table 13) subjected to transients if the cable is not intended (by installation instructions or similar) to be routed outside the building. (See first condition of Table 13.)
Please refer to a previous Q&A for more detail on this subject - https://62368-ul-solutions.com/engineers/how-do-the-requirements-in-clause-5.4.11,-which-requires-external-circuits-to-be-separated-from-earth-in-normal-pluggable-equipment-type-a,-apply-to-the-shield-of-an-external-cable/.
As the complete answer to this topic can be complex, and the submitter appears to have a specific, detailed construction that needs review/analysis, we encourage the submitter to contact UL for an in-depth consultation, either via your local account executive or via https://62368-ul-solutions.com/contact-ul.html.