When are POE and USB ports required to be marked with the output voltage and the output current according to CSA / UL 62368-1 F.3.3.9DV.1? For POE, can we mark "POE" or "POE+" etc. to replace voltage and current?
More specifically you asked: UL 62368-1 F.3.3.9: Output terminals provided for supply of other equipment except mains supply shall be marked with the nominal output voltage and frequency and, in addition, the maximum output current or power, unless the terminals are marked with the type references of the equipment which are permitted to be connected. According to our understanding of the sentence "unless the terminals are marked with the type references of the equipment," for POE we will add "POE" or "POE+" or "POE++" near the POE port. For USB, we will add USB 2.0 symbol or USB 3.0 symbol near the USB port. Can you help check whether the strategy can meet the requirement of UL 62368-1 and NEC (National Electrical Code)?
In response, first let’s clarify – National Difference, F3.3.9DV only is intended to apply to equipment with ‘terminals’ that need to be hard-wired to supply power to other equipment. This marking has been in CSA / UL 62368-1 since its Edition No. 1, and this marking was not intended to apply to USB, PoE and similar standardized ports with standardized connectors. However, now there are other newer requirements in CSA / UL 62368-1 that apply to some of these ports.
More specifically, based on new requirements in Section 725.121 of the 2017 NFPA 70 (NEC), there is a new marking that applies to output ports that supply power (Class 2 or LPS) to other equipment through long lengths of cables (building wiring). Please look closely at 725.121(A)(4) and 725.121(C), which require certain outputs supplying building wire, such as PoE, to have maximum voltage and current markings or labels so cable installers (electricians) can correctly size the cabling, in particular bundled cables, in accordance with new NEC Section 725.144, Transition of Power and Data. CSA / UL 62368-1 Ed 3 now covers this NEC requirement in regulatory annex, Annex DVA (Q), Power Sources for Class 2 circuits. Note, there is an exception to this marking / labeling for power sources providing 0.3 amperes nominal current or less (based on a Tentative Interim Agreement (TIA) that was issued by NFPA after the 2017 NEC was published).
Therefore, for your example (POE output port), it now will need to comply with above National Difference in Annex DVA. However, marking the PoE port as “POE" or "POE+" etc. does not meet the requirement since it does not allow for the equipment to comply with the installation requirements in NEC Article 725, i.e., the cable installer (electrician) and / or Authority Having Jurisdiction (AHJ) will be looking for the maximum voltage and current to be marked or labeled so they can determine compliance of the installed cabling with new Section 725.144. Note, for the 2020 NEC there is some further refinement of the requirements in 725.121, but these requirements have not been published in CSA / UL 62368-1 yet. However, we recommend that you review them in the 2020 NEC.
Please note too, Annex DVA (Q) only applies to output circuits / ports connected to building wiring. Generally, “USB” is intended to be used for relatively short interconnects between equipment, and not for connection to building wiring. Therefore, generally USB ports are not covered by the NEC Article 725.121 and Annex DVA (Q). As a result, for USB the output voltage and output current are not required to be marked as for PoE.