Note the following requirements when applying for the UL 1310 Class 2 unit for the in-line power adapter:

If CUL is included, The CSA standard CAN/CSA-C22.2 NO.233-M91 section 4.13.1 Open-Circuit Secondary Voltage "The open-circuit secondary voltage. shall not be more than 30Vrms (42.2V peak or DC)"

The spacing requirements, in accordance with Articles 22.1, 22.2, are as follows:

22.1 Spacings between live parts of opposite polarity, between live and dead metal parts, and between live

parts and a metal enclosure, shall be as specified in Table 22.1 or Table 22.2, as appropriate. If a live part is not rigidly secured in position by a means other than friction between surfaces, or if a movable dead metal part is in proximity to an uninsulated live part, the construction shall be such that at least the minimum spacings will be maintained.

Exeption No.1: Spacings between traces on a printed wiring board need not comply with Tables 22.1 and 22.2 if the printed wiring board complies with the abnormal operation test in 38.7.1-38.7.5. See also 20.3. The requirements specified in 20.3 and 38.7.1 -38.7.5 do not substitute for the minimum requied  spacings between the printed wiring board foils and dead metal parts or the spacings between the primary and secondary foils of the printed wiring board as specified in Table 22.1 or 22.2.

Read recommendations:

18W Side plug Switching Power Supply

Adapter 6W charger

5W Single USB charger

PD100W Interchangeable CHARGER wholesaler

Dust - proof and Sealed Power Adapter