Checking whether the small power distribution unit (SPDU) device is qualified needs to be operated in accordance with relevant national regulations and standards. Here are some possible steps:

Check the marking on the small power distribution unit (SPDU) unit to make sure it complies with national standards and is clearly visible. The marking shall include information such as the rated voltage, rated current and rated short-circuit breaking capacity of the device.

Check the exterior of the electrical box to make sure it is intact and there are no obvious electrical leakage or fire risks.

Check the wiring inside the small power distribution unit (SPDU) device to ensure that the wiring is firm, the cable insulation is good, the standard wiring meets the requirements, and there is no leakage.

Use specific testing instruments, such as voltmeters, ammeters, grounding resistance testers, etc., to conduct necessary electrical tests on the small power distribution unit (SPDU) to ensure that it meets national standards and safety requirements.

Make necessary records and inspections of small power distribution unit (SPDU)es, such as inspection sheets, record sheets, test results, etc.

If you do not have professional electrician knowledge and skills, it is recommended to find a qualified electrician for inspection and maintenance. This can ensure that your small power distribution unit (SPDU) is safe and reliable, and avoid electrical accidents.