All live parts are required to be covered
Answered by Sarah, Electrical Safety Expert
All live parts are required to be covered.
The requirements are: IP4X/IPXXD (1mm) for the top surface and IP2X/IPXXB (which is access with a finger) for the rest of the enclosure.
However, if you just mean the cover over the trip switches, there is no requirement for a cover as long as the enclosure without the cover meets the above requirements.