LEXAN cover for disconnect

Found in spec.: "All disconnects will be guarded with a clear LEXAN cover to previen accidental grounding in accordance with...."

I understand the cover part, but I always thought the covers
were provided to reduce exposure to electric shock.

Anybody have any useful insight to this statement??

I think you could consider an electrical shock as an example of 'accidental grounding'. Other examples might be a dropped screwdriver, metal chips, or mice.