Peter Ramm wrote:

(There will also be "gaps" adjacent to cable at entry point - ie
unlike cable in a closed/blind grommet - where it would be possible -
if unlikely - to "poke" in to the unit)

To satisfy the requirements for protection against direct contact, any
enclosure containing live parts - which obviously includes a CU - must
meet IP2x. This means that you must leave no openings through which a
12.5 mm dia. sphere could pass. [Reg. 412-03-01]

In addition any opening in the top surface of an enclosure, if readily
accessible, should meet IP4x. This means having no openings which could
pass a 1 mm dia. sphere and effectively forbids taking open T&E cables
in through grommets in the top of the unit, if the top is readily
accessible. [412-03-02]

--
Andy