Maintenance of LV components inside HV cabinet

Good Morning All,

I am from the Safety Office and our organization prohibits working on electrical components/systems above 600V. I have a situation that I need advice on. Here is the background:

There is a group of Electronics Technicians/Engineers who believes they are responsible of an electrical system just because it resides in their occupied building. Inside this building is an 15kV CB which disconnects a transformer bank 11.5kV:570V, 540V and an 8.32kV harmonic filter (in a cabinet) from the substation (11.5kV). In this cabinet, there are LV fans and pressure sensors that they guys want to maintain and do housekeeping such as dusting. The management is fully supportive of getting contractors to do this work for them but they are very much adamant that they can do this work since they will be in an electrically safe condition utilizing LOTO (their LOTO procedure was not approved).

Our office has told them they cannot access this cabinet and the lead engineer is very persistent and insisting that they are only working on the LV side inside the HV cabinet. ANY THOUGHTS? READ MORE.