It is ok to have the cu (fuseboard) inside a locked cupboard to prevent unauthorised fiddling about.
Do you feel that's compliant with 513.1 - which, as I said previously, includes "Such facility shall not be significantly impaired by mounting equipment in an enclosure or compartment" ?
Are you also going to ignore the requirements to be able to switch off parts, or all, of the installation in an emergency?513.1, another one for the ignore list.
They also have the right not to suffer loss and injury whilst waiting for the landlord or his representative to respond to a request to come and unlock the cupboard so that they can turn off the circuit which has a smouldering cable in it.Switchgear in all sorts of premises is installed inside locked cupboards/switchrooms to prevent unauthorised access. One main reason being the tenants have no right of access to the landlords equipment.
Unauthorised fiddling is one thing - preventing people from responding to an emergency is quite another.