Q: Please clarify if electrical closets and /or electrical rooms can be accessible to anyone. The NFPA70 National Electrical Code seems to require warning signs limiting access to authorized personnel only.
A: For many years there has not been any specific standard that says access to electrical control panels has to be restricted to authorized individuals only. But with the new NFPA 99-2012, section 126.96.36.199.1.3 now says access to over-current protective devices (i.e. circuit breakers) serving Category 1 or Category 2 rooms is restricted to authorized individuals only. This standard actually only applies to new construction.
But be aware that for many years accreditation organization have cited healthcare facilities for not securing their circuit breaker panels from unauthorized access, and they base this on their “Safe Environment” standard, or as some people call it the ‘General Duty’ clause.
So, it has been enforced for years by accreditation organizations, and by some state agencies, while there has not been an actual standard that required securing the panels. So, I would suggest you do secure all electrical rooms from unauthorized access.