Are there any specific regulations or documents that prohibit operator stations in electrical rooms? Our plant is 30+ years old and has several
operator stations in electrical rooms. This seems to have been common design practice years ago.

Can you post a picture? I am not sure what type of OP station you may speak of. Do you know the highest IE in your room? What is the distance from that IE to the Operator working area?

Your question IMO needs more data. But basically, I would say this is not allowed without proper PPE based on the highest fault potential of the room.

More then likely, the 30 year old system will have a high IE with a large clearing time >2sec. Does an operator actually work in this area?

As far as documentation the NFPA 70E would be your material of choice. However, you may not get a specific answer you may be looking for without some understanding of the fault that may occur.

Also, the electrical room is open to interruption. Do you mean switchgear that is commonly racked in and out for maintenance? Motor control centers, and electrical drives in a room could be an electrical room. A PLC panel and controls in a controlled environment room could be an electrical room.

Sorry, I am sure everyone would need specifics to help answer your question. We see's so many different configurations.
Thanks
MB

Not we see's but we see----

It’s not a good practice to place the op stations in the MCC room, but you’re correct; It was common in the past. More a case of putting the MCC room in the operator control room though.

If the equipment is maintained and the doors are kept latched with no openings in the gear, you can allow the operators to stay in the room with the gear so long as maintenance isn’t taking place. When the maintenance guys show up and start opening doors or performing switching operations, then the calculated boundaries (or from the table) are in force and the operators must respect those distances, oftentimes leaving the room. The best solution is to separate the two areas but that takes time and money. You’ll need to train the operators on the electrical hazards of the equipment and document that since they are working in close proximity.