Service separation and fire walls

[JGenette7132]

I have one existing structure 240.000sq ft and a 3hour firewall creating 2 buildings with separate addresses on one property.
bldg. one has a 1600 amp 120/240 volt three phase overhead service, Building two has two separate services a 1200 amp 120/240 volt
three phase and a 277/480 volt three phase service. The empty bldg. was being renovated, during which time a correctly listed fire
rated overhead door and a listed man door were installed in the fire wall. I felt the rating on the wall was compromised and that it
was now one building with 3 services and had to be reviewed by a DTE service planner (who had no problem with the services, but I could
make them install one service if I wanted per 2023 NEC 230-2). Another suggestion I got was to install signage on doors saying " Doors
must be closed when occupied. Is this still 2 separate buildings or one building

 

[rc/retired]

I have one existing structure 240.000sq ft and a 3hour firewall creating 2 buildings with separate addresses on one property.
bldg. one has a 1600 amp 120/240 volt three phase overhead service, Building two has two separate services a 1200 amp 120/240 volt
three phase and a 277/480 volt three phase service. The empty bldg. was being renovated, during which time a correctly listed fire
rated overhead door and a listed man door were installed in the fire wall. I felt the rating on the wall was compromised and that it
was now one building with 3 services and had to be reviewed by a DTE service planner (who had no problem with the services, but I could
make them install one service if I wanted per 2023 NEC 230-2). Another suggestion I got was to install signage on doors saying " Doors
must be closed when occupied. Is this still 2 separate buildings or one building

This is more of a building code question. However, (there's always a however in life), I believe if you had the properly rated doors, it would still be considered 2 buildings.
I wouldn't install the sign as I think the doors should close in the event of a fire.
That's how it was on a large student housing building I inspected a few years ago. Good luck.

Ron

 

[augie47]

There are a number of methods that address the fire doors closing in the event of a fire.
Some mechanical and some connected to alarms systems if they are installed.
The local building officials should be able to tell you what is needed top maintain the separate building status.