Multiple services

[SOwings]

Section 230.2 allows only one service to a building or structure, with several exceptions. I am being asked to allow a second service on a building/structure that is about 10000 sq ft and currently has a 600 service for 6 units. They are in the process of turning one of the units into a restaurant with a 300 amp service which will overload the 600 amp main with thew other 5 units. They want me to allow a second service at the building and their justification is that the restaurant will have a fire wall on each side (1 hour, restaurant is small enough to classify as business occupancy (reading the definition form the NEC for building). I am fighting this but getting told other local jurisdictions allow it (one is a city over 500k people). I need some input.
Thanks!

 

[Dennis Alwon]

Myunderstanding is that if there is a firewall then the structure is considered separate from the original building even though it is physically attached. I also think the exception would apply

 

[david luchini]

A 1 hour rated wall on each side of the restaurant wouldn't constitute a "fire wall." A fire wall would need a 3 hour rating (or possibly 2 hour based on construction type.) It would also need sufficient structural stability to allow collapse in fire conditions, of construction on either side of the fire wall without collapse of the fire wall. I'd say you don't have "separate" structures.

Of course, you could allow a second service per 230.2(C)(3) "By special permission."

 

[kwired]

230.2(B)(1) kind of leaves this to the AHJ discretion, for cases like what you have, and is done frequently for multiple occupancy buildings.

Around here a 2 hr fire wall is considered separation to qualify as a separate building - even if the two separate areas are the same owner/occupant. No circuits are to be supplied via the other "building" though.

Often the fire/building codes will want at least 1 hour and sometimes even 2 hour separation between each occupancy. One more layer of 5/8 rock on each side of wall will give you 2 hr rating but it needs to extend into attics/crawlspaces.