Standby Generator Rooms with Diesel Day Tanks
Standby Generator Rooms with Diesel Day Tanks
(OP)
I am currently designing a standby generator room with a 300 gallon day tank. From an IBC standpoint my room will classified as a H-2 Occupancy. What type of NEC Hazardous Space Classification would this room have. Based on the 2011 NEC 500.5(B)(2)(1) it appears that now if combustible liquid-produced vapor are present due to accidently rupture the space needs to be rated Class I, Div. 2. The combustible liquid language was not present in previous version of the NEC. Is anyone aware of anything I can do to avoid rating the space.





RE: Standby Generator Rooms with Diesel Day Tanks
You can avoid area classification if your tank is properly engineered. 2009 IFC Section 603.3.2 requires the tank fill connection to be located on the exterior of the building. The tank's normal and emergency vent are also required to be terminated outdoors. If your tank is specified with integral secondary containment, a rupture of the primary tank would prevent the escape of vapors. Such an abnormal operation is contained within the unit equipment or vented outside the building. I would not apply area classification in such a case.
RE: Standby Generator Rooms with Diesel Day Tanks
RE: Standby Generator Rooms with Diesel Day Tanks
RE: Standby Generator Rooms with Diesel Day Tanks