This is new construction and we have a 13.8kv utility feed being tapped ahead of the main Med. Vltg. SWGR. the tap 4"C. goes to a FSS then from the FSS 4"C. to an XFMR 13.8kv to 480V then MI type cable to an ATS. This is the normal source side of the ATS. The dwgs. call for the feed from the FSS to XFMR to be encased in the slab, but this is not feasible because the slab is only 12" thick and is not enough for the radius of a 4" 90 to stub up under the XFMR. I have the same issue with the secondary/emergency source. It is also called out to be in the slab and is a 4"C.
1. Since I cant embed the the 4"C. on the load side of the FSS what type of 15kv cable in conduit can be used to achieve the 2hr. rating required by theNEC 695.6 B. I didn't see a UL 2196 listing in the specs for type MV-105 15kv. cable. Also I plan to use type RHH wire in conduit for the 480V side instead of the MI cable. Any help would be greatly appreciated.
1. Since I cant embed the the 4"C. on the load side of the FSS what type of 15kv cable in conduit can be used to achieve the 2hr. rating required by theNEC 695.6 B. I didn't see a UL 2196 listing in the specs for type MV-105 15kv. cable. Also I plan to use type RHH wire in conduit for the 480V side instead of the MI cable. Any help would be greatly appreciated.