Customer has Primary power run from utility pole, under street (where it becomes customer responsibility) around side of building (aprox 700') where it enters outside switch. Cabling us direct burial CN wire. We need to replace said cabling. Thing is years ago owner added on to the building (25'x25') over top of the laterals. We cannot go around building with new cabling because of property boundary issues. Proposing to go under building with new laterals. I cannot find where NEC mentions any restrictions of this. Thought I would check here.
Have trench run from street (customer side) to where we need to go under building. Lined up directional drill co to go under building. Dug down today to locate footer. Footer down 48" from 8" concrete floor. Dug three ft below top of footer and still did not find bottom. Other side of building to HV switch is only 30 ft. Directional drill starts at 20 deg angle than levels off at desired depth. Coming out other side of building at 7' or more does not give us the distance directional drill needs to get back up to switch. Also any trench below 4' needs to be shored to prevent cave in. We went to plan B and will be trenching across floor of building inside than coring holes at either end for 4" sch 40. Conductors are JCN Jacketed Concentric Neutral) #2.
We also have a Photo Upload website for larger photos at https://www.electrical-photos.com/ where you can upload electrical related photos into your own personal album and use the links to post pictures in this forum as well as others.