5 (A) provides minimum cover requirements for direct-buried cables, conduits, or other raceways installed underground. There are 5 columns in Table 300. 5 (A); each of which specifies different burial depths that apply to the specific wiring methods named at the top of. NEC Table 300. 5 (A) for underground installations. Where the cable emerges, connects, or is suspended, specialized hardware ensures security and longevity. Termination & Suspension: Use Preformed Dead Ends. Fiber optic cables are typically buried between 12 and 36 inches (30–90 cm), depending on installation environment, soil conditions, and load requirements. However, simply hitting this depth isn't enough to guarantee your network survives.