Nec Underground Cover: general to airport_runway
NEC (NFPA 70) Table 300.5 — minimum burial cover depths for underground wiring installations by location type and wiring method (direct burial cable, rigid metal conduit/IMC, nonmetallic raceway, residential GFCI branch circuit, irrigation at 30 V or less)
| location id | col1 direct burial mm (mm) | col2 rmc imc mm (mm) | col3 nonmetallic raceway mm (mm) | col4 residential gfci mm (mm) | col5 irrigation 30v mm (mm) | location description | nec section | standard |
|---|---|---|---|---|---|---|---|---|
| general | 600 | 150 | 450 | 300 | 150 | All locations not specified below | 300.5 | NEC (NFPA 70) 2017 Table 300.5 |
| below_2in_concrete | 450 | 150 | 300 | 150 | 150 | In trench below 50 mm (2 in.) thick concrete or equivalent | 300.5 | NEC (NFPA 70) 2017 Table 300.5 |
| under_4in_exterior_concrete_slab | 450 | 100 | 100 | 150 | 150 | Under minimum 102 mm (4 in.) thick concrete exterior slab, no vehicular traffic, slab extends 152 mm beyond installation | 300.5 | NEC (NFPA 70) 2017 Table 300.5 |
| under_building | 0 | 0 | 0 | 0 | 0 | Under a building (in raceway or Type MC/MI cable) | 300.5 | NEC (NFPA 70) 2017 Table 300.5 |
| airport_runway | 450 | 450 | 450 | 450 | 450 | In or under airport runways, including adjacent areas where trespassing prohibited | 300.5 | NEC (NFPA 70) 2017 Table 300.5 |
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