Most of the rules involve protection of the wiring from damage.
Gfci protected underground feeder cable.
At 18 inches you can use thwn 2 conductors inside a continuous length of pvc conduit which protects the wire all the way through the trench to the house.
Article 240 overcurrent protection.
Permitted for use underground including direct burial in earth as feeder or branch circuit cable where provided with overcurrent protection.
As with installing indoor wiring there are some rules to follow.
Type uf underground feeder cable permitted to be used to supply service entrances.
Bury uf cables 24 inches below the soil surface and 18 inches deep when protected by 2 inches of concrete.
Initially it was only required for temporary wiring at construction sites and in dwelling unit bathrooms but in recent years.
Article 300 wiring methods.
Use a direct burial cable placed in the soil without conduit.
Both methods have to be gfci ground fault circuit interrupter protected before the wires enter the ground to guard against electrocution in case.
Q i have a 400 ampere service supplied by a three phase four wire delta system.
Article 250 grounding.
Underground feeder cables labeled uf can be buried without additional protection from conduits because they have a tough jacket designed for burial.
Three phase four wire delta service.
Gfci protected circuit to an outdoor pole light run under a paved driveway is.
On in ground pools there must be at least one gfci protected convenience outlet located between 6 feet and 20 feet from the edge of the pool.
Lighting track in residential installations shall not be cut to length in the field unless permitted by the.
Deep direct burial of type uf underground feeder cable is another easy alternative.
Outlet receptacles for general use can be no closer than 20 feet from a pool or in ground spa if they are not gfci protected and no closer than 6 feet away if they are gfci protected.
Since 1971 the nec has expanded the requirements for ground fault circuit interrupters gfci to protect anyone who plugs into an electrical system.
Article 408 switchboards and panelboards.
Underground wire for a residential circuit usually is installed with underground feeder uf cable which is rated for outdoor use and direct burial such an installation is typical when running a circuit to an outdoor location such as a garage shed or other outbuilding or to a yard light or water feature.
Underground feeder uf b solid or stranded type thhn thwn conductors are laid parallel with an uninsulated grounding conductor with overall outer pvc jacket.
We recommend the pvc conduit because it offers more protection against physical damage.
In an effort to safeguard even more electrical installations the nec has expanded requirements for gfci type receptacles.
Article 310 conductors for general wiring.
