Does UF-B cable have to be in conduit?

At 24-in. -deep, run direct-bury UF-B wire cable. There’s one restriction: It needs a conduit where the cable is exposed on the outside of the house and to 18 inches below the ground.

What type of wire is UF-B?

Copper UF-B wire is typically used as an underground feeder cable to distribute power from an existing building to outdoor lighting fixtures, pumps, outbuildings and other outdoor equipment. The cable can also be used as direct burial cable.

What does UF-B mean on wire?

Underground Feeder and Branch-Circuit Cable

​Type UF-B (Underground Feeder and Branch-Circuit Cable) is generally used in underground, direct burial installations as branch circuits and/or feeders to outside floodlights, sewer pumps and motors, electric gates and other loads typically supplied from a distribution system.

Can UF cable be used for service conductors?

This type of cable cannot be used for service entrances, in commercial garages, in theaters, in storage battery rooms, in motion picture studios, in hazardous locations, in hoistways, in poured cement except as permitted in 424.43, where exposed to direct rays of sun unless approved for sunlight installation, where

Can you bury UF wire without conduit?

UF cable can be direct buried (without conduit) with a minimum of 24 inches of cover. Wiring buried inside rigid metal (RMC) or intermediate metal (IMC) conduit must have at least 6 inches of ground cover; wiring in PVC conduit must have at least 18 inches of cover.

Can I direct bury UF-B wire?

UF-B may be directly buried or installed where exposed to sunlight. When used as an NM cable it must comply with the requirements in NEC 2008 and NEC 2011 Article 334.

Are Thhn and THWN the same?

THHN stands for Thermoplastic High Heat-resistant Nylon-coated. THWN wire is the same, but the “W” stands for water-resistant. The main difference between these two standards is their maximum temperature in wet locations.

What is the difference between UF and UF-B Wire?

The regular UF cable is well-suited only to be buried in conduit. The difference between them is UF-B construction indicates a better resistance to water and corrosion, as well as a superior temperature range.

What is the difference between UF-B and Romex?

UF (or Underground Feed) cable is necessary any time you’re laying cable underground. The wires in UF are individually insulated. They’re then wrapped together in more insulation for further protection from weather and sunlight. On the other hand, Romex® is wire coated in plastic and is only suitable for indoor use.

What is UF conductor?

The conductors of Type UF shall be one of the moisture-resistant types listed in Table 310.4(A) that is suitable for branch-circuit wiring or one that is identified for such use. Where installed as a substitute wiring method for NM cable, the conductor insulation shall be rated 90°C (194°F).

What is the difference between UF B and NM b wire?

Outdoors- Critical Difference. The most crucial difference between UF and NM-B is that the latter is prohibited for outdoor use. Though UF and NM-B have many things in common, NM-B wire can quickly rot if mistakenly used outside because it does not have the extra-protection of UF-B.

What is THWN copper wire?

What is THWN Cable. THWN is a code for thermoplastic heat and water resistant which is suitable for use in both dry and wet locations with a maximum temperature rating of 75ºC (167ºF).

How deep should UF cable be buried?

Underground feeder cables, labeled UF, can be buried without additional protection from conduits because they have a tough jacket designed for burial. Bury UF cables 24 inches below the soil surface, and 18 inches deep when protected by 2 inches of concrete.

Can UF B cable be exposed?

The use of UF cable on the exterior surface of buildings or structures is permitted by Sec. 225.10(18) and Sec. 334.10(3) of the NEC. If the cable is exposed to physical damage it must be protected in accordance with Sec.

Can UF cable be encased in concrete?

Installing Buried UF Electrical Cable
Underground Feeder, UF cable, cannot be run inside concrete.

What is the difference between NM and UF wire?

The primary difference between standard NM and underground feeder (UF) cable is in the cable construction. Standard NM cable contains wires that are wrapped with paper and a relatively loose plastic sheath. UF cable has wires that are completely encased in solid plastic.

What kind of electrical wire can be buried underground?

Common types of cables with a copper conductor suitable for direct burial are USE-2, UF-B Underground Feeder Cable, and Tracer Wire. Aluminum URD Direct Burial Wire is the most commonly used direct burial aluminum wire.

What does type NM B mean?


NMB stands for non-metallic because it has a PVC jacket instead of a metal-clad jacket. It is a basic indoor electrical wire used to deliver power from an electrical box to lights, outlets and appliances. It cannot be used outdoors because the jacket is not prepared to handle wear and tear.

Can I use UF B instead of NM-B?

UF electrical wire is perfectly suitable for most NM-B applications, though it is unnecessary to use it because it is too expensive for indoor applications. When used as NM, UF-B has to comply with the standards found in NEC 2008 and NEC 2011 Article 334.

What is the difference between Thhn and NM-B?

Whereas THHN is a cable with a single thermoplastic high heat-resistant nylon wire, NM-B wire is a sheathed cable with multiple conductors. The conductors inside the NM-B wire are either insulated or uninsulated, and the former is actually THHN, which commonly leads to confusion between the two types of cables.

Does nm-B need to be in conduit?

In fact. NEC calls for it to be in conduit, when protection from physical damage is required.

Can you bury nm B in conduit?

Show activity on this post. You cannot use nonmetallic sheathed cable (Type NM, NMS) in conduit in any damp, or wet location (NEC 2011 300.5(B), 300.9, 334.12(B)(4)). Instead, you’ll want to use individual conductors rated for wet/damp locations.

Can UF B cable be exposed?

The use of UF cable on the exterior surface of buildings or structures is permitted by Sec. 225.10(18) and Sec. 334.10(3) of the NEC. If the cable is exposed to physical damage it must be protected in accordance with Sec.