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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.
What is nm-B wiring?
NM-B is a non-metallic electrical wire used in residential building wiring for various devices and outlets. It is suitable for direct burial without an electrical conduit because of the durable rubber sheathing that protects it from damage during installation and maintenance.
What does B mean in NM?
12-3 w/G: Cable contains three insulated wires plus a ground wire; the wires are 12-gauge. 600 V: Cable is rated for a maximum of 600 volts; this is standard for residential NM cable. TYPE NM-B: Non-metallic type-B cable; this is the current standard for residential installations.
What is Romex type NM-B?
NM-B cable is primarily used in residential wiring as branch circuits for outlets, switches, and other loads. NM-B cable may be run in air voids of masonry block or tile walls where such walls are not wet or damp locations. Voltage rating for NM-B cable is 600 volts.
Can you use nm-b outside?
Under the 2008 code, you must use UF cable anytime NM-style cable (even in conduit) exits the side of the house. That is, you are no longer allowed to put NM-B cable in watertight conduit outside of the house in wet locations.
What is the B in NMB wire?
Indoor NMB cable or Romex® 12/2 cable 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.
What is the difference between NM and NM-b wire?
Type NM is identified by the size of the conductors and number of them. For example, the very commonly used Type NM 12-2 cable contains two 12 American Wire Gauge (AWG) insulated conductors. When the letter B is appended, as in NM-B cable, it indicates that the conductor insulation is rated for 90 degrees C.
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.
Can type NM-B Romex be exposed to corrosive vapors?
Section 334.12(B) does not allow type NM cable to be installed in wet locations or where exposed to corrosives such as chlorine but without the revised code language, sections 334.10 and 334.12(B) were in conflict with one another.
What’s Romex?
Romex is the trade name for a type of electrical conductor with non-metallic sheathing that is commonly used as residential branch wiring. Romex™ is a common type of residential wiring that is categorized by the National Electrical Code (NEC) as underground feeder (UF) or non-metallic sheathed cable (NM and NMC).
What is UF B wire used for?
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 nm B be exposed?
It could be installed exposed in a residential garage or in an attic or basement. In most cases, the NM cable must closely follow the building surface or another means of support for the cable must be provided.
Can you run NMB wire in conduit?
7 Answers. Yes, NM cable can be in conduit. In fact. NEC calls for it to be in conduit, when protection from physical damage is required.
Can you direct bury Romex?
Romex cannot be used in the situation you describe as buried conduit is considered a wet location. You must use conductors such as THWN. That being said, run yourself a 1″ PVC at 18″ depth and pull all your current and future need conductors in one shot.
Can I use Romex wire outside?
Romex© Outdoor Conduit. Romex is a type of electrical wire used in various applications. Romex wires cannot be used outdoors because, if it gets wet with water, gas, oil or another solvent, these liquids could penetrate the jacket and ruin the connection by getting in contact with the bare copper ground wire.
What happens if Romex gets wet?
In most homes, ROMEX® wire is used for electricity, where the copper ground wire is wrapped in paper and then, in turn, wrapped in the live and neutral wires. If this wiring is exposed either through a break in the plastic coating or even at the socket, the moisture can be soaked up by the paper, creating rust.
Can Type UF-B wire be used indoors?
Types of Direct Burial Cables Type UF cable is usually gray and comes in rolls that look like standard non-metallic (NM) sheathed cable. While standard NM cable is rated only for dry, interior applications, UF cable can be used outdoors as well as indoors.
Can UF-B wire be buried?
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.
