Romex Cable / Wire
Cable / Wire
Plug / Connector
Locking / corrosion
Pin / Sleeve
Ray's Electric, a division of EduSoftMax (www.edusoftmax.com), is located in Toronto Canada. The goal of toronto electric distributor is to provide our customers with high quality and lower price electrical Romex wire and cable which include toronto romex cable, buy cheap romex wire in toronto, 10/2-nmd90, 10/2-nmwu-75, 14/3-nmwu-75, 14/2-nmwu-75, 12/2-nmwu-75, 12/3-nmwu-75, 14/2 nmd90-75, 14/3 nmd90, 12/2-nmd90 75, 12/3-nmd90 75, 10/3-nmd90-75, 8/3 nmd90-75, 14-1t90-black-1, 14-1t90-white-2, 14-1t90-red-3, 14-1t90-blue-2, 14-1t90-green-8, 14-19t90-black-1, 14-19t90-white-2, 14-19t90-red-3, 14-19t90-blue-2, 14-19t90-green-8, 10-7-rw90-4, 10-7-rw90-1, 10-7-rw90-2, 10-7-rw90-8, 10-7-rw90-3, 16-26-tew-1, 16-26-tew-2, 16-26-tew-3, 16-26-tew-8, 16-26-tew-4, 8t90-1, 8t90-2, 8t90-8, 8tw75-1, 8tw75-4, 2/0-tw75-2, 3/0-rw90-2, 3-rw90-1, 3rw90-2, 3/0-t90, 3/0 rw90-wh, 1/0 t90, 3/0 rw90, 3/0 to90-2, 3 t90-2, and more.
Romex is a brand name for a type of plastic insulated wire. Sometimes called non-metallic sheath. The formal name is NM. This is suitable for use in dry, protected areas (ie: inside stud walls, on the sides of joists etc.), that are not subject to mechanical damage or excessive heat. Most newer homes are wired almost exclusively with NM wire. There are several different categories of NM cable.
BX cable -- technically known as armored cable or "AC" has a flexible aluminum or steel sheath over the conductors and is fairly resistant to damage.
TECK cable is AC with an additional external thermoplastic sheath.
Protection for cable in concealed locations: where NM or AC cable is run through studs, joists or similar wooden members, the outer surface of the cable must be kept at least 32mm/1.25" (CEC & NEC) from the edges of the wooden members, or the cable should be protected from mechanical injury. This latter protection can take the form of metal plates (such as spare outlet box ends) or conduit.
[Note: inspector-permitted practice in Canada suggests that armored cable, or flexible conduit can be used as the mechanical protection, but this is technically illegal.]
Additional protection recommendations: [These are rules in the Canadian codes. The 1993 NEC has many changes that bring it close to these rules. These are reasonable answers to the vague "exposed to mechanical damage" in both the NEC and CEC.]
- NM cable should be protected against mechanical damage where it passes through floors or on the surface of walls in exposed locations under 5 feet from the floor. Ie: use AC instead, flexible conduit, wooden guards etc.
- Where cable is suspended, as in, connections to furnaces or water heaters, the wire should be protected. Canadian practice is usually to install a junction or outlet box on the wall, and use a short length of AC cable or NM cable in flexible conduit to "jump" to the appliance. Stapling NM to a piece of lumber is also sometimes used.
- Where NM cable is run in close proximity to heating ducts or pipe, heat transfer should be minimized by means of a 25mm/1" air space, or suitable insulation material (a wad of fiberglass).
- NM cable shall be supported within 300mm/1' of every box or fitting, and at intervals of no more than 1.5m/5'. Holes in joists or studs are considered "supports". Some slack in the cable should be provided adjacent to each box. [while fishing cable is technically in violation, it is permitted where "proper" support is impractical]
- 2 conductor NM cable should never be stapled on edge. [Knight also insists on only one cable per staple, referring to the "workmanship" clause, but this seems more honoured in the breach...]
- cable should never be buried in plaster, cement or similar finish, except were required by code [Ie: cable burial with shallow bedrock.].
- cable should be protected where it runs behind baseboards.
- Cable may not be run on the upper edge of ceiling joists or the lower edges of rafters where the headroom is more than 1m (39").
Whenever BX cable is terminated at a box with a clamp, small plastic bushings must be inserted in the end of the cable to prevent the clamps forcing the sharp ends of the armor through the insulation.
Whenever BX cable is buried in thermal insulation, 90C wire should be selected, but derated in current carrying capacity to 60C.
BX is sometimes a good idea in a work shop unless covered by solid wall coverings.
In places where damage is more likely (like on the back wall of a garage ;-), you may be required to use conduit, a UL- (or CSA-) approved metal pipe. You use various types of fittings to join the pipe or provide entrance/exit for the wire.
Service entrances frequently use a plastic conduit.
In damp places (eg: buried wiring to outdoor lighting) you will need special wire (eg: CEC NMW90, NEC UF). NMW90 looks like very heavy-duty NMD90. You will usually need short lengths of conduit where the wire enters/exits the ground.
Thermoplastic sheath wire (such as NM, NMW etc.) should not be exposed to direct sunlight unless explicitly approved for that purpose.
Many electrical codes do not permit the routing of wire through furnace ducts, including cold air return plenums constructed by metal sheeting enclosing joist spaces. The reason for this is that if there's a fire, the ducting will spread toxic gassesfrom burning insulation very rapidly through the building. Teflon insulated wire is permitted in plenums in many areas.
Canada appears to use similar wire designations to the US, except that Canadian wire designations usually include the temperature rating in Celsius. Eg: "AC90" versus "AC". In the US, NM-B is 90 degrees celcius.
Wire selection table (incomplete - the real tables are enormous,uncommon wire types or applications omitted)
Condition Type CEC NEC
Exposed/Concealed dry plastic NMD90 NM
armor AC90 AC
Exposed/Concealed damp plastic NMD90 NMC
Exposed/Concealed wet plastic NMWU90
Exposed to weather plastic NMWU
Direct earth burial/ plastic NMWU* UF
Service entrance RWU
[* NMWU not for service entrance]