When is bx cable required

Underneath the aluminum casing, you will find some water blocking tape which expands if moisture makes it through the jacket. Within the water blocking tape, you will find the fiber cores which are tight-buffered.

Just like with the outdoor fiber, the indoor armored fiber is meant to deter creatures such as rodents from chewing on the fiber cores. Because indoor cable is meant to be shifted and moved constantly, the PVC jacket and cores inside are meant to be a lot more flexible than the outdoor armored fiber cable.

While you may be able to get away with cutting a copper wire cable with a hacksaw, fiber cable requires a little more care.

Fiber cleavers ensure that the fibers are cut to the desired length without the fear of broken or damaged glass cores. These may be a bit on the pricier side, but will save you time and money trying to find an alternative.

There are plenty of benefits to other cables as well. Besides being a little more expensive, there is really no downside to purchasing armored cable over regular fiber cable. Here is a more robust pros and cons list. At the very least we hope this has helped you out a bit.

Whether you are planning on purchasing some of our armored cable or you were just curious about what mc cable or bx cable is, We hope that you were able to find what you needed. For more blogs or products just visit our website at FiberSavvy. If you have a question, feel free to reach out to us. The plastic sheathing also has a very high melting point thus is heat and flame resistant. Splices are done in junction boxes, thus protected from the elements and pests. Plus all the wires needed for a circuit are right there together in one neat package.

One added benefit of NM cable over knob and tube is that knob and tube emits fairly high levels of low frequency alternating current magnetic fields, due to the separation of the hot and neutral conductors.

The magnetic field strength around knob and tube carries a good distance from the wires and is proportional to the distance between the hot and neutral conductors. Inside NM cable, the hot and neutral conductors are side by side, thus NM emits a much smaller, more localized and weaker magnetic field. The magnetic field strength drops very quickly with distance from the NM cable.

BX is sheathed in a flexible metal spiral made either from aluminum or galvanized steel. BX provides all the advantages of NM cable plus some additional benefits. The flexible metal sheathing is easy to install, about as easy as NM cable.

It resists puncture by nails and screws, and, as I will describe later, is more resistant to being chewed through by rodents and other pests than NM cable and knob and tube. The metal sheathing absorbs the electric fields emitted by the wires and shunts it to ground.

The plastic sheathing of NM cable does not shield electric fields. The main drawback is that BX is more expensive. It is also slightly more difficult to install, as cutting the metal sheathing takes slightly more time, than cutting NM cable.

While widely used in the past, BX cable is not relegated to the past. Even with new projects, you still have the choice of using either metal-armored BX cable or plastic-sheathed NM cable.

Going under alternative names such as metallic sheathed cable, type AC, MC, Greenfield, or armored cable, BX cable is a collection of plastic-coated insulated wires typically or gauge , bundled together and protected by a ribbon-like metal sheathing. BX's metal sheathing runs in a helix-like or twisted manner around the wires.

BX is contrasted with a newer cable, NM, which stands for "non-metallic. Romex is one popular brand of NM electrical cable. This casing needs to be attached to metal boxes. Another distinction is that some types of BX cable can be installed in exposed locations, either indoors or outdoors. NM cable and wiring must always be installed in an enclosed location typically within a wall, ceiling, or under a floor. Always be sure to check with your local building and electrical codes as to whether BX cable may be left exposed.

Like any other cable, if the armor is nicked, cut, or shredded, the wires inside can be compromised. BX's armor, while much stronger than NM's vinyl, can still be pierced by a determined and ill-placed nail or screw.

However, with the exception of electrical wires that run through rigid metal conduits, no other type of electrical cable has as strong an outer casing as BX cable. Wires within the armor may display degradation of their rubber insulation. But this may just be at the exposed ends. If you rip back the metal sheathing, you may find that the insulation is still good. If old BX wiring is in good condition and can carry today's higher power demands, there is usually no reason to replace it.

Unlike the older knob-and-tube wires from the early 20th century, the wire sheathing will not turn gummy and degrade over time. There are three methods of removing the outer metal armor of BX cable: with a special BX cutting tool, a hacksaw, or manually with pliers. Some will refer to this cable as Greenfield cable.

There were originally two initial versions of armored cable. These two cable assemblies are very similar in construction. See note on FMC below. The biggest difference between the two cable systems is that MC has full size ground wire while AC uses a combination of the jacket and a thin bonding strip or wire to function as the equipment ground.

The bonding wire is unique to AC cable and this allows the outer metal armor in conjunction with the bonding wire to be used as an equipment ground.