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. If you expect to be doing a lot of cutting, you may wish to invest in a special BX cutter, such as the Roto-Split. After you insert the cable into the tool's groove, you turn the handle to cause the cutting wheel to cut away the metal sheathing.
The tool is calibrated to cut the metal but stops short of touching the inner wires. It is possible to cut and rip the armor without a BX cutting tool. You can cut the outer armor with a hacksaw, assisted with a strong pair of wire snippers or pliers.
With this method, there is the danger of nicking the insulation on the inner wires , not to mention lacerating your fingers on the sharp metal armor. BX is one of the earliest types of electrical cable developed for both residential and commercial uses in the early part of the 20th century.
Forms of BX can still be found by homeowners renovating their homes. It is not certain how the term "BX" came to represent metal-armored cable, but it may have something to do with the product first being produced in the Bronx borough of New York.
As a do-it-yourself residential electrician, you likely will find it easier to handle, rip, and pull NM, or Romex brand, electrical cable. These are often found in cable ducts, are used for power networks, and also buried in underground power transmission situations. The size of armoured cable you choose to use depends primarily on the application you intend to wire. Additionally, the types of armored cable chosen must also factor the voltage drop to make the application safe and effective.
As a rule of thumb, the further the distance, the higher the cable size. Increase the armoured electric cable one size up for every feet of additional distance. Another rule of thumb to determine armoured electrical cable size is the amount of voltage involved. Low voltage applications require special emphasis on voltage drop when determining cable size.
For how voltage applications, when determining armored cable sizes, take into consideration the current-carrying capacity of the cable. When laying armored cable in an outdoor environment, it is important to protect the cable from potential external shock or damage.
For instance, any cable laid out on a roadway or across a field, even though it might be steel armoured cable, runs the risk of damage due to traffic, field ploughs or tractors running over it. There is no regulated depth at which armored cables must be buried in the UK. However, one could use the NJUJ guidelines and recommendations to determine the depth to bury them.
It is important to remember that these stipulations apply to public roadways and pathways. Alternately, although no specific regulations exist to govern how deep armoured cables can be buried on private property, BS does offer some hints on what to do.
These regulations require that cables be buried deep enough so as not to be disturbed by any reasonably foreseeable activity — such as digging with a spade or a lawnmower and that a yellow warning tape be used to alert of the presence of buried cable.
To be safe therefore, you may look at burying armored cable at a depth of at least mm so that reasonably expected activity on the property does not unearth the cables. It is extremely important that when you install armored cable, there should be no damage to the body or interior core of the cable. A damaged m armoured cable will only compromise the entire electrical project in which it is used.
However, one place where damage is most likely is when cutting the cable. LSZH would be recommended for public areas or in tunnels. At Keystone we would also include UV stabilizer and anti-termite additives in our cable sheath material. When do we use Armoured Cables? Keystone Academy Oct 8, Consequently, it is best to check your local wiring laws before performing any underground installation. You need to note that there are different armored cables, each with a specific use.
For instance, an armored fire alarm cable is only applicable in alarm wiring applications. Likewise, an armored marine cable is specifically ideal for marine-related applications. To put it simply, you need to make a choice based on your specific wiring needs.
Armor-clad cables provide adequate protection and durability in the absence of conduits. In most cases, people are forced to use conduits in areas prone to external risks such as corrosion and cable abrasion. Thus, it is correct to say that an armored cable is suitable for use in hazard-prone areas. A standard electrical cable is most likely to incur irreparable damage in areas exposed to moisture.
A PVC armored cable is suitable for such an environment because it can withstand moisture exposure. Generally, it is advisable to use armor-clad cables in hazardous locations, including beneath stairwells, barns, and basements, to name a few. These cables can guarantee maximum safety and durability, provided you choose the right type of cable. For high voltage applications, it would be best to go for an XLPE armored cable.
It is also essential to remember that wires have varying current-carrying capacities depending on different factors including, their size, number of cores, and length.
For example, a 6 mm 3 core armored cable with XLPE insulation can transmit up to volts. The same cannot be said about other variations of armor-glad electrical wires. An armored-type cable has a callous exterior.
This feature is highly beneficial, especially when dealing with harsh environments. In most instances, people cut an electrical wire when it turns out to be too long for its intended application. How exactly do you cut an armoured cable? Logically, the first thing you need to do is obtain a reliable cutting tool.
With such a contrivance in hand, you can easily cut the cable while holding the apparatus at a steady degree angle. It is prudent to take all the essential safety precautions. An armored electrical cable is tough to cut and may propel the cutting tool towards your eye. Consequently, you must wear protective eye gear when cutting this cable type.
The first and most crucial stage of installing any cable is choosing the right one. It is best to use a 15 kV armored cable or a 35kV one depending on your voltage needs for construction applications.
0コメント