A Guide to Armored Fiber
Recently, some new terms have been gaining popularity in the cable community, which is probably why you’re here reading this. If you’ve looked for cables recently, you may have noticed These terms are MC cable and BX cable. What kind of cables are these? What can they be used for and why have they recently gotten more attention? We hope to clear up any sort of confusion you might have about these cables and more.
BX vs MC Cable: Which is Better?
The first thing you need to know about these terms is that BX cable and MC cable are both referring to armored cable. BX cable is actually a branded name for AC or armored cable. The same way we refer to any medical adhesive strip as Band-Aids, BX cable is simply the name a company chose for their armored cable and it just stuck. MC cable is easier to remember because it’s an abbreviation for “metal clad” or “metallic-sheathed cable.”
So is there any significant difference between BX vs MC cable? They’re very similar in most regards, but there is one big difference between the two cables. In the electrical world, AC or BX cables do not come with a ground wire while MC cables do. So, if you’re looking to buy armored fiber then MC Armored Cable is not what you’re looking for. But since we’re here to sell fiber, not electrical cable, there is no significant difference. Both are essentially just names for armored cable. When fiber is armored, it has a conductive jacket because the material is made from metal, usually aluminum or steel. Because of this, the cable jacket will read OFCP or OFCR depending on your jacket’s fire rating. For more information, please read our Guide to Cable Jackets blog.
Outdoor Fiber MC Cable
Now we can talk about the application for armored fiber cable. Let’s start with outdoor armored fiber optic cable. Outdoor cable consists of a black PVC jacket which contains the loose strands of fiber along with a ripcord. However, because this cable is an MC cable, surrounding the loose tube fiber is a steel tape. Because this cable is meant for direct burial, the steel tape is meant to add a layer of extra protection. This steel tape is meant to deter outdoor rodents such as moles and gophers from chewing on the cable jackets and ruining the fiber cores inside. Underneath the tape is a water blocking strip that absorbs water and keeps moisture from getting to the fiber cores within. This combination is specifically designed to protect from the harsh outdoor elements. The cable within the water blocking strip is typically a loose tube rather than a tight buffer because it’s cheaper to manufacture for long runs. Outdoor cable is usually OS2 or Single Mode fiber, which simply means that it’s meant to send one signal for significantly longer distances. If you’re looking for outdoor armored fiber cable, our best selling option is Taihan OSP Outdoor Armored Fiber. However, because the outdoor bx armored cable isn’t fire rated, you’re not allowed to run this cable more than 50 FT indoors. For that, you will need some indoor/outdoor fiber optic cable.
A reason why you might typically use outdoor armored cable are for building to building runs on a school campus or facilities with larger distances between buildings. Outdoor armored fiber will ensure that your fiber is protected from most elements with little to no damage or latency to your signal.
Indoor Fiber BX Cable
The body of the indoor armored fiber cable is obviously meant for indoor use. It’s designed with a more flexible PVC jacket and is colored depending on the type of fiber mode you purchase. Indoor fiber is usually OM1, OM3, or OM4 fiber, also known as Multimode. Multimode sends multiple light signals for shorter distances. The jacket for indoor fiber also comes in plenum and riser varieties. Riser cables are most commonly used and found in areas where cable travels up a building and can be used as the main form of cabling in smaller buildings. Plenum on the other hand, is cabling that is used in plenum air spaces or areas of a building where unseen fires might occur. This cable is also reserved for taller multi-story buildings. These are required in building codes. For more information on Jacket varieties, check out our blog on Fiber Cable Jackets. The indoor fiber mc cable is made up of the aluminum casing which spirals around the fibers. 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. Unlike the outdoor armored cable, the indoor cable’s tight-buffering makes fiber organization easier. 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. If you’re interested in a solid choice for indoor armored fiber optic cable, then we carry a variety of great options from Corning. Our recommendation would be the Plenum OM4 Armored Cable varieties.
Working With Armored Cable
One of the common complaints that most people have with using armored cable is that they can’t figure out how to cut it open, or strip it once it’s cut. While you may be able to get away with cutting a copper wire cable with a hacksaw, fiber cable requires a little more care. Cutting fiber with the wrong tools could crack the glass and ruin it’s usability. The jacket and armor itself can be cut off with a cable stripping tool but for the fiber itself, it’s recommended that you use a special cutter called a cleaver. 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.
Is Armored Cable Right for You?
Pros and Cons When Dealing with Armored Cable
So you’ve read this far and still aren’t convinced about the benefits of armored cable? Well, maybe this type of cable isn’t actually the best choice for you. There are plenty of benefits to other cables as well. Just remember that every cable will have it’s benefits and downsides. While regular outdoor fiber cable might be cheaper than armored, you also need to think about the conduit that your cable will be running through as it can’t be directly buried like armored cable can. For indoor cable, if rodents begin chewing on the cable jackets, you won’t have the benefit of the aluminum shielding of armored cable. 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.
Pros
- Armored fiber is pre ran and already pulled into the armoring
- Armored fiber is more flexible than normal fiber and can be much easier to install than mounting conduit then having to pull the cables through the conduit.
- It comes on a spool so it can be shipped and some conduit lengths are too long to ship
- Great from protecting the cable from rodents, boxes falling on them and light foot trafficked areas. In some cases, it can even be buried in dry or covered climates.
Cons
- Spools are heavy to maneuver
- Armor isn’t going to protect the cable if ran over by a forklift or truck
- Can be difficult to cut without the right tools
- Not ideal for direct burial because it can rust and can only hold lightweight so they would have to be buried shallow.
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.com.