Security alarm cables are only some of the specialty cables we provide here at EWCS Wire, but like all of our unique products, they are made to an exacting range of specifications and standards. No two cables or wires are necessarily the same, as they are engineered to deliver specific performance in their given scopes of applicability.

That makes marine battery cable very different from building wire, photovoltaic (or solar) cables, welding cables, tray cables, armored cables and everything in between.

As you become more familiar with the many different types of electrical wires and cables used in infrastructure and engineering, you’re going to come across traits and specifics that are relatively unique. If you find yourself asking any of the following questions, look no further for the answers.

1.Do security alarm cables need to be shielded?

First on the list is the question of whether or not security alarm cables need to be shielded. The answer is that it depends. Sometimes they should be and sometimes a situation can get away without it. To answer this question in more detail we need to understand more about shielding and its purpose.

Security alarm cables relay information between the nodes on control and alarm systems, such as burglar alarm systems and fire alarm systems. Because the emphasis of their design is on sensitivity and accuracy, they are susceptible to what is called electromagnetic interference, or EMI. EMI is interference caused by the proximity or emissions of other nearby electronic devices, and it can scramble and confound the signals of alarm systems.

Security alarm cables shielded usually take the form of a metallic foil insulation to block out competing signals. It is necessary in any situation in which the cables themselves are to be exposed to a high level of EMI, though it is a good idea to use shielded cables over long distances as a safeguard against EMI even if little is to be expected.

2.What traits must a quality fire alarm cable have, besides shielding?

In addition to the fact that fire alarm cables may need to be shielded to protect against EMI, there are other traits it should possess to remain useful. You don’t need to be an electrical engineer to understand some of these.

Consider only that fire alarm cables are used in the wiring of fire alarm systems and that they may as a matter of course be exposed to high heat and flames. For this reason, fire alarm cables must also be rated to withstand significantly higher temperatures than some other forms of wires or cables. In addition, they are typically produced with insulation that does not produce toxic smoke when it burns.

3.What does “plenum-rated” mean?

Another word you may come across reading about or researching security alarm cables is “plenum.” You will find that some cables are plenum rated, whereas others are riser rated. To understand this, you need to know what is meant by these words.

Plenum space is the space above a building’s drop ceiling that is usually meant to accommodate HVAC ductwork. Naturally, it also makes way for other fixtures of civil engineering like conduits, pipes and more. However, these spaces are sometimes subject to harsh conditions; only plenum rated cables should be used there.

This stands in contrast to a riser rating, which indicates that cables can be used in riser space. Riser space is the vertical open space between the floors of a building that, like plenum space, is meant to accommodate pipes, communications lines, and more.

4.What is the purpose of security and alarm cable?

Generally speaking, security and alarm cables are used to relay information between the nodes of a security or alarm system. They can be used to power the system although they may not necessarily be used to do so. Their purpose is in communication, transmitting signals, video, audio and other sensitive information for the purposes of monitoring, regulating, or remote control.

5.Why are wires voltage-rated, and what does that mean?

Without going too far back to physics, voltage is a measure of electrical potential. It may also be called electromotive force or electric pressure in addition to these. The formula for voltage is to multiply current by the resistance of a circuit, given by V=IR. Current, measured in amps, measures how much actual electricity flows through a circuit, and resistance, measured in ohms, gives a measure of how much the circuit material “pushes back.”

Since wires and cables are made of a fixed amount of conductor material, resistance in the wires is fixed. That means the wires can only safely accommodate a certain amount of current. This works out to a voltage rating for the wire, accounting for the wires resistance and the current that can be passed through it.

6.Why are wires color coded?

In addition to being given a voltage rating, wires and cables are also sometimes color-coded, signifying the proper uses for which a wire may be used or applied. Sometimes the color coding does not designate the wire for a specific use but simply enables electricians to easily distinguish between the wires with which they are working.

As a quick example, wires that are used as leads for batteries are typically color coded as red or black. Black wires serve the negative terminal of the battery and red wires are used as connections for the positive terminal.

In addition to this recognizable use of color-coded, wires may also be colored green, orange, pink, blue, white, brown, and other colors, the purposes of which may vary according to the application.

7.What is the purpose of the acronymous coding on some wires?

You will also not be able to get too familiar with the variety of wires and cables on our website without taking note of the fact that many of them are given acronymous designations such as THHN, XLPE and THHW. Each of these descriptions means something specific for the wire or cable to which it is applied.

For example, XLPE stands for cross-linked polyethylene and it is used to create insulation for some wires. It is strong, relatively rigid, and very tough and abrasion resistant. This protects the wires and cables it insulates from a number of environmental stressors.

THHN, as another example, stands for thermoplastic, high-heat resistant, nylon coated wire. This type of insulation is useful in situations in which the wires or cables may be thermally stressed.

You can learn more about some Wire Types and Labeling in our blog of the same name or reach out to us directly for more information.

8.What are bare wires used for?

You may have noticed that some of the wires we sell are bare copper wires. Since insulation is so important to the cables in a circuit, why would we sell any that are bare?

This is a valid question. These bare wires are commonly used in grounding which protects your home and appliances from electrical damages in the event of an excess discharge. Ground wires, which are frequently bare copper (but may also be commonly coated with green insulation) direct excess charges into the ground beneath your home where the charge will be safely dissipated. This is where the term “grounded” comes from, is the main purpose of bare copper wires, and is an essential component of safety in almost any electrical system.

9.Why does marine cable need to be so flexible?

Marine electrical cables must be as flexible as possible because they are subjected to a number of mechanical stresses including but not limited to the motion of the vessel and those inflicted by forcing the cable into tight spaces and around unforgiving structures.

Because of this, marine grade cables are made from an exceedingly high strand count of very thin conductors to preserve their flexibility.

10.Marine cable looks like aluminum cable but it isn’t. What is it?

Another interesting fact about marine grade cables is that they look silvery. You might have assumed from the look of them that they are made from aluminum conductors but this is not the case.

In addition to being subjected to an undue number of mechanical stressors requiring a high conductor count, marine grade cables are also subject to corrosive influences such as seawater, salts, oils and more. For this reason, they are produced with individually tinned conductors that make them better resistant to corrosion, and gives them a silvery appearance.

11.Why are some cables made of aluminum?

Since we mentioned aluminum in the last section it would be wise to shed a little light on how and why aluminum wiring is used in electrical systems.

For one thing, aluminum has a similar conductivity to copper, making it useful as a conductor. Aluminum is also cheaper than copper and was historically available at times when copper was rationed. Additionally, aluminum is significantly lighter than copper and much more ductile and malleable. For these reasons and others it has been widely used as a conductor in the past.

12.What is a tray cable? What’s the purpose?

Trays are open raceways along which cables can be laid to provide power to a system. These stand in contrast to conduits, which are solid, enclosed containers through which cables must be drawn.

Trays have advantages over conduit, being that they are easier to maintain, less labor intensive to install and outfit, and are better at releasing heat than conduits. On the flipside, conduits provide better insulation to the cables within them, despite the higher costs of setup and maintenance.

We sell a variety of tray rated cables here at EWCS Wire that are expressly suited to use in trays.

13.Can welding cable be used as battery leads?

Go through our collection of welding cables and you will notice that they are all either red or black. Voltage rating notwithstanding, this is because our welding cables may be suitable for use as leads for batteries. Outfitting them with black and red cable makes them safer and more suitable for this application.

14.Why does welding cable need to be so flexible?

In addition to the color coding exhibited by our welding cables, you will also note that they are advertised as highly flexible and abrasion resistant. The reason for this flexibility is because welding must often be done on site, on location, wherever two media need to be welding.

This also means the welder (and the cable) need to get into position at the location. The cables sometimes must carry high currents, necessitating a specific voltage rating and AWG thickness. These things both make a cable stiffer; to ensure the cables can be managed on location, they, like marine grade cables, are made with a higher strand count to create more flexible welding cables.

15.What is the purpose of armored cable?

Armored cables such as DLO (Diesel Locomotive Cable) are used in industrial and agricultural settings for supplying power to heavy machinery and equipment. As a result, it is often subject to a variety of environmental stressors and hazards.

Because of this, it is safest to outfit the cable with interlocking, corrosion resistant metal armor that protects the cable from a variety of hazardous conditions.

16.Is there a good reason to use a cable instead of a wire, all else being equal?

There is a very basic difference between a wire and a cable, despite the fact that the terminology is so often interchanged. Wires are constituted by a single strand conductor, whereas cables are made of many conductors braided or twisted together.

The main reason that cables are produced in preferences to wires is because they are much more flexible than wires, which makes them more useful in welding, marine wiring, and other applications.

Do you have additional questions that have not been answered throughout this course of this article? Did the questions enumerated herein cause you to think of others in their wake?

Give us a call at 800-262-1598 or email us at sales@ewcswire.com to learn more about the unique products we sell and how they can be used.