Multi-Conductor Cable: 7 Questions to Ask Before Buying one

FACTS CHECKED BY  Jose George​

As you are working on a project, reliability plays a huge part. You want to make sure that every piece of equipment works fine on its own and with the other products. Multi-conductor cable is one of the essential pieces for your project. However, there are several options available in the market. So how can you find the right one? The application is usually essential to consider when choosing the best multi-conductor cable for your project. Now, let’s get into some basics. 

Wiring Box
Wiring Box

What’s a Multi-Conductor Cable?

Cables with more than one conductor can be found all over the place, from small electronic parts to industrial automation applications. It is safe for them to send signals and electricity over one cable.

Also, multi-conductor cables put separate conductors together inside a jacket. Also, you may hear the term “multi-pair cable.” It refers to a multi-conductor cable that protects the shielded conductors inside it from electronic interference and crosstalk by twisting them together to form pairs before they’re wrapped in a jacket.

These cables come in many different shapes and sizes. For instance, for indoor and outdoor usage, you can use portable wires. 

Typical Multiconductor Wire

Caption: Typical Multiconductor Wire

Types

Multi-conductor comes in both bulks and cable assemblies

You can get it in feet or on a wire reel in bulk. However, the measurements do not include end connectors.

As in cable assemblies, several wires and cables are bound together and have a connector on one or both ends.

Conductors

The conductor of a cable consists of a single solid wire of copper or other metal or a group of strands twisted with each other. Inside the insulation, these are responsible for the current passage. However, the current passing rate in electrical cables depends on the material, size, and number of strands present.

Material can be any conducting metal. The most common is copper, as it has excellent corrosion resistivity and thermal conduction. Aluminum is also a popular material since it is light in weight. It is primarily present in the power cable. Other than that, lines are also available with steel conductors.

As for size, you will find it measured in AWG in the US. The greater the AWG number is, the thinner the wire is. Moreover, thick wires can conduct the current with less resistance, and thus, energy waste is lowered.

Additionally, the conductivity of a cable also depends on the number of strands it has. For example, if there is one solid conductor wire, the cable hardens, and its current rate is lowered in bent areas. But, with multi-strand cables, the wire is flexible and can pass electricity in different regions.

Wires with different conductors

Caption: Wires with different conductors

Jacket and Insulation Material

On top of the conductor portion, it is essential to have a jacket of the insulation layer. For that, you can use either of these materials.

  • Neoprene
  • Silicon
  • Mica Tape
  • Thermoplastic
  • Ethylene Propylene Diene Elastomer (EPDM)
Colored Power Cables 

Caption: Colored Power Cables 

Shielding

The manufacturer’s multi-conductor cables may include a shielding material around the cable under the outer jacket. It is essential to prevent electrical noise from interfering with the signal and reduce noise in the wire. 

Metal braiding, metal tape, and foil braiding are the most common types of shielding used today. Moreover, a drain or grounding wire may also be present in shielded cables.

Picking the Right Multi-Conductor Cable

Before picking a multi-conductor for your project, you need to ask the following questions from yourself and the team.

Are temperatures highly high in your plant, or is there any chance of fire?

High heat can tear the insulation and affect a wire’s conductivity. Moreover, the cables also melt, causing electrical hazards in a facility. Thus the performance of a cable lowers, and you cannot get the power to work efficiently.

For such an environment, it is essential to buy heat-resistant cables. By giving special attention to cable jacketing or insulation, you can lower the chances of hazards. Also, you will not waste money on incompatible wires. In such cases, you can choose Silicone or Thermoplastic Elastomer as insulation on cables.

Moreover, even though fires can start almost anywhere, certain environmental conditions are particularly favorable for possible fires:

  • dust abundance,
  • flammable materials and vapors,
  • welding or other high-temperature work,
  • overloaded electrical connections, or
  • friction inside construction equipment.

To cater to that, you need to buy Fire-rated cables to install your system.

On what type of surfaces will you install the cable?

In some situations, you have to install the cable on rough surfaces. Failure can occur if the cables’ jackets are too soft or thin for the shielding and conductors inside. Hence, heavy-duty PUR cable jackets are ideal for such situations, resistant to cutting or scratches. There is a proper jacket on the cable; it will require many strokes before the insulation fails.

Which environment will you use it?

For every area, such as underwater or plenum spaces, the manufacturers develop the cable rated adequately. Thus, by checking the cable rating, you can quickly know whether the insulation will endure the heat or smoke in that area. Such cables support Sensors, HVAC, security, and communication systems.

Is there any moisture or humidity present around the cable?

Most application areas require cables to run under the water, e.g., Communication cables. You need to select a wire with a conductor with less corrosion rate. Although bare copper is the first choice for many industrial sites, tinned copper is better for wet locations. Moreover, it is easy to solder and performs as simple copper wires.

Is there any electrical noise present on the site?

Electrical interference in the form of magnetic or static waves is present everywhere. It can impact the cable’s performance while creating crosstalk in the system.

To overcome the problem, you can use appropriate cable shielding. Also, you can use a combination of two shielding types as well. For example, foil works best in high-frequency interference, whereas spiral is good in low-frequency interference.

You can also use some multipair cable applications to protect against noise. These cables have a noise-dampening design (insulated conductors twist into pairs before being enclosed in a jacket).

Are the cables used in movement and automation?

Flexibility determines a cable’s ability to be used in a given situation. Today’s industries need flexible cables and a slight bend radius to fit tight spaces and maximize space. Thus, to use in automation and moving robots, you instead choose stranded wires than solid conductors. Here, the higher the number of strands is, the more flexible the wire is. Thus, you need to inspect the space available and the cable routing requirements. That way, you’ll be able to accommodate the required flexibility and bend radius.

Also, there is a difference in flexibility between the insulation and jacketing materials. 

Will Cable Glands secure the ends?

The cable’s diameter matters as long as a cable gland (cord grip) has to avoid accidental cable withdrawal, reduce stress, and strain, and establish a tight seal to keep dust and moisture out.

For example, jacketed cables preserve roundness with a uniform diameter eliminating dimensions. When combined with cable glands or cord grips, they provide a tighter seal.

Thus, if you are using cable glands, you need to consider the insulation and diameter, but if not, you can choose any multi-conductor cable.

The parts of a CW-type Steel Wire, Armour cable gland

Caption: The parts of a CW-type Steel Wire, Armour cable gland.

Source: https://en.wikipedia.org/

Conclusion

Choosing the correct type of multi-conductor is a well-thought process. For that, you need to access different parameters of the environment and select a wire accordingly. These parameters can be humidity, moisture, ability to catch fire, close settings, and movements. Here at Bloom, we offer wiring harnesses and cable assemblies. Your connection is made with attention to detail. To avail of our services, contact us now.

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