How to choose the right cable or wire for your application

Choosing the right cable or wire doesn’t have to be complicated, but it does mean knowing what actually matters for your specific setup. Rather than looking at everything at once, it’s easier to break the decision down into a few key questions.

1. How will the cable be used?

Start by thinking about movement.

If the cable will be installed once and left in place (for example, inside a wall or control panel), a solid conductor is usually the best option. It’s more rigid and holds its shape well over time.

If the cable will be moving, bending or exposed to vibration, go for a stranded conductor. These are much more flexible and far less likely to break under repeated motion.

Is a solid conductor easier to terminate than stranded wire?

Generally, a solid conductor is easier to terminate in specific types of connectors, such as breadboards or IDC (insulation displacement connector) blocks, because it can be inserted directly without the strands splaying out. However, for crimp-on connectors it requires high-quality tools to ensure the terminal grips the smooth surface of the solid wire securely.

2. How many connections do you need?

This determines whether you need a single-core or multi-core cable.

• Single-core cables are typically used inside equipment, panels or machines where only one electrical path is required.
• Multi-core cables bundle multiple conductors together, making them ideal for powering or controlling more complex systems like appliances or industrial equipment.

3. Will interference be an issue?

In environments with lots of electrical noise, such as factories or near heavy machinery, signal interference can become a problem.

That’s where screened (shielded) cables come in. They protect the signal inside the cable from external interference and stop the cable itself from emitting unwanted noise.

Depending on the level of protection needed, you’ll come across options like foil, braided or combined shielding.

How do screened cables protect against electrical interference?

In high-noise environments such as factories, screened (or shielded) cables are used to maintain signal integrity. These cables feature a layer of foil or braided mesh that acts as a Faraday cage, blocking external electromagnetic interference (EMI) from disrupting the signal and preventing the cable itself from emitting noise that could affect nearby sensitive electronics.

4. What environment will the cable be in?

This is one of the biggest factors. The outer sheath of the cable needs to handle whatever conditions it’s exposed to.

Here are some common sheath materials and where they work best:

Choosing the wrong sheath can shorten the cable’s lifespan dramatically, so it’s worth getting this part right.

How does temperature affect the conductivity of a cable or wire?

The electrical resistance of a cable or wire increases as the temperature rises. In high-heat environments, the current-carrying capacity of the wire must be “derated”, meaning it can safely handle less power than it would at room temperature. This makes heat-resistant sheathing materials like PTFE essential for maintaining safety in high-performance applications.

5. Does it need to meet any standards?

Depending on the application, certifications may be essential rather than optional.

Some of the most common include:

• BASEC – confirms compliance with British and international cable standards
• UL – globally recognised safety certification
• DEF STAN – used for military and aerospace-grade cables
• Tri-rated – approved for use across the UK, USA and Canada
• RoHS & REACH – ensure the cable meets environmental and chemical safety regulations

If you’re working on regulated projects or exporting products, these can be critical.

6. What type of cable do you actually need?

Once you’ve worked through the points above, choosing the category becomes much simpler:

• Equipment wire – for internal wiring in electronics, panels and low-voltage systems
• Control cables (CY, SY, YY) – for managing signals and operations in machinery and industrial setups
• Power cables – for distributing electrical power in buildings and infrastructure
• Communication cables – for data transfer, including Ethernet, coaxial and fibre

Standard building power might rely on heavy-duty single-core cables or multi-core cables, depending on the installation method.

Final thought

The “right” cable isn’t just about performance, it’s about matching the cable to the environment, movement and standards required. Get those three things right and everything else tends to fall into place.