How do I select the correct control cable?

Stefan Wehrmann | 5. June 2020

In my product training courses for new sales employees, I traditionally impart a lot of theory. This ranges from the fundamentals of electrical engineering to cable production and cable materials.

When I explain the different types of cables, their intended use and specifications, I have a very important perspective: the real practice.

I teach my students the most important facts and throw light on issues to help them find their way through the jungle of cables and find the right solution for the customer.
 
In the following I would like to give a small insight into this. As an example, I dedicate myself to the so-called “standard” cables: the control cables. Therefore I pick up the question: “How do I choose the right control cable?”

What is actually meant by a control cable and where are they used?

Control cables can be found in almost all industrial applications. As the name suggests, they are used to control machine components or their energy supply (e.g. for small motors). They are used to transmit simple control signals (I/0 commands). Examples are machine status signals or simple switches.

What are the typical characteristics of a control cable?

In the industrial environment, the term control cable refers to an unshielded or shielded multi-core connection cable with a smaller cross section.

The characteristic here is the manufacturer definition in the data sheet (control cable) and the typical voltage class of 300/500V.

How do I now select the right control cable for my application?

An important criterion for selecting the right cable is the voltage class. For control cables this is already defined by the designation 300/500V. The voltage class can also be found in the respective technical documentation of the machine components to be controlled.

If no technical documentation is available, the inscription on the cable can also help to determine the correct setup. Details such as the core cross-section combination, cable shield data if any and the voltage level are usually inscribed. Depending on the standard fulfilled, further details are also included.

The final step to the right control cable

It is therefore necessary to clarify the following criteria:

• Number of cores
• Cross section
• Voltage class
• Necessity of a cable shield

Only then comes the final step:

The selection of the cable quality or the outer jacket material.

To make the right choice here, you should ask yourself the following questions:

• Is it a fixed, moving or chain application?
• What is the (chain’s) bend radius?
• What is the target number of cycles or service life?
• How long is the travel of the cable (in the chain if applicable)?
• How high is the speed and acceleration of the energy supply system?
• What are the ambient conditions (heat/cold)?
• What are the media influences?
• What was the reason for the failure of the previously used cable solution?
• Specifications and standards to be met

Once these points are clarified, the ideal cable can be selected. Those who prefer digital technology can also use tools like our product finder.

Conclusion

With a little background knowledge and simple queries you can quickly and easily find the right cable. Of particular importance here are the electrical and mechanical criteria. You also need information about the intended use.
If the cable is correctly dimensioned, downtime can be avoided and maintenance costs actively reduced