A motor is supplied with energy via a motor cable that contains cores – three black cores for Phases L1, L2 and L3, and a green/yellow core for the earth core. Today, coil windings in the motor are usually interconnected to form a star or triangle. This is how the number of cores is limited to four. Depending on what is required of the cable due to interference or environment sensitivity, a cable with or without shielding can be selected. And, of course, the cable is manufactured with a variety of jacket qualities and mechanical classes.
When a professional mentions engine outputs, they generally do not just mean the supply for a motor. A four-core control cable can do that. They are talking about connecting a frequency converter to the motor. The requirement for this is that the core insulation fulfils the 600/1000V voltage levels. This is necessary because the frequency converter uses the principle of pulse width modulation to control frequency and thus motor speed. This leads to voltage peaks, which the insulation must be able to handle. This is why a higher voltage class is chosen than for a control cable.
It is now possible to design cables with single cores, especially for large drives. This solution offers several advantages over classical four-core versions. Probably the biggest is the much lower price that can be offered due to a different, more cost-effective manufacturing process. The single-core solution is also more robust and thus suitable to the small installation space available in energy chains and still delivers a longer service life. This is particularly noticeable on long travels. Connection to the motor is easier with thinner single-core cables, but they need special mounting. We have lots of experience with this sort of challenge, so we always have the products necessary for a solution in stock.
The majority of our motor cables have outer jackets made of the TPE high-end material, which is especially well-suited to applications in extreme temperature ranges. The temperature range for TPE motor cables is defined as -35°C to +90°C in energy chains. This means that applications in deep-freeze areas or very warm environments are just the right ones for this material. TPE has another feature – extremely high abrasion resistance. A direct comparison of TPE to PVC and PUR shows that the former has better abrasion behaviour, making it exceptionally well-suited for a very long service life in high-end applications.
igus has been equipping crane systems with energy chains for many years. Around the world, far more than 10,000 crane system have been in continuous operation for years. Cables and chains stand up to the toughest conditions, from -40°C in the Siberian winter to 50°C in the port of Dubai. Cable failure is unthinkable in crane and trolley drives. They require the greatest reliability. That is why individual cores of the CF330.D or CF340 series are used to supply the hoist with nominal conductor cross-sections of up to 185mm. This can be regarded as a development toward a standard. That is why, the next time you plan an application with large cross sections, we should definitely discuss a concept with single cores that involves a high-quality braided conductor.