Innovation: Compressed Cable Solutions

Cable manufacturers are introducing new RMC Class 2 copper cables to the market, which can have a working core diameter up to 15% smaller than their currently used counterparts (RM Class 2).

Thanks to the new design, cable manufacturers can produce smaller and lighter cables while maintaining the same electrical parameters as in the past.

However, the reduction in the conductor diameter has caused a serious problem. All tubular lugs produced to date were designed for cables with RM Class 2 conductor structure. The reduced conductor diameter in the new cables has resulted in the current lugs being too large and unable to be properly crimped onto the cable using previously used crimping tools and dies.

COMPARISON OF CABLE PROFILES   

When using the standard cable lug (designed for RM-type cables) and its corresponding crimping die size on a cable with an RMC-type construction, it is not possible to achieve the required deformation. Consequently, the mechanical and electrical parameters of the crimped connection do not meet the requirements of standards: EN IEC 61238-1-1:2019 and EN IEC 61238-1-3:2019.

Although it is technically possible to produce special crimping dies (with specific cavity sizes and shapes), the wide range of outer diameters specified for compressed cables in the standard would require manufacturing numerous dies even for the same cross-section, depending on the cable manufacturer.

To address this issue and meet customer needs, we have designed a special type of cable lugs (CKOR) and connectors (CKL) dedicated to Class 2 copper cables with an RMC profile.

Both the cable lugs and connectors feature an internal diameter precisely matched to the reduced cross-sectional size of the conductors in the new compressed RMC cables. Dedicated crimping dies have been developed specifically for this cable–lug system, ensuring the appropriate cavity size and crimping width.

Cable lugs compressed copper cables  

CKOR			CKL
Material	CU		Material	CU
Coating	Tin-plated		Coating	Tin-plated
Conductor construction	Compressed		Conductor construction	Compressed
Conductor cross-section	10 - 240 mm2		Conductor  cross-section	10 - 240 mm2
Identify method			Identify method		RMC - copper cable class  2

The cable lug/connector and crimping die system developed by our engineers ensures that the required quality of crimp connections is achieved on RMC cables reliably, quickly and efficiently.