Ferrules and crimping

The most commonly used aid in the assembly of cables is the ferrule. These are standardized in DIN 46228.

Ferrules for fine strand copper conductors:

In the field of electro technology, the use of an extremely effective aid, the ferrule, is on the rise for the processing of fine strand copper conductors in different terminal points. Originally, non-insulated ferrules were used, but from 1970 onward, the insulating sleeve became common. In 1991, the market for ferrules was revolutionized by the invention of a ferrule for two conductors with the same cross section.

Uniform color coding of insulating collars


Another milestone in the history of the ferrules was set in 1990 when the DIN 46228 standard came into force. This standard deals mainly with the uniform color coding of insulating collars.

The cross section of the connected conductor can be recognized immediately with the standardized ferrules supplied by PHOENIX CONTACT.




Advantages of insulated ferrules from a safety point of view


Ferrules without plastic collar
The operational reliability of electrical plants is of utmost priority. The use of insulated ferrules plays a significant role in fulfilling these requirements:
  • Time-saving processing of the conductor in the connection or terminal space
  • Secure contacting even after several reconnections
  • Long-term operational reliability as a result of avoiding wire break and damage due to vibration
  • Fast assembly with the ferrule due to the funnel effect of the insulating collar
  • Good long-term contact resistance
  • Torque is retained when mounted in screw connections
  • Bending and wire break is avoided, since the conductor insulation is supported by the insulating collar
  • Splice-free connection with the insulating collar avoids disturbances at startup



Normalization of ferrules with insulating collar


Normalization of ferrules with insulating collar
Twin ferrule
The technical requirements for ferrules with a plastic collar are described in part 4 of DIN 46228. The copper sleeve to accommodate the conductor is made of soft electrolyte copper (E-CU 57) with excellent electrical properties and adapts perfectly to the conductor shape when crimped.

To guarantee good contacting and durability of the electrical connection, the copper sleeve is coated with a thin layer of tin (3/1000 mm thick) applied using a galvanizing process. The plastic sleeve is made of polypropylene for use in permanent temperatures of 105°C.




Table


For use in modern automatic crimping tools, the ferrules must adhere strictly to the dimensions to guarantee trouble-free operation. A particular advantage of the ferrule with insulating collar is the color coding of the plastic collar. The normalization of the colors makes it possible to clearly recognize the corresponding cable cross section from the color of the insulating collar alone. A ferrule for a cable cross section of 1.5 mm², for example, has a black plastic insulating collar. Mixups are ruled out and the operational safety of plants is increased. In the past, different manufacturers produced different color series and this often resulted in mistakes when assigning the cross sections to the conductor. The introduction of the DIN color series rules out the possibility of these mistakes.

The normalization of the ferrules can be compared to the conversion of the various screw threads to the standard thread. Not until the thread was standardized did implementation worldwide become a simple matter. Just as we nowadays take standard threads for granted, we should in future be able to have the same approach to ferrules.




Tip:


PHOENIX CONTACT offers various designs of ferrules.

DIN color code, long version or TWIN ferrules. Ferrules without a plastic collar and taped ferrules for the PHOENIX CONTACT automatic crimping tool... To cover every application.

The matching tool is also supplied.

Crimping pliers CRIMPFOX ZA 3



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