EMC-compliant cable connections

EMC-compliant cable connections

Components for crimp technology, cable clamps and blind plugs

Components for crimp technology, cable clamps and blind plugs

The correct assembly of shielded cables is a crucial criterion for electrical and mechanical functionality of HF-shielding connector hoods as well as for direct cable entries and passages in shielded terminal devices. 

The connection between a connector hood and its cable and cable shield in particular has to comply with a number of essential requirements:

  • A low-resistance connection between cable shield and hood with a constant performance over long periods of use as well as under mechanical stress.
  • A gap-free HF-sealing of the cable entry.
  • Traction and torque relief with high retention forces remaining operative even in harsh conditions.
  • An easy, efficient and economic assembly.

By developing the crimp flange technology Inotec has focused on this critical interface in particular and offers its customers an optimal solution for every cable type, appropriate mounting tools included. Special device configurations or the use of individually assembled cables may sometimes require a traction relief to be realized with a conventional cable clamp technique. For those cases Inotec has also developed appropriate components fitting to the double-dovetail cable entries of the HF-protecting Inotec full metal hoods.

The operational reliability of an entire application depends decisively upon a cable-specific matching of the components and assembly tools. For this reason the customer- and cable-specific determination and definition of the assembly parameters is a crucial part of the Inotec offer and ensures a safe, robust and reliable cable assembly.


Standard assembly procedure KV0001

The standard procedure described below allows an easy and reliable assembly process for the major part of all shielded cables. Variations in cable construction or materials may require the processing following different assembly procedures. With the cable-specific crimp data definition we determine the required assembly parameters, component diameters and tool sizes for every specific application as a service for our customer.

 

1. Dismantle the cable down to the braid and cut the braid, leaving it approx. 10 mm longer than the jacket.

 

2. Fold back the braid over the cable sheath and slide the crimp ferrule on the cable.

 

3. Slip the crimp flange over the conductors and possible intermediate layers and slide it underneath the shield mesh and the cable sheath. Enter the flange with cautious rotation while holding back the shield mesh. In this step, do not enter the flange completely but keep approx. 1 mm distance to the cable sheath in order to facilitate the cutting of the shield mesh.

 

4. Cut off any overlapping braid around the flange. Only now slide the crimp flange completely underneath shield mesh and cable sheath. Please note: Our insertion tool CFE facilitates the handling of the flange in step 3 and 4.

 

5. Slide the crimp ferrule forward until it is in contact with the flange. Keep it in position and crimp it with the indicated crimp dies. Important: During the crimping process the flange has to lay on the crimp dies. The faces of the hexagon should be parallel to the straight sides of the crimp flanges (see illustration).


The Inotec crimp data definition

A basic requirement to achieve sufficient mechanical strength and optimal cable shield contact is to match components, tools and applied assembly procedures for every specific cable assembly. Unlike comparable crimp technologies the Inotec system provides a finely graduated diameter range (0,5 mm steps) and covers a very wide range of crimp flange, ferrule and crimp die diameters.

As an exclusive customer service Inotec electronics GmbH provides a crimp data definition for every specific cable and all cable manufacturers.

Required input data and sample:

  • Cable sample (min. 0,5 m)
  • Intended use (Inotec hood type)
  • Cable data sheet (if available)

Based on this information, the Inotec mechanical laboratory realizes assembly tryout, traction and torque test in order to find out the optimal combination of convenient assembly, reliable cable shield contact and best possible mechanical resistance of the crimped connection.Once the crimp data definition is accomplished, the customer receives a crimp data sheet and a crimped cable sample.The customer’s data sheet contains the following relevant information.

  • Documentation of the cable sample provided.
  • Definition of the most suitable and reliable assembly procedure (if standard procedure KV0001 cannot be recommended, a corresponding data sheet with detailed processing instructions is provided)
  • Definition of the most appropriate components (crimp flange and ferrule)
  • Definition of the appropriate crimp die type and size
  • Additional recommendations or assembly instructions if required.

Example for cable specific Inotec crimp data sheets
 

Advantages of the crimp flange technology

  • Low shielding or transition resistances by 360° contacting of the cable shield
  • High traction and torque resistance, typically even above the maximum tensile strength of the cables
  • No compression of the cable cores, twisted wires are not “untwisted” by compression
  • Fast, reliable and repeatable assembly process
  • HF-sealing interface to the connector hood with the unique dovetail geometry

Alternative components for cable and shield connection

  • Cable clamps with various cross sections for specific cablings
  • Cable entry through BNC plug
  • All components in die-cast zinc and with Inotec dovetail design for low transition resistances