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Use Of Cable Ferrules

Former Community Member
Former Community Member
Morning gentlepeople of the IET forum.


I'm just throwing this out there to try a get some opinions on cable ferrules and if people use them and where.

From my understanding, they are mainly used during panel builds, IT equipment and even on flexible cables. However, I recently went to a domestic property to perform an EICR and every cable connected to the RCBOs (ignore the earth fly lead which already comes crimped from the manufacturers) had ferrules clamped on the ends.

Clamped on every cable with the exception of the cooker and garage supply, which from memory i believe were both 6mm cables.

in hindsight, i should have taken a picture and shared this, but i didnt, so I failed you all!

To be fair, the electrician who did this, I can see committed to being very neat and tidy. One of the nicest installs i have seen in a while.


I personally have never done this with T+E so just found the ferrule thing a bit strange and wondered if it's something others do, and maybe this could or should be a future reg!?? Pro's and Con's i suppose. 

My thinking was that it does protect the copper cable inside the ferrule, allowing for a better connection too i suppose!?
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  • Former Community Member
    0 Former Community Member
    I work all over Europe on electro-technical systems and the national regulations (All CENELEC based), in some countries, locally require that ANY flexible cable in a terminal not specifically designed for flex (Such as a Wago connector) is terminated in a ferrule.


    The logic goes (so I have read in those regulations) that flexible stranded cables are more prone to the strands spreading under the terminal screw when subject to movement or resonance and the use of a ferrule reduces the risk of increased contact resistance and consequently fire. They certainly seem to maintain tightness better under long term inspection tests of cables from hire stocks that I have been involved in testing..


    It is certainly good practice to put ferrules on flex, and does improve the mechanical connection under a screw terminal. I use ferrules on all the work I do with flex where it would help, that way we keep compliance in any jurisdiction, and it results in a far better job for almost no cost.

    We also crimp the ferrules before inserting. I have seen some just pushed on and tightened under the screw.

    They are so cheap and easy to use it is a no-brainer to use them on flex, and anyone who takes pride in their work appreciated the better look of the install. 


    Quite a lot of connectors (Such as Phoenix connectors or Powercon connectors) have a small metal shim between the screw and the cable and are specifically intended for use with flex and do not require a ferrule in those jurisdictions. I haven't found any detriment to putting ferrules on those connectors.


    I can't see any reason to use a ferrule on a solid core cable other than cosmetic reasons, although maybe under extreme misuse (such as gross overtightening of the terminal screw) it may help.
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  • Former Community Member
    0 Former Community Member
    I work all over Europe on electro-technical systems and the national regulations (All CENELEC based), in some countries, locally require that ANY flexible cable in a terminal not specifically designed for flex (Such as a Wago connector) is terminated in a ferrule.


    The logic goes (so I have read in those regulations) that flexible stranded cables are more prone to the strands spreading under the terminal screw when subject to movement or resonance and the use of a ferrule reduces the risk of increased contact resistance and consequently fire. They certainly seem to maintain tightness better under long term inspection tests of cables from hire stocks that I have been involved in testing..


    It is certainly good practice to put ferrules on flex, and does improve the mechanical connection under a screw terminal. I use ferrules on all the work I do with flex where it would help, that way we keep compliance in any jurisdiction, and it results in a far better job for almost no cost.

    We also crimp the ferrules before inserting. I have seen some just pushed on and tightened under the screw.

    They are so cheap and easy to use it is a no-brainer to use them on flex, and anyone who takes pride in their work appreciated the better look of the install. 


    Quite a lot of connectors (Such as Phoenix connectors or Powercon connectors) have a small metal shim between the screw and the cable and are specifically intended for use with flex and do not require a ferrule in those jurisdictions. I haven't found any detriment to putting ferrules on those connectors.


    I can't see any reason to use a ferrule on a solid core cable other than cosmetic reasons, although maybe under extreme misuse (such as gross overtightening of the terminal screw) it may help.
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