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Ferrules or fork-crimps in screw-clamp terminals

Udtwmc
Currently in a dispute with a customer over bootlace ferrules I have used in screw-clamp type terminals - this is an industrial control panel designed to BS EN 60204-1, the wire used is class 5 tri-rated.


The customer says bootlace ferrules are the wrong type and wants them changing to fork-type crimps, arguing that the screw-clamp applies even pressure on fork crimps and a better contact but not so when ferrules are used - if you can picture the bootlace-ferrule on one side of the screw- with its clamp being at an angle as there is nothing on the other side of the screw. However, the termination is tight and makes a good solid contact with the ferrule so I think this is perfectly acceptable.


While I wouldn't generally disagree with a customer, there are hundreds of terminals to change, they didn't specify fork-crimps at design stages and I don't interpret anywhere in BS 60204-1 or BS 60947-1 that ferrules are wrong in screw-clamps.


Any opinions much appreciated.


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  • Former Community Member
    0 Former Community Member
    I have done panels for many clients over the years and I have never seen a requirement for fork connections rather than bootlace ferrules in a screw clamp connection.

    The panels have been supplied to global blue chip clients across many industries without issue.

    I would never snag this on a panel whether working for the equipment manufacturer or the buyer, unless it was in a specification document.

    Unless it is written into the signed contract I would be telling the client to jog on.

    I have yet also to see a screw clamp terminal on a device that the device manufacturers state as unsuitable for a single ferruled class 5 or 6 conductor.

    If it’s a machine panel then 60204-1 will take precedence over 61439 anyway.

    Designing and building to 60204 meets the LVD (EESR) anyway.  Where as the 61439 series does not meet the requirements for the MD (SMSR).

    When it comes to it effectively the two pieces of legislation are mutually exclusive.  It’s a declaration to one or the other for final piece of machinery.  Which obviously has to be the MD/SMSR, as the LVD/EESR do not cover machinery, but MD/SMSR, covers the requirements of the LVD/EESR anyway.

     The only reason why you would have to change, apart from placating the customer is if the connected device OEM states that a single ferrule is not acceptable in their product.

    There is nothing in standards that requires a fork in a screw clamp connection.
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  • Former Community Member
    0 Former Community Member
    I have done panels for many clients over the years and I have never seen a requirement for fork connections rather than bootlace ferrules in a screw clamp connection.

    The panels have been supplied to global blue chip clients across many industries without issue.

    I would never snag this on a panel whether working for the equipment manufacturer or the buyer, unless it was in a specification document.

    Unless it is written into the signed contract I would be telling the client to jog on.

    I have yet also to see a screw clamp terminal on a device that the device manufacturers state as unsuitable for a single ferruled class 5 or 6 conductor.

    If it’s a machine panel then 60204-1 will take precedence over 61439 anyway.

    Designing and building to 60204 meets the LVD (EESR) anyway.  Where as the 61439 series does not meet the requirements for the MD (SMSR).

    When it comes to it effectively the two pieces of legislation are mutually exclusive.  It’s a declaration to one or the other for final piece of machinery.  Which obviously has to be the MD/SMSR, as the LVD/EESR do not cover machinery, but MD/SMSR, covers the requirements of the LVD/EESR anyway.

     The only reason why you would have to change, apart from placating the customer is if the connected device OEM states that a single ferrule is not acceptable in their product.

    There is nothing in standards that requires a fork in a screw clamp connection.
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