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421.1.201.

Zoomup
Mornin' All,

                      is there available an insulated enclosure, non conducting, suitable for a double pole D.I.N. rail mounted R.C.D. that complies with 421.1.201 please.


Z.
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    An ordinary "REC2" enclosure?


    A simple RCCB in a box isn't a CU or similar switchgear so wouldn't come under the scope of 421.1.201.


      - Andy.
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    AJJewsbury:

    An ordinary "REC2" enclosure?


    A simple RCCB in a box isn't a CU or similar switchgear so wouldn't come under the scope of 421.1.201.




    Agreed!

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    I'd assume any of   these  so long as you do not make it into a CU .

    or a bit dearer, but if you prefer the REC look most companies make  dp isolators   that can be sealed, though you get a switch left over to put in the spares pile.

    flippancy aside the  hagar one  has a nice cord grip for the tails.

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    Thanks all. I was just checking to see if anything had changed after the long discussions about this subject in the past. I intend to place a 100mA S type R.C.D. before a new metal cased consumer unit on a TT earthed installation.


    Z.
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    Zoomup:

    Thanks all. I was just checking to see if anything had changed after the long discussions about this subject in the past. I intend to place a 100mA S type R.C.D. before a new metal cased consumer unit on a TT earthed installation.


    Z.




    Could the S type not go in the CU as per section 2.2.6 of the OSG?


    F

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    Farmboy:




    Zoomup:

    Thanks all. I was just checking to see if anything had changed after the long discussions about this subject in the past. I intend to place a 100mA S type R.C.D. before a new metal cased consumer unit on a TT earthed installation.




    Could the S type not go in the CU as per section 2.2.6 of the OSG?



    Yes, that seems to be the common way, but if an isolator is going to be installed in a (domestic) TT installation, then why would you not use an RCD "main switch" instead of an ordinary one in your REC2 (or similar) enclosure? The you can stop worrying about your tails flapping about or getting chaffed - as if that could happen when competently installed!

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    Farmboy:




    Zoomup:

    Thanks all. I was just checking to see if anything had changed after the long discussions about this subject in the past. I intend to place a 100mA S type R.C.D. before a new metal cased consumer unit on a TT earthed installation.


    Z.




    Could the S type not go in the CU as per section 2.2.6 of the OSG?


    F


     




    I like the idea of an R.C.D. before the metal consumer unit in a TT system, because if a fault occurs inside the consumer unit, (however unlikely) say a short from L tail to metal case, the whole enclosure could become live along with the metal cased appliances within the installation and all bonded metalwork as well. The R.C.D. before the consumer unit will prevent this happening.


    Z.

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    Chris Pearson:




    Farmboy:




    Zoomup:

    Thanks all. I was just checking to see if anything had changed after the long discussions about this subject in the past. I intend to place a 100mA S type R.C.D. before a new metal cased consumer unit on a TT earthed installation.




    Could the S type not go in the CU as per section 2.2.6 of the OSG?



    Yes, that seems to be the common way, but if an isolator is going to be installed in a (domestic) TT installation, then why would you not use an RCD "main switch" instead of an ordinary one in your REC2 (or similar) enclosure? The you can stop worrying about your tails flapping about or getting chaffed - as if that could happen when competently installed!


     




    Reasons why the L could flap about and touch the metal consumer unit enclosure these days.


    1. Tails are like spring steel due to hard copper, that could cause  stresses that may move the tail from its terminated position to a dangerous one. 


    2. Modern terminals are p.p. and do not reliably grip the tails in my opinion. They are only a single screw device with shallow grip on the conductor.


    3. Breakdown of the main switch due to poor quality or lightning damage.


    4. X. The unknown as yet fault that causes the L tail to liven up the consumer unit enclosure and everything else.


    Z.

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    A CU can be far more dangerous and confusing place than the REC enclosure . Yes the tail could comeout, but that is only the half of it, especially with a normal main switch and DP RCBOs as some advice suggests.

    There are many wires from final circuits of all shapes and sizes, and in some boards extra wires flapping about from circuits now isolated, but  seemingly left in either just  for luck or it was too hard to untangle, or perhaps in case of later need. Thinner wires like 1mm CPC can be quite springy, and may miss the terminals altogether and if it slips down the back of the MCBs could catches the bus-bar, all is lost, or they could hit the pre-switch live.

    Even without the TT hazard there is a lot to be said for an isolator with only 4 clearly defined terminals and wires that pretty well fill them, and with TT, there is merit in it being an RCD, and no metal or CPC anywhere near it..
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    Zoomup:




    Farmboy:




    Zoomup:

    Thanks all. I was just checking to see if anything had changed after the long discussions about this subject in the past. I intend to place a 100mA S type R.C.D. before a new metal cased consumer unit on a TT earthed installation.


    Z.




    Could the S type not go in the CU as per section 2.2.6 of the OSG?


    F


     




    I like the idea of an R.C.D. before the metal consumer unit in a TT system, because if a fault occurs inside the consumer unit, (however unlikely) say a short from L tail to metal case, the whole enclosure could become live along with the metal cased appliances within the installation and all bonded metalwork as well. The R.C.D. before the consumer unit will prevent this happening.


    Z.


     




    I prefer it too but it was frowned upon by the niceic so I was towing the line and going with OSG, but think I'll go back to the insulated enclosure.


    F

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