1

I need to extend a 32Amp ring-main. Can I use Wago connectors to tap and extend the existing ring?

3

Yes, but a few points need to be observed to make sure it complies with BS7671 IET 17th Edition.

Firstly, the terminals must be installed in a Wagobox (when breaking into existing ring wiring). This needs to be UK sourced to ensure you get ones that are stamped with [MF], meaning that it's classed as BS 5733 Maintenance Free box.

To comply with the IET regulations, each Wagobox is limited to 50Amps in total. The compatible terminals, 773(solid) and 222 (lever), are also derated to 20Amps.

Therefore, for a regular 32Amp ring main, you will need to use two Wagoboxes - one at the start and one at the end of the extension. As the load from any socket is shared in both directions of the ring (albeit unevenly), the derated 20Amp terminals are sufficient.

Before:

                         +---------+
     L                   |         |
    +--------------------+  |   |  +-----------+
    |                    | - - - - |           |
    |                    |         |           |
+---+---------+          +---------+           |
|             |                                |
|  Consumer   |                                |
|  Unit       |                                |
|             |                                |
|             |                                |
+---+---------+          +---------+           |
    |                    |         |           |
    +--------------------+  |   |  +-----------+
     L                   | - - - - |
                         |         |
                         +---------+

After:

                         +---------+           +-----------+
     L                   |         |           |           |
    +--------------------+  |   |  +-----------+  Wagobox  +--------+
    |                    | - - - - |           +-----------+        |
    |                    |         |                           +----+----+
+---+---------+          +---------+                           |         |
|             |                                                |  |   |  |
|  Consumer   |                                                | - - - - |
|  Unit       |                                                |         |
|             |                                                +----+----+
|             |                                                     |
+---+---------+          +---------+           +-----------+        |
    |                    |         |           |           |        |
    +--------------------+  |   |  +-----------+  Wagobox  +--------+
     L                   | - - - - |           +-----------+
                         |         |
                         +---------+
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  • 1
    AIUI you only have to use the wagoboxes if the joints will not be "accessible for inspection". Otherwise any normal electrical enclosure is fine. – Peter Green Jul 19 '17 at 18:26
  • Wago connectors can be used inside normal socket back boxes. No need to use a Wagobox. – John Jan 22 at 0:01
  • @John of course, if you can easily get 2x new T+E into an existing back box, then do that. Then you only need to use 2x Wago connectors to extend the ring on one side (using the socket terminal for the other side). But the situation I was detailing was one where it's easier to tap into the wiring than it is to tap into the backbox, e.g. under the floorboards. – Alastair McCormack Jan 22 at 12:28
1

In first fix, I use the spring lever Wagos with three connections inside the socket backboxes. Four connection Wagos for the earth. Then test the wiring. Then the plasterers and painters do their work.

Then on a bench, I then fix flexible 2.5mm cable tails about 5 inches long to the L, N and E of the sockets (could be over 30 of these). Then insert the flexes into the Wagos inside the boxes. The socket being on flexible wire just easily push into position. The time it saves is substantial. Easy as a lot is on a bench. The Wagos also ensure the ring is is always complete, not relying on the screw connections on the back of sockets having two 2.5mm cables run into them. Wago connections do not work loose over time, so the rings is not compromised.

In Germany they have sockets with Wago connections on the back. The UK does not have them yet.

There is talk of all Wago connection consumer unit, even the 25mm connections.

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