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

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