Tag: Smart Designer

Building a 4-way “industrial looking” junction box

Note: this post continues our adventure of converting a workshop into a flat.

After the successful build of the terminal blocks of our distribution enclosure I continued to design a junction box for the electric wiring in the rooms.

First, I had to decide on the maximum number of connections I would expect to have in a single junction box. I came up with the number of 4. And here is why:

Most of the time, we will have a standard “Tee” to either connect sockets or to distribute to a different part of a room; and sometimes we will have a “Tee” and additionally connect a socket which will be a Feller 2xT23 Standard to which we run 5-core (3LNPE) to distribute phases. Besides, much more than 4 connections to and from the box would be difficult to achieve.

In order to facilitate testing and maintenance, I decided to equip the junction boxes with a neutral-disconnect. For this the Wago 2003-6641 comes in handy (which is much harder to get than the Wago 2003-764x models). It has a lever with a “disconnect knife” that cuts the neutral. As I want a 3LNPE 4-way junction, we have to use 2 of these next to each other with a jumper. That means, depending on what circuit we want to test, we have to remove that jumper as well.

Our initial version would therefore look like this and would fit easily within 2 modules (including stop-ends):

  • Top view: 4-way junction with neutral-disconnect and jumpers
  • Side view with end plate and stop-end
  • PE is connected via DIN rail

For most of our lights we want to use an Intertechno radio receiver to switch the loads. We already have some existing ITL-1000 which we will be repurposing for this conversion. However, there is also a newer version, the ITL-2000, which can switch two 1000W loads independently – which is actually the preferred way. But this means we have to split the neutral and have additional PE terminals. For this, we use the “Tested and Approved” (anyone remembering this from the 90?) Wago 221-413 connectors mounted on a mounting carrier. So, here is the final layout:

  • 4-way junction box with 35mm DIN rail-mounted terminal blocks
  • Junction box with neutral-disconnect
  • Top view with dimensions
  • Part numbers
  • Junction box with Intertechno ITL-1000 receiver

But to make this junction box look “industrial” we have to find a suitable enclosure. In my opinion it must have a transparent cover. Like this (which I found on Amazon):

Junction box with transparent cover, image taken from https://www.amazon.de/dp/B07BM58W29

And here the box as a prototype with the terminal blocks with 2003-764x, jumpers missing and an ITL-1000 (the other parts are still in the mail). As soon as I have installed one of these on the wall with all the cabling I will post an update.

Wago: LEGO for grown-ups

Note: this post continues our adventure of converting a workshop into a flat.

Most of the electrical parts arrived. So it was time to draw the rest of the electricial installation inside the enclosure – and of course to apply some last minute changes …

The first thing I had to change was the vertical bus bars due to a bug in the Hager Ready software which turned out to be not so ready. Based on my RCBOs the software suggested to use a Hager FWB72N3 7-row 2-field 150mm field enclosure – in combination with the 125mm quickconnect bus bars. Surprisingly they did not play along that well. So now, I exactly had to do what I did not want to do: excessive cabling from row to row inside the enclosure. What a bummer. Luckily, there are fixed vertical jumpers available from Hager in the required size:

Problem solved – just not with “quickconnect”. On the other hand, even with quickconnect I would have had to screw in the vertical bus bars anyway.

But now back to our terminal blocks. As we have a total of 11 RCBOs I see no point to install a bunch of separate neutral bus bars. Instead I opted for rail-mount terminal blocks from Wago that are also known as Wago TOPJOB S (how this rolls off the tongue). And Wago provides a web-based Smart Designer to help layout the terminal blocks and fight through their jungle of product names.

And this is what I came up with first:

3D view: terminal blocks w/o N disconnect
Top view: terminal blocks w/o N disconnect

Looks neat?! The software goes even further and produces a comprehensive bill of material which facilitates ordering the right stuff:

Wago bill of material for our terminal blocks including acessories, taken from Wago Smart Designer

But there the next problem was already waiting for me. As I wanted to connect the RCBOs not directly to the cabling that led to the appliances, but via a row of terminal blocks, I found out that despite the FWB72N3 being a Type II enclosure the upper to DIN rails were not insulated from the main chassis. So, I could not use these DIN rails to distribute PE over it – unless I replaced them with 4 UTC22C. Another “bug” in the Hager Ready software? Ok, not really a bug, but definitely a nuisance. The longer the more I began to question the advantage of buying a pre-fitted and pre-installed enclosure and using an app that calls itself “Ready” (with capital R).

And just when I thought I was finished, I changed my mind and added a neutral-disconnector into every outgoing RCBO connection – to facilitate testing an future maintenance. Now, I just have to lift the orange lever and the neutral is disconected – no plugging and unplugging of cables, no lose ends …

And this is what the final model of our layout looks like (and it just fits onto a 210mm 12 module DIN rail):

  • 3D view: mains in, 4x3x4 with neutral disconnect
  • View with material information
  • Bottom view
  • Top view
  • Side with with height information
  • Upside down

I must say, playing with the Wago configurator is a lot of fun. And unpacking it is also great – reminds me of my long-gone days of LEGO:

Wago – LEGO for grown-ups

With these 2 rows of terminal blocks I can easily change my configuration inside the enclosure or the cabling in the rooms without affecting each other.

The main terminal blocks accept 16mm2 for fine-strained wire and 25mm2 for fixed wire and the rest of the blocks accepts 2.5mm2 (fine-strained) or 4mm2 (fixed). Enough for all of our cabling needs. Each of the smaller terminal blocks accepts up to 20A whereas the larger terminal blocks accept 76A (all at 230V)

The next thing is to design a junction box for the rooms to distribute the cabling to the appliances.

Will keep you posted.