Redesigning the sub-distribution board

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Redesigning a sub-distribution board in the house can make sense in various cases: for example, when completely renewing the electrical wiring or replacing an old fuse system with a new one, possibly with RCD(s).

Feed-through terminal installation box

In both cases, the old cables turn out to be too short, which is why they are shortened to a suitable standard length and made available for forwarding to the downstream busbars and automatic machines, etc. using PHOENIX-CONTACT UT 2.5 BU feed-through terminals, for example.

If higher capacities than for 2.5 mm²If the 2.5 mm feed-through terminals have to be used instead of the 2.5 mm feed-through terminals. The wiring must also be designed for the required cross-sections.

Installation in a separate, wide 1-row distribution board is recommended if the new distribution board is narrower than the previous one.

Distribution cabinet

The size of the distribution cabinet depends on the additional components to be installed. In 3-phase systems, it should have 4 rows.

The first row is used to accommodate the 5-pole main line branch terminal (the three phases, neutral and earth conductor), the 3-pole main switch (for the three phases) and the 4-pole RCD (for the neutral conductor and the 3 phases). The following three rows are assigned to the three phases and fitted with the appropriate circuit breakers.

Normally, all cables come in from above. In some installation situations, cables may also enter the distribution box from below.
To avoid having to thread all the cables behind the rows of vending machines through to the upper floor (which is usually difficult simply due to the limited space available behind the DIN rails), feed-through terminals are also available here at the end of the last three rows, from which the cables can be conveniently routed upwards along the edge.

And the finished distribution ...

Performance measurement

If you don't just want to read off your total consumption at the meter, but also want to find out how much you consume in phases, you can use various devices that cover a wide range of applications and conveniently display data via an app.

However, the use of such devices is not only advisable for the sake of clarity, but in particular for the purpose of determining a largely uniform utilization of the individual phases.

If you want to process the data further or, for example, switch consumers, such as the charging process of a vehicle, at certain times and depending on the phased utilization, you should make sure that the device also allows integration into such SmartHomes and that the required protocol is supported, such as Shelly products.

This device is available in two versions: "T" stands for terminal connections, which are intended for direct mounting on an RCD. The "W" variant has a cable with a cable end lug for each socket instead.

Both record consumption and feed-in equally via inductive sensors in a housing designed in the grid dimension of RCDs.

During installation, the direction of the current flow must be observed so as not to register yields that should actually be allocated to the consumption side ... - Accordingly, "L" indicates the consumer side, "K" the supply / feed-in side (PV).

Each phase is connected to the three plug contacts via three cable lugs and the neutral conductor is also connected.
The phases should be protected by fast-acting 100 mA 20×5 mm glass fuses in appropriate fuse holders. It is said to have happened that such a device has quietly gone up in flames ...

Setting up the device is really plug & play. Using the app, which can be downloaded via QR code from the relevant app store, you connect to the device via Bluetooth, which is recognized immediately. A connection to the local WLAN is then offered. Once the relevant security queries have been approved, the device connects to the home Wi-Fi network and can be accessed from then on.

The display of consumption data in the app is clear, if not spectacular.

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All information without guarantee - installations on electrical systems may only be carried out by authorized specialist personnel!