Extending supply from one CU to the next with internal connectors

Just been browsing parts and seen these


Wondering if in some cases they are a more elegant way of effectively splitting the supply to two consumer units.

Run supply into first unit and then use one of these to connect to the second unit. Struggling to get my head around how I would connect inside the consumer unit and maintain a supply capable of carrying ideally 100 amps.

Presumably the bus bar is ok if the connector is next to the incoming device, second board would use another one of these instead of a switch.

Then presumably use a short internal neutral cable from hager or similar from the neutral bar.

Wondering why I haven't seen others doing something like this. I am mainly looking at EV installs.

I assume these are aimed at when CU's are stacked and enabling effectively internal interconnection, where as for me I would probably have the boards next to each other, maybe with a gap. 

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  • I did one recently, I wasnt at all happy in doing it, as it was just messy.

    This was a Hager 3 phase +N board, they actually sell a kit for it, at the top of the DB busbar cover, there is a plastic cover, around 50mm square, this comes off, and 3 bolt on connectors are put on, the 3 legs+N then go through to the adjacent DB. Of course, 4x 25mm tails take up a lot of room, and are not particularly easy to bend, so it looks a mess.

    I also brought up that Henly blocks would be a far easier solution, and being as there was 100mm ducting under the DB's, it would be neater too, but I was over-ruled.

    The Hager one is a poor option, as if you turn off the first DB, the second is turned off as well.

  • Alan, could we be told the part number please?

    I find this bizarre. It implies that there may be times when the first half of the installation is drawing no load and the second half is drawing the whole 100A.

    My own 40 y.o. DBs are rated at 80 A. The first breaker is rated at 60 A: the cables look rather like consumer's tails and pass through a short length of 32 mm galvanized conduit to the second DB, which has its own main switch. I assume that this arrangement was used because the manufacturers did not make a sufficiently long DB for all of the circuits.

    In any event, that sort of dummy main switch could have been used had one existed because there does have to be some means of attaching the busbar.

    I do wonder whether this device goes against the spirit as opposed to the latter of 314.

  • Link below, now I've seen the price, I know it would have been better to get some service connector blocks with 2 sets of tails.

    Hager tap off kit.