My New Creation

Hi,


I wanted a simpler, faster way of connecting C-Bus cables so I created the PC board shown in the attached image.

It has three rows of Krone IDC connectors. Each row can terminate up to 2 C-Bus cables using a Krone punch-down tool.

There is an RJ-45 socket for easy connection to DIN units and push-clamp terminals that provide quick & easy access to the override pairs.

The board fits inside a large junction box.

What do you think?

 

Well done

It is definitely what a lot of people have been looking for.

I would add a second RJ45 socket so that more could be added by using the small patch leads available.

How do you plan to mount it?
Where is it intended to be mounted?

Can it be made to fit a surface mounting block (SMRJ88A5/4 for example - remove the insides and put this board in its place)

I know some like to home run their c-bus cables and this goes towards helping this design.

Mick

 

I plan to use these in the roof space to star-wire runs to switches in a retro-fit. The board is 50mm x 70mm and fits inside a standard clipsal large junction box, which was my target enclosure.

My initial design had more RJ-45 connectors but these take more space, plus for longer runs you need to fit off RJ-45 plugs onto the cable. Then I had the idea to use the Krone blocks, which as well as being fast to terminate are easier to terminate when working in a roof space.

It would be pretty easy to replace the override terminal block with a second RJ-45 socket and keep the board dimensions the same.

You could probably use an SMRJ88A5/4 as a C-Bus "Hub" pretty easily by just looping the sockets together with some Cat-5 by punching down with the non-cutting blade on your punch-down tool.

Paul

 

The explanation helps a lot in understanding what you have done and why.

The problem with looping the cables is that is you want say four cables coming in and four RJ connectors then you need to double up on some of them (on the punch down side). Not strictly correct procedure for punch down but it will work. This is where your creation works better. That was what my line of thinking was in my statement.

Would you use the over-ride pairs in the ceiling?

Mick

 

You are right, you probably wouldn't use override pairs in the ceiling, but I wanted to make the board as general purpose as possible.
In most cases I won't fit the connectors for the override or the RJ-45 socket where it isn't needed.

Paul

 

What I have used in my place are the DIN rail shorting blocks in small DIN rail boxes. I run the cable from the device, put bootlace crimps on the wires then screw them into the modules. The way I have the DIN rails modules I have +-+-+-+-+-+-+- and each colour coded. Seems to work. Cannot get a picture because my house is currently rented out.

Just one question with the Krone method is there any current issues? Afterall the IDC modules only make surface contact with 2/3 to 3/4 of the wire.

 

Clipsal recommend the use of surface mount blocks near a switchboard an these are a punch down design, so I would assume that there are no current issues.

Mick

 

I use looped rj45 sockets on a solid mounting block

and put rj45 plugs on all the ends. While this is a bit of work at the time of the installation (and a bit of extra cost) it makes it very handy to isolate individual parts of the network later.

 

What would you expect these to cost to manufacture? I'm sure that if you were to manufacture, or have manufactured, a batch of these, that you would sell them pretty quickly, especially considering you've designed them to fit inside a standard large junction box.
Might as well find out what they would cost to manufacture if you're interested, I'm sure you could make some money out of them, especially considering that CIS themselves don't have anything that will to the job that you have designed this board to do.
Very neat and clever design Paul, well done

 

Darpa,

I'm sure CIS are copying it as we speak...

 

I know, I was thinking the same thing, but c'mon Peter, I have to give Paul some words of encouragement, I mean, he's obviously put alot of thought and effort into it, so he deserves a pat on the back, although I'm sure he would prefer a cheque in the mail from CIS buying him out though

 

Alright Alright, so I live in a fantasy world!
But with the state of affairs in this world of late, can you blame me Peter?

 

Another possible solution

We should be able to use this product as a C-Bus network distribution point.

The StarServe 8054/6TL Series Telephone Distribution Hub distributes up to four incoming telephone lines to six locations.

The StarServe 8054/8TLEX Series Telephone Expansion Hub is a companion accessory for the 8054/6TL, designed to extend the telephone routing capability.

http://www3.clipsal.com/cis/pdf_files/Telephone_Hub_8054-6TLxx.pdf

There are lots of variations of these products out there. You should be able to find one that meets the need.
(I am trying this method on my current job) Should easily handle the volts and current I believe.

 

Looks like Clipsal actually DO have something suitable out there in the wild that can be used for this purpose.

Have a look at the Clipsal 8058/8RJ Harmonica

It appears to have a 4 pair IDC punch-down connector at the back, and 8 RJ45 connectors at the front, all wired together.
Maybe worth looking at? (Although not particularly cheap...)

It is also available with a 30mm mounting bracket (8058/8RJSMB)
and a 60mm Mounting Bracket (8058/8RJDMB)

Link to Clipsal PDF HERE.

Darpa

 

Harmonica as a star point

The Clipsal Hamonica is available in two basic versions; the 8058/8RJ has 8 lines in (punch down on the rear) each connected to a RJ45 on the front.

The 8052/4RJ has two sets of 2 lines in (punch down on the rear) to 4 commoned RJ45's on the front.

Each of the above are available in a shallow or deep frame mount.

I recently used a 8052/4RJ as a central star point for a C-Bus network. By just adding 4 very short straps on the rear you end up with 8 RJ45's on the front all commoned together using the correct 4 pins for C-Bus wiring. I divided the cable network into 6 sections and then commoned the cables at the 8052/4RJ (plugged into the front). If I get a problem in the future I can unplug each cable in turn to isolate a faulty cable, etc. It also gives me 2 spare RJ45's which could be used for future expansion. I also plug the laptop into one of the spare outlets for normal Toolkit operations.

This arrangement has been working for 5 months without any problems.