cabling issues

The house I bought came with a fairly large fully operational c-bus network (52 units) with output units spread out in 3 different locations.

I am worried that the cabling done by the installer is not very "pro".


picture 1: c-bus ethernet (very long) cables running from one output unit in one location to another output unit in another location: the cables on one end are as pictured below (i suspect this is a crossover). What clipsal part should i use to clean this mess ?


picture 2: it turns out 3 (very long) cables going to output units in "remote" locations are all connected to one single output unit in the main location, by having those 4 cables split and each color soldered together (picture 3). Is this proper (in terms of cabling) ? Is there a clipsal part to do this cleanly ?

Thank you

 

Hi nsa195
Ashleigh is correct.

It really is time to get someone out there to check the installation and rectify the segregation.

I've mentioned this to you before but I want to make it clear that CBus network wiring is not Ethernet.
It may use the same cable and plugs but shares nothing else especially the wiring connections.

I'd be horrified if a tradesman joined my Ethernet cables like that in a data enclosure but it's a whole lot worse since he has done that inside an electrical switchboard.

You can read all about how it should be done here. http://www2.clipsal.com/cis/technic...ing2/cbus_control_and_management_system/basic

Every single CBus component also has detailed installation instructions on CIS web site.
It's a lot of reading I know but clearly some people who should be reading it aren't.

You could read all that and definitely be much wiser than the electrician who wired that board but unless you are an electrician your really shouldn't be doing it yourself.
It's not just some Cat5 cable for data, it is Cat5 cable stuffed into an electrical switchboard.

I also agree that the electrician who did that work should probably be prosecuted.
Perhaps you could investigate that path to having the repairs made.
Or even better find someone with some CBus experience to fix the wiring and get you up and running with the programming.

 

How about feeding the pink cables into a 30 series outlet enclosure (Part number 4PS31). Make sure they are fixed in, maybe cable tie and with no single insulation showing. Use an RJ45 socket in place of a switch and you have a C-Bus socket available at your board.
Still, I agree with the others here and would strongly suggest getting someone qualified in to have a look. If this is the standard in the accessible board, what is the rest of the install like?

 

I agree and disagree with the comments posted in response.

Firstly, I think it's a little unfair to paint a picture of gloom and doom on this installation. Yes, it is not legal and potentially dangerous but... it should not be an expensive exercise to fix and get it up to spec, so don't feel it will cost the earth to fix and try to do it yourself

Engage a professional who will know how to make this legal and safe. I won't say what needs to be done (offer advice) but any reasonable installer should be able to tidy this up in an hour or two.

BTW, the tape used does look like white electrical insulation tape, but the installation is still not legal or safe as Ashleigh has indicated.

 

Hi conformist
I agree that the homeowner does not need to be alarmed excessively but this definitely does need to be fixed.
Hopefully he will take the advice from everyone here.

It's very disappointing to see such poor workmanship on the CBus install but I also think that making it much safer is not that huge a task.

If the guy who did the wiring also did the commissioning it would be another good reason to get someone with some experience to look at it.

 

Agree that this install is crap, but you raise an interesting point about separation.

I had it put to me that even though C-bus carries ELV signals, it in fact should be treated as if the cable is LV (240v) due to the (lack of) isolation within relays and dimmers. Hence why C-bus should be using mains rated cable. So by rights it should be run with other LV cables, and should NEVER be run with data cable and the like.

Must admit cannot find any specific reference to this, though DALI, which uses a similar principle of using ELV signals on a mains rated 'data cable' does quite clearly state the cable should actually be treated as LV and run as such.

 

Hi Ashley W
I am not aware of any CBus installation instructions which suggest segregation from data cabling but there definitely are instructions to avoid running CBus cables alongside power cables.
In the case of this installation it sounds like it is perfectly functional.
But the segregation is poor and does need to be fixed.

It's taking it to another level if someone was to suggest that a fault on the CBus network could potentially make the CBus cabling 240V and also incorporate a breach of it's mains rated insulation and the data cabling insulation at the same time.
This is exactly why this installation needs to be fixed because the risk of 240V being applied to the CBus cables is high.

 

It is an interesting issue and one I don't think any regulation covers all that accurately.

I mean to say from a separation issue, it is fine to run C-bus in a switchboard enclosure with 240V present so long as you use the pink C-bus cable. In fact you need to, to get to output modules etc. But in the next breath you need to maintain separation from mains. So begs the question is that cable then a SELV data cable, a power cable or something different?

As mentioned DALI is similar in the electrical characteristics on the control cable, but is NOT considered to be an SELV cable and may be run with power and certainly shouldn't be run with data.

So where is the difference.

Buy yeah in this case it is very poor and having exposed terminations certainly goes against Clipsals own advice.

 

Interestingly Clipsals own training material doesn't quite say that. What they say is using the pink cable inside a switchboard.

So closer than normally would be allowed, meaning it isn't really the same as an SELV data cable, and practice is to keep as far apart and cross at 90 degrees for noise immunity, no mention of safety, which is the crux of data cabling rules. So about as clear as mud really.

 

Hi Ashley W
This is my take from Introduction to CBus training manual.

CBus cabling is classed as SELV.
I can find no recommendation to separate CBus Cat5 from data cabling around the installation.

A well laid out board will not have the pink cable in contact with mains cabling.
I find this practically achieved by considering the following.
Ensure the pink cable enters the left side of the board, keep the mains wiring to the right, one output unit per switchboard row, control breakers and RCD's to the right side of output units, that the board is of a suitable size and layout, other measures such as ducting and whatever else needs to be done to make it safe.
At the end of these instructions is the quite critical requirement to anchor the CBus cables and the mains conductors within the switchboard so that they cannot move and inadvertently touch each other.

Some bits from the manual

A bit from a relay instruction sheet regarding bungs for the RJ45 sockets.

 

Don't need to convince me, I've been working with C-bus since 1999 and been working in the communications industry since 1990.

I only raised the question because it was put to me in the context of the electrical characteristics of DALI with the question why DALI treats the control cable as LV, whereas it seems C-bus it is SELV with some exceptions in the switchboard. I must admit I think the question is still very valid, especially in the context of the picture in the first post which we all agree is bad practice and dangerous.