Cabling

how far should Cat5 cable for cbus be ran from mains power.

Also, is there any problem running cat5 for data/tele, caox cable & Speaker cable along the cbus cable.

Im planning to pre-wire the house. There is going to be a lot of cable. and not sure how to arrange it all. Should mains power be cabled first?

 

The ACA cabling requirements (pretty much based on the same root standards that cover installations around the World) are that Data (covers phone/computer) must be at least 150mm away from mains and should only cross at 90* and parelell runs should be avoided, all these are to limit interference between the mains and the Data cables. As far as electrical safety is concerned as long as the mains cable is double insulated (with each of the two insulation layers being individually rated to mains requirements) then the Data/Comms cable theoreticall could be run right next to the mains stuff but with the risk of interference (and in any case this is specifically not allowed under the ACA cabling regs). In most cases C-bus cable should follow the same rules as Data/Comms but where the C-bus cable comes into the switch board it cannot avoid comming into closer than 150mm to single insulated mains which is typically being taken to the power supplies and output channels of C-bus relays and dimmers in the board. However this will not breach the wiring regulations as long as the PINK C-bus Cat 5 UTP is used as it has been specifically designed to have a mains rated outer sheath (the PINK bit).

Because the C-bus comms are relativly slow and robust with error checking the likelyhood of mains interference from this close running with mains (as it is typically over a very short distance) is not of concern to the correct operation of C-bus.

Running additional services along the same Cat 5 cable is not recommended:

1. typically the C-bus cable 'daisy chains' around an installation with only 4 of the total 8 conductors being terminated at each key input so extra inline terminations would have to be made to provide continuation of other services.

2. the remote override on and off for C-bus relays and dimmers runs down the 4 conductors not used for C-bus +ve and -ve.

3. The C-bus cable may run for 1,000m much longer than most other services can run over Cat 5 UTP.

4. while it is unlikely that the C-bus comms will be effected by phone or data messages being passed down adjascent cables I would not be so sure that the phone or data messages would not be effected by the C-bus comms.

5. the C-bus PINK cat 5 UTP is that colour for a very good reason - so that people working on the phone or data system don't cut in to the C-bus cable by mistake (and Vice Versa) the whole idea is to make sure it is kept seperate.

 

cable bundles

the issues with seperation of mains voltage cables and data/comms cables are very clearly laid out as above. Pesonally I have had no trouble running c-bus cables together with those for data, phone, TV, and security. I should clarify that, I am only concerned with the c-bus system and it has not effected my system, I'm not sure of the effect on the other systems and even then it would only be the data lines (Cat 5) that would probably be effected and even this I think would be unlikely.

 

The only issue that I have heard of in regard to the bus cable being bundled with other cables came from Inner Range security. Their LAN cables use a data clock, similar to C-Bus, and they are wary of that being corrupted by C-Bus. They advise keeping the cables seperate.
My advise would be to install all the Low Voltage cables last, after the other trades have all finished their first fix.

 

I agree, if you are worried, let everyone else run their cables first, then you can control the segregation.
The probability of C-Bus corrupting any data on a cat 5 cable is very minimal considering most cat5 installations can run 1G (with varing amount of errors)but mostly only run 100meg or 10meg.

I really dont think there is any issue of C-Bus corrupting data in a household environment, If it was a commercial cat 6+ situation then that maybe different but that would only show up if you did the data testing when C-Bus was fully operational.

 

The Question I was answering was if it was wise to use the 'unused' pairs in the C-bus Cat 5 for Phone, Fax, Data, Speaker ETC. There should be no problem running the C-bus Cat 5 in the same tray or conduit as these other services I just don't think they should run in the same cable.

 

my plan is to run pink cat 5 for Cbus, blue Cat 5 for phone and date (seperate cables for each, might get grey cable for phones) RG6 coaxial and speaker cables along each other in the same channel.

Basically my question has been answered.

One the plumber and sparky have completed their work, I will come in and run the above cables in the same channel where possible,