Taking over a Lutron Install

Hi all,

I've been to a job today that has been wired for Lutron and the customer has fallen out with the client who did the 1st fix and found me.

All the circuits go back to a central point and the switches are all looped in and out just like in CBus however the cable used isn't a Cat5 but is this

http://www.mr-resistor.co.uk/item.aspx?v=1&i=3745&gclid=COyro-eYzsMCFQoEwwodh0UAIg

It says data is purple and white so can I just use these instead of the usual orange + blue (pos) white orange/white blue (neg)

Also while I'm on the subject I don't do the installation just the commissioning but every electrician who installs it for me always asks why they can't just use orange/orange white pos) and blue/blue white neg so they don't have to untwist and retwist every switch/sensor.

Is there a reason for this or as long as this enters the Cbus dimmer/relay int the correct + and - would this be ok?

Thanks as always

 

Lutron cable

Hi ,
Had similar situation around 3 years ago with a customer who had first fixed for Lutron and had a fall out with integrator , we used the Lutron cable and everything has been working correctly since installation .
On your point ref cable pairs , the reason you pick a colour from each pair is to insure that it is still a twisted pair when you twist each core together if they don't do this it won't be a twisted configuration just a doubled up cable . Hope that makes sense .

Cheers
Conor

 

While not "Clipsal certified" recommended, it will work on a suitably rated twisted pair cable (almost 20years ago, C-Bus first came out for use with telephone wire!), so either the purple and white OR the red and black should work.

No Not OK. (off the top of my head) The reason is to keep the twisted pair integrity, to minimise noise to/from the cable. The twist keeps the opposite magnetic fields together so they cancel each other out.
(It may work, but you may also have unexplainable issues)

 

That Lutron cable doesn't look twisted, ie it should have a minimum twists per inch. The idea of twisted cores is that any emf noise that makes it into one core makes it equally into the other and cancels itself out.

However, that cable looks shielded, so you can tie ONE END ONLY to earth and that will drain any emf noise before it gets to the signal wires. Earthing both ends is worse than not earthing either end and you.

In all seriousness though, second/third year electrical apprentices should know most of this stuff. If your sparky's are asking a question like this i'd be looking for other sparky's.

At the end of the day they should RTFM and follow the manufacturers instructions, it tells you what to do. Google UTP cable ( unshielded twisted pair ) cable, it will tell you why.