My Design

Hello

I?m putting together a CBUS scheme with the knowledge I have learned through readying the various materials on the web and contributions to this forum.

I?m hoping the group could given me some confidence that I?ve got the right idea.

So here?s my high level design. I am in the UK and will have 44 areas of lighting (or circuits) spread across three floors. 32 of these will just need to be simple on/off states and will use either a CFL or LED bulb. 12 of the areas will need to be dimmable and will use only CFLs.

I have come up with the following hardware list:

1 x L5512RVF - 12-Channel Voltage Free Relay, 240V AC, 10A, with power supply
3 x L5512RVFP - 12-Channel Voltage Free Relay, 240V AC, 10A, without power supply
3 x L5104D5 - 4 Channel Dimmer, 240V AC, 5A, with power supply
1 x 5500PCU - PC Interface, DIN Rail Range USB
12 x E5058NLGB - NEO Range, 8 Gang Input, Metal/Grey Finish

Does that look right or have I missed the point somewhere?


Thanks for your help guys!


Giuseppe

 

I am going to suggest what I do in case it offers an alternative to your design.

I would find a dead space on each floor, then wire to that space and only run a backbone down to the main area.

In such house designs I propose that clients use a riser (a cabling chimney) and wire into that channel all of the main backbone cabling.

Think about how many metres of material get used running the length of building from top to bottom, compared to placing 20% of your cbus on that level and running one power cable and a pink backbone cable for data.

This may result you having to buy more C-Bus hardware as you will be having spare channels on each level perhaps. However, it does simplify installation as you prepare each floor on its own and then simply feed back to the main board for power.

As I say, it is just my concept. It has disadvantages too. One of the downsides is that it needs a wiring location and that needs space.

 

You definitely have the right idea. What you have there will definitely work, although it can probably be tweaked a bit to make your life a bit easier.

As tobex says, I'd recommend having multiple sub-boards around the house where you mount some of the C-Bus units. If you do it in one place only you'll have a lot of cables coming in to a single point. You'll also have some really long cable runs, costing you in installation time and cable. Multiple sub-boards also generally makes it easier when running additional circuits that weren't installed at construction-time.

If you can afford it, it pays to have a spare dimmer channel and a couple spare relay channels in each sub-board. They're gold when you decide that you "just need another light over there".

12 switches doesn't seem very many for an installation with 44 circuits, although that may work for you, given the layout of your house.

I'd swap one of the P-version (no power supply) relay units for a non-P version (inc. power supply). Your present design has enough C-Bus network power to handle adding 94mA of additional devices, which is only another 4 Neo switches or 5 motion sensors. Having another 200mA of C-Bus power in your system will save you having to buy a stand-alone C-Bus power supply as your system expands in future.

Run the pink C-Bus cable now, to every conceivable location where one day you might want an additional switch, a motion sensor, an additional sub-board, a direct C-Bus connection, etc. The cable is cheap and a loop of pink cat-5 down a wall cavity may just save you having to open up a wall or cut through some brick. At the very least it will save you heaps of time in the future.

Assuming you're going to cable your home Ethernet network now, I'd consider adding a C-Bus Ethernet interface (5500CN) or, even better, a Wiser. That way you can program your system using laptop WiFi whilst sitting on your sofa, not standing in a dark corner somewhere balancing your laptop on your knees with a cable plugged into the switchboard.

The L5104D5 dimmer is a curious choice, given you're talking about a domestic house. The only reason I can think that you'd want to use one domestically is if you have more than 2.5A of load, or if the DIN leading edge or universal dimmers are simply not suitable for some reason. One of the beauties of C-Bus is that you can independently group different load sets and set them all to different levels using Scenes. If all your loads are grouped together, you can only dim them as a whole.

The L5104D5 also takes up quite a bit of space in your switchboard, whereas the DIN dimmers are much more compact and available in 8 x 1A (leading edge), 4 x 2A (leading edge) or 4 x 2.5A (universal) versions. Cabled conduit entry to the Professional dimmers is also a little more work than just putting a DIN dimmer in a switchboard.

If you genuinely have a need for circuits greater than 2.5A then I'd also consider the newer C-Bus Infinity Professional dimmers, which are available in 3, 6 & 12 channel versions with current ratings of 3A, 5A, 10A, 16A and 20A per-channel. They work with a wider range of load types and have in-field replaceable channel cards. They also include the circuit breakers for the loads.

 

Question: The L5104D5 Dimmer, where you talk about independant groups/grouped together, do you mean that the L5104D5 will group all the 4 Channels going into it so that those channels can only all be on at the same time and only dimmer controled as a set of 4 channels? If so I definately don't want that and will need to swap over to the other type you mention.

Thanks guys
Giuseppe

 

No, that is not what I mean. The 4 channels of the L5104D5 are controlled independently (although they can also be controlled together if you want to).

I mean to say that to be using L5104D5's with CFL loads I am making the assumption (maybe wrongly) that you must have lots and lots of very low capacitance lamps combined onto a single circuit. If this were not the case, you would be using a smaller and cheaper dimmer that is easier to install. As a follow-on from that assumption, I'm suggesting that combining such a large number of lamps together in this way might frustrate you in future, because you won't have independent control of smaller groups of lights.

It's very common to have a multiple groups of lights in a room. For example there could be 3 separate circuits for feature lighting, task lighting and main illumination, and setting these different circuits at different illumination levels is called a Scene. Scenes are one of the things that really differentiate C-Bus from conventional wiring.

I'm also pushing you a bit to see how well you understand dimmers, and to understand your justification for choosing the L5104D5. I'm not trying to talk you out of using it, just trying to see if you have thought through the different feature/price/load compatibility/installation requirements of the different dimmer types, and to see how you decided that the L5104D5 was the particular dimmer you needed, as there are several to choose from.