out door c-bus run

[Bad Boy Bubby]

i have to run c-bus from a house to a shed/garage a couple of hundred metres away, total cable not an issue but would i be better running it as a seperate network to protect the house network from the effect of cable damage, water damage etc, if so do i mont the networkbridge at the house or shed end (house end i'm thinking) do i need use Gell filled or waterproof cat 5 if i am running the cable above ground, any ideas or comments apreciated

[Age]

The Network bridge should be on the house side. Therefore the cable run will be part of the shed's C-Bus network. This will ensure that the main house network will always function.

Another option would be to have both the house and shed operating as 2 single networks with no control (if that is ok). Another option would be to use the new C-Bus wireless range.

Adrian

[znelbok]

I have exactly the same problem

I have a shed 40m away from the house running a c-bus network with c-bus cable running underground in conduit. There is no bridge segregating the networks to minimise the risk of the impact on the house should the cable integrity be compromised.

This network is then connected again to another network underground as well in a similar fashion, with the exception of a bridge in place this time.

The only hassel with using bridges is that cost start to go up for things such as c-gate etc.

Maybe an isolation unit needs to be designed, no so much that it is a bridge but for joinging a single network between structures, so as cable problems dont bring the network down.

That or a gel filled c-bus cable.

I personally do not think wireless is acceptable for such installations. retrofitting maybe, but greenfield - no.

As to where the bridge is located, which network can you accept a failure on, that is the building that does not have the bridge.

[2dogs]

Dudes,

To minimise the potential issue of which network can essentially be sacrificed, then put a network bridge at the point of exit from the house and connect to an transitory network that connects to another network bridge at the point of entry of the shed.

Yes you now have 3 networks, but the sacrificial (transitory) network really only has 2 x bridges and a power supply to replace, cheaper that input and output units should you have a lightning strike in a 2 network configuration.

[znelbok]

plane jane c-gate is useless then when the bridges are used. That was the point I was trying to make

[Phil.H]

2dogs suggestion of using a middle "sacrificial" network is the top shelf method of protecting your installation, however the extra bridges and a PS comes at a cost.

In relation to the type of cable for use underground the main consideration is gel filled (moisture barrier) as opposed to cat 5. If you have trouble getting hold of cat5 gel filled go for a good quality gel filled cable suitable for ballanced pair operation. Cat 5 speed is not paramount as we know the C-Bus baud rate is quite low and the C-Bus protocol is strong enough for coms to work on two bits of fence wire - well almost.

On the C-Gate issue which is also relevant once you go past a single network the newtork licence jumps to 5.

Final point. If you have to extend a C-Bus netork outside a building do it via a bridge especially in lightning prone areas. The down side of not doing this is significant and a problem in this area (if it happens) is potentially huge...

[znelbok]

one consideration to make with the gel filled cable is to not run it into the distribution board unless it has a sheath rating suitable - remember thats why we use the clipsal cat 5 and not standard cat 5.

So thinking along this line, the use of gel filled cat 5 is ok as long as you terminate it at the entry and exit points of the building and then go back to using the standard c-bus cable.

[Bad Boy Bubby]

thanks for the advice, my main worry is physical damage to buried cable by back-hoes etc hence the question about buried v airial cable. hadn't warried about lightning strikes, not common here and if one did occur would a network bridge provide any protection? the real killer is the C-gate network licence i had not thought about that at all oh crap :mad: