Hadware Protection

Gday,

installing cbus at home - will have several dimmer and relay units installed.
In terms of protecting the hardware, do I need to consider circuit breakers/surge protectors etc. If i do, what shall I use.

Look forward to some advice based on your experiences.

 

Yes. I use clipsal 970RM protective devices on all c-bus installations, c-bus devices can be expensive to replace when compared to cost of installing surge protection. In today's electronic enviroment I advise installing surge protection within the electrical switchboard even if you dont install cbus.

allgo

 

installations

it never ceases to amaze me when someone will ask these questions about installing c-bus!
i asume you are a licenced electrician?
that was nearly as good as the pink cable in the mortar...ha ha

 

Stick to the AS

There is nothing wrong with pink cable in mortar.........

As long as the cable is wrapped in 16 or 20mm of conduit, of course ;-)

 

And you make accurate asbuilts for future reference so the next trades don,t drill straight through your cables in the mortar.

 

i apologise Marka for posting my query. I was wrong to think this was a forum for a non-tech minded guy to seek some advice from a varied group of cbus followers

oh..your presumption i'm a sparky is wrong!!!!

i presume you're a moron!

 

I thought it was a good question, exactly the sort of question any smart householder might ask when contemplating a smartwiring job. One does not need to be a sparky or installer to make decisions about budgets, feasibility and how or what to install. IMHO in an age when most people are familiar with computers, networks and immediate online information, it will be increasingly common for customers to make their own decisions about smartwiring and the like.

That does not mean they will be bozos and install it all themselves, it just means they want to and are capable of taking part in decisionmaking and non-mains work, including programming.

In this case, somebody looking online will quickly see that in the UK it is apparently advisable to protect each output channel, while in Australasia there seems to be a consensus that an RCD is sufficient. Can they both be correct? It is a good question.

My concern: when these potential customers look online and see C-Bus installers high-fiving and belittling somebody just like them who has asked what seems to be a perfectly reasonable question, I wonder what effect that will have.

 

The correct answer, of course, is none of the above.

To answer the question requires a assessment taking into account local legislative practice, quality of supply, types of loads and the faults they encounter, and cost, and probably several other factors as well. These variables may well be different on an installation by installation basis.

Do you want to spend more now on protection and hope it protects the sensitive electronics, or save money now, and if the electronics pops in the future replace it? In my (more general than CBus) experience, it is remakable how effectively a triac will lay down its life to protect the fuse.

In the UK RCDs were only used on lighting circuits in new installs for a short period of time (before the rulers figured out how bad an idea it was) whereas in NZ (and probably AU) RCDs are required from just recent times.

 

But wait there's more

Let's take the UK for example, my understanding is that you don't need to be a Sparky to install electrical products run mains wiring etc unlike in OZ where it is a definate no no. The UK wiring regs require any light circuit to be able to be Isolated via a 'local' switch - or words to that effect (just what the definition of 'Isolate' and 'local' are I'm not sure and this definition gets used in different ways in countries around the World - particularly in SE Asia where they folloe the IEEE wiring rules from the UK- so that it may mean adding individual MCB's for each C-bus relay or dimmer channel or even standard light switches mounted in the swichboard along side the C-bus, one for each channel and a normal light swich isn't an isolator in the strict definition of the word coz it can weld closed and the dolly can be switched to the off pozzi) . Where as in OZ there is no similar requirement except a mains isolating switch at the switchboard and of couse an RCD on all power and light circuits. So the moral is this forum receives questions from all over the Globe and the Electrical regulations in each of those countries may be different. So don't get too far up on your high horse!

To the subject of the post:- As noted before some over voltage protection is cheap insurence for what may be thousands of dollars of C-bus and is highly reccomended by Clipsal in their C-bus training and Installation Instructions. In addition depending on the region of the World where you live Lightning may be more or less prevalent so some air gap lightning arresters may be in order.

Electronic components (particularly for the purpose of C-bus ourput devices) are getting more and more robust and are more able to withstand day to day voltage excursions over and above the normal mains (most supply authorities claim to stick to Nominal Voltage +/- 10%, so for 240V, +/- 10% = 216-264V but every now and again (due to supply failures, transformer faults, squirrls in the roof etc) you may much higher voltages. When the only loads in your house were light globes, stove elements etc these rapid high voltages where often harmless (Although they may shortent the life of a globe and cause the lights in a house to flash bright momentarily) but now with so much electronic equipment installed it can cause damage even to the best designed stuff.