Non-Harmonized cable in Enclosure

[dellboy13]

Hi All

I am currently designing a complete home automation system based around CBUS dimmers and relays. I have now built the enclosures with the dimmers and relays in so I can start programming / testing them. I have going to get a full spark to install the actual cables and connect the lights.
All the CBUS units need breakers feeding them and fuses on their outputs, which I have wired using red and black 1.5mm cables to DIN rail terminators & MCB in the cabinet which are obviously not Harmonized. Is this OK, the spark (when I find one) will do everything external with Harmonized cable!

 

[Charlie_]

On all of the multiple channel dimmers I have installed each channel has it's own MCB covering that output, the incoming is protected at the DB or switchfuse feeding it.

Why?? What make of dimmer unit?

On the dimmers I normally install all of the output terminals are in a row running up the centre of the unit with the dimmer modules spread throughout the whole enclosure.

Sounds messy. Where do you locate your neutral and earths?

My point: just because you have only installed dimmers with one protection arrangement or terminal layout it does not mean that every dimmer must be made the same!

No need to shout!
I'm not saying they must be made the same.
i am just explaining a better way of doing things and highlighting what is not necessary.
I have installed many C-Bus systems as well as KNX systems so I am fully aware of the different types.

 

[dellboy13]

I'm now confused, this is take out of the installation training manual from Clipsal

4.1.2 Output side of C-Bus output unit
To protect the C-Bus dimmer unit and meet the safety requirements of IEC60669-2-1, a MCB should be installed in each output channel (as in Figure 3 & Figure 4).

If I do not install the units as per Clipsal documentation, this would not invalidate the warranty? - A question not a statement!

I obviously understand that the fuse would not protect against short circuit but it would protect from overload!

 

[spark 68]

No need to shout!
I'm not saying they must be made the same.
i am just explaining a better way of doing things and highlighting what is not necessary.
I have installed many C-Bus systems as well as KNX systems so I am fully aware of the different types.

I didn't think Dave was Shouting Charlie, he is making a valid point though, you cannot really make a sweeping statement that the OP is doing it wrong, the manufacturer has told the OP what they want, whilst he does not have to follow their recommendation it may affect any warranty or cause other problems down the line if he does not take their advice into consideration.

I would be more interested to see if the manufacturer had drawn up any design guides for the panels and/or offered any type testing data, and what, if any, mandatory testing needs to be done on the panels.
Does the manufacturer offer any pre-built panels presumably already certified and type tested ?

 

[dellboy13]

I have contacted Clipsal and had a very brief chat, yes there should be overload protection on the outputs as per their install manual. The reasoning being that an electrician could install and sign off a build with say 40w bulbs and 3 months down the line the owner would change all the the bulbs for 100w bulbs and knacker the dimmer unit, leaving the owner to foot the bill.
They also said that if a MCB was used an electrician would have the ability to isolate a single output from a dimmer unit and work on it without having to knock off all 8 channels of a dimmer unit or 12 channels of a relay unit to work one one single fitting.

 

[Charlie_]

Yes I appreciate what you are saying and I'm aware of Clipsal UK requirements but they are not necessary as the units have integral overload protection and also protection is afforded by the supply MCB's.
Ive serviced Clipsal equipment for many years, in the UK and AUS..
The majority of installers do not fit output fuses as they know this is pointless.
I have yet to come across a blown unit due to overload..
The dimmers themselves should be IEC compliant we don't need to make them compliant by other means.

If somebody puts larger lamps in then they can also easily install larger fuses.
It is then down to the integral protection of the dimmer to kick in.

 

[DPG]

I know nothing about these systems, but surely if the manf. stipulates to use MCBs on the outputs then it should be done? Daz