Fw: DIN Enclosure for CBus modules

[Gareth Cook <g@xxxxxxxxxx>]

Gah ! More confused !

No-one seems to have the same setup - and there's me thinking electrical
regs were fixed ! So I'm still not there on what I need to do yet on
providing the electricals to the CBus cabinet - AND which cabinet :-(

G.

Gareth Cook
SWG EMEA North Account Manager
IBM SWG - BTE Office - Lotus Park, Staines, TW18 3AG
Office: +44 (0)1784 445166 - Mobile: +44 (0)7980 445166
AIM Chat : TheBoyG - MSN Chat : chat@xxxxxxx
email: g@xxxxxxx


----- Forwarded by Gareth Cook/UK/IBM on 10/04/2005 08:35 -----

Discussion
Main Topic

"Paul Robinson" <ukcueman@xxxxxxx>
Today 03:11

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Subject:
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Re: [ukha_d] DIN Enclosure for CBus modules
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Category:




>
> Hi Paul
>             Wouldnt be too keen on using plywood ,as its not fire
rated
> ??.....Usually these panels have an internal metal plate............
Will check on that....

> Here in Oz  i havent heard of anyone using c/b,s on the load
side.....Have
> you had any trips on yours when a bulb pops ???...I would imagine the
c/b
> would be too slow to react....
Short answer: yes.

Longer answer....

I have an incoming supply that goes to my consumer unit. There is one 32A
MCB feeding my
main CBus boxes. There, it goes into two 16A MCBs (because my dimmers are
split across two
boxes).

Each of those 2 16A MCBs feed 3 or 4 dimmers, protected by a 10A MCB per
dimmer on the
input side and a 6A MCB per channel on the output side. Ideally it would
have been 1A on
the output side, but this was much cheaper.

That means electricity must pass through the following route:
32AMCB --> 16A MCB --> 10A MCB --> dimmer --> 6A MCB -->
light

When I first set this up all MCBs were of the same type and same
manufacturer. A main
halogen blowing would trip the last three MCBs - so I would lose half my
lights. This
happened on three separate occasions.

I then changed the 16A MCBs from 'B' type to 'C' type, so they react more
slowly. Now when
a halogen blows, it trips only the 10A and 6A MCBs - so I lose power to
one dimmer.

In this scenario, I'm not sure that the 6A MCBs are actually doing any
significant work in
protecting the dimmers because the MCBs on both sides blow anyway.

However, having had a shock from dimmers that have been turned off
(there's a good reason
there's a sticker on them to say the load side isn't isolated when turned
off), I really
like the idea that I can isolate a light if I want to, as Li says.

Paul