Re: DIN Enclosure for CBus modules

["Frank Mc Alinden" <fmcalind@xxxxxxxxxxxxxx>]

Hi Paul

As far as i am aware "C" curve type circuit breakers are normally
used in a
Domestic install here in Oz.....Wasnt aware of  "B" curve 
circuit
breakers(although have used "D"curve for motors)  , which seems
to be what
people should be using on the load side for each dimmer channel...... Would
be good to get something smaller than 6amp..........2amp available in B
curve ???...........

> 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.

Had i had room in my enclosure i would have installed circuit breakers for
each load , and when finishing off my cbus install i turned off my lighting
circuits but forgot i had some power circuits being switched and got a nice
little belt ;-( ............

Frank


----- Original Message -----
From: "Paul Robinson" <ukcueman@xxxxxxx>
To: <ukha_d@xxxxxxx>
Sent: Sunday, April 10, 2005 12:11 PM
Subject: Re: [ukha_d] DIN Enclosure for CBus modules


>
> >
> > 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
>
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>