I have been advised to ask on this NewsGroup so here goes.

Been having an argument with a friend just lately over consumer units, or
rather the placing fuses, yes I know modern day it's circuit breakers but
principal is the same, within.

I was always told that next to the main switch, you start with the lower
current, lighting circuits (6A) building to the larger Shower/Cooker
circuits (32A) being farthest away. This is so that if the lights went out,
you would be able to find lighting fuse in the dark.

Friends says higher current first next to switch.

Is there a rule for this or is it just personal preference.
--
the_constructor

the_constructor wrote:
I have been advised to ask on this NewsGroup so here goes.

Been having an argument with a friend just lately over consumer units, or
rather the placing fuses, yes I know modern day it's circuit breakers but
principal is the same, within.

I was always told that next to the main switch, you start with the lower
current, lighting circuits (6A) building to the larger Shower/Cooker
circuits (32A) being farthest away. This is so that if the lights went out,
you would be able to find lighting fuse in the dark.

Friends says higher current first next to switch.

Is there a rule for this or is it just personal preference.

IMO, personal preference.
IMO also, you have in the CU box a torch that is charged from the mains,
and goes on if the mains/lighting circuit fails.

As a cheap alternative, go to ebay, and search for keyring tritium, and
put it next to a cheap torch with a lithium AA battery in in the CU
cupboard.

the_constructor wrote:
I have been advised to ask on this NewsGroup so here goes.

Been having an argument with a friend just lately over consumer units, or
rather the placing fuses, yes I know modern day it's circuit breakers but
principal is the same, within.

I was always told that next to the main switch, you start with the lower
current, lighting circuits (6A) building to the larger Shower/Cooker
circuits (32A) being farthest away. This is so that if the lights went out,
you would be able to find lighting fuse in the dark.

Friends says higher current first next to switch.

Is there a rule for this or is it just personal preference.
--
The instruction sheet that came with the CU that I fitted a couple of
months ago recommended your friend's way. Reduces voltage drop along
the bus bar. And you can find the lighting breaker just as easily as
it is the one furthest from the switch. Anyway you should have an
emergency light (aka torch) by the CU.

Dave

"the_constructor" writes:

I was always told that next to the main switch, you start with the lower
current, lighting circuits (6A) building to the larger Shower/Cooker
circuits (32A) being farthest away. This is so that if the lights went out,
you would be able to find lighting fuse in the dark.

If it's a traditional wired fuse you're better than me if you can
locate your wire and change it in the dark. If modern MCBs anybody can
check them from either end with their eyes closed.

Electrically yes your system might be .001% more efficient if high
current loads are closer to the switch.

At the end of the day I believe it's just preference.

Jon

On Mon, 4 Dec 2006 20:22:15 UTC, "the_constructor"
wrote:

I was always told that next to the main switch, you start with the lower
current, lighting circuits (6A) building to the larger Shower/Cooker
circuits (32A) being farthest away. This is so that if the lights went out,
you would be able to find lighting fuse in the dark.

Friends says higher current first next to switch.

Instructions with the last CUs I fitted (MK) said higher current next to
switch. Presumably to reduce voltage drop along the busbar. And I've
always done it that way.

I wouldn't want to be feeling around a CU in the dark, just in case
something had melted and left stuff exposed (pessimist that I am!).

I'd fit a non-maintained light above the CU, that came on if the
lighting circuit for that area had failed.
--
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
Avenue Supplies, http://avenuesupplies.co.uk

On Mon, 4 Dec 2006 20:22:15 -0000 someone who may be
"the_constructor" wrote this:-

I was always told that next to the main switch, you start with the lower
current, lighting circuits (6A) building to the larger Shower/Cooker
circuits (32A) being farthest away. This is so that if the lights went out,
you would be able to find lighting fuse in the dark.

One traditional way to deal with this is to put a light near the
consumer unit that is fed from another lighting circuit, eg the
upstairs one if the consumer unit is downstairs. That deals with all
but major failures.

Now that non-maintained emergency lights are so cheap these are
another option.

Alternatively torches and candles, in places where everyone knows
where they are.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

"the_constructor" wrote in message
...
I have been advised to ask on this NewsGroup so here goes.

Been having an argument with a friend just lately over consumer units, or
rather the placing fuses, yes I know modern day it's circuit breakers but
principal is the same, within.

I was always told that next to the main switch, you start with the lower
current, lighting circuits (6A) building to the larger Shower/Cooker
circuits (32A) being farthest away. This is so that if the lights went
out,
you would be able to find lighting fuse in the dark.

Friends says higher current first next to switch.

Is there a rule for this or is it just personal preference.
--
the_constructor


Any way you like. If someone is telling you something - why not simply ask
them why?
They must know why they are giving you particular advice.
Fuses are labelled and colour coded - circuit breakers are labelled.
You can even write what each is for. For what reason would the lights go
out and nothing else?
Keep a torch handy and the phone number for your electric supplier. Don't
rely on mains operated cordless phones either.

"David Hansen" wrote

Now that non-maintained emergency lights are so cheap these are
another option.




Got one on Ebay the other week, 3 hour, for a tenner. Haven't fitted it yet
so I can't say how good it is but it looks fine.

H

the_constructor wrote:

Been having an argument with a friend just lately over consumer units, or
rather the placing fuses, yes I know modern day it's circuit breakers but
principal is the same, within.

I was always told that next to the main switch, you start with the lower
current, lighting circuits (6A) building to the larger Shower/Cooker
circuits (32A) being farthest away. This is so that if the lights went out,
you would be able to find lighting fuse in the dark.

Friends says higher current first next to switch.

I have always opted for the way your friend suggests - the highest loads
nearest the incomer. This is to keep the high current loads near the
start of the bus bar.

Is there a rule for this or is it just personal preference.

There is not alot in it either way.

I also always fit a maintained[1] emergency light above the CU powerd
from teh lighting circuit that would normally illuminate it. So when
there is a trip you can still see what you are doing.


[1] I use a maintained one so that you can manually switch the light as
well - makes life easier if you want to see in the cupboard.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In article ,
Owain writes:
HLAH wrote:
Now that non-maintained emergency lights are so cheap these are
another option.
Got one on Ebay the other week, 3 hour, for a tenner. Haven't fitted it yet
so I can't say how good it is but it looks fine.

Got one in my local junk shop for £2 a few years back. I didn't know if
it worked but I thought it was worth taking a chance on, as I'd had two
power cuts in the preceeding two days.

I got a pile from work. The batteries are supposed to be changed
every 5 years, but they change out the whole thing. Given that a
new battery pack seems to cost considerably more than the whole
thing, I'm not surprised. Batteries are 10 years old now, and
still give over 3 hours.

I also picked up a couple from a builder's merchant. They were
a quid each as they'd gone past their sell-by date (again, due
to the batteries), although still brand new and sealed in their
boxes. Likewise, they still work for over 3 hours.

One issue with all these is they are horribly inefficient as they
have very dum chargers. They are required to charge quite fast
so they are ready for use again reasonably quickly, but there's
no intelligence in them to drop back to a trickle/topup charge
when the main charge is complete -- they just carry on charging
at high current forever. Although the batteries are designed for
this, it does mean they consume around 3-4W continuously (which
is more than they give off during a power cut!)
In buildings full of them, this adds up -- it's probably another
one of these wall-wart effects if you add up how many power
stations are being used to keep the lights off ;-).

--
Andrew Gabriel

"the_constructor" wrote in message
...
I have been advised to ask on this NewsGroup so here goes.

Been having an argument with a friend just lately over consumer units, or
rather the placing fuses, yes I know modern day it's circuit breakers but
principal is the same, within.

I was always told that next to the main switch, you start with the lower
current, lighting circuits (6A) building to the larger Shower/Cooker
circuits (32A) being farthest away. This is so that if the lights went
out,
you would be able to find lighting fuse in the dark.

Friends says higher current first next to switch.

Is there a rule for this or is it just personal preference.

Putting the high current stuff nearest the incomer reduces the average
current flow in the bus bar, reducing the heating effect. I don't see that
putting a lighting fuse next to the main switch makes it easier to find than
putting it at the other end of the row.

My house has two separate lighting circuits on the ground floor,
specifically so that one or other provides light at the consumer unit even
though, with MCBs, you can find the one that has tripped by touch.

Colin Bignell

On 05 Dec 2006 08:29:17 GMT someone who may be
(Andrew Gabriel) wrote this:-

One issue with all these is they are horribly inefficient as they
have very dum chargers. They are required to charge quite fast
so they are ready for use again reasonably quickly, but there's
no intelligence in them to drop back to a trickle/topup charge
when the main charge is complete -- they just carry on charging
at high current forever. Although the batteries are designed for
this, it does mean they consume around 3-4W continuously (which
is more than they give off during a power cut!)
In buildings full of them, this adds up -- it's probably another
one of these wall-wart effects if you add up how many power
stations are being used to keep the lights off ;-).

In a large building the wise use a central battery system. The
chargers for these are rather more sophisticated.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

"nightjar .uk.com" nightjar@insert my surname here wrote in message
...

"the_constructor" wrote in message
...
I have been advised to ask on this NewsGroup so here goes.

Been having an argument with a friend just lately over consumer units, or
rather the placing fuses, yes I know modern day it's circuit breakers but
principal is the same, within.

I was always told that next to the main switch, you start with the lower
current, lighting circuits (6A) building to the larger Shower/Cooker
circuits (32A) being farthest away. This is so that if the lights went
out,
you would be able to find lighting fuse in the dark.

Friends says higher current first next to switch.

Is there a rule for this or is it just personal preference.

Putting the high current stuff nearest the incomer reduces the average
current flow in the bus bar, reducing the heating effect. I don't see that
putting a lighting fuse next to the main switch makes it easier to find
than putting it at the other end of the row.

My house has two separate lighting circuits on the ground floor,
specifically so that one or other provides light at the consumer unit even
though, with MCBs, you can find the one that has tripped by touch.

Colin Bignell


My thanks to everyone who has replied.
--
the_constructor

In article ,
"Bob Eager" writes:
Instructions with the last CUs I fitted (MK) said higher current next to
switch. Presumably to reduce voltage drop along the busbar.

I don't buy that explanation. I just measured the bus bar in
a cheap SquareD CU, and it's 36mm², quite likely substantially
thicker than the meter tails. In the previous generation MK ones,
it measures 30mm².

The instructions I've seen with some MCB's say that high current
rated ones which are run at high current for long periods should
not be placed adjacent to each other. Also some single width RCBOs
must not be placed next to high current MCBs.

--
Andrew Gabriel