I've put some photographs of my consumer unit etc at the following address:

http://tinyurl.com/dfsfj

I'm just trying to make sure I understand what's going on - could anyone
confirm my understanding
and fill gaps in my understanding.

What I see is:

1. Meter connected to a 60 amp circuit breaker (is that right? is an mcb?
it's not an rcd is it?)
There's an additional one to its left not connected up - this was for an old
storage heater system I believe)
2. Circuit breaker (if that what it is) connects to some from of
distribution box connecting on left to
RCD for electric shower circuit, and on the right connecting to consumer
unit on top right of main
picture.
3. In consumer unit there's fused circuits for: 1 30 amp radial for cooker
circuit (connects to cooker dual-pole
plus 13 amp socket), 2 30 amp ring circuits for power, 3 5 amp lighting
circuits, and 1 15 amp circuit
for immersion heater.

Am I anywhere near????

Graham

After serious thinking Graham Dean wrote :
I've put some photographs of my consumer unit etc at the following address:

http://tinyurl.com/dfsfj

I'm just trying to make sure I understand what's going on - could anyone
confirm my understanding
and fill gaps in my understanding.

What I see is:

1. Meter connected to a 60 amp circuit breaker (is that right? is an mcb?
it's not an rcd is it?)

It looks like an MCB, certainly not an RCD - Though it might just be a
basic 60amp switch/isolator

There's an additional one to its left not connected up - this was for an old
storage heater system I believe)
2. Circuit breaker (if that what it is) connects to some from of distribution
box connecting on left to
RCD for electric shower circuit, and on the right connecting to consumer unit
on top right of main
picture.
3. In consumer unit there's fused circuits for: 1 30 amp radial for cooker
circuit (connects to cooker dual-pole
plus 13 amp socket), 2 30 amp ring circuits for power, 3 5 amp lighting
circuits, and 1 15 amp circuit
for immersion heater.

Am I anywhere near????

Your description appears to be spot on judging by the photographs
alone. Age of the main part of installation somewhere between 1965 and
1979-ish, with the RCD installed in the past ten years or so.




--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.org

"Harry Bloomfield" wrote in message
...
After serious thinking Graham Dean wrote :
I've put some photographs of my consumer unit etc at the following
address:

http://tinyurl.com/dfsfj

I'm just trying to make sure I understand what's going on - could anyone
confirm my understanding
and fill gaps in my understanding.

What I see is:

1. Meter connected to a 60 amp circuit breaker (is that right? is an mcb?
it's not an rcd is it?)

It looks like an MCB, certainly not an RCD - Though it might just be a
basic 60amp switch/isolator

There's an additional one to its left not connected up - this was for an
old storage heater system I believe)
2. Circuit breaker (if that what it is) connects to some from of
distribution box connecting on left to
RCD for electric shower circuit, and on the right connecting to consumer
unit on top right of main
picture.
3. In consumer unit there's fused circuits for: 1 30 amp radial for
cooker circuit (connects to cooker dual-pole
plus 13 amp socket), 2 30 amp ring circuits for power, 3 5 amp lighting
circuits, and 1 15 amp circuit
for immersion heater.

Am I anywhere near????

Your description appears to be spot on judging by the photographs alone.
Age of the main part of installation somewhere between 1965 and 1979-ish,
with the RCD installed in the past ten years or so.


Thank you - I feel a little happier now! (I think...) I think it may be an
mcb as it's got a yellow
test button in lower middle which breaks circuit on pressing?

This leads on to two further questions - (1) should I really replace the mcb
between the meter and distribution
unit with an RCD?, (2) the cooker radial circuit is unused presently, but
the dual-pole / 13 amp is absolutely in
the right place in the kitchen to use as a starting point for a spur for a
double-gang socket - is it possible to dothis in any way,
through a fused fcu eg? If not, can I easily convert the dual-pole etc to a
double-gang 13 amp itself?

Graham

Are the two yellow dots just dots or buttons?
If they are buttons then they could be voltage operated ELCBs.

"Fred" wrote in message
...
Are the two yellow dots just dots or buttons?
If they are buttons then they could be voltage operated ELCBs.


Hi Fred,

They're buttons - i.e. press here to test type of thing.

Graham

On Tue, 30 Aug 2005 19:41:16 +0000 (UTC), "Graham Dean"
wrote:



Thank you - I feel a little happier now! (I think...) I think it may be an
mcb as it's got a yellow
test button in lower middle which breaks circuit on pressing?



This leads on to two further questions - (1) should I really replace the mcb
between the meter and distribution
unit with an RCD?,


I think that these might be old style voltage operated ELCBs.


Do you have a TT incoming supply? In other words, does it arrive by
overhead wires and you have an earth rod or is there some other
arrangement? If it is a TT supply, then an ELCB was the old way of
providing a measure of protection in case of earth leakage. THe
present way with a TT supply is to use a 100mA RCD with time delay at
this position. You would then normally have a split consumer unit
with a 30mA RCD part way across. Then circuits needing 30mA RCD
protection such as downstairs and outside circuits would go downstream
of this and others such as lights upstream (i.e. between the 100mA and
30mA breakers.

To be honest, considering the age of the CU and the rest of the
components, I would be inclined to rip the lot out and put in a new
DIN rail consumer unit like an MK Sentry. That way, everything could
be housed inside the box for a much neater installation.
You can get up to 20 way ones. THe two RCDs are 2ways each leaving 16
breaker positions which should be enough for most installations.

However, if you are going to swap ELCB for RCD etc., (assuming it is a
TT system) then the earth rod etc. needs to be checked and measured
with proper test gear. If you are going to DIY it, you would need
to arrange a building notice and inspection anyway to comply with Part
P of the Building Regulations.

If it's not a TT system, but TN-S (earthing via sheath of underground
cable) or TN-C-S (aka protective multiple earth or PME) then you don't
need an RCD between supply and CU, but you do for certain of the
circuits as described above.




(2) the cooker radial circuit is unused presently, but
the dual-pole / 13 amp is absolutely in
the right place in the kitchen to use as a starting point for a spur for a
double-gang socket - is it possible to dothis in any way,
through a fused fcu eg? If not, can I easily convert the dual-pole etc to a
double-gang 13 amp itself?


You can do either. However, the circuit MCB must be reduced to 20A
if you wire on from the existing outlet in 4mm^2 cable or 16A if you
use 2.5mm^2.


However, there may be a practical issue of fitting the cables into the
sockets. They are normally designed for up to three possibly 4x
2.5mm^2 cables.






Graham


--

..andy

To email, substitute .nospam with .gl

Graham Dean wrote:

I've put some photographs of my consumer unit etc at the following address:

http://tinyurl.com/dfsfj

Could we have another one showing where the supply comes into the
system? I.e. what is to the left of the first pic?

1. Meter connected to a 60 amp circuit breaker (is that right? is an mcb?
it's not an rcd is it?)

The meter is feeding an old voltage operated Earth Leakage Circuit
Breaker (ELCB) - the rightmost one of the pair. These detect current
flowing to earth and cut the supply. The test button ought to trip the
device if pushed. I can't see anything connected to the top of the left
hand one.

There's an additional one to its left not connected up - this was for an old
storage heater system I believe)

Ah, that would explain it ;-)

2. Circuit breaker (if that what it is) connects to some from of
distribution box connecting on left to

This in known as a "Henley Block" (after a company associated with
making them) or a "Service Connector Block". As you susspect it is just
a high current rating junction box designed for meter tails. It is
splitting the supply into two sub mains. One goes off to the Wylex
rewireable CU, the other to what looks like a small CU added on for a
high current device - a shower typically.

RCD for electric shower circuit, and on the right connecting to consumer
unit on top right of main
picture.

OK yup

3. In consumer unit there's fused circuits for: 1 30 amp radial for cooker
circuit (connects to cooker dual-pole
plus 13 amp socket), 2 30 amp ring circuits for power, 3 5 amp lighting
circuits, and 1 15 amp circuit
for immersion heater.

Am I anywhere near????

Yup pretty much. It would be handy to see the head end (i.e. where the
power comes in to work out what type of supply you have).

--
Cheers,

John.

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