I'll get the obvious out of the way so as to avoid silly posts and
questions.

Yes I am rewiring my house.
Yes I am aware of Part P.
Yes I have a building notice in force allowing me to do this.
Yes I have a friendly competent to help test and advise when needed.
Yes I have spent months preparing and researching.
Yes my house is currently a non-complaint mess that I am trying to
fix.
No, I threw out all my non harmonized cable and have no intention of
using any.
Yes I will sleeve up any remaining non-harmonized and test it
thoroughly before using (I have some cable buried behind stuff I do
not want to move at this time).
Yes I have the correct test equipment.
And, finally, yes all the work will be tested before the LABC will
sign it off.
(and yes, I realize the design/installation sections of the paperwork
will not be signed)

There, now onto the questions (sorry about the preamble, but I am
getting tired of this).

The existing CU is a Tenby, I've decided that even though 17th is a
while off I'll be 17th compliant (why not, it makes sense). So I see
three obvious options :-

1. RCBO the current CU - this is probably the easiest option, no doubt
the most expensive.

2. Buy a 16th split and swap one RCD for a switch and then RCBO that
half. Currently 16th splits are cheap as chips (no doubt wholesalers
are getting cold feet about unsold stock and impending 17th). Also
this is an expensive option as well.

3. Swap the CU for a 17th part CU.

1 is a problem because its a temby. I know its compatible with Legrand
and I suspect Contactum - but the RCBO are a teary 48+VAT each. Thats
probably going to be a show stopper for me - so does anybody know a
cheapio source of RCBOs for this make. (no not fleabay, I don't want
to have to play around testing them until the circuit is finalised).
If I could get them for the more normal 26+VAT then I would probably
go for this option as it is much less hassle.

2 should be compliant by my understanding, but then I'd still want a
switch (cheap) and 3 or 4 RCBOS (not so cheap). But all the makes are
flogging the 16th CU cheap and the main brands (MK would probably be
my choice) have RCBOS for the 26+VAT.

3 my local wholesaler has a 17th contactum CU which seems like a good
deal (http://www.tlc-direct.co.uk/Products...80slash80.html)
and I know they deliver next day as I have used them before. This
seems like an attractive offer.

Any advice people?

Also its worth pointing out that I have not changed a CU before
(fitted one out yes, so 1 is also an easy option) so any advice people
can offer would be gratefully received. I do have a lot paperwork and
a few instructional DVDs so I am not that concerned. Also, most
importantly, when I had the meter and inlet moved a few years ago I
had an 100A isolator fitted between the CU and tails so for me the job
is much, much safer then for most people.

Still - I'm not proud and I gracefully accept advice from people with
experience. My main question is making sure all fittings and
attachments are good and tight and proper - I would guess there are
some tricks of the trade to be learned there. I don't want to bother
my friendly competent too much (I am relying on him to test all the
works once finished, and that will be one time consuming job).

The last question is about isolation in kitchens. I have been reading
up in my copy of 16th and it clearly states that isolation is only
needed for fixed kitchen units and a switched socket counts as an
isolator for non-fixed units. My friendly competent says that he would
mark down any installation that did not have an isolator for all units
regardless of if they were on sockets or not. I'm talking freezers and
fridges that are not fixed but slide under the work surface. What is
the viewpoint on that? how should 16th part be read on this issue? If
he is correct then my only real option is the spur the two under work
surface sockets up over the work surface and then back down and fit a
FCB at he top as the isolation. A right royal pain that would be to
remove some tiles and refit - but if I must. Also it would be more or
less impossible to meet the recommended 2m distance, I could manage
maybe 1m but my kitchen is tiny, I would more or less have to have the
unit under the worksurface and the isolation direct over it 1ft over
the worksurface. That is a recommendation naturally, not an obligation
- but one I could not meet. By my reading as they are removable items
(floor standing) and on switched sockets they are isolated anyhow and
do not need additional isolation. Comments?

Many thanks in advance to people to read this and have sensible
helpful comments.

wrote:
I'll get the obvious out of the way so as to avoid silly posts and
questions.

Yes I am rewiring my house.
Yes I am aware of Part P.
Yes I have a building notice in force allowing me to do this.
Yes I have a friendly competent to help test and advise when needed.
Yes I have spent months preparing and researching.

Snip
Got bored here.

You're asking people to help you... FREE. If you can't put up with a few
stupid answers go and get an electrician.

Si

Got bored here.

You're asking people to help you... FREE.

er, yes. Isn't that the point of uk.d-i-y? Post seemed reasonable to me....

wrote:

[... big snip ...]

1 is a problem because its a temby. I know its compatible with Legrand
and I suspect Contactum - but the RCBO are a teary 48+VAT each.

Is that a list price or your wholesaler's best offer? It sounds to me
like the former, with room for at least 45-55% discount. As you need
several tell your wholesaler how much you're expecting to pay and see if
they'll bite.

2 should be compliant by my understanding, but then I'd still want a
switch (cheap) and 3 or 4 RCBOS (not so cheap). But all the makes are
flogging the 16th CU cheap and the main brands (MK would probably be
my choice) have RCBOS for the 26+VAT.

MK have long offered a "main switch and dual RCD kit" (hitherto for TT
installations) making it easy to build a so-called '17th edition CU'
with two 30 mA RCDs. Divide your lighting circuits between the two
sides, for obvious reasons.

The last question is about isolation in kitchens. I have been reading
up in my copy of 16th and it clearly states that isolation is only
needed for fixed kitchen units and a switched socket counts as an
isolator for non-fixed units. My friendly competent says that he would
mark down any installation that did not have an isolator for all units
regardless of if they were on sockets or not.

The best source of guidance here is the EGBR - the Electrician's Guide
to the Building Regulations, published by the IEE/IET. It's fairly clear:

- sockets supplying equipment pushed under a work surface should be
accessible when the appliance is pulled out, examples cited are
dishwasher, tumble dryer, fridge;

- built-in (integrated) appliances should be supplied via sockets or
FCUs that are readily accessible when the appliance is in place and in
normal use, or supplied via sockets/FCUs that are controlled by a
readily accessible DP switch or switched FCU;

- "readily accessible" above means that control switches must not be
hidden inside storage cupboards;

- all wiring accessories to be mounted on the building fabric, not on
kitchen furniture.

I'm talking freezers and fridges that are not fixed but slide under
the work surface. What is the viewpoint on that?

See first point above. No separate switching is required if the sockets
are accessible when the appliances are pulled out.

Also it would be more or less impossible to meet the recommended 2m
distance, I could manage maybe 1m but my kitchen is tiny,

What 2 m distance is this? Cooker control switches for ovens and hobs
should be no further than 2 m from the appliance(s) they control (but
should not be directly over the appliance) - that's the only 2 m rule I
know of.

--
Andy

wrote:

The existing CU is a Tenby, I've decided that even though 17th is a
while off I'll be 17th compliant (why not, it makes sense). So I see
three obvious options :-

1. RCBO the current CU - this is probably the easiest option, no doubt
the most expensive.

probably...

2. Buy a 16th split and swap one RCD for a switch and then RCBO that
half. Currently 16th splits are cheap as chips (no doubt wholesalers
are getting cold feet about unsold stock and impending 17th). Also
this is an expensive option as well.

Not much better than 1

3. Swap the CU for a 17th part CU.

or make up an equivalent using MK like Andy described or by having more
than one CU fed from split tails after your isolater.

1 is a problem because its a temby. I know its compatible with Legrand
and I suspect Contactum - but the RCBO are a teary 48+VAT each. Thats

Not tried Temby, so can' comment directly. Contactum / Hager / MK are
all generally interchangeable though.

3 my local wholesaler has a 17th contactum CU which seems like a good
deal (http://www.tlc-direct.co.uk/Products...80slash80.html)
and I know they deliver next day as I have used them before. This
seems like an attractive offer.

I have used lots of contactum CUs in the past, and generally find them
quite nice to work on. Plenty of space.

Any advice people?

Also its worth pointing out that I have not changed a CU before
(fitted one out yes, so 1 is also an easy option) so any advice people
can offer would be gratefully received. I do have a lot paperwork and
a few instructional DVDs so I am not that concerned. Also, most
importantly, when I had the meter and inlet moved a few years ago I
had an 100A isolator fitted between the CU and tails so for me the job
is much, much safer then for most people.

Since you have a switch, changing the CU is hardly any harder than
fitting one out.

If fitting one from scratch make sure to check the default wiring in
them first - I had one out of the box that would have shorted the supply
if it had been connected up as supplied!

Still - I'm not proud and I gracefully accept advice from people with
experience. My main question is making sure all fittings and
attachments are good and tight and proper - I would guess there are
some tricks of the trade to be learned there. I don't want to bother
my friendly competent too much (I am relying on him to test all the
works once finished, and that will be one time consuming job).

Using a big enough screwdriver seems to be the main thing.

The last question is about isolation in kitchens. I have been reading
up in my copy of 16th and it clearly states that isolation is only
needed for fixed kitchen units and a switched socket counts as an
isolator for non-fixed units. My friendly competent says that he would
mark down any installation that did not have an isolator for all units
regardless of if they were on sockets or not. I'm talking freezers and
fridges that are not fixed but slide under the work surface. What is
the viewpoint on that? how should 16th part be read on this issue? If

My personal preference is to have above counter isolation switches for
anything that obscures it's socket. This is not actually required by the
regs, but in practice seems to make sense. I have seen a tumble drier
burst into flames before; and I want not want to have to pull it out of
a recess under a worktop to be able to reach its plug to isolate it!

A common workaround is to place the supply socket at the back of an
adjacent cupboard such that the plug can be withdrawn without moving the
appliance. Its arguable whether this still counts as "readily accessible"

he is correct then my only real option is the spur the two under work
surface sockets up over the work surface and then back down and fit a
FCB at he top as the isolation. A right royal pain that would be to
remove some tiles and refit - but if I must. Also it would be more or
less impossible to meet the recommended 2m distance, I could manage

The only reference I have seen to 2m I have seen is as a maximum between
a cooker and its isolator.



--
Cheers,

John.

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

wrote:
I'll get the obvious out of the way so as to avoid silly posts and
questions.

snip a load of stuff

1. RCBO the current CU - this is probably the easiest option, no doubt
the most expensive.


If RCBOs turn out to be ubiquitous for 17th Edition compliance, then the
price of them will fall dramatically as demand goes up 100-fold.
Currently, RCBO's are rarely used for domestic installations (compared
with MCB's), hence the ridiculous price.

Might be worth playing a waiting game and seeing what happens with the
price of RCBO's over the course of the year.

Rumble wrote:

If RCBOs turn out to be ubiquitous for 17th Edition compliance, then the
price of them will fall dramatically as demand goes up 100-fold.
Currently, RCBO's are rarely used for domestic installations (compared
with MCB's), hence the ridiculous price.

Might be worth playing a waiting game and seeing what happens with the
price of RCBO's over the course of the year.

It seems more likely that CUs with multiple splits will become the
"normal" solution.

--
Cheers,

John.

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