Running 6mm cable along outside of house?
AL_n
Is it OK to run some 6mm T&E cable along the outside of my house?
I want to run cable from my fuse box to my garage. I have have enough
armoured 6mm cable to run from the garage to the end of the house, but I
need to get from that point to the fuse box. I have enough 6mm (Not
armoured) T&E cable to do that. By far, the easiest route to the fusebox
would be along the outside of the house,and then through the wall into the
fuse box cupboard. Is it OK to just staple the cable to the wall, say 8"
above ground level?
Also, while you are here, I also found a reel of 4-core flex (8mm overall
dia). What do they use such 4-core flex for?
Thanks,
Al
Owain
> Is it OK to run some 6mm T&E cable along the outside of my house?
Wellll ... not really, ordinary T&E isn't protected against UV light,
impact etc. It was a few feet to an outside light and high up on the
wall I would probably do it, but for a submain(?) at 8" above ground,
no. You could use plastic conduit but that's not proof against anyone
kicking it or trying to stand on it.
> Also, while you are here, I also found a reel of 4-core flex (8mm overall
> dia). What do they use such 4-core flex for?
Central heating pumps?
Really hefty phone extensions?
Bi-wired loudspeakers?
Two-way pear switches?
Owain
js.b1
length you need.
#2 - Run 6mm FTE in 25mm black conduit, which gives "good bump"
protection but not against vandalism etc.
#3 - Sell the 6mm FTE on Ebay and buy 6mm 6491X Br & Bl and 2.5mm
6491X Gr/Ye and run then in 20mm conduit the entire run (singles MUST
be in conduit for the entire run re out of one "fusebox" and into the
second "fusebox"). TradingDepot and TLC Direct and others do 6491X
"singles" in cut lengths. If you need a short bit of flexible black
conduit with glands TLC Direct also carry that in cut lengths.
Remember RCD protection is required re outdoor appliances. There is a
wiki diy article re terminating SWA glands etc.
AL_n
news:88bb07b7-3064-469c...@t7g2000vbj.googlegroups.com:
>> Also, while you are here, I also found a reel of 4-core flex (8mm
>> overall dia). What do they use such 4-core flex for?
>
> Central heating pumps?
>
> Really hefty phone extensions?
>
> Bi-wired loudspeakers?
>
> Two-way pear switches?
>
> Owain
Thank you. It sounds like I won't be needing a lot of 4-core cable in
future, so I'll go ahead and use it to wire up my security lights.
Al
Andrew Gabriel
"AL_n" <fgdf...@fghfghfg.com> writes:
>
> Is it OK to run some 6mm T&E cable along the outside of my house?
Yes, providing it's not likely to be subject to knocks.
People often post fears about UV. I've seen lots of T&E which
has been exposed for decades, and never came across a single case.
You could paint it with oil based gloss (top coat only) if you are
really worried about that. (Slide a piece of paper behind it to
prevent getting paint on the wall.)
> I want to run cable from my fuse box to my garage. I have have enough
> armoured 6mm cable to run from the garage to the end of the house, but I
> need to get from that point to the fuse box. I have enough 6mm (Not
> armoured) T&E cable to do that. By far, the easiest route to the fusebox
> would be along the outside of the house,and then through the wall into the
> fuse box cupboard. Is it OK to just staple the cable to the wall, say 8"
> above ground level?
No, at only 8" off the ground, it will be too vulnerable.
I would suggest a minumum of 1m, but in some situations, that would
not be acceptable either, and you would want it out of reach. You
want it out of reach if it's somewhere it might get nicked too.
>
> Also, while you are here, I also found a reel of 4-core flex (8mm overall
> dia). What do they use such 4-core flex for?
3-phase delta
Circuit which is both part permanently live and part switched,
or has two separately switched parts.
A switch which requires requires a neutral connection, such as
some thermostats, some dusk/dawn/PIR switches, etc.
Controls around heating and other such systems.
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]
AL_n
36abb9...@q9g2000vbd.googlegroups.com:
> #1 - Sell the SWA you have on Ebay (it sells well), then buy the
> length you need.
>
> #2 - Run 6mm FTE in 25mm black conduit, which gives "good bump"
> protection but not against vandalism etc.
>
> #3 - Sell the 6mm FTE on Ebay and buy 6mm 6491X Br & Bl and 2.5mm
> 6491X Gr/Ye and run then in 20mm conduit the entire run (singles MUST
> be in conduit for the entire run re out of one "fusebox" and into the
> second "fusebox"). TradingDepot and TLC Direct and others do 6491X
> "singles" in cut lengths. If you need a short bit of flexible black
> conduit with glands TLC Direct also carry that in cut lengths.
Thanks. I have just found another roll of SWA that is long enough for the
entire stretch. I'm not sure what the rating is; it is 15mm overall
diameter, has two cores (red & black) each cored with 2mm thick copper
single-strand. There is no earth. I presume one therefore uses the
armouring as the earth. Does this sound like 4mm or 2.5mm?
Do you think this will do the job? In the double-garage/workshop I'm
running the cable to, I will not be running any heaters. I only need to
run a couple of power tools one of which is a bench grinder and I'll also
want to power a few flourescent strips, and perhaps an electric kettle.
> Remember RCD protection is required re outdoor appliances. There is a
> wiki diy article re terminating SWA glands etc.
I'm assuming that an appliance in my garage/workshop can be classed as an
indoor appliance.
Al
AL_n
news:i8uuhm$gs8$2...@news.eternal-september.org:
>> I want to run cable from my fuse box to my garage. I have have enough
>> armoured 6mm cable to run from the garage to the end of the house,
>> but I need to get from that point to the fuse box. I have enough 6mm
>> (Not armoured) T&E cable to do that. By far, the easiest route to the
>> fusebox would be along the outside of the house,and then through the
>> wall into the fuse box cupboard. Is it OK to just staple the cable to
>> the wall, say 8" above ground level?
>
> No, at only 8" off the ground, it will be too vulnerable.
> I would suggest a minumum of 1m, but in some situations, that would
> not be acceptable either, and you would want it out of reach. You
> want it out of reach if it's somewhere it might get nicked too.
>
>>
>> Also, while you are here, I also found a reel of 4-core flex (8mm
>> overall dia). What do they use such 4-core flex for?
>
> 3-phase delta
> Circuit which is both part permanently live and part switched,
> or has two separately switched parts.
> A switch which requires requires a neutral connection, such as
> some thermostats, some dusk/dawn/PIR switches, etc.
> Controls around heating and other such systems.
Thank you for the info.
Al
Andy Burns
> I have just found another roll of SWA that is long enough for the
> entire stretch. I'm not sure what the rating is; it is 15mm overall
> diameter, has two cores (red& black) each cored with 2mm thick copper
> single-strand. There is no earth. I presume one therefore uses the
> armouring as the earth. Does this sound like 4mm or 2.5mm?
Sounds like at least 4mm^2, does it not have anything printed/embossed
in the outer sheath?
> Do you think this will do the job?
How long is the run?
As well as using the armour as the CPC for the cable, do you intend to
export the earth from your house to the garage, or provide a local
earth? What type of earth does your house supply have?
There are sections on the wiki you might find useful for this ...
> In the double-garage/workshop I'm
> running the cable to, I will not be running any heaters. I only need to
> run a couple of power tools one of which is a bench grinder and I'll also
> want to power a few flourescent strips, and perhaps an electric kettle.
You need to do some calculations of voltage drop at the maximum current
you're designing for, the lighting circuit will set your maximum drop.
http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html
John Rumm
> Is it OK to run some 6mm T&E cable along the outside of my house?
>
> I want to run cable from my fuse box to my garage. I have have enough
> armoured 6mm cable to run from the garage to the end of the house, but I
> need to get from that point to the fuse box. I have enough 6mm (Not
> armoured) T&E cable to do that. By far, the easiest route to the fusebox
> would be along the outside of the house,and then through the wall into the
> fuse box cupboard. Is it OK to just staple the cable to the wall, say 8"
> above ground level?
I would not use it in that situation unprotected... In trunking on
conduit maybe if you are confident no one will try standing on it etc.
> Also, while you are here, I also found a reel of 4-core flex (8mm overall
> dia). What do they use such 4-core flex for?
Commonly used in CH wiring or other applications where you want say a L,
N, E, & Switched L.
--
Cheers,
John.
/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
AL_n
news:06OdnXBM9sa5sC7R...@brightview.co.uk:
> AL_n wrote:
>
>> I have just found another roll of SWA that is long enough for the
>> entire stretch. I'm not sure what the rating is; it is 15mm overall
>> diameter, has two cores (red& black) each cored with 2mm thick
>> copper single-strand. There is no earth. I presume one therefore uses
>> the armouring as the earth. Does this sound like 4mm or 2.5mm?
>
> Sounds like at least 4mm^2, does it not have anything printed/embossed
> in the outer sheath?
"BS 6345 600/1000V Made in England" That's all I can find.
>> Do you think this will do the job?
>
> How long is the run?
17 meters.
Thanks,
Al
Andy Burns
Sounds like you would be OK even with 2.5mm^2 then, assuming it'll be
fed from e.g. a 20A MCB at the house end, with a 6A MCB for a lighting
circuit and 16A MCB for sockets on a radial in the garage
But do use the calculator, and consider the effect of losing lights and
power while your grinding wheel is still spinning away one dark night as
you brew a cuppa too ...
AL_n
130.133.4.11:
> Andy Burns <usenet....@adslpipe.co.uk> wrote in
> news:06OdnXBM9sa5sC7R...@brightview.co.uk:
>
>> AL_n wrote:
>>
>>> I have just found another roll of SWA that is long enough for the
>>> entire stretch. I'm not sure what the rating is; it is 15mm overall
>>> diameter, has two cores (red& black) each cored with 2mm thick
>>> copper single-strand. There is no earth. I presume one therefore uses
>>> the armouring as the earth. Does this sound like 4mm or 2.5mm?
>>
>> Sounds like at least 4mm^2, does it not have anything printed/embossed
>> in the outer sheath?
>
>
> "BS 6345 600/1000V Made in England" That's all I can find.
PS - Sorry - correction: It's "BS 6346" (the cable is very scuffed)
It also says "BICC SASEC" elsewhere on the cable.
Al
AL_n
>> 17 meters.
>
> Sounds like you would be OK even with 2.5mm^2 then, assuming it'll be
> fed from e.g. a 20A MCB at the house end, with a 6A MCB for a lighting
> circuit and 16A MCB for sockets on a radial in the garage
>
> But do use the calculator, and consider the effect of losing lights and
> power while your grinding wheel is still spinning away one dark night as
> you brew a cuppa too ...
You're very helpful - thanks.
Al
Andy Burns
> thanks.
Once you have a plan, post it here, someone else may chip in with
comments and further things for you to bear in mind ...
John Rumm
> "js.b1"<js...@ntlworld.com> wrote in news:380d0abf-b248-4090-82c0-
> 36abb9...@q9g2000vbd.googlegroups.com:
>
>> #1 - Sell the SWA you have on Ebay (it sells well), then buy the
>> length you need.
>>
>> #2 - Run 6mm FTE in 25mm black conduit, which gives "good bump"
>> protection but not against vandalism etc.
>>
>> 6491X Gr/Ye and run then in 20mm conduit the entire run (singles MUST
>> be in conduit for the entire run re out of one "fusebox" and into the
>> second "fusebox"). TradingDepot and TLC Direct and others do 6491X
>> "singles" in cut lengths. If you need a short bit of flexible black
>> conduit with glands TLC Direct also carry that in cut lengths.
>
>
> Thanks. I have just found another roll of SWA that is long enough for the
> entire stretch. I'm not sure what the rating is; it is 15mm overall
> single-strand. There is no earth. I presume one therefore uses the
> armouring as the earth. Does this sound like 4mm or 2.5mm?
Looking at the size quoted here:
http://wiki.diyfaq.org.uk/index.php?title=Cables#SWA
Probably 4mm^2
> Do you think this will do the job? In the double-garage/workshop I'm
> running the cable to, I will not be running any heaters. I only need to
> run a couple of power tools one of which is a bench grinder and I'll also
> want to power a few flourescent strips, and perhaps an electric kettle.
Work out your total load, and design back from that. Details here:
http://wiki.diyfaq.org.uk/index.php?title=Taking_electricity_outside#Sub_main_design
SWA is not that expensive, so there is no point hampering the whole
installation by using too small a cable at this stage. Having said that,
unless you cable run is long, a 4mm^2 feed ought to give you a fair bit
to play with at the remote end.
>> Remember RCD protection is required re outdoor appliances. There is a
>> wiki diy article re terminating SWA glands etc.
>
> I'm assuming that an appliance in my garage/workshop can be classed as an
> indoor appliance.
Generally yes, although see the comments about earthing in the above
article.
As a general point, if using power tools in a workshop, you probably
want RCD protection for the sockets, but want it separate from any
protection for the lights, so tripping one does not leave you in the dark!
chris French
<and...@cucumber.demon.co.uk> writes
>In article <Xns9E0E7247...@130.133.4.11>,
> "AL_n" <fgdf...@fghfghfg.com> writes:
>>
>> Is it OK to run some 6mm T&E cable along the outside of my house?
>
>Yes, providing it's not likely to be subject to knocks.
>People often post fears about UV. I've seen lots of T&E which
>has been exposed for decades, and never came across a single case.
Yeah, we have cable here, that has probably been out there for a bout
25 years. Seems perfectly sound still.
Similar at our old house.
Thiough when I did some more external wiring I used plastic conduit, and
whilst more obvious in some ways it looked much neater IMO
--
Chris French
AL_n
news:QoCdnZzP2Pmlry7R...@brightview.co.uk:
>
> Looking at the size quoted here:
>
> http://wiki.diyfaq.org.uk/index.php?title=Cables#SWA
>
> Probably 4mm^2
Yes, it does appear to be.
>> Do you think this will do the job? In the double-garage/workshop I'm
>> running the cable to, I will not be running any heaters. I only need
>> to run a couple of power tools one of which is a bench grinder and
>> I'll also want to power a few flourescent strips, and perhaps an
>> electric kettle.
>
> Work out your total load, and design back from that. Details here:
>
> http://wiki.diyfaq.org.uk/index.php?title=Taking_electricity_outside#Su
> b_main_design
>
> SWA is not that expensive, so there is no point hampering the whole
> installation by using too small a cable at this stage. Having said
> that, unless you cable run is long, a 4mm^2 feed ought to give you a
> fair bit to play with at the remote end.
>
>>> Remember RCD protection is required re outdoor appliances. There is
>>> a wiki diy article re terminating SWA glands etc.
>>
>> I'm assuming that an appliance in my garage/workshop can be classed
>> as an indoor appliance.
>
> Generally yes, although see the comments about earthing in the above
> article.
>
> As a general point, if using power tools in a workshop, you probably
> want RCD protection for the sockets, but want it separate from any
> protection for the lights, so tripping one does not leave you in the
> dark!
Thanks. Any idea how shallow I can bury the SWA? I buried a length of
22mm water pipe along the same stretch a few months ago. The trench could
easily be dug up again to take the SWA, but it was only about 9" deep.
Where it goes along the side of the house, it was even shallower. The
problem is, the ground is like hardcore around here. There's more
limestone than soil in the earth... I guess if someone did manage to put
a pickaxe through the SWA, the cucuit breaker would flip, so no big deal,
yes?
Al
AL_n
> I would not use it in that situation unprotected... In trunking on
> conduit maybe if you are confident no one will try standing on it etc.
Thanks - I think I'm gonna use SWA for the full run. It won't be buried
very deep though.
>> Also, while you are here, I also found a reel of 4-core flex (8mm
>> overall dia). What do they use such 4-core flex for?
>
> Commonly used in CH wiring or other applications where you want say a
> L, N, E, & Switched L.
I'd better save it then; I'll be installing a central heating system here
soon..
Al
A.Lee
> Thanks. Any idea how shallow I can bury the SWA? I buried a length of
> 22mm water pipe along the same stretch a few months ago. The trench could
> easily be dug up again to take the SWA, but it was only about 9" deep.
> Where it goes along the side of the house, it was even shallower. The
> problem is, the ground is like hardcore around here. There's more
> limestone than soil in the earth... I guess if someone did manage to put
> a pickaxe through the SWA, the cucuit breaker would flip, so no big deal,
> yes?
600mm deep IIRC.
Not a good idea to put it that shallow anyway, far too easily damaged.
Put it in PVC conduit along the wall. You can get it on white or black,
so shouldnt look too bad.
Alan.
--
To reply by e-mail, change the ' + ' to 'plus'.
John Rumm
> Thanks. Any idea how shallow I can bury the SWA? I buried a length of
There are no hard and fast rules - you need to be guided by the
situation. Under garden that may be lightly dug over, the minimum
recommendation would be 450mm - more if you expect heavy digging. Under
a path or patio etc, then it can be far shallower since the chance of it
being damaged is far less. It can also be run above ground clipped to a
solid surface (although one is supposed to avoid temporary structures
like fences[1]).
> 22mm water pipe along the same stretch a few months ago. The trench could
> easily be dug up again to take the SWA, but it was only about 9" deep.
> Where it goes along the side of the house, it was even shallower. The
> problem is, the ground is like hardcore around here. There's more
If its a place you are unlikely to dig over, you could decide that is
deep enough. Remove sharp stones and line the base of the trench with
soft sand or pea shingle, then back fill a bit. Lay a cable warning tape
a few inches above the cable so that future diggers will reach that first.
> limestone than soil in the earth... I guess if someone did manage to put
> a pickaxe through the SWA, the cucuit breaker would flip, so no big deal,
> yes?
Possibly. The most annoying situation is subtle damage that then cause
nuisance RCD trips later etc.
[1] I will admit to having fixed runs along the concrete gravel boards
at the base of a fence before, since it did not seem at all "temporary"!
ARWadsworth
> [1] I will admit to having fixed runs along the concrete gravel boards
> at the base of a fence before, since it did not seem at all
> "temporary"!
I have done that. I suspect that the gravel boards will outlive the wooden
shed that the cable supplied.
--
Adam
AL_n
Thanks for the input/suggestions. When I buried that 22mm water pipe, there
is a section where a vehicle could concievably cross. I lined the base of
that section of trench with pea gravel and laid concrete blocks over the
top. I'll ease up the concrete blocks and now lay the SWA underneath too.
The alternative possibility was to run the came overhead from the house to
the garage. But that looks ugly.
Al
Spamlet
"AL_n" <fgdf...@fghfghfg.com> wrote in message
news:Xns9E0E7247...@130.133.4.11...
It depends on the alignment of house and garage, but our supply comes from
the first floor of the house straight through conduit to a high corner of
the garage - which is only about 6ft away - so the cable is all out of the
way above where anyone is likely to kick it.
On the other hand our gas pipes (not put in by us) are just tacked along the
house wall and could easily be kicked off, though they haven't been in 20
odd years.
S
![george [dicegeorge]'s profile photo](http://lh3.googleusercontent.com/a-/ALV-UjVy3egmWxdo6kgdNwXDn-6EE54MDMuR9kO5wF-DhVhewlzxjNY=s40-c)
george [dicegeorge]
>
>
> Thanks. I have just found another roll of SWA that is long enough for the
> entire stretch. I'm not sure what the rating is; it is 15mm overall
> single-strand. There is no earth. I presume one therefore uses the
> armouring as the earth. Does this sound like 4mm or 2.5mm?
>
Is it OK to use red and black,
I thought it all has to be blue and brown these days?
[g]
Andy Burns
> Is it OK to use red and black,
No, but ...
Andy Wade
> [...]
> Thanks. I have just found another roll of SWA that is long enough for the
> entire stretch. I'm not sure what the rating is; it is 15mm overall
> diameter, has two cores (red& black) each cored with 2mm thick copper
> single-strand. There is no earth. I presume one therefore uses the
> armouring as the earth. Does this sound like 4mm or 2.5mm?
The cable you have there is almost certainly 2.5 mm^2, not 4 mm^2. 2.5
is the largest size where you'll normally find single solid cores (of
diameter 1.78 mm not 2 mm). '4 mil' SWA would have 7-strand conductors
(7/0.85).
BS 6346 is the standard for PVC insulated SWA which does tend to be a
little larger than for the same CSA with XLPE insulation (BS 5467) which
is what is normally used nowadays (and for the last ~20 years, in fact).
The current rating for a single-phase circuit in 2.5 PVC SWA is 28 amps
clipped direct, or 29 amps where buried. As others have said it's
voltage drop that may be the size-determining factor.
>> Remember RCD protection is required re outdoor appliances.
>
> I'm assuming that an appliance in my garage/workshop can be classed as an
> indoor appliance.
But you still need 30 mA RCD protection for the sockets in the shed.
--
Andy
AL_n
news:8hhht0...@mid.individual.net:
>> Thanks. I have just found another roll of SWA that is long enough for
>> the entire stretch. I'm not sure what the rating is; it is 15mm
>> overall diameter, has two cores (red& black) each cored with 2mm
>> thick copper single-strand. There is no earth. I presume one
>> therefore uses the armouring as the earth. Does this sound like 4mm
>> or 2.5mm?
>
> The cable you have there is almost certainly 2.5 mm^2, not 4 mm^2. 2.5
> is the largest size where you'll normally find single solid cores (of
> diameter 1.78 mm not 2 mm). '4 mil' SWA would have 7-strand
> conductors (7/0.85).
I think you are right. I examined the cores under a magnifying glass and
they are under 2mm in diameter.
> BS 6346 is the standard for PVC insulated SWA which does tend to be a
> little larger than for the same CSA with XLPE insulation (BS 5467)
> which is what is normally used nowadays (and for the last ~20 years,
> in fact).
>
> The current rating for a single-phase circuit in 2.5 PVC SWA is 28
> amps clipped direct, or 29 amps where buried. As others have said
> it's voltage drop that may be the size-determining factor.
>
>>> Remember RCD protection is required re outdoor appliances.
>>
>> I'm assuming that an appliance in my garage/workshop can be classed
>> as an indoor appliance.
>
> But you still need 30 mA RCD protection for the sockets in the shed.
OK - thanks. When were RCD consumer units introduced? The reason I ask is
that the unit in my house is probably a early 1980s vintage and orginally
had wire fuses. I fitted MCBs when I bought the house six months ago. I
think someone once suggested I should swap the box for a RCD one, but
warned me that I'd experience a lot more trippings of the circuit breakers
when there was no actual fault to speak of, so I left it as it was to avoid
the hassle. My logic was, that I couldn't remember hearing of anyone having
a life threatening accident due to the failure of a fuse or circuit breaker
prior to the introduction of RCD boxes, so why change it end experience
more nuisance MCB trippings.
I can put a small RCD box in the garage no problem. Should I be worried
that the house has no RCD?
Al
John Rumm
> On 11/10/2010 16:12, AL_n wrote:
>
>> [...]
>> Thanks. I have just found another roll of SWA that is long enough for the
>> entire stretch. I'm not sure what the rating is; it is 15mm overall
>> diameter, has two cores (red& black) each cored with 2mm thick copper
>> single-strand. There is no earth. I presume one therefore uses the
>> armouring as the earth. Does this sound like 4mm or 2.5mm?
>
> The cable you have there is almost certainly 2.5 mm^2, not 4 mm^2. 2.5
> is the largest size where you'll normally find single solid cores (of
> diameter 1.78 mm not 2 mm). '4 mil' SWA would have 7-strand conductors
> (7/0.85).
Might be worth sticking a vernier or micrometer on the actual wire core
to make an accurate measurement to be sure....
> BS 6346 is the standard for PVC insulated SWA which does tend to be a
> little larger than for the same CSA with XLPE insulation (BS 5467) which
> is what is normally used nowadays (and for the last ~20 years, in fact).
Yup, well spotted - I did not see the BS 6346 bit at the time...
Odd thing is the overall diameters on the smaller sizes of two core
don't seem as different as one might expect if table 7 in BS 6346 is to
be believed:
CSA PVC Diameter XLPE Diameter
1.5 12.3 12.1
2.5 13.6 13.6
4 15.1 14.7
6 16.5 15.9
10 20.1 18.0
16 21.9 20.4
Needless to say 2.5 and 4 mil being the hardest to differentiate!
(PVC diameter from BS 6346 Table 7, XLPE Diameter from BS 5467 Table 6)
John Rumm
>>>> Remember RCD protection is required re outdoor appliances.
>>>
>>> I'm assuming that an appliance in my garage/workshop can be classed
>>> as an indoor appliance.
>>
>> But you still need 30 mA RCD protection for the sockets in the shed.
>
> OK - thanks. When were RCD consumer units introduced? The reason I ask is
They started to be common from about the mid 80's IIRC (during the time
of the 15th edition of the wiring regs)
> that the unit in my house is probably a early 1980s vintage and orginally
> had wire fuses. I fitted MCBs when I bought the house six months ago. I
> think someone once suggested I should swap the box for a RCD one, but
> warned me that I'd experience a lot more trippings of the circuit breakers
> when there was no actual fault to speak of, so I left it as it was to avoid
You may have been getting a mixed message there. Swapping from fuses to
MCBs can raise the nuisance trip level on things like lighting circuits,
due to the high (but brief) current surge that can occur when a filament
lamp fails. Nuisance tripping of a MCB on a socket circuit is going to
be pretty rare unless you are starting up large induction motors or
transformers!
Nuisance tripping of a RCD (assuming the basic installation design is
sound, and there are not too many circuits protected by the same device)
is usually indicative of a deeper problem. So basically it ought not
happen if everything is working ok.
Having a RCD will not effect the trip rate of a MCB at all (no way it
can). It will introduce a separate and different trip mechanism. However
it is one that is particularly well suited to preventing serious injury.
> the hassle. My logic was, that I couldn't remember hearing of anyone having
> a life threatening accident due to the failure of a fuse or circuit breaker
> prior to the introduction of RCD boxes, so why change it end experience
> more nuisance MCB trippings.
RCDs are particularly valuable for protecting supplies used for power
tools in the garden etc, where the risk of exposure to a hazardous
voltage is greater in the first place (e.g. mowed, & hedge trimmed
flexes etc), and the risks from shock are far greater (e.g. in a damp
environment with a very good personal connection to earth). Here RCDs
have resulted in notable reduction in serious injuries.
(due to the generally high standards that we apply to domestic
electrical installations in this country, fatalities resulting from
electrocution are typically very low (usually less than 20/year), most
of which come from accidents with appliances. However it is a fairly
safe bet that the presence of a working RCD would prevent most of those)
> I can put a small RCD box in the garage no problem. Should I be worried
> that the house has no RCD?
That is a deeper question ;-)
Start by having a read of:
http://wiki.diyfaq.org.uk/index.php?title=RCD
to get the background.
Let's start from the assumption that you have a RCD protected plug-in
extension lead or similar, so that you can safely take power outside.
This is the first place RCD protection is a no brainer. If you don't
have at least this, then get something. Its up there with smoke alarms
as a cheap, worthwhile common sense thing to do.
Now you need to look at the particular risks in your household:
How likely are you or other people in the house to get a shock in the
first place?
A reasonably modern wiring install with decent earthing provision[1],
with not too many extension leads or stacked socket adaptors floating
about the place, and no kids that might decide to play with a socket,
probably means relatively little risk while inside (assuming the
equipotential bonding is up to scratch in the bathrooms etc).
Various things can increase the risks; if you do plenty of DIY for
example, or have a wiring install of questionable integrity and age, or
young kids romping about the risks go up. Having a garden or a workshop
where you may use power tools raises the risks a bit. If you live out in
the sticks and find rodents frequently noshing your cables, or have a
thatched roof, then risks increase again. Most of these are not large in
themselves (you are statistically far more likely to trip over and break
your neck or slip with a carving knife, than go out in a shower of
sparks!), but they help form a overall picture.
[1] If you have a TT install, then RCDs become essential.
http://wiki.diyfaq.org.uk/index.php?title=TT_Earthing
Frank Erskine
It's entirely up to you - it's nobody else's business on your own
premises, is it?
--
Frank Erskine
tony sayer
>
>OK - thanks. When were RCD consumer units introduced? The reason I ask is
>that the unit in my house is probably a early 1980s vintage and orginally
>had wire fuses. I fitted MCBs when I bought the house six months ago. I
>think someone once suggested I should swap the box for a RCD one, but
>warned me that I'd experience a lot more trippings of the circuit breakers
>when there was no actual fault to speak of, so I left it as it was to avoid
>the hassle. My logic was, that I couldn't remember hearing of anyone having
>a life threatening accident due to the failure of a fuse or circuit breaker
>prior to the introduction of RCD boxes, so why change it end experience
>more nuisance MCB trippings.
>
I'd trade any day a few nuisance trips for hanging across the mains
which from personal experience is EXTREMELY PAINFUL let alone somewhat
life threatening..
>I can put a small RCD box in the garage no problem. Should I be worried
>that the house has no RCD?
I would. We make it a condition that any plant we work on anywhere and
some is located in remote places, has RCD protection and is tested
periodically..
As to spurious tripping usually only when there is reason to trip.
Electrical leakage in heating elements, Neutral to Earth shorts, and
occasional odd trips in thunderstorms and such like.
Some times a lot of Capactive leakage if you have a LOT of IT like
equipment around..
Here around one nuisance trip every three years on average;!.
Just fit it, one day you might be rather grateful..,...
--
Tony Sayer
AL_n
news:gezb5jIC...@bancom.co.uk:
>>I can put a small RCD box in the garage no problem. Should I be
>>worried that the house has no RCD?
>
> I would. We make it a condition that any plant we work on anywhere and
> some is located in remote places, has RCD protection and is tested
> periodically..
>
> As to spurious tripping usually only when there is reason to trip.
> Electrical leakage in heating elements, Neutral to Earth shorts, and
> occasional odd trips in thunderstorms and such like.
>
> Some times a lot of Capactive leakage if you have a LOT of IT like
> equipment around..
>
> Here around one nuisance trip every three years on average;!.
>
> Just fit it, one day you might be rather grateful..,...
Thanks. What is the cheapest way to do it (in the house)? Do I need to buy
an entire new distribution box with new MCB's - of is there a RCD device
that I can install between the Electric meter and the distribution box?
If the former, can anyon recommend a cheap online supplier?
Al
David Robinson
> On Mon, 11 Oct 2010 23:24:53 +0100, "george [dicegeorge]"
>
>
> >> Thanks. I have just found another roll of SWA that is long enough for the
> >> entire stretch. I'm not sure what the rating is; it is 15mm overall
> >> diameter, has two cores (red& black) each cored with 2mm thick copper
> >> single-strand. There is no earth. I presume one therefore uses the
> >> armouring as the earth. Does this sound like 4mm or 2.5mm?
>
> >Is it OK to use red and black,
> >I thought it all has to be blue and brown these days?
>
> It's entirely up to you - it's nobody else's business on your own
> premises, is it?
Are people here too "polite" to mention Part P to the OP?
New circuit. No RCD. Wrong colour cable.
Just asking...!
Cheers,
David.
Fredxx
Didn't the OP say he was going to make it a spur off an existing circuit?
John Rumm
> Thanks. What is the cheapest way to do it (in the house)? Do I need to buy
> an entire new distribution box with new MCB's - of is there a RCD device
Probably, yes...
You may be able to get RCBOs for your particular box, in which cas you
could protect the socket circuits with one.
> that I can install between the Electric meter and the distribution box?
You can, but you don't want to. Firstly it does not meet the current
requirements for containing a fault by isolating close to the source and
leaving other circuits unaffected (i.e. a trip loses power to
everything). Secondly, that is a good way to make nuisance trips far
more likely.
> If the former, can anyon recommend a cheap online supplier?
TLC are pretty good:
http://www.tlc-direct.co.uk/Main_Index/index.html
js.b1
wrote:
> Are people here too "polite" to mention Part P to the OP?
> New circuit. No RCD. Wrong colour cable.
Hmmm....
"The installation of prefabricated, "modular" systems (for example...
armoured garden cabling) linked by plug and socket connectors is not
notifiable, provided that products are CE-marked and that any final
connections in kitchens and special locations are made to existing
connection units or points (possibly a 13A socket outlet)".
SI2006, p9, part "k.".
So he could legitimately have a Pre-Fab run of Double-Socket glanded
off to Flex for thro wall (sleeved), Jn-Box, CW SWA-Gland, SWA, CW SWA-
Gland, Jn-Box, Flex for thro wall (sleeved), RCD-plug and plug into a
socket.
Indeed I recall such systems being available with armoured and flex
attached - not many, but they are out there. More commonly available
are outdoor sockets with flex for poking through a wall and connecting
to an RCD plug on the inside.
It does not define "prefabricated", which could mean a bloke down the
pub, john prescott, yuang dong province of china on a friday etc.
The OP should add RCD protection to the house as soon as possible. For
a garage it does without saying. Another note is does the garage have
incoming services etc re export of house earth. Nothing to stop the OP
putting the Red Black 2-core SWA on Ebay, plenty of people will buy it
if and only if he puts postage on it. Just coil it up, band-tie with
serial cable ties, tape over the sharp ends, put in a "rubble sack",
ship via www.interparcel.com or www.parcel2go.com for about £5.95 to
£6.99 + VAT, so charge the buyer £5.99 to make things attractive.
AL_n
adndhJ_L7rMinRn...@brightview.co.uk:
> You may be able to get RCBOs for your particular box, in which cas you
> could protect the socket circuits with one.
>
>> that I can install between the Electric meter and the distribution box?
>
> You can, but you don't want to. Firstly it does not meet the current
> requirements for containing a fault by isolating close to the source and
> leaving other circuits unaffected (i.e. a trip loses power to
> everything). Secondly, that is a good way to make nuisance trips far
> more likely.
>
>> If the former, can anyon recommend a cheap online supplier?
>
> TLC are pretty good:
>
> http://www.tlc-direct.co.uk/Main_Index/index.html
Thanks. I suspect they're all built to a BS so one box is as good as
another, yes?
Funnily enough, it appear my garage already has some primitive RCD box with
big old-fasioned black circuit breakers, but it's rusty and has no cover,
so I'll prolly buy a new plastic one to replace it.
Al
John Rumm
I would guess that most don't actually give a toss.
> New circuit. No RCD. Wrong colour cable.
I don't recall anyone recommending not using an RCD, and there is
nothing wrong with using a new circuit for this application.
As to the "wrong" colour cable its hardly a big issue in this context
(i.e. self use rather than supplying to a customer etc). It will have no
negative effect on the safety of the installation. It hardly seems like
an environmentally sound idea to dispose of cable and then buy it all
over again just to get it in a different colour.
> Just asking...!
Why?
The OP has had the good sense to ask for advice on the best way of doing
this, and has received a number of sensible replies with good advice. I
(rightly or wrongly) get the impression you seem to be advocating a
nanny knows best response consisting of finger waving and a sharp intake
of breath.
js.b1
1985 1982 PVC SWA 2c was 7-strand even on 1.5mm. If the cable is older
than that, check for white slimey deposits on the zinc armour, because
it means the ends have been wet and water has tracked into it by
thermal cycling.
John Rumm
> John Rumm<see.my.s...@nowhere.null> wrote in news:w-
> adndhJ_L7rMinRn...@brightview.co.uk:
>
>> You may be able to get RCBOs for your particular box, in which cas you
>> could protect the socket circuits with one.
>>
>>> that I can install between the Electric meter and the distribution box?
>>
>> You can, but you don't want to. Firstly it does not meet the current
>> requirements for containing a fault by isolating close to the source and
>> leaving other circuits unaffected (i.e. a trip loses power to
>> everything). Secondly, that is a good way to make nuisance trips far
>> more likely.
>>
>>> If the former, can anyon recommend a cheap online supplier?
>>
>> TLC are pretty good:
>>
>> http://www.tlc-direct.co.uk/Main_Index/index.html
>
>
>
> Thanks. I suspect they're all built to a BS so one box is as good as
> another, yes?
They will all be of an adequate quality certainly - none are going to be
unsafe. What varies is the range of accessori1es that will fit, the ease
of wiring, the long term availability of parts, aesthetic appearance etc.
MK tend to be very nice in most of these respects, but you pay for the
brand. Contactum are not as swish but very much cheaper. Hager and Wylex
are somewhere between them etc. There is also a fair bit of badge
engineering that goes on, with one maker producing parts badged for
another etc.
John Rumm
> On 12/10/2010 15:07, David Robinson wrote:
>> Just asking...!
>
> Why?
>
> The OP has had the good sense to ask for advice on the best way of doing
> this, and has received a number of sensible replies with good advice. I
> (rightly or wrongly) get the impression you seem to be advocating a
> nanny knows best response consisting of finger waving and a sharp intake
> of breath.
I know, bad form replying to myself, but:
David, apologies if that sounded harsh - having just read your later
post about BCO / electrical disagreements etc, I realise you probably
had other reasons for bringing this point up!
David Robinson
> On 12/10/2010 22:37, John Rumm wrote:
>
> > On 12/10/2010 15:07, David Robinson wrote:
> >> Just asking...!
>
> > Why?
>
> > The OP has had the good sense to ask for advice on the best way of doing
> > this, and has received a number of sensible replies with good advice. I
> > (rightly or wrongly) get the impression you seem to be advocating a
> > nanny knows best response consisting of finger waving and a sharp intake
> > of breath.
>
> I know, bad form replying to myself, but:
>
> David, apologies if that sounded harsh - having just read your later
> post about BCO / electrical disagreements etc, I realise you probably
> had other reasons for bringing this point up!
Yep! I certainly don't believe that "nanny knows best"! The sooner
Messrs Cameron and Clegg sack nanny the better! ;-)
(not holding my breath on this one, sadly)
I've just been through house selling/buying, so know how painful some
lenders (and some solicitors) make the process - any excuse to scupper
it in the current financial climate. Otherwise I would have zero
interest in anything building control have to say on this matter.
Follow the regs (On site guide is enough for normal domestic work
IMO!) and do a good job. Put your feet up at the end, happy in the
knowledge that your house is now 10x safer with RCD protection
throughout and the 6-way rewireable fuse "consumer unit" in a skip!
End of.
Cheers,
David.
AL_n
c6d6ff...@a36g2000yqc.googlegroups.com:
> Is the OP sure it is single strand, I thought it was always class-2?
The two cores are definitely single strand.
Al