UK equivalent of a GFCI (Ground Fault Circuit Interrupter)?
terry
situations.Especially in new construction. They are now manadatory in
many jurisdictions for 'wet' or 'outside' locations. Bathrooms, garden
pools, electric lawn mowers/trimmers patio outlets etc.
Typically there are six to eight three prong duplex outlets on each
radial circuit (the limit varies somewhat depending on jurisdiction
and usage) provided at approximately intervals of six feet along each
appropriate wall.
For certain 'heavy' locaions such as kitchens there may be several
dedicated radial circuits for such things as toasters, electric fry-
pans etc. After all for the same wattage we need twice the amperes of
the 230 volt system!
AFIK 'ring' circuits are not used at all. Duplex outlets are
unswitched
The GFCIs, which cost about $10 to $15 each compared to a basic good
quality duplex outlet at around $2 or $3, can either be wired
individually or most can be wired as the first or any intermediate
outlet on a radial run and thereby 'protect' all regular outlets down
stream of them.
For example if installed as the first outlet in a run the GFCI can
protect all outlets further along that circuit. However that is
frequently not convenient or necessary. Because one has to remember
which is the actual first outlet on a circuit and go and find it if it
becomes tripped!
With my luck it would be behind the TV set or something!
As an example; we have one circuit with two outlets; one in the garage
and higly accessible and one outside for electric garden tools etc. So
the GFCI was installed in the first outlet in the garage and protects
both. It is highly visble and accessible if it does trip.
GFCI are generaly not recommended or used for 115 volt appliances with
motors such as fridges/freezers because unbalances during start can
trip the GFCI. And one comes home to bad food!
Actually 'Ground fault ...... ' may be a misnomer because they
actually operate to disconnect when an unbalance occurs betweeen the
live and neutral wire currents. Although all outlets have the third
prong earth/ground GFCI operate without it. A potentially lethal
leakge of a few milliamps to any earth/ground would also cause an
unbalnce and safely disconnect the voltage.
By the way they DO work; nothing dangerous yet but leaving something
out in the rain/damp has caused them to disconnect.
For heavier appliances, such as cooking stoves, hot water tanks,
clothes dryers etc. 230 volts is used. Those circuits are dedicated to
each appliance with individual two pole circuit breakers.
Understanding that in the UK RCDs, mounted in or near the consumer
unit (main fuse/circuit breaker panel) are used? Here is the nub of my
question.
Is there any such thing as a 230 volt GFCI (or RCD equivalent) that
can be mounted as an individual outlet, or an immediate adjunct to
it.
Reason for asking is that I will inherit some 230 volt appliances and
already have some 230 volt tools, and if when using these in a damp
location such as garage, patio etc. it would be nice to have an outlet
that would trip on slight leakage etc.
I also occasionaly do at-home servicing of some 230 volt items and
again the equivalent of a resettable GFCI/RCD on the work bench would
be nice to have.
Any advice appreciated; am presently in a country that 'sort of'
follows UK 230 volt 50 hertz wiring practices. So may be able to
purchase one or two of something and take back to Canada?
Bob Mannix
news:4f6a3a1f-03b2-4ecf...@c33g2000hsd.googlegroups.com...
You can purchase outlets that incorporate an RCD or connectors for your
appliances that incorporate one very easily( as well as extension leads
etc):
http://www.screwfix.com/prods/83049/Electrical/RCDs/Volex-13A-RCD-FCU
http://www.screwfix.com/prods/15263/Electrical/RCDs/RCD-Adaptor
http://www.screwfix.com/prods/16930/Electrical/RCDs/RCD-Plug
http://www.screwfix.com/prods/12374/Electrical/RCDs/Power-Breaker-2G-RCD-Skt
http://www.screwfix.com/prods/16353/Electrical/RCDs/Power-Breaker-1G-RCD-Skt-White
--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)
terry
> "terry" <tsanf...@nf.sympatico.ca> wrote in message
>
> http://www.screwfix.com/prods/16353/Electrical/RCDs/Power-Breaker-1G-...
>
> --
> Bob Mannix
> (anti-spam is as easy as 1-2-3 - not)- Hide quoted text -
>
> - Show quoted text -
Thank you Bob. Went and had a shower, came back and there was your
reply! Thanks much; exactly the sort of thing looking for.
Terry.
d...@gglz.com
I'm surprised that Canadian GFCI/RCD's sockets also protect further
sockets downstream on the radial.
UK sockets RCD's are designed for ring mains so only protect that
outlet.
John Rumm
> In Canada we use 115-120 volt GFCI outlets in certain domestic
> situations.Especially in new construction. They are now manadatory in
> many jurisdictions for 'wet' or 'outside' locations. Bathrooms, garden
> pools, electric lawn mowers/trimmers patio outlets etc.
Yup, same here... in fact becoming mandatory for most circuits in the
near future.
> Typically there are six to eight three prong duplex outlets on each
> radial circuit (the limit varies somewhat depending on jurisdiction
> and usage) provided at approximately intervals of six feet along each
> appropriate wall.
We don't have a fixed limit on the number of sockets per radial since
each appliance has a fuse in its plug the main breaker does not need to
be sized to protect the appliance flex, it just needs to be sized to
protect the radial wire.
> For certain 'heavy' locaions such as kitchens there may be several
> dedicated radial circuits for such things as toasters, electric fry-
> pans etc. After all for the same wattage we need twice the amperes of
> the 230 volt system!
Its become common place to run a dedicated 7.2kW ring circuit for the
sockets in a kitchen here, plug dedicated radials for any big fixed
loads like cookers.
> AFIK 'ring' circuits are not used at all. Duplex outlets are
> unswitched
Rings seem to be mostly uk specific. Its a concept that only works
because we have fused plugs. However they are very well suited to
typical patterns of modern usage with lots of sockets and appliances and
diverse usage.
> The GFCIs, which cost about $10 to $15 each compared to a basic good
> quality duplex outlet at around $2 or $3, can either be wired
> individually or most can be wired as the first or any intermediate
> outlet on a radial run and thereby 'protect' all regular outlets down
> stream of them.
OK, we don't usually do it like that, although there is nothing that
would actually stop you in practice.
> As an example; we have one circuit with two outlets; one in the garage
> and higly accessible and one outside for electric garden tools etc. So
> the GFCI was installed in the first outlet in the garage and protects
> both. It is highly visble and accessible if it does trip.
Yup, sockets with built in RCD protection are often used like that here
as well.
> GFCI are generaly not recommended or used for 115 volt appliances with
> motors such as fridges/freezers because unbalances during start can
> trip the GFCI. And one comes home to bad food!
Traditionally, one would have provided non RCD sockets on a radial
dedicated for that purpose...
> Actually 'Ground fault ...... ' may be a misnomer because they
> actually operate to disconnect when an unbalance occurs betweeen the
> live and neutral wire currents. Although all outlets have the third
> prong earth/ground GFCI operate without it. A potentially lethal
> leakge of a few milliamps to any earth/ground would also cause an
> unbalnce and safely disconnect the voltage.
Yup, what we call a RCD - residual current device
> Understanding that in the UK RCDs, mounted in or near the consumer
> unit (main fuse/circuit breaker panel) are used? Here is the nub of my
> question.
>
> Is there any such thing as a 230 volt GFCI (or RCD equivalent) that
> can be mounted as an individual outlet, or an immediate adjunct to
> it.
Yes, you can get RCDs in a number of different forms:
http://wiki.diyfaq.org.uk/index.php?title=RCD#Types_of_RCD
> Reason for asking is that I will inherit some 230 volt appliances and
> already have some 230 volt tools, and if when using these in a damp
> location such as garage, patio etc. it would be nice to have an outlet
> that would trip on slight leakage etc.
Well worth have RCD protection in the situation, even though most tools
these days will be class II insulated so will pose little indirect shock
risk. However chopping through a cable is still an issue.
--
Cheers,
John.
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|-----------------------------------------------------------------|
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Andrew Gabriel
"d...@gglz.com" <d...@gglz.com> writes:
>
> I'm surprised that Canadian GFCI/RCD's sockets also protect further
> sockets downstream on the radial.
That's standard practice in the US and Canada.
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]
mcdona...@rediffmail.com
ring circuits
mcdona...@rediffmail.com
> RCBOs may be another possibility is you want to protect individual
> ring circuits
sorry - this is probably not relevant
Derek Geldard
<tsan...@nf.sympatico.ca> wrote:
>
>Any advice appreciated; am presently in a country that 'sort of'
>follows UK 230 volt 50 hertz wiring practices. So may be able to
>purchase one or two of something and take back to Canada?
Is the 230v supply in Canada 155 - 0 - 115 ?
Our 230v is 230 - 0 - Gnd.
Not 100% sure how well one of our RCDs would work on a 115 - 0 - 115
installation. It might be alright ;-)
DG
Andrew Gabriel
There certainly have been some that detect excessive Neutral-Earth
voltage and trip. I don't think this is the norm though. The other
thing is that you need a double-pole switching type -- again I don't
know how common that is with the socket outlet types, hardly ever
having used them myself.
The Natural Philosopher
What they care about is more current coming in one wire than goes out or
vice versa ;-)
So as long as the lakage to earth is not on average, the same from both
'live'and 'neutral' they should be OK..
Appin
from and...@cucumber.demon.co.uk (Andrew Gabriel) contains these words:
Appin
from and...@cucumber.demon.co.uk (Andrew Gabriel) contains these words:
> In article <5glrr3lhsmslgspaj...@4ax.com>,
Quite apart from which for many appliances the frequency difference
makes the whole exercise fraught with difficulty and a bit pointless.
Take electric kettles. Electric blankets. Your favourite lamps as long
as they have ES lampholders, take anything else that presents a purely
resitive load and forget about the rest.
Derek Geldard
wrote:
>>
>Our RCDS dont use, or care, about ground.
>
>What they care about is more current coming in one wire than goes out or
>vice versa ;-)
>
>So as long as the lakage to earth is not on average, the same from both
>'live'and 'neutral' they should be OK..
Just because they dont *use* the ground connection you can't assume
that.
a) There may be differential capacitive effects.
b) They will certainly not have been type tested under those
conditions.
DG
meow...@care2.com
There are some that do additional checking involving ground, and
those ones would not work on 115-0-115. Then again they would if
you fed the right one of the incoming live wires to the RCD ground
connection, and the output side had its ground wire rerouted to the
real ground.
RCD sockets cost about £20, and RCD plugs around £7. But I dont
know why the OP doesnt get one back home. Theres no
connection on our RCD skts to allow them to cover other sockets, so
plugs are a far cheaper option. Dont forget to get sockets for the RCD
plugs!
Its also possible to make RCDs - though not worth bothering
unless you really need something specialist, eg a 0.5mA trip or
something.
NT
meow...@care2.com
Oh, afaik ours only switch one pole, so you'd need to either
a) use the RCD output to drive a 2 pole relay and accept longer
disconnect times
or
b) use a 110v RCD, with a minor mod to make it work ok on 230v.
The dropper that supplies the internal electronics would need
replacing with one of twice the resistance and half the capacitance,
and twice the capacitor voltage rating.
FWIW we do have 2 pole 240v RCDs that fit into CUs (breaker
panels), and it shouldnt be hard to make up a case for them back
home. Might be your best bet, a row of them in a case.
All the types are here:
http://www.screwfix.com/search.do;jsessionid=WT3MWDDKPNZCUCSTHZPCFFA?_dyncharset=UTF-8&fh_search=rcd
NT