On the new sink which I just bought I am instructed that it must be earthed,
certainly the sink in my utility room is so earthed - although the old sink
which I just removed from the kitchen wasn't.

While I understand the legalities, I cannot for the life of me see that earthing
the sink decreases risk.  If someone picks up a badly earthed kitchen item with
a "live" casing, touching the earthed sink will give a good path to ground
through the body. If the sink was insulated from earth, there would be no such
path.

What's the logic of this earthing, just out of interest?
--
Jim
"a single species has come to dominate ...
reproducing at bacterial levels, almost as an
infectious plague envelops its host" 
http://tinyurl.com/c88xs

In article ,
	Jim Lawton <ucan@use.your.initiative> writes:

> On the new sink which I just bought I am instructed that it must be earthed,
> certainly the sink in my utility room is so earthed - although the old sink
> which I just removed from the kitchen wasn't.
> 
> While I understand the legalities, I cannot for the life of me see that earthing
> the sink decreases risk.  If someone picks up a badly earthed kitchen item with
> a "live" casing, touching the earthed sink will give a good path to ground
> through the body. If the sink was insulated from earth, there would be no such
> path.
> 
> What's the logic of this earthing, just out of interest?


There's no requirement for equipotential bonding in a kitchen at all.
It is often fitted though, particularly around the sink.
As you correctly point out, there are cases where the bonding would
make a fault more dangerous, but there are also cases where it makes
it safer -- it's a difficult call, and up to you. It's now generally
thought to be a bad idea where plastic piping has been used, as 0.5m
of plastic piping, even with tap water in it, is effectively an
insulator, and in this case having the sink insulated rather than
grounded is safer. If you have a metal sink and/or metal taps and
pipes, I do fit equipotential bonding, which at least prevents some
fault generating 240V between the taps, or between a tap and the
sink.

-- 
Andrew Gabriel

"Andrew Gabriel"  wrote in message 
news:42de4db2$0$38046$5a6aecb4@news.aaisp.net.uk...

> In article ,
> Jim Lawton <ucan@use.your.initiative> writes:
>> On the new sink which I just bought I am instructed that it must be 
>> earthed,
>> certainly the sink in my utility room is so earthed - although the old 
>> sink
>> which I just removed from the kitchen wasn't.
>>
>> While I understand the legalities, I cannot for the life of me see that 
>> earthing
>> the sink decreases risk.  If someone picks up a badly earthed kitchen 
>> item with
>> a "live" casing, touching the earthed sink will give a good path to 
>> ground
>> through the body. If the sink was insulated from earth, there would be no 
>> such
>> path.
>>
>> What's the logic of this earthing, just out of interest?
>
> There's no requirement for equipotential bonding in a kitchen at all.
> It is often fitted though, particularly around the sink.
> As you correctly point out, there are cases where the bonding would
> make a fault more dangerous, but there are also cases where it makes
> it safer -- it's a difficult call, and up to you. It's now generally
> thought to be a bad idea where plastic piping has been used, as 0.5m
> of plastic piping, even with tap water in it, is effectively an
> insulator, and in this case having the sink insulated rather than
> grounded is safer. If you have a metal sink and/or metal taps and
> pipes, I do fit equipotential bonding, which at least prevents some
> fault generating 240V between the taps, or between a tap and the
> sink.
>
> -- 
> Andrew Gabriel


Sounds like your a Sparky Andrew?

Are you registered for Part P yet?

Bruno

In article <dbls4j$lde$1@newsg4.svr.pol.co.uk>,
	"Bruno"  writes:

> 
> Sounds like your a Sparky Andrew?
> 
> Are you registered for Part P yet?


No on both counts. ;-)

My reading of the trade press is that most sparks are still
not intending to register for Part P, and are either:
a) ignoring it
b) decided to retire if they were near retirement age
c) switched to commercial work only.

Part P will probably just push most domestic electrical work
on to the black market, which is the exact opposite of what
it was intended to do. That's the inevitable effect of pushing
though very bad legislation of this form, which was never
required in the first place.

-- 
Andrew Gabriel

Just like  CORGI, all the good guys have given up registration

-- 
regards
dave batter
mobile email # +447718648737@mmail.co.uk
www.kitchenman.co.uk
www.sxmitres.info
www.marks-family.co.uk
www.essex-sandivers.info

http://oneandone.co.uk/xml/init?k_id5568652

"Andrew Gabriel"  wrote in message
news:42de7c8e$0$38046$5a6aecb4@news.aaisp.net.uk...

> In article <dbls4j$lde$1@newsg4.svr.pol.co.uk>,
> "Bruno"  writes:
> >
> > Sounds like your a Sparky Andrew?
> >
> > Are you registered for Part P yet?
>
> No on both counts. ;-)
>
> My reading of the trade press is that most sparks are still
> not intending to register for Part P, and are either:
> a) ignoring it
> b) decided to retire if they were near retirement age
> c) switched to commercial work only.
>
> Part P will probably just push most domestic electrical work
> on to the black market, which is the exact opposite of what
> it was intended to do. That's the inevitable effect of pushing
> though very bad legislation of this form, which was never
> required in the first place.
>
> -- 
> Andrew Gabriel