Working for a regular customer in an industrial unit today & he asked me to
check why a 230v socket wasn't working. Socket tester showed no live but
all wires were properly in place. No mcb tripped on the panel.

Found another socket on an adjacent wall not working either, but sockets in
between them work fine.

There is metal trunking running all around the unit just over head height &
conduit running down to sockets. Since its a cash & carry type place I
couldn't get to a lot of the sockets to check them because of the display
shelving. Must be at least 20 double sockets though judging by the conduit
drops.

Big scary cabinet on wall with stickers saying 415v and 100 amps - not going
anywhere near that!

I'm guessing, but are industrial units wired up with some 230v sockets
running from each of the three phases? Is this to spread the load out?

Seems logical to me if some sockets are fine & others not. Is every third
socket from phase A, every forth socket from B etc?

He is getting a sparky in, but I'm curious.



--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

The Medway Handyman wrote:

I'm guessing, but are industrial units wired up with some 230v sockets
running from each of the three phases? Is this to spread the load
out?
Seems logical to me if some sockets are fine & others not. Is every
third socket from phase A, every forth socket from B etc?

He is getting a sparky in, but I'm curious.

Yeah, it's something like that - we have problems at work sometimes where we
lose a 'random' assortment of 13a sockets due to a phase going out.

On 24 Oct, 22:19, "The Medway Handyman"
wrote:
Working for a regular customer in an industrial unit today & he asked me to
check why a 230v socket wasn't working. Socket tester showed no live but
all wires were properly in place. No mcb tripped on the panel.

Found another socket on an adjacent wall not working either, but sockets in
between them work fine.

There is metal trunking running all around the unit just over head height &
conduit running down to sockets. Since its a cash & carry type place I
couldn't get to a lot of the sockets to check them because of the display
shelving. Must be at least 20 double sockets though judging by the conduit
drops.

Big scary cabinet on wall with stickers saying 415v and 100 amps - not going
anywhere near that!

I'm guessing, but are industrial units wired up with some 230v sockets
running from each of the three phases? Is this to spread the load out?

Seems logical to me if some sockets are fine & others not. Is every third
socket from phase A, every forth socket from B etc?

He is getting a sparky in, but I'm curious.

--
Dave - The Medway Handymanwww.medwayhandyman.co.uk
01634 717930
07850 597257

Leave it to the sparks, what do you know. You is only a handyman.

Chas wrote:
On 24 Oct, 22:19, "The Medway Handyman"
wrote:
Working for a regular customer in an industrial unit today & he
asked me to check why a 230v socket wasn't working. Socket tester
showed no live but all wires were properly in place. No mcb tripped
on the panel.

Found another socket on an adjacent wall not working either, but
sockets in between them work fine.

There is metal trunking running all around the unit just over head
height & conduit running down to sockets. Since its a cash & carry
type place I couldn't get to a lot of the sockets to check them
because of the display shelving. Must be at least 20 double sockets
though judging by the conduit drops.

Big scary cabinet on wall with stickers saying 415v and 100 amps -
not going anywhere near that!

I'm guessing, but are industrial units wired up with some 230v
sockets running from each of the three phases? Is this to spread
the load out?

Seems logical to me if some sockets are fine & others not. Is every
third socket from phase A, every forth socket from B etc?

He is getting a sparky in, but I'm curious.


Leave it to the sparks, what do you know. You is only a handyman.

But a handyman who likes to know about these things..............


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

"The Medway Handyman" wrote in message
. uk...
Working for a regular customer in an industrial unit today & he asked me
to check why a 230v socket wasn't working. Socket tester showed no live
but all wires were properly in place. No mcb tripped on the panel.

Found another socket on an adjacent wall not working either, but sockets
in between them work fine.

There is metal trunking running all around the unit just over head height
& conduit running down to sockets. Since its a cash & carry type place I
couldn't get to a lot of the sockets to check them because of the display
shelving. Must be at least 20 double sockets though judging by the
conduit drops.

Big scary cabinet on wall with stickers saying 415v and 100 amps - not
going anywhere near that!

I have accidentally worked on live 415v, but putting down an insulating
floor mat first and automatically making sure I never touched two different
metal objects at the same time, meant I didn't notice until I traced the
cables later.

I'm guessing, but are industrial units wired up with some 230v sockets
running from each of the three phases? Is this to spread the load out?

Seems logical to me if some sockets are fine & others not. Is every third
socket from phase A, every forth socket from B etc?

Maybe, maybe not. It was always considered good practice to keep at least 6
feet between sockets on different phases. If they are closer, they are
likely to be wired in blocks, with several adjacent sockets on one phase. If
they are widely spaced, they might be wired on alternate phases. Again, good
practice would be to mark phase colours, either with phase disks by the
socket or by sleeving the live with a phase colour.

Colin Bignell

"nightjar" cpb@insert my surname here.me.uk wrote:

It was always considered good practice to keep at least 6
feet between sockets on different phases.

Isn't there a requirement for a warning sign if this is not the
case?

Chris
--
Chris J Dixon Nottingham UK


Have dancing shoes, will ceilidh.

On 2007-10-24 22:42:06 +0100, Chas said:

On 24 Oct, 22:19, "The Medway Handyman"
wrote:
Working for a regular customer in an industrial unit today & he asked me to
check why a 230v socket wasn't working. Socket tester showed no live but
all wires were properly in place. No mcb tripped on the panel.



He is getting a sparky in, but I'm curious.

--
Dave - The Medway Handymanwww.medwayhandyman.co.uk
01634 717930
07850 597257

Leave it to the sparks, what do you know. You is only a handyman.

.... but probably bigger than you.....

"Chris J Dixon" wrote in message
...
"nightjar" cpb@insert my surname here.me.uk wrote:

It was always considered good practice to keep at least 6
feet between sockets on different phases.

Isn't there a requirement for a warning sign if this is not the
case?

I've not done any three phase since the latest regs came in, so I'm not up
on them, but there never used to be. The requirement was for a warning sign
where two or more phases are present inside equipment that might normally be
expected to be single phase, such as light switch banks.

Colin Bignell

On Wed, 24 Oct 2007 21:19:18 GMT someone who may be "The Medway
Handyman" wrote this:-

I'm guessing, but are industrial units wired up with some 230v sockets
running from each of the three phases?

If the building is large enough for a three phase supply to be
sensible.

Is this to spread the load out?

It is to attempt to balance the load on each phase as much as
possible. If they are perfectly balanced then there is no current in
the neutral, the more they are out of balance the higher the current
in the neutral. Obviously it is not possible to perfectly balance a
random collection of single phase loads, but they can balance
reasonably well.

Large single phase loads can cause problems within the electricity
system, which is why they are discouraged. An exception is AC trains
where it is not really possible to make them three phase within the
constraints of picking up electricity on a moving train. While the
electricity system is generally robust enough not to have a problem
with them there are places where the system is not robust enough. In
such places there may be restrictions on the number and speed of
electric trains, especially when some railway sub-stations are not
in use due to maintenance and trains are being fed from other
railway sub-stations.

Seems logical to me if some sockets are fine & others not. Is every third
socket from phase A, every forth socket from B etc?

Best practice is to have areas of the building on one phase. The
designer will try and split the building into suitably arranged
circuits to keep phases separate where the public encounter
electricity.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

Colin Bignell wrote;

SNIP
I'm guessing, but are industrial units wired up with some 230v
sockets running from each of the three phases? Is this to spread
the load out? Seems logical to me if some sockets are fine & others not.
Is every
third socket from phase A, every forth socket from B etc?

Maybe, maybe not. It was always considered good practice to keep at
least 6 feet between sockets on different phases. If they are closer,
they are likely to be wired in blocks, with several adjacent sockets
on one phase. If they are widely spaced, they might be wired on
alternate phases. Again, good practice would be to mark phase
colours, either with phase disks by the socket or by sleeving the
live with a phase colour.

Thanks for that Colin, makes sense.

This is an industrial estate built in the late 1960's. I guess the sockets
are 8 to 10' apart, alas no markings on the two I looked at.

Looks like they could be wired alternately.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

Andy Hall wrote:
On 2007-10-24 22:42:06 +0100, Chas said:

On 24 Oct, 22:19, "The Medway Handyman"
wrote:
Working for a regular customer in an industrial unit today & he
asked me to check why a 230v socket wasn't working. Socket tester
showed no live but all wires were properly in place. No mcb
tripped on the panel.



He is getting a sparky in, but I'm curious.


Leave it to the sparks, what do you know. You is only a handyman.

... but probably bigger than you.....

I'm bigger than most people :-)


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

The Medway Handyman wrote:
snip
Big scary cabinet on wall with stickers saying 415v and 100 amps - not going
anywhere near that!
/snip

You do realise that 415V is just the difference between two 230V phases?

Andy

Andy Champ wrote:
The Medway Handyman wrote:
snip
Big scary cabinet on wall with stickers saying 415v and 100 amps - not
going anywhere near that!
/snip

You do realise that 415V is just the difference between two 230V phases?

Andy

He does and he also has the common sense to ask questions rather than
just poke about in a system that is unusual for his normal sphere of work.

Steve

In article ,
Andy Champ writes:
The Medway Handyman wrote:
snip
Big scary cabinet on wall with stickers saying 415v and 100 amps - not going
anywhere near that!
/snip

You do realise that 415V is just the difference between two 230V phases?

Actually, it's the difference between two 240V phases ;-)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Thu, 25 Oct 2007 19:44:35 UTC, (Andrew
Gabriel) wrote:

In article ,
Andy Champ writes:
The Medway Handyman wrote:
snip
Big scary cabinet on wall with stickers saying 415v and 100 amps - not going
anywhere near that!
/snip

You do realise that 415V is just the difference between two 230V phases?

Actually, it's the difference between two 240V phases ;-)

And, possibly, the difference between life and death! TMH was right to
ask...

--
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
http://www.diybanter.com

Andy Champ wrote:
The Medway Handyman wrote:
snip
Big scary cabinet on wall with stickers saying 415v and 100 amps -
not going anywhere near that!
/snip

You do realise that 415V is just the difference between two 230V
phases?

No. I just know is scares the sh*t out of me so I stay well away :-)


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

... but probably bigger than you.....
I'm bigger than most people :-)

Just say "cuddly" rather than phat phucker :-p

(unless of course, you meant tall !)

Colin Wilson wrote:
... but probably bigger than you.....
I'm bigger than most people :-)

Just say "cuddly" rather than phat phucker :-p

(unless of course, you meant tall !)

"Big Boned" sums it up :-)


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

No. I just know is scares the sh*t out of me so I stay well away :-)

Sit watching wisps of oil smoke rise from a loop-in
single phase lead-sheathed-oiled-paper service cable.

You sit wondering... nah... just my imagination... sip...
its coffee steaming... no... whereupon two eyeballs are
all that is left hanging momentarily in mid-air as you run.

Neighbours with electric shower, cooker and a welder
all combine with your load to play Diversity Roulette.


Never assume anything about 415V installation, leave it
to lazy electricians who switch off RCBO by shorting N-E
only to find out someone got even lazier with colours.

You would think electricians would figure it out when we
cover the floor with rubber & plastic. Get it wrong and we
just roll you up in it and turn you into CEF counter staff.
--
DB.

On 2007-10-25 22:04:23 +0100, "The Medway Handyman"
said:

Andy Champ wrote:
The Medway Handyman wrote:
snip
Big scary cabinet on wall with stickers saying 415v and 100 amps -
not going anywhere near that!
/snip

You do realise that 415V is just the difference between two 230V
phases?

No. I just know is scares the sh*t out of me so I stay well away :-)

... and you were telling us that you were a "big guy". Is it a size
28 blouse? ;-)

In message , Andrew Gabriel
writes
In article ,
Andy Champ writes:
The Medway Handyman wrote:
snip
Big scary cabinet on wall with stickers saying 415v and 100 amps -
not going
anywhere near that!
/snip

You do realise that 415V is just the difference between two 230V phases?

Actually, it's the difference between two 240V phases ;-)

can someone please explain these statements

230 x 2 != 415
&
240 x 2 even more so != 415!

--
Ai

On Fri, 26 Oct 2007 06:29:48 UTC, Si $3o&m wrote:

can someone please explain these statements

230 x 2 != 415
&
240 x 2 even more so != 415!

It's (as I recall, rustily) the vector sum of the two 240v components,
out of phase by 120 degrees.

--
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
http://www.diybanter.com

In message , Bob Eager
writes
On Fri, 26 Oct 2007 06:29:48 UTC, Si $3o&m wrote:

can someone please explain these statements

230 x 2 != 415
&
240 x 2 even more so != 415!

It's (as I recall, rustily) the vector sum of the two 240v components,
out of phase by 120 degrees.

Oh Fsck! - sounds vaguely like something I learned for A-Level Physics
in the 70s! I also will stay well away from such boxes.

Thanks Bob,

--
Si

nightjar cpb@ wrote:
"The Medway Handyman" wrote in message
. uk...
Working for a regular customer in an industrial unit today & he asked me
to check why a 230v socket wasn't working. Socket tester showed no live
but all wires were properly in place. No mcb tripped on the panel.

Found another socket on an adjacent wall not working either, but sockets
in between them work fine.

There is metal trunking running all around the unit just over head height
& conduit running down to sockets. Since its a cash & carry type place I
couldn't get to a lot of the sockets to check them because of the display
shelving. Must be at least 20 double sockets though judging by the
conduit drops.

Big scary cabinet on wall with stickers saying 415v and 100 amps - not
going anywhere near that!

I have accidentally worked on live 415v, but putting down an insulating
floor mat first and automatically making sure I never touched two different
metal objects at the same time, meant I didn't notice until I traced the
cables later.

I'm guessing, but are industrial units wired up with some 230v sockets
running from each of the three phases? Is this to spread the load out?

Seems logical to me if some sockets are fine & others not. Is every third
socket from phase A, every forth socket from B etc?

Maybe, maybe not. It was always considered good practice to keep at least 6
feet between sockets on different phases. If they are closer, they are
likely to be wired in blocks, with several adjacent sockets on one phase. If
they are widely spaced, they might be wired on alternate phases. Again, good
practice would be to mark phase colours, either with phase disks by the
socket or by sleeving the live with a phase colour.

IIRC there is a legal requirement for something like that distance.


Colin Bignell

can someone please explain these statements

230 x 2 != 415
&
240 x 2 even more so != 415!

--
Ai

The UK (and many other countries) use 3 phases equally spaced at 120
degrees (I'll explain the phase angle thing in a mo).

First, what's a phase?

Electricity is generated and distributed in the UK on a 3 wire system,
each wire carries a *phase*.

Each phase is an alternating current - it goes 0V, +325V, 0V, -325V,
0V etc, and completes 50 of those cycles per second.

Now for the purposes of power calculations, it's much more useful to
know the *average* voltage than the peak voltage. However if we just
took the average of the numbers above the answer would be 0V. So we
take the RMS (root mean square) which in our case comes out at 230V
(and gives identical results in simple power calculations as if it was
the same d.c. voltage). We find this by dividing the peak voltage by
1.414 (see http://en.wikipedia.org/wiki/Root_mean_square for a
detailed explanation)

Now this alternating voltage has a shape known as a sine wave. And 3
phase is a set of 3 sine waves, each on it's own wire. Each of the 3
phases is identical in voltage and frequency - the only difference
between them is they *peak* at slightly different times. The 3 phases
are identified by colours, red, yellow, blue under the old colour code
or brown, black, grey under the new colours.

So red peaks, then yellow peaks, then blue, then red again. A useful
way of picturing this in many electrical calculations, is to imagine 3
points equally spaced around a circle. 360 degrees in a circle, so
they're 120 degrees apart.

Now the answer to your question, because there's a time difference
between the phases, but one phase is just a delayed version of
another, NOT the exact opposite of another - it's not as simple as
adding the numbers together to get the difference in voltage between
them. (Again we're interested in the RMS voltage, as the exact
instantaneous voltage between them varies all the time - what we're
interested in is how much power we can draw by connecting between the
phases).

For 3 equally spaced sine waves, we need to multiply the RMS phase to
neutral voltage by 1.732 to get the phase to phase voltage. So 230V
phase to neutral comes out as 398V phase to phase.

(see detailed explanation here http://en.wikipedia.org/wiki/Three-phase_electric_power)

Now for industrial premises drawing lots of power, they're usually
supplied with all 3 phases and large machines are connected directly
to these (and not necessarily to the neutral wire). The main reason
being that it's much more practical both to generate electricity and
to use it to power large motors with 3 phase.

For the domestic consumer, usually only 1 of these 3 phases goes into
your house (along with a neutral wire, nominally at 0V) and you get
what you're familiar with - 230V a.c. at 50Hz.

Finally for the sake of completeness, although the phases are
nominally sine waves of 230V, 50Hz and their phase difference 120
degrees, in real-world operating condition all of these can change and
the calculations get far more complicated.

"The Natural Philosopher" wrote in message
...
nightjar cpb@ wrote:
....
Maybe, maybe not. It was always considered good practice to keep at least
6 feet between sockets on different phases. If they are closer, they are
likely to be wired in blocks, with several adjacent sockets on one phase.
If they are widely spaced, they might be wired on alternate phases.
Again, good practice would be to mark phase colours, either with phase
disks by the socket or by sleeving the live with a phase colour.

IIRC there is a legal requirement for something like that distance.

I used to think that, but it was discussed at length some time ago, possibly
on another group, and nobody could come up with any piece of legislation.

Colin Bignell

nightjar cpb@ wrote:
"The Natural Philosopher" wrote in message
...
nightjar cpb@ wrote:
...
Maybe, maybe not. It was always considered good practice to keep at least
6 feet between sockets on different phases. If they are closer, they are
likely to be wired in blocks, with several adjacent sockets on one phase.
If they are widely spaced, they might be wired on alternate phases.
Again, good practice would be to mark phase colours, either with phase
disks by the socket or by sleeving the live with a phase colour.
IIRC there is a legal requirement for something like that distance.

I used to think that, but it was discussed at length some time ago, possibly
on another group, and nobody could come up with any piece of legislation.


Definitely back in e 90's our eletricians fresh out of HNC's said there
was..

Or at least 'good practice guidelines'.


Mm. My building reg book ignores electricity except in respect of fire
issues.

Colin Bignell

On Fri, 26 Oct 2007 08:45:41 +0100, The Natural Philosopher
wrote:

nightjar cpb@ wrote:
"The Medway Handyman" wrote in message
. uk...
Working for a regular customer in an industrial unit today & he asked me
to check why a 230v socket wasn't working. Socket tester showed no live
but all wires were properly in place. No mcb tripped on the panel.

Found another socket on an adjacent wall not working either, but sockets
in between them work fine.

There is metal trunking running all around the unit just over head height
& conduit running down to sockets. Since its a cash & carry type place I
couldn't get to a lot of the sockets to check them because of the display
shelving. Must be at least 20 double sockets though judging by the
conduit drops.

Big scary cabinet on wall with stickers saying 415v and 100 amps - not
going anywhere near that!

I have accidentally worked on live 415v, but putting down an insulating
floor mat first and automatically making sure I never touched two different
metal objects at the same time, meant I didn't notice until I traced the
cables later.

I'm guessing, but are industrial units wired up with some 230v sockets
running from each of the three phases? Is this to spread the load out?

Seems logical to me if some sockets are fine & others not. Is every third
socket from phase A, every forth socket from B etc?

Maybe, maybe not. It was always considered good practice to keep at least 6
feet between sockets on different phases. If they are closer, they are
likely to be wired in blocks, with several adjacent sockets on one phase. If
they are widely spaced, they might be wired on alternate phases. Again, good
practice would be to mark phase colours, either with phase disks by the
socket or by sleeving the live with a phase colour.

IIRC there is a legal requirement for something like that distance.


AFAICS, there is no mention in the 16th edition of segregation, as
there was in earlier editions.

I'm a volunteer at an industrial museum which, until a good few years
ago, had night storage heaters. The heating side of these was fed from
three-phase, distributed about the building, but the fans were all fed
from one phase.
Where the phases didn't coincide there were stickers on the double
switches feeding each heater, warning of 250V inside.

--
Frank Erskine

On 2007-10-26 08:58:19 +0100, "nightjar" cpb@insert my surname
here.me.uk said:


"The Natural Philosopher" wrote in message
...
nightjar cpb@ wrote:
...
Maybe, maybe not. It was always considered good practice to keep at least
6 feet between sockets on different phases. If they are closer, they are
likely to be wired in blocks, with several adjacent sockets on one phase.
If they are widely spaced, they might be wired on alternate phases.
Again, good practice would be to mark phase colours, either with phase
disks by the socket or by sleeving the live with a phase colour.

IIRC there is a legal requirement for something like that distance.

I used to think that, but it was discussed at length some time ago, possibly
on another group, and nobody could come up with any piece of legislation.

Colin Bignell

Perhaps the point was that it would then be impossible to stick your
fingers in two sockets on different phases at the same time. 400v
across the chest at suitable current would probably spoil the day for
most people.

On 24 Oct, 22:19, "The Medway Handyman"
wrote:
Working for a regular customer in an industrial unit today & he asked me to
check why a 230v socket wasn't working. Socket tester showed no live but
all wires were properly in place. No mcb tripped on the panel.

Found another socket on an adjacent wall not working either, but sockets in
between them work fine.

/snip//

The most likely explanation is that the fuse (or perhaps a contactor)
on one of the phases has blown (or tripped), though there's other
possibilities.

There are several reasons for using 3 phase in industrial & high load
installations, amongst them being economy of generation and
distribution and better control of electrically driven machinery.
Downside, if it is one, is that single phase loads need to be equally
balanced between phases so far as possible, plus the higher voltage
between adjacent single phase fittings when on different phases.

IIRC there was once a 6ft distance between accessible_by_touch single
phase fittings requirement (IEE 14th Ed???) but that has long since
disappeared from the IEE regs.

However there is one other important reason for using 3 phase derived
lighting (ie lighting shared between phases over one area) when
rotating electrical machinery is in use and that is to avoid the
strobe effect of a motor appearing to be standing still when in fact
it is going at full tilt. It is in the back of my head that it is or
was a legal requirement under one or other of the Factories Acts or
similar, but cannot vouch for it.

Flourescent tubes, including CFLs, flicker much more than ordinary
GLS, so is this a looming problem if CFLs become common place?

Lastly, whilst 3 phase is rare in homes in the UK unless used for
storage heaters, it is far more common on the continent.

BTW you need a waste transport licence (around £340 for 3 years from
Environment Agency IIRC) for even thinking about taking away
virtuially anything from a job site where you've been working. Even
your Mars bar wrapper is deemed scrap by the Blairite shock
troops ;-) And yes, even the filaments in the scrap flourescent
tubes;-)))

HTH

In message . com, jim
writes

There are several reasons for using 3 phase in industrial & high load
installations, amongst them being economy of generation and
distribution and better control of electrically driven machinery.
Downside, if it is one, is that single phase loads need to be equally
balanced between phases so far as possible, plus the higher voltage
between adjacent single phase fittings when on different phases.

IIRC there was once a 6ft distance between accessible_by_touch single
phase fittings requirement (IEE 14th Ed???) but that has long since
disappeared from the IEE regs.

Quite correct 14th. edition reg. A.20

*All socket outlets in any one room shall be connected to the same phase
(or pole of a 3-wire system).

Exemption. -In non-domestic premises, if it is clearly
impracticable to comply with regulation A. 20, more than one phase (or
pole) of the supply may be utilized provided that all socket outlets on
one phase (or pole) are grouped together and are not intermingled with
socket-outlets connected to a different phase (or pole) ; and provided
that in no circumstances may a socket-outlet be installed at a distance
less than 2m from any socket -outlet connected to a different phase (or
pole).*

regards


--
Tim Lamb

"The Medway Handyman" wrote in message
.uk...
Colin Wilson wrote:
... but probably bigger than you.....
I'm bigger than most people :-)

Just say "cuddly" rather than phat phucker :-p

(unless of course, you meant tall !)

"Big Boned" sums it up :-)

Getting towards Christmas I like to think of myself as festively plump :-)

On Oct 26, 11:38 am, Andy Hall wrote:
On 2007-10-26 08:58:19 +0100, "nightjar" cpb@insert my surname
here.me.uk said:







"The Natural Philosopher" wrote in message
. ..
nightjar cpb@ wrote:
...
Maybe, maybe not. It was always considered good practice to keep at least
6 feet between sockets on different phases. If they are closer, they are
likely to be wired in blocks, with several adjacent sockets on one phase.
If they are widely spaced, they might be wired on alternate phases.
Again, good practice would be to mark phase colours, either with phase
disks by the socket or by sleeving the live with a phase colour.

IIRC there is a legal requirement for something like that distance.

I used to think that, but it was discussed at length some time ago, possibly
on another group, and nobody could come up with any piece of legislation.

Colin Bignell

Perhaps the point was that it would then be impossible to stick your
fingers in two sockets on different phases at the same time. 400v
across the chest at suitable current would probably spoil the day for
most people.

Anyone doing that sort of thing is unlikely to be missed from the Gene
pool.

MBQ

Andy Hall wrote:
On 2007-10-25 22:04:23 +0100, "The Medway Handyman"
said:

Andy Champ wrote:
The Medway Handyman wrote:
snip
Big scary cabinet on wall with stickers saying 415v and 100 amps -
not going anywhere near that!
/snip

You do realise that 415V is just the difference between two 230V
phases?

No. I just know is scares the sh*t out of me so I stay well away :-)

.. and you were telling us that you were a "big guy". Is it a size
28 blouse? ;-)

When it comes to 415v 100a its brown trousers :-)


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

wrote:
can someone please explain these statements

230 x 2 != 415
&
240 x 2 even more so != 415!

--
Ai

The UK (and many other countries) use 3 phases equally spaced at 120
degrees (I'll explain the phase angle thing in a mo).

First, what's a phase?

Electricity is generated and distributed in the UK on a 3 wire system,
each wire carries a *phase*.
SNIP

Thanks for that matey - I am a wiser man. Still not going anywhere near it
though :-)


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

jim wrote:
On 24 Oct, 22:19, "The Medway Handyman"
wrote:
Working for a regular customer in an industrial unit today & he
asked me to check why a 230v socket wasn't working. Socket tester
showed no live but all wires were properly in place. No mcb tripped
on the panel.

Found another socket on an adjacent wall not working either, but
sockets in between them work fine.

/snip//

The most likely explanation is that the fuse (or perhaps a contactor)
on one of the phases has blown (or tripped), though there's other
possibilities.

Aha. That sounds right.

There are several reasons for using 3 phase in industrial & high load
installations, amongst them being economy of generation and
distribution and better control of electrically driven machinery.
Downside, if it is one, is that single phase loads need to be equally
balanced between phases so far as possible, plus the higher voltage
between adjacent single phase fittings when on different phases.

This particular unit is now a hair & nail supplies house, full of pink
girlie stuff. It was obviously once a real industrial unit doing manly
stuff. Loads of sockets, two what look like forklift charger sockets
visible behind racks of emery boards, big FO cables now hidden by racks of
shampoo.

Everything seems to run off a mcb board which is marked up wih various
areas. I do recall once moving a socket for them that wouldn't turn off
when the mcb was tripped, the main power switch had to be turned off.


BTW you need a waste transport licence (around £340 for 3 years from
Environment Agency IIRC) for even thinking about taking away
virtuially anything from a job site where you've been working. Even
your Mars bar wrapper is deemed scrap by the Blairite shock
troops ;-) And yes, even the filaments in the scrap flourescent
tubes;-)))

Scrap flourescent tubes seem one up from Anthrax if you read the ads by the
recycling companies :-)


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

On Fri, 26 Oct 2007 20:58:52 +0100, Owain
wrote:

The Medway Handyman wrote:
wrote:
Electricity is generated and distributed in the UK on a 3 wire system,
each wire carries a *phase*.
Thanks for that matey - I am a wiser man. Still not going anywhere near it
though :-)

It only hurts more if you touch two different phases at once. Which, as
you shouldn't be doing live work anyway, shouldn't happen.

Oh, and you have to remember to connect blue to black and black to blue....

Red to red
Black to black
Green to the pipes, and
Blue to f$ck.

--
Frank Erskine

Andy Hall wrote:
On 2007-10-25 22:04:23 +0100, "The Medway Handyman"
said:

Andy Champ wrote:
The Medway Handyman wrote:
snip
Big scary cabinet on wall with stickers saying 415v and 100 amps -
not going anywhere near that!
/snip

You do realise that 415V is just the difference between two 230V
phases?

No. I just know is scares the sh*t out of me so I stay well away :-)

.. and you were telling us that you were a "big guy". Is it a size
28 blouse? ;-)

I cut through a 415v cable once - it was just a phase I was going
through...........


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

On 2007-10-27 23:49:52 +0100, Owain said:

The Medway Handyman wrote:
I cut through a 415v cable once - it was just a phase I was going
through...........

Were you feeling blue at the time, or did you see red?

Owain

These days he would have caused a black out.

now Andy you know that could be a Grey area it could be called a Brown out
..
Either way he was probably White with fear.

CJ