🚀 go-pugleaf

On Nov 24, 10:10 am, Sylvia Else <syl...@not.at.this.address> wrote:
> I have to phases of power supply to my house - so three power lines, two
> phases plus neutral.
>
> I've on occasion wondered what would happen if we lost the neutral line.
> It seems to me that we'd then have the voltage between the two phases
> across two sets of appliances, one set attached to one phase, and the
> other set attached to the other phase, with the two sets in series as a
> result of their common connection to the neutral wire. Since the two
> sets are unlikely to represent equal loads, the net result would be a
> large overvoltage on one set of appliances.
>
> My electrician says it's not an issue, but I can't see why.
>
> Any thoughts?
>
> Sylvia.


You are both right and wrong as in the absence of Neutral line, a lot
of the neutral current (imbalance) would probably flow via your earth
stake back to the transformer neutral or to a neighbours neutral via
their earth stake and while its not a perfect situation, imbalance
probably would not be as bad as you might think ?

Of course, if there is a long run through earth (terra firma) back to
the nearest neutral, the soil is really dry, the earth stake is sub-
standard etc etc it might not work very well.





Years and years back I once saw the result of this at a 3 phase
installation at a carnival, we were called out to fix

They would have with them, and take from site to site portable fuse
boxes with a 3 phase plug, going to a box with breakers feeding rows
of power points going to each phase (like in a normal building
installation, but portable). They would plug in all their gear to
these sockets, and plug the 3 phase into the 3 phase sockets provided
at the venues.

Of course, a lot of the carnival workers would probably just plug
things in at random, and who knows what load would be on the end of
each lead.  There could also be very large numbers of flashing lights
on one lead too, so the load would be less than perfect, and surely
not anywhere near balanced or stable ;)

One case, the neutral lead broke off.  On one phase there was a lot of
damage to computer gear / arcade games (same sort of thing -
switchmode power supplies)  etc.  Some was just blown fuses, some
worse.
Note, they didn't have the earth and neutral bonded inside the box,
and didn't have a separate earth stake, where in a home fuse box they
would.

2 phase situation like yours would be a similar result, unless the
load was really well balanced, and consisting of mostly NON-switchmode
power supply type devices.  The phase with the lowest load would
suffer overvoltage.

This load imbalance and voltage difference would change all the time
as various appliances automatically switch off and on, like fridges,
air cons, electric HWS etc.  Light bulbs may blow from overvoltage,
this would also change the balance



Try connecting 12v bulbs of different wattages in series across 24v
and see what happens.  The voltage will not be the same across each.
Much the same thing.

"Stupider than Anyone  Else"

>I have to phases of power supply to my house - so three power lines, two 
>phases plus neutral.
>
> I've on occasion wondered what would happen if we lost the neutral line. 
> It seems to me that we'd then have the voltage between the two phases 
> across two sets of appliances, one set attached to one phase, and the 
> other set attached to the other phase, with the two sets in series as a 
> result of their common connection to the neutral wire. Since the two sets 
> are unlikely to represent equal loads, the net result would be a large 
> overvoltage on one set of appliances.
>
> My electrician says it's not an issue, but I can't see why.


** Loss of the neutral conductor in a 3 phase ( or 2 phase) AC supply system 
can easily be a DISASTROUS  event.

For example:

In the live entertainment productions -  high powered lighting and sound 
systems operate from 3 phase outlets via a hefty 5 pin plug and socket.  If, 
due to wear and tear or damage to the plug or socket, one of the phases 
drops out  -  that is an annoyance but not a disaster.

However, if the pin carrying the neutral fails to connect or as is often the 
case *disconnects* during a show because of overheating   -  ALL HELL 
BREAKS  LOOSE !!

Typically, some of the lamps will glow very brightly for a second or two and 
fail, then other previously dim lamps will follow suit.  The AC fuses in 
amplifiers will pop instantly and some equipment will be seriously damaged 
when the PSU sections are destroyed. It all happens in a few seconds, while 
the operators stand there with their mouths open  !!!

The MEN system:

In Australia, AC power delivery uses a system called " Multiple Earth 
Neutral "  -  which requires that the neutral conductors in a premises be 
connected to the plumbing system at the distribution board (ie power box). 
It also requires that an earth stake be installed for the same purpose, but 
some older premises may not have this.

Because EVERY premises has MEN installed, the ground itself and underground 
metal plumbing act as an alternative neutral, should the supply conductor 
feeding a given premises fail. The disastrous event sometimes experienced in 
live entertainment systems is hardly possible in domestic or commercial 
premises.

So the sparky is right.



....  Phil

Sylvia Else wrote:
> I have to phases of power supply to my house - so three power lines,
> two phases plus neutral.
>
> I've on occasion wondered what would happen if we lost the neutral
> line. It seems to me that we'd then have the voltage between the two
> phases across two sets of appliances, one set attached to one phase,
> and the other set attached to the other phase, with the two sets in
> series as a result of their common connection to the neutral wire.
> Since the two sets are unlikely to represent equal loads, the net
> result would be a large overvoltage on one set of appliances.
>
> My electrician says it's not an issue, but I can't see why.
>
> Any thoughts?

**Not an issue, due to the MEN system used in AUSTRALIA. Cross-posting to an 
international group will guarantee a bunch of useless comments. Pay 
attention to Australian posters only.

Your electrician is correct.


-- 
Trevor Wilson
www.rageaudio.com.au

Phil Allison wrote:
> "Dave Platt"
>> Sylvia Else
>>
>>> I have to phases of power supply to my house - so three power lines, two
>>> phases plus neutral.
>>>
>>> I've on occasion wondered what would happen if we lost the neutral line.
>>> It seems to me that we'd then have the voltage between the two phases
>>> across two sets of appliances, one set attached to one phase, and the
>>> other set attached to the other phase, with the two sets in series as a
>>> result of their common connection to the neutral wire. Since the two
>>> sets are unlikely to represent equal loads, the net result would be a
>>> large overvoltage on one set of appliances.
>>>
>>> My electrician says it's not an issue, but I can't see why.
>> It's a huge issue.
> 
> 
> ** Sylvia lives in Sydney, Australia and is a  MASSIVE  TROLL.
> 
> Nuts of her the post such a COUNTRY  SPECIFIC  message to a US newsgroup.

Last time I checked, multiphase power supply was pretty universal, and 
the principles to be applied in understanding the consequences of faults 
would be the same. Or perhaps you want to argue that the different 
voltage in Australia is the deciding factor.

Sylvia.

Trevor Wilson wrote:
> Sylvia Else wrote:
>> I have to phases of power supply to my house - so three power lines,
>> two phases plus neutral.
>>
>> I've on occasion wondered what would happen if we lost the neutral
>> line. It seems to me that we'd then have the voltage between the two
>> phases across two sets of appliances, one set attached to one phase,
>> and the other set attached to the other phase, with the two sets in
>> series as a result of their common connection to the neutral wire.
>> Since the two sets are unlikely to represent equal loads, the net
>> result would be a large overvoltage on one set of appliances.
>>
>> My electrician says it's not an issue, but I can't see why.
>>
>> Any thoughts?
> 
> **Not an issue, due to the MEN system used in AUSTRALIA. Cross-posting to an 
> international group will guarantee a bunch of useless comments. Pay 
> attention to Australian posters only.
> 
> Your electrician is correct.
> 
> 

 From the replies, the same system applies in the US. But people have 
still had problems.

Sylvia.

Sylvia Else wrote:
> Trevor Wilson wrote:
>> Sylvia Else wrote:
>>> I have to phases of power supply to my house - so three power lines,
>>> two phases plus neutral.
>>>
>>> I've on occasion wondered what would happen if we lost the neutral
>>> line. It seems to me that we'd then have the voltage between the two
>>> phases across two sets of appliances, one set attached to one phase,
>>> and the other set attached to the other phase, with the two sets in
>>> series as a result of their common connection to the neutral wire.
>>> Since the two sets are unlikely to represent equal loads, the net
>>> result would be a large overvoltage on one set of appliances.
>>>
>>> My electrician says it's not an issue, but I can't see why.
>>>
>>> Any thoughts?
>>
>> **Not an issue, due to the MEN system used in AUSTRALIA.
>> Cross-posting to an international group will guarantee a bunch of
>> useless comments. Pay attention to Australian posters only.
>>
>> Your electrician is correct.
>>
>>
>
> From the replies, the same system applies in the US. But people have
> still had problems.

**AFAIK, the US system is fundamentally different to ours.


-- 
Trevor Wilson
www.rageaudio.com.au

"Stupider than Anyone Else Alive "

>
>> ** Sylvia lives in Sydney, Australia and is a  MASSIVE  TROLL.
>>
>> Nuts of her the post such a COUNTRY  SPECIFIC  message to a US newsgroup.
>
> Last time I checked, multiphase power supply was pretty universal, and the 
> principles to be applied in understanding the consequences of faults would 
> be the same.


** 100 % WRONG  !!!

The question this insane bitch posted  IS country SPECIFIC !!!

Cos it was about her house in * Sydney, Australia *.

See Trevor Wilson's reply.



....  Phil

"Stupider than Anyone Else on Earth "
>
> Trevor Wilson wrote:
>>
>> My electrician says it's not an issue, but I can't see why.
>>>
>>> Any thoughts?
>>
>> **Not an issue, due to the MEN system used in AUSTRALIA. Cross-posting to 
>> an international group will guarantee a bunch of useless comments. Pay 
>> attention to Australian posters only.
>>
>> Your electrician is correct.
>>
>
> From the replies, the same system applies in the US.


** Wot  INSANE  FUCKING  CRAPOLOGY   !!

The only relevant reply from the US so far indicates the DIRECT OPPOSITE .

Piss off  -  TROLLING  BITCH.



.....  Phil

On Nov 24, 12:16 pm, Sylvia Else <syl...@not.at.this.address> wrote:
> Phil Allison wrote:
> > "Dave Platt"
> >> Sylvia Else
>
> >>> I have to phases of power supply to my house - so three power lines, two
> >>> phases plus neutral.
>
> >>> I've on occasion wondered what would happen if we lost the neutral line.
> >>> It seems to me that we'd then have the voltage between the two phases
> >>> across two sets of appliances, one set attached to one phase, and the
> >>> other set attached to the other phase, with the two sets in series as a
> >>> result of their common connection to the neutral wire. Since the two
> >>> sets are unlikely to represent equal loads, the net result would be a
> >>> large overvoltage on one set of appliances.
>
> >>> My electrician says it's not an issue, but I can't see why.
> >> It's a huge issue.
>
> > ** Sylvia lives in Sydney, Australia and is a  MASSIVE  TROLL.
>
> > Nuts of her the post such a COUNTRY  SPECIFIC  message to a US newsgroup.
>
> Last time I checked, multiphase power supply was pretty universal, and
> the principles to be applied in understanding the consequences of faults
> would be the same. Or perhaps you want to argue that the different
> voltage in Australia is the deciding factor.
>
> Sylvia.


From what I can gather, pretty much every home in the US has a 120v -
0 - 120v system where the 2x 120v's are 180 degrees out of phase.
Between the 2 phases 240v is available for stoves, air conditioners
etc.

In Australia, most separate homes have a straight single phase 240v
supply, its not common for there to be 2,3 separate phases to the
average house.  Therefore the scenario Sylvia mentions is less likely
to occur, as not many people have this multi phase system.

The exception here could be blocks of flats, if the main neutral to
the building fails, and there isn't a good earth, the imbalance could
be a risk.

"Trevor Wilson"

>
> **AFAIK, the US system is fundamentally different to ours.


** In the US and Canada  -   it is  NOT  permitted to link neutral and earth 
or plumbing within a premises.

See here under the heading "Regulations".

http://en.wikipedia.org/wiki/Earthing_system

The MEN system used here in Australia seems to be unique.

See last para on same page.


.....  Phil 

"kreed"

> From what I can gather, pretty much every home in the US has a 120v -
> 0 - 120v system where the 2x 120v's are 180 degrees out of phase.
> Between the 2 phases 240v is available for stoves, air conditioners
> etc.
>
> In Australia, most separate homes have a straight single phase 240v
> supply, its not common for there to be 2,3 separate phases to the
> average house.  Therefore the scenario Sylvia mentions is less likely
> to occur, as not many people have this multi phase system.
>
> The exception here could be blocks of flats, if the main neutral to
> the building fails, and there isn't a good earth, the imbalance could
> be a risk.


** There is always a good "earth"  available  - courtesy of the water mains 
in the street being linked to neutral at every premises.


.....  Phil

On Nov 24, 10:58 am, "Phil Allison" <phi...@tpg.com.au> wrote:
> "Stupider than Anyone  Else"
>
> >I have to phases of power supply to my house - so three power lines, two
> >phases plus neutral.
>
> > I've on occasion wondered what would happen if we lost the neutral line.
> > It seems to me that we'd then have the voltage between the two phases
> > across two sets of appliances, one set attached to one phase, and the
> > other set attached to the other phase, with the two sets in series as a
> > result of their common connection to the neutral wire. Since the two sets
> > are unlikely to represent equal loads, the net result would be a large
> > overvoltage on one set of appliances.
>
> > My electrician says it's not an issue, but I can't see why.
>
> ** Loss of the neutral conductor in a 3 phase ( or 2 phase) AC supply system
> can easily be a DISASTROUS  event.
>
> For example:
>
> In the live entertainment productions -  high powered lighting and sound
> systems operate from 3 phase outlets via a hefty 5 pin plug and socket.  If,
> due to wear and tear or damage to the plug or socket, one of the phases
> drops out  -  that is an annoyance but not a disaster.
>
> However, if the pin carrying the neutral fails to connect or as is often the
> case *disconnects* during a show because of overheating   -  ALL HELL
> BREAKS  LOOSE !!
>
> Typically, some of the lamps will glow very brightly for a second or two and
> fail, then other previously dim lamps will follow suit.  The AC fuses in
> amplifiers will pop instantly and some equipment will be seriously damaged
> when the PSU sections are destroyed. It all happens in a few seconds, while
> the operators stand there with their mouths open  !!!
>
> The MEN system:
>
> In Australia, AC power delivery uses a system called " Multiple Earth
> Neutral "  -  which requires that the neutral conductors in a premises be
> connected to the plumbing system at the distribution board (ie power box).
> It also requires that an earth stake be installed for the same purpose, but
> some older premises may not have this.
>
> Because EVERY premises has MEN installed, the ground itself and underground
> metal plumbing act as an alternative neutral, should the supply conductor
> feeding a given premises fail. The disastrous event sometimes experienced in
> live entertainment systems is hardly possible in domestic or commercial
> premises.
>
> So the sparky is right.
>

The scenario you mention with live entertainment is particularly bad,
as when you think about it, unlike a fixed installation you can't bond
the earth and neutral in these portable 3 phase to 240v outlet mains
boxes.  If you did, it would trip any earth leakage breakers upstream
- if these are fitted.


To make matters worse, in live entertainment, the major loads are
almost all amplifiers, and lighting. None of these are stable loads
(amplifiers are changing their load current draw constantly with the
music and lights are being dimmed, flashed often in large groups. )


Therefore if the neutral lead fails, there is no bonding to earth to
back it up, unlike a residence, and with the inherent instabilty of
the load balance , massive damage is guaranteed.


> ....  Phil

Phil Allison wrote:
> "Trevor Wilson"
>
>>
>> **AFAIK, the US system is fundamentally different to ours.
>
>
> ** In the US and Canada  -   it is  NOT  permitted to link neutral
> and earth or plumbing within a premises.
>
> See here under the heading "Regulations".
>
> http://en.wikipedia.org/wiki/Earthing_system
>
> The MEN system used here in Australia seems to be unique.
>
> See last para on same page.

**Interesting. I'd have thunk that some places in Europe might employ a 
similar system. Guess not. Ever since I ran across my first US audio product 
with a high value resistor to chassis from (allegedly) Neutral, I realised 
that the US system was highly flawed.


-- 
Trevor Wilson
www.rageaudio.com.au

> My electrician says it's not an issue, but I can't see why.
>
> Any thoughts?
>
> Sylvia.


Sylvia

Thought one. Get rid of the electrician.

In my experience with loss of neutrals it is the number one cause of
electrical equipment/lighting failure.

Bob  AZ

Sylvia Else wrote:
> I have to phases of power supply to my house - so three power lines, two
> phases plus neutral.
>
> I've on occasion wondered what would happen if we lost the neutral line.
> It seems to me that we'd then have the voltage between the two phases
> across two sets of appliances, one set attached to one phase, and the
> other set attached to the other phase, with the two sets in series as a
> result of their common connection to the neutral wire. Since the two
> sets are unlikely to represent equal loads, the net result would be a
> large overvoltage on one set of appliances.
>
> My electrician says it's not an issue, but I can't see why.
>
> Any thoughts?
>
> Sylvia.
not a neutral problem but.
I can remember an old lady complaining that every time she turned the 
hot water tap the lights came on half brilliance.and sure enough they did.
she had three phase and an instantaneous three phase water heater.

one phase had gone and the heater caused the dead phase to be live in 
series with element.(the water flow closes the heater circuit)

On Nov 23, 6:36 pm, "Phil Allison" <phi...@tpg.com.au> wrote:
> "Trevor Wilson"
>
>
>
> > **AFAIK, the US system is fundamentally different to ours.
>
> ** In the US and Canada  -   it is  NOT  permitted to link neutral and earth
> or plumbing within a premises.
>
> See here under the heading "Regulations".
>
> http://en.wikipedia.org/wiki/Earthing_system
>
> The MEN system used here in Australia seems to be unique.
>
> See last para on same page.
>
> .....  Phil

Rubbish. In most of Canada, it is manditory that the neutral be bonded
to earth at only ONE point, the service entrance switch enclosure.
From that point an earth conductor is connected to 2 ground rods and
to any metallic piping system(s).
Neutral failure is a not uncommon problem especially with overhead
aluminum 'triplex' service drops. A seagull deficates on the bare
aluminum neutral and it soon rots off leaving an open neutral
condition.
Ground rod to earth resistances of 5 ohms are not uncommon, so a 10A
unbalance between 'phases' could give a 50V offset of the neutral.

Neil S.

On Nov 23, 6:40 pm, "Phil Allison" <phi...@tpg.com.au> wrote:
> "kreed"
>
> > From what I can gather, pretty much every home in the US has a 120v -
> > 0 - 120v system where the 2x 120v's are 180 degrees out of phase.
> > Between the 2 phases 240v is available for stoves, air conditioners
> > etc.
>
> > In Australia, most separate homes have a straight single phase 240v
> > supply, its not common for there to be 2,3 separate phases to the
> > average house.  Therefore the scenario Sylvia mentions is less likely
> > to occur, as not many people have this multi phase system.
>
> > The exception here could be blocks of flats, if the main neutral to
> > the building fails, and there isn't a good earth, the imbalance could
> > be a risk.
>
> ** There is always a good "earth"  available  - courtesy of the water mains
> in the street being linked to neutral at every premises.
>
> .....  Phil

All new construction [last 30 years] around here uses iron mains with
rubber sealed joints and plastic service pipe into all homes, so there
is NO bond from the house to the main. The Gas main is plastic, as are
the service drops. So, the only earth connection is the rather 'iffy'
pair of 8' ground rods usually in the rain shadow of the roof
overhang.

Neil S.

On Tue, 24 Nov 2009 11:10:26 +1100, Sylvia Else wrote:

> the net result would be a
> large overvoltage on one set of appliances.

It would be across both sets, but......
> 
> My electrician says it's not an issue, but I can't see why.

The neutral is actually grounded to the earth for such a case; hence MEN 
(Multiple Earth Neutral), so the neutral would actually travel through 
the ground to your neighbours earth stake and back into the neutral phase 
there.

If the USA Godzilla remake is to be believed, all your earth worms will 
come to the surface as an indicator, (or is that only for correct DC 
connections?).

If you are worried about such an event happening, dump a bucket of wter 
on your earth stake quarterly and encourage your neighbours to do the 
same.

On Nov 24, 12:40 pm, "Phil Allison" <phi...@tpg.com.au> wrote:
> "kreed"
>
> > From what I can gather, pretty much every home in the US has a 120v -
> > 0 - 120v system where the 2x 120v's are 180 degrees out of phase.
> > Between the 2 phases 240v is available for stoves, air conditioners
> > etc.
>
> > In Australia, most separate homes have a straight single phase 240v
> > supply, its not common for there to be 2,3 separate phases to the
> > average house.  Therefore the scenario Sylvia mentions is less likely
> > to occur, as not many people have this multi phase system.
>
> > The exception here could be blocks of flats, if the main neutral to
> > the building fails, and there isn't a good earth, the imbalance could
> > be a risk.
>
> ** There is always a good "earth"  available  - courtesy of the water mains
> in the street being linked to neutral at every premises.
>
> .....  Phil


That is true in a lot of cases, however I have noticed with a lot of
newer houses, (in QLD anyway) they are using some kind of either black
or grey pvc or poly pipe for home water mains.  To make it worse, it
looks to me to be "crimped" together at joins, sometimes with what
look like soft metal rings but not always.

Copper or the old cast iron pipes would provide an excellent Earth,
and excellent soil electrical contact due to the enormous surface area
of the water main in contact with the soil over distance



Mine is all copper, all the way back to the water main, so no problems
here.

On 2009-11-24, Sylvia Else <sylvia@not.at.this.address> wrote:
> Phil Allison wrote:
>> In Australia, AC power delivery uses a system called " Multiple Earth 
>> Neutral "  -  which requires that the neutral conductors in a premises be 
>> connected to the plumbing system at the distribution board (ie power box). 
>> It also requires that an earth stake be installed for the same purpose, but 
>> some older premises may not have this.
>
> If as you say, neutral has to be tied to Earth at the premises, then I 
> can indeed see that the situation might not be so bad.
>
> On the face of it, having significant current flowing from neutral to 
> Earth would have to indicate a fault. It would be nice for the breakers 
> to trip in such a situation, but I can't see that they will.

Having the breakers trip because a faulty neutral in an neighbours
house (which would cause his neutral current to flow through his earth and
your earth (etc) to the common neutral) could be an annoyance.

bye.

kreed wrote:
> On Nov 24, 12:40 pm, "Phil Allison" <phi...@tpg.com.au> wrote:
>> "kreed"
>>
>>> From what I can gather, pretty much every home in the US has a 120v
>>> - 0 - 120v system where the 2x 120v's are 180 degrees out of phase.
>>> Between the 2 phases 240v is available for stoves, air conditioners
>>> etc.
>>
>>> In Australia, most separate homes have a straight single phase 240v
>>> supply, its not common for there to be 2,3 separate phases to the
>>> average house.  Therefore the scenario Sylvia mentions is less
>>> likely to occur, as not many people have this multi phase system.
>>
>>> The exception here could be blocks of flats, if the main neutral to
>>> the building fails, and there isn't a good earth, the imbalance
>>> could be a risk.
>>
>> ** There is always a good "earth"  available  - courtesy of the
>> water mains in the street being linked to neutral at every premises.
>>
>> .....  Phil
>
>
> That is true in a lot of cases, however I have noticed with a lot of
> newer houses, (in QLD anyway) they are using some kind of either black
> or grey pvc or poly pipe for home water mains.  To make it worse, it
> looks to me to be "crimped" together at joins, sometimes with what
> look like soft metal rings but not always.
>

**It's going to be a lot more popular too. The stuff is around half the 
price of copper pipes, is very easy to handle and use.


-- 
Trevor Wilson
www.rageaudio.com.au

Phil Allison wrote:
> 
> The MEN system:
> 
> In Australia, AC power delivery uses a system called " Multiple Earth 
> Neutral "  -  which requires that the neutral conductors in a premises be 
> connected to the plumbing system at the distribution board (ie power box). 
> It also requires that an earth stake be installed for the same purpose, but 
> some older premises may not have this.

Actually, the Neutral conductors are *NOT* connected to the plumbing 
system. The Neutral conductor is connected by the MEN link to the main 
earthing conductor, which is connected to the appropriate earth 
electrode. AS/NZS 3000 then requires that conductive pipe work be 
equipotentially bonded to the main earth conductor or earth terminal or 
bar (NOT to the neutral).

David

In sci.electronics.repair kreed <kenreed1999@gmail.com> wrote:
> On Nov 24, 10:10 am, Sylvia Else <syl...@not.at.this.address> wrote:
>> I have to phases of power supply to my house - so three power lines, two
>> phases plus neutral.
>>
>> I've on occasion wondered what would happen if we lost the neutral line.
>> It seems to me that we'd then have the voltage between the two phases
>> across two sets of appliances, one set attached to one phase, and the
>> other set attached to the other phase, with the two sets in series as a
>> result of their common connection to the neutral wire. Since the two
>> sets are unlikely to represent equal loads, the net result would be a
>> large overvoltage on one set of appliances.
>>
>> My electrician says it's not an issue, but I can't see why.
>>
>> Any thoughts?
>>
>> Sylvia.
> 
> 
> You are both right and wrong as in the absence of Neutral line, a lot
> of the neutral current (imbalance) would probably flow via your earth
> stake back to the transformer neutral or to a neighbours neutral via
> their earth stake and while its not a perfect situation, imbalance
> probably would not be as bad as you might think ?
> 
> Of course, if there is a long run through earth (terra firma) back to
> the nearest neutral, the soil is really dry, the earth stake is sub-
> standard etc etc it might not work very well.
> 
> 
> 
> 
> 
> Years and years back I once saw the result of this at a 3 phase
> installation at a carnival, we were called out to fix
> 
> They would have with them, and take from site to site portable fuse
> boxes with a 3 phase plug, going to a box with breakers feeding rows
> of power points going to each phase (like in a normal building
> installation, but portable). They would plug in all their gear to
> these sockets, and plug the 3 phase into the 3 phase sockets provided
> at the venues.
> 
> Of course, a lot of the carnival workers would probably just plug
> things in at random, and who knows what load would be on the end of
> each lead.  There could also be very large numbers of flashing lights
> on one lead too, so the load would be less than perfect, and surely
> not anywhere near balanced or stable ;)
> 
> One case, the neutral lead broke off.  On one phase there was a lot of
> damage to computer gear / arcade games (same sort of thing -
> switchmode power supplies)  etc.  Some was just blown fuses, some
> worse.
> Note, they didn't have the earth and neutral bonded inside the box,
> and didn't have a separate earth stake, where in a home fuse box they
> would.
> 
> 2 phase situation like yours would be a similar result, unless the
> load was really well balanced, and consisting of mostly NON-switchmode
> power supply type devices.  The phase with the lowest load would
> suffer overvoltage.
> 
> This load imbalance and voltage difference would change all the time
> as various appliances automatically switch off and on, like fridges,
> air cons, electric HWS etc.  Light bulbs may blow from overvoltage,
> this would also change the balance
> 
> 
> 
> Try connecting 12v bulbs of different wattages in series across 24v
> and see what happens.  The voltage will not be the same across each.
> Much the same thing.

I actually had the neutral fail (break) a few years back during a
winter wind-storm. No deleterious effects. The imbalance (neutral)
current was carried by the ground, a copper water pipe that's probably
at least 10 feet below gound level and 20 0r so feet long.

	Jerry

Phil Allison wrote:

> 
> "kreed"
> 
>> From what I can gather, pretty much every home in the US has a 120v -
>> 0 - 120v system where the 2x 120v's are 180 degrees out of phase.
>> Between the 2 phases 240v is available for stoves, air conditioners
>> etc.
>>
>> In Australia, most separate homes have a straight single phase 240v
>> supply, its not common for there to be 2,3 separate phases to the
>> average house.  Therefore the scenario Sylvia mentions is less likely
>> to occur, as not many people have this multi phase system.
>>
>> The exception here could be blocks of flats, if the main neutral to
>> the building fails, and there isn't a good earth, the imbalance could
>> be a risk.
> 
> 
> ** There is always a good "earth"  available  - courtesy of the water
> mains in the street being linked to neutral at every premises.
> 
> 
> .....  Phil

Except where plastic is in use.  Mine is all plastic and the safety
earth is linked to the armouring on the incoming mains feed cable.

-- 
Best Regards:
                     Baron.

Meat Plow wrote:

> On Tue, 24 Nov 2009 11:10:26 +1100, Sylvia Else
> <sylvia@not.at.this.address>wrote:
> 
>>I have to phases of power supply to my house - so three power lines,
>>two phases plus neutral.
>>
>>I've on occasion wondered what would happen if we lost the neutral
>>line. It seems to me that we'd then have the voltage between the two
>>phases across two sets of appliances, one set attached to one phase,
>>and the other set attached to the other phase, with the two sets in
>>series as a result of their common connection to the neutral wire.
>>Since the two sets are unlikely to represent equal loads, the net
>>result would be a large overvoltage on one set of appliances.
>>
>>My electrician says it's not an issue, but I can't see why.
>>
>>Any thoughts?
>>
>>Sylvia.
> 
> Removing the return leg isn't going to cause problems in a properly
> wired US home. Don't know about the UK.

The lights would go out !  Domestic properties usually have just a 240v
single phase feed.  Usually you would get a single phase running down
one side of the street and another phase running down the other.

-- 
Best Regards:
                     Baron.

"David the  PEDANTIC  TWAT  FROM  HELL "


> Actually, the Neutral conductors are *NOT* connected to the plumbing 
> system.

**  Wot  INSANE  CRAPOLOGY   !!


> The Neutral conductor is connected by the MEN link to the main earthing 
> conductor, which is connected to the appropriate earth electrode.

**  Da knee bone's connected to da thigh bone ....


> AS/NZS 3000 then requires that conductive pipe work be equipotentially 
> bonded to the main earth conductor or earth terminal or bar (NOT to the 
> neutral).


** Folks -  you have to forgive David cos he is mentally defective.

    Bad genes from his mother and his father.

    Congenital autism is a curse....



.....  Phil

On Tue, 24 Nov 2009 13:40:46 +1100, Phil Allison wrote:


> 
> ** There is always a good "earth"  available  - courtesy of the water
> mains in the street being linked to neutral at every premises.

Is this something new(<40 yrs) in the Standards in Australia?
No plumbing link here. Just an earth stake under the box.

kreed wrote:
> You are both right and wrong as in the absence of Neutral line, a lot
> of the neutral current (imbalance) would probably flow via your earth
> stake back to the transformer neutral or to a neighbours neutral via
> their earth stake and while its not a perfect situation, imbalance
> probably would not be as bad as you might think ?
> 
> Of course, if there is a long run through earth (terra firma) back to
> the nearest neutral, the soil is really dry, the earth stake is sub-
> standard etc etc it might not work very well.

Sometimes, just to make things really exciting, some of the neutral 
current flows over alternate paths to a neighbor's house.  These 
alternate paths can include things like cable TV shields.

Phil Allison the unqualified drop out wrote:

 >
 >> Actually, the Neutral conductors are *NOT* connected to the plumbing
 >> system.

  **  Wot  INSANE  CRAPOLOGY  !!

 >
 >> The Neutral conductor is connected by the MEN link to the main earthing
 >> conductor, which is connected to the appropriate earth electrode.
 >
 > **  Da knee bone's connected to da thigh bone ....


But the Neutral not connected to the water pipe....

 >
 >
 >> AS/NZS 3000 then requires that conductive pipe work be equipotentially
 >> bonded to the main earth conductor or earth terminal or bar (NOT to the
 >> neutral).
 >
 >

This should explain it for you Phil. Not too technical.

http://www.standards.org.au/downloads/080725_Electrical_Earthing_Standards_Alert.pdf


David

"David the  PEDANTIC  TWAT  FROM  HELL "


> Actually, the Neutral conductors are *NOT* connected to the plumbing 
> system.

**  Wot  INSANE  CRAPOLOGY   !!


> The Neutral conductor is connected by the MEN link to the main earthing 
> conductor, which is connected to the appropriate earth electrode.

**  Da knee bone's connected to da thigh bone ....


> AS/NZS 3000 then requires that conductive pipe work be equipotentially 
> bonded to the main earth conductor or earth terminal or bar (NOT to the 
> neutral).


** Folks -  you have to forgive David cos he is mentally defective.

  Bad genes from his mother and his father.

  Congenital autism is a curse.

  This dude is is   TOTALLY FUCKED WITH  IT.



.....  Phil

On Nov 24, 7:54 am, Meat Plow <m...@petitmorte.net> wrote:

> Removing the return leg isn't going to cause problems in a properly
> wired US home. Don't know about the UK.

That's just false.  A properly wired US home without a neutral
wire to the transformer has 240V across both phases, which
can leave either phase anywhere from zero to 240 VAC.  Damage
to 120V appliances will result unless the breakers trip first.

The 'ground' connection would have to carry the whole house's
current imbalance load in place of that neutral, through the earth to
some nearby dwelling that DOES have a proper neutral wire,
to the same pole-pig transformer, for this calamity not to occur.

Leaving the neutral failure issue aside, what would happen if I disabled 
the Earth leakage detectors and drew power across the two phases.

Would the two utility meters correctly reflect the energy I consumed?

Sylvia.

Sylvia Else wrote:
> Leaving the neutral failure issue aside, what would happen if I disabled 
> the Earth leakage detectors and drew power across the two phases.
> 
> Would the two utility meters correctly reflect the energy I consumed?
> 
> Sylvia.

On second thoughts, it's pretty obvious that they wouldn't be correct, 
and that I'd be significantly overcharged for the power.

Sylvia.

Sylvia Else <sylvia@not.at.this.address> writes:

> Sylvia Else wrote:
>> Leaving the neutral failure issue aside, what would happen if I
>> disabled the Earth leakage detectors and drew power across the two
>> phases.
>> Would the two utility meters correctly reflect the energy I consumed?

yes.

>> Sylvia.
>
> On second thoughts, it's pretty obvious that they wouldn't be correct,
> and that I'd be significantly overcharged for the power.
>
> Sylvia.

No you wouldn't.

Each of the meters will indicate what you draw from the phases, and as
you now have a higher voltage, you will also draw more power, which is
what you are paying for.

Thomas

"Sylvia Else" <sylvia@not.at.this.address> wrote in message 
news:006c3c5f$0$8071$c3e8da3@news.astraweb.com...
> Leaving the neutral failure issue aside, what would happen if I disabled 
> the Earth leakage detectors and drew power across the two phases.

**Depends on the equipment you connected. The damage might range from mild 
to catastrophic.

>
> Would the two utility meters correctly reflect the energy I consumed?

**Briefly, yes.


-- 
Trevor Wilson
www.rageaudio.com.au

"Trevor Wilson"

>> "Sillier than Anyone Else Alive "

>> Leaving the neutral failure issue aside, what would happen if I disabled 
>> the Earth leakage detectors and drew power across the two phases.
>
> **Depends on the equipment you connected. The damage might range from mild 
> to catastrophic.


** TW has misread the Q.

 It is only about how domestic watt hour meters respond.


>> Would the two utility meters correctly reflect the energy I consumed?
>
> **Briefly, yes.

** Indefinitely, actually.



....   Phil

On Thu, 26 Nov 2009 22:12:24 +1100, Phil Allison wrote:


>>> Would the two utility meters correctly reflect the energy I consumed?
>>
>> **Briefly, yes.
> 
> ** Indefinitely, actually.

Yep, that is how 415VAC is obtained.

Sylvia Else wrote:
> I have to phases of power supply to my house - so three power lines, two 
> phases plus neutral.
> 
> I've on occasion wondered what would happen if we lost the neutral line. 
> It seems to me that we'd then have the voltage between the two phases 
> across two sets of appliances, one set attached to one phase, and the 
> other set attached to the other phase, with the two sets in series as a 
> result of their common connection to the neutral wire. Since the two 
> sets are unlikely to represent equal loads, the net result would be a 
> large overvoltage on one set of appliances.
> 
> My electrician says it's not an issue, but I can't see why.
> 
> Any thoughts?
> 
> Sylvia.

With the exception of some pump motors, nothing in the house runs on 
220. Even the stove splits 110 to the burners and 110 to the oven. No 
neutral and no 110's to anything.

terryc wrote:
> On Thu, 26 Nov 2009 22:12:24 +1100, Phil Allison wrote:
> 
> 
>>>> Would the two utility meters correctly reflect the energy I consumed?
>>> **Briefly, yes.
>> ** Indefinitely, actually.
> 
> Yep, that is how 415VAC is obtained.

But is it how it's metered?

I haven't gone through the math, and I'd overlooked the fact that each 
meter sees a power factor of less than one, so I can't say now whether I 
think the meters would read correctly. But if there's a way of looking 
at the problem that makes the answer obvious, I've yet to see it.

Sylvia.

On Thu, 26 Nov 2009 16:46:51 -0500, Van Chocstraw
<boobooililililil@roadrunner.com> wrote:

>Sylvia Else wrote:
>> I have to phases of power supply to my house - so three power lines, two 
>> phases plus neutral.
>> 
>> I've on occasion wondered what would happen if we lost the neutral line. 
>> It seems to me that we'd then have the voltage between the two phases 
>> across two sets of appliances, one set attached to one phase, and the 
>> other set attached to the other phase, with the two sets in series as a 
>> result of their common connection to the neutral wire. Since the two 
>> sets are unlikely to represent equal loads, the net result would be a 
>> large overvoltage on one set of appliances.
>> 
>> My electrician says it's not an issue, but I can't see why.
>> 
>> Any thoughts?
>> 
>> Sylvia.
>
>With the exception of some pump motors, nothing in the house runs on 
>220. Even the stove splits 110 to the burners and 110 to the oven. No 
>neutral and no 110's to anything.

Ummmm ...   The O/P is in AUSTRALIA, where the supply is nominal 230V
single phase, NOT in Merka like you presumably are.

On Fri, 27 Nov 2009 10:33:40 +1100, Sylvia Else
<sylvia@not.at.this.address> wrote:

>terryc wrote:
>> On Thu, 26 Nov 2009 22:12:24 +1100, Phil Allison wrote:
>> 
>> 
>>>>> Would the two utility meters correctly reflect the energy I consumed?
>>>> **Briefly, yes.
>>> ** Indefinitely, actually.
>> 
>> Yep, that is how 415VAC is obtained.
>
>But is it how it's metered?
>
>I haven't gone through the math, and I'd overlooked the fact that each 
>meter sees a power factor of less than one, so I can't say now whether I 
>think the meters would read correctly. But if there's a way of looking 
>at the problem that makes the answer obvious, I've yet to see it.
>
>Sylvia.


Do it the old fashioned way: make a test! Can't be that difficult, can
it?

On Thu, 26 Nov 2009 16:46:51 -0500, Van Chocstraw
<boobooililililil@roadrunner.com> wrote:

>Sylvia Else wrote:
>> I have to phases of power supply to my house - so three power lines, two 
>> phases plus neutral.
>> 
>> I've on occasion wondered what would happen if we lost the neutral line. 
>> It seems to me that we'd then have the voltage between the two phases 
>> across two sets of appliances, one set attached to one phase, and the 
>> other set attached to the other phase, with the two sets in series as a 
>> result of their common connection to the neutral wire. Since the two 
>> sets are unlikely to represent equal loads, the net result would be a 
>> large overvoltage on one set of appliances.
>> 
>> My electrician says it's not an issue, but I can't see why.
>> 
>> Any thoughts?
>> 
>> Sylvia.
>
>With the exception of some pump motors, nothing in the house runs on 
>220. Even the stove splits 110 to the burners and 110 to the oven. No 
>neutral and no 110's to anything.

WHere are you located that this is true? Surely not in the US/North
America. 

PeterD wrote:
> On Fri, 27 Nov 2009 10:33:40 +1100, Sylvia Else
> <sylvia@not.at.this.address> wrote:
> 
>> terryc wrote:
>>> On Thu, 26 Nov 2009 22:12:24 +1100, Phil Allison wrote:
>>>
>>>
>>>>>> Would the two utility meters correctly reflect the energy I consumed?
>>>>> **Briefly, yes.
>>>> ** Indefinitely, actually.
>>> Yep, that is how 415VAC is obtained.
>> But is it how it's metered?
>>
>> I haven't gone through the math, and I'd overlooked the fact that each 
>> meter sees a power factor of less than one, so I can't say now whether I 
>> think the meters would read correctly. But if there's a way of looking 
>> at the problem that makes the answer obvious, I've yet to see it.
>>
>> Sylvia.
> 
> 
> Do it the old fashioned way: make a test! Can't be that difficult, can
> it?

Of course not. I'll just get out the 415VAC resistive load I happen to 
have lying around, and see what registers.

Sylvia.

On Nov 27, 7:46 am, Van Chocstraw <boobooililili...@roadrunner.com>
wrote:
> Sylvia Else wrote:
> > I have to phases of power supply to my house - so three power lines, two
> > phases plus neutral.
>
> > I've on occasion wondered what would happen if we lost the neutral line.
> > It seems to me that we'd then have the voltage between the two phases
> > across two sets of appliances, one set attached to one phase, and the
> > other set attached to the other phase, with the two sets in series as a
> > result of their common connection to the neutral wire. Since the two
> > sets are unlikely to represent equal loads, the net result would be a
> > large overvoltage on one set of appliances.
>
> > My electrician says it's not an issue, but I can't see why.
>
> > Any thoughts?
>
> > Sylvia.
>
> With the exception of some pump motors, nothing in the house runs on
> 220. Even the stove splits 110 to the burners and 110 to the oven. No
> neutral and no 110's to anything.


Different system, there is no 110 here, only 240v and 415v


As for Sylvia, yes you would be charged for the consumption.
this situation would work similarly to a 3 phase delta type load

The load, even unbalanced as it is, would be a certain VA at 415v -
across the 2 phases

How the meter responds to power factor of the load in question would
be the only thing that may or may not register less KWH than actually
used, but this should be to the same degree as the same load in a
single phase install.


IF this wasn't the case, we would have big problems regarding billing
on installs having both single and 3 phase loads on the same meters in
3 phase premises.

Sylvia Else wrote:
> PeterD wrote:
>> On Fri, 27 Nov 2009 10:33:40 +1100, Sylvia Else
>> <sylvia@not.at.this.address> wrote:
>>
>>> terryc wrote:
>>>> On Thu, 26 Nov 2009 22:12:24 +1100, Phil Allison wrote:
>>>>
>>>>
>>>>>>> Would the two utility meters correctly reflect the energy I
>>>>>>> consumed?
>>>>>> **Briefly, yes.
>>>>> ** Indefinitely, actually.
>>>> Yep, that is how 415VAC is obtained.
>>> But is it how it's metered?
>>>
>>> I haven't gone through the math, and I'd overlooked the fact that
>>> each meter sees a power factor of less than one, so I can't say now
>>> whether I think the meters would read correctly. But if there's a way
>>> of looking at the problem that makes the answer obvious, I've yet to
>>> see it.
>>>
>>> Sylvia.
>>
>>
>> Do it the old fashioned way: make a test! Can't be that difficult, can
>> it?
>
> Of course not. I'll just get out the 415VAC resistive load I happen to
> have lying around, and see what registers.
>
> Sylvia.
Two large lamps in series.

F Murtz wrote:
> Sylvia Else wrote:
>> PeterD wrote:
>>> On Fri, 27 Nov 2009 10:33:40 +1100, Sylvia Else
>>> <sylvia@not.at.this.address> wrote:
>>>
>>>> terryc wrote:
>>>>> On Thu, 26 Nov 2009 22:12:24 +1100, Phil Allison wrote:
>>>>>
>>>>>
>>>>>>>> Would the two utility meters correctly reflect the energy I
>>>>>>>> consumed?
>>>>>>> **Briefly, yes.
>>>>>> ** Indefinitely, actually.
>>>>> Yep, that is how 415VAC is obtained.
>>>> But is it how it's metered?
>>>>
>>>> I haven't gone through the math, and I'd overlooked the fact that
>>>> each meter sees a power factor of less than one, so I can't say now
>>>> whether I think the meters would read correctly. But if there's a way
>>>> of looking at the problem that makes the answer obvious, I've yet to
>>>> see it.
>>>>
>>>> Sylvia.
>>>
>>>
>>> Do it the old fashioned way: make a test! Can't be that difficult, can
>>> it?
>>
>> Of course not. I'll just get out the 415VAC resistive load I happen to
>> have lying around, and see what registers.
>>
>> Sylvia.
> Two large lamps in series.
> 

I don't have any. I'd have to buy them.

Anyway, all a test would do is show that the answer is probably correct. 
  It wouldn't make it any more obvious.

Sylvia.

On Fri, 27 Nov 2009 13:21:08 +1100, Sylvia Else
<sylvia@not.at.this.address> wrote:

>PeterD wrote:
>> On Fri, 27 Nov 2009 10:33:40 +1100, Sylvia Else
>> <sylvia@not.at.this.address> wrote:
>> 
>>> terryc wrote:
>>>> On Thu, 26 Nov 2009 22:12:24 +1100, Phil Allison wrote:
>>>>
>>>>
>>>>>>> Would the two utility meters correctly reflect the energy I consumed?
>>>>>> **Briefly, yes.
>>>>> ** Indefinitely, actually.
>>>> Yep, that is how 415VAC is obtained.
>>> But is it how it's metered?
>>>
>>> I haven't gone through the math, and I'd overlooked the fact that each 
>>> meter sees a power factor of less than one, so I can't say now whether I 
>>> think the meters would read correctly. But if there's a way of looking 
>>> at the problem that makes the answer obvious, I've yet to see it.
>>>
>>> Sylvia.
>> 
>> 
>> Do it the old fashioned way: make a test! Can't be that difficult, can
>> it?
>
>Of course not. I'll just get out the 415VAC resistive load I happen to 
>have lying around, and see what registers.
>
>Sylvia.

If you can't find it, you can borrow mine... Oh, wait, too far away!
<bg> Couple of (identical) resistance electric heaters, in series? 

Sylvia Else Inscribed thus:

> terryc wrote:
>> On Thu, 26 Nov 2009 22:12:24 +1100, Phil Allison wrote:
>> 
>> 
>>>>> Would the two utility meters correctly reflect the energy I
>>>>> consumed?
>>>> **Briefly, yes.
>>> ** Indefinitely, actually.
>> 
>> Yep, that is how 415VAC is obtained.
> 
> But is it how it's metered?
> 
> I haven't gone through the math, and I'd overlooked the fact that each
> meter sees a power factor of less than one, so I can't say now whether
> I think the meters would read correctly. But if there's a way of
> looking at the problem that makes the answer obvious, I've yet to see
> it.
> 
> Sylvia.

I have three meters, one for each phase.

-- 
Best Regards:
                Baron.

Sylvia Else wrote:
> 
> Anyway, all a test would do is show that the answer is probably correct. 
>  It wouldn't make it any more obvious.
> 
> Sylvia.

Sylvia,

Draw yourself a vector diagram. Then with some simple trigonometry it 
*should* be more obvious.

Assume a resistive load between two of the three phases, with a load of 
1 unit current and 1 unit voltage. The load will thus be 1 unit power.

Each single phase meter will see the in phase voltage as 1 / sqrt(3) 
(240/415).

Each single phase meter will see an in phase current of 1 x cos(30). 
Remember that cos(30) = 1/2 sqrt(3).

This gives the power measured by each meter as
	V*I = 1/sqrt(3) * 1/2 sqrt(3)

The two square roots of three cancel, which, unsurprisingly leaves 1/2. 
Thus each meter records 1/2 the power in the load, and you will thus get 
billed correctly.

David

David wrote:
> Sylvia Else wrote:
>>
>> Anyway, all a test would do is show that the answer is probably 
>> correct.  It wouldn't make it any more obvious.
>>
>> Sylvia.
> 
> Sylvia,
> 
> Draw yourself a vector diagram. Then with some simple trigonometry it 
> *should* be more obvious.

<sigh>

The test wouldn't make it more obvious.

I said I hadn't done the math. The math would give the result, not make 
it obvious.

Sylvia.