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.

Sylvia Else wrote:
I have to phases of power supply to my house - so three power lines, two
phases plus neutral.

I suspect it is really "single phase" (think: center tapped
transformer) -- though in Oz they probably do things differently! :

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.

"Large" is a relative term. Homes are typically wired to
try to distribute the loads roughly equally on the two
legs. And, REALLY BIG loads (e.g., air conditioner compressor)
tend to straddle *both*.

My electrician says it's not an issue, but I can't see why.

"Luck"? But, in theory, he is wrong.

The more significant issue is *how* you would lose neutral.
Here (US), your house is tied to *earth* at the main panel.
And, neutral is similarly tied to earth. So, you would
have to lose the neutral feed from the utility *and* the
earth at your house.

This has happened to two neighbors in the past 10 years,
though. I think in both cases it was caused by a cable
actually failing (corrosion). In one case, the folks
sharing his distribution transformer (typically four homes
to a transformer) lost power when the incoming power was
effectively *shorted* to ground, (I don't know what the
distribution transformers are fused at but it was enough
to set some adjacent utilities -- below grade -- on fire)

D Yuniskis wrote:
Sylvia Else wrote:
I have to phases of power supply to my house - so three power lines,
two phases plus neutral.

I suspect it is really "single phase" (think: center tapped
transformer) -- though in Oz they probably do things differently! :

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.

"Large" is a relative term. Homes are typically wired to
try to distribute the loads roughly equally on the two
legs. And, REALLY BIG loads (e.g., air conditioner compressor)
tend to straddle *both*.

I imagine that's the case in terms of large potential loads, but if I
think about what's actually running in my house at the moment, apart
from a couple of lights, it'd be the refrigerator and my computers. I
don't know whether they're on difference phases, but if they are they'd
represent significantly different loads.

Sylvia.

Sylvia Else wrote:
D Yuniskis wrote:
Sylvia Else wrote:
I have to phases of power supply to my house - so three power lines,
two phases plus neutral.

I suspect it is really "single phase" (think: center tapped
transformer) -- though in Oz they probably do things differently! :

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.

"Large" is a relative term. Homes are typically wired to
try to distribute the loads roughly equally on the two
legs. And, REALLY BIG loads (e.g., air conditioner compressor)
tend to straddle *both*.

I imagine that's the case in terms of large potential loads, but if I
think about what's actually running in my house at the moment, apart
from a couple of lights, it'd be the refrigerator and my computers. I
don't know whether they're on difference phases, but if they are they'd
represent significantly different loads.

Exactly. And, those loads *change*. So, when the refrigerator's
compressor kicks off, *that* load is gone (here, refrigerator
sits between one leg and neutral; yours may straddle both legs?)

On Nov 24, 10:10 am, 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.


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.

In sci.electronics.repair kreed wrote:
On Nov 24, 10:10 am, 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.


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

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.

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.

I had exactly this happening two years ago.
My supply has 3 phases and I lost part of the neutral connectivity through
corrosion on the terminal coming in from the power pole.

The result was a brown out on some and over voltage on other phases. In top of
this I got a tingling zapping in the shower.

I guess, depending on the quality of the earth rod, this can be a pretty bad
situation. Where will the returning current go if there is no neutral? Through a
different phase I guess. Neutral will have a more or less floating potential.

Tony

On Tue, 24 Nov 2009 09:28:48 +0800, TonyS 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?

I had exactly this happening two years ago.
My supply has 3 phases ... -snip-

Oh?? Really?!?!

Allodoxaphobia wrote:
On Tue, 24 Nov 2009 09:28:48 +0800, TonyS 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?
I had exactly this happening two years ago.
My supply has 3 phases ... -snip-

Oh?? Really?!?!

Yes, why??

In article ,
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.

It's a huge issue.

It has happened twice, at my house. In both cases, a squirrel had
chewed through the neutral wire (they apparently like to sharpen /
exercise their teeth on the rubbery insulation).

The symptoms were much as you suggest. Voltage goes wonky, with the
voltage being fed to each phase being dependent on the various loads
connected to both phases. Voltages at the high-amperage appliances
can drop (and this can result in burned-out motors) while voltages on
the opposite phase can spike upwards (burning out incandescent lights,
damaging other appliances through over-voltage). Worst case would be
a heavy load on one phase, and only very light loads on the other
phase... the lightly loaded side could jump up to almost double
voltage.

The oddest symptom we noticed was that when a heavy load switched on
(e.g. refrigerator or microwave), room lights would suddenly
brighten... just the opposite of what would normally occur.

Both times this happened, we noticed the weirdness immediately, called
the electric company (PG&E), and they dispatched a service team on a
priority basis.

The dispatcher told me that they consider *any* sort of "high voltage,
low voltage" trouble report to justify an urgent response. She had
understood my use of the phrase "open neutral", and I infer that this
is a not-terribly-unusual situation for them.

After the second time this happened, the PG&E guys decided that our
existing pole-drop was not repairable (it had already been spliced at
least one). They installed a newer, higher-amperage-rated drop (which
might even have had some armoring). The problem hasn't recurred...
I'm keeping my fingers crossed.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

"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.




...... Phil

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.

"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

Phil Allison wrote:
"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 *.

Wow, why all the hostility? A "personal gripe"?

Can I suggest that if you don't want to see posts by a particular
person, you simply add his/her name to your "kill file" (or
whatever Microsoft Outlook Express 6.00.2900.2180 uses for that
feature)?

Speaking solely for myself -- but, perhaps, reflecting the
experiences of many "fellow countrymen" -- I think most Americans
have very little exposure to "other cultures/societies/power
distribution systems/etc : " owing, perhaps, to the large size
of our country and its relative homogeneity. I find it
interesting to hear how things are done "elsewhere" and,
especially, *why*.

("Driving on the PARKWAY and parking in the DRIVEWAY...") ;-)

On Nov 24, 12:16 pm, Sylvia Else 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.

"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

"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

On Nov 24, 10:58 am, "Phil Allison" 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:

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

"David the PEDANTIC **** 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

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/download...ards_Alert.pdf


David

"David the PEDANTIC **** 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 ****ED WITH IT.



...... 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

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

"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

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

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.

"*within* a premises". The neutral *is* "earthed" right outside
the home, typically. The Code goes to great lengths telling
you exactly *how* to earth the mains at the service entrance.

However, this ignores the fact that most residential wiring
is grandfathered into "acceptance". Previously, homes *were*
grounded through their "water main" (e.g., my parents home
has ground at the water meter).

So, you can encounter all sorts of different situations
here in the US (I've even worked on homes with knob & tube
wiring!)

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.

On Nov 23, 6:36*pm, "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.

..... *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.

"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 ****ING CRAPOLOGY !!

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

**** off - TROLLING BITCH.



...... Phil

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 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.

Hi!

I've on occasion wondered what would happen if we lost the neutral line.

(speaking from a 110V perspective as I'm in the US where power is delivered
as 2x110 volt hot leads with one neutral)

The voltage between the two fluctuates wildly, that's what. The more heavily
loaded of the two will have a voltage drop while the lightly loaded one goes
up.

CRT computer monitors get the jitters even when things are relatively
normal. I don't know why this is. Damage can occur to devices when they get
nailed with high voltage.

It won't be a huge issue up to a point for simple devices, or those with
autoranging power supplies that may try to compensate. Everything else will
suffer--motors, transformer type power supplies, etc...and your electrican
*should* know that. A fire could start depending upon how badly something
reacts to the over or under voltage.

William (had it happen here some years ago - one TV and a few surge
protectors got burnt. Curiously, the TV was not completely dead afterwards,
just temperamental about turning on when warm.)

William R. Walsh wrote:
Hi!

I've on occasion wondered what would happen if we lost the neutral line.

(speaking from a 110V perspective as I'm in the US where power is delivered
as 2x110 volt hot leads with one neutral)

The voltage between the two fluctuates wildly, that's what. The more heavily
loaded of the two will have a voltage drop while the lightly loaded one goes
up.

CRT computer monitors get the jitters even when things are relatively
normal. I don't know why this is. Damage can occur to devices when they get
nailed with high voltage.

It won't be a huge issue up to a point for simple devices, or those with
autoranging power supplies that may try to compensate. Everything else will
suffer--motors, transformer type power supplies, etc...and your electrican
*should* know that. A fire could start depending upon how badly something
reacts to the over or under voltage.

William (had it happen here some years ago - one TV and a few surge
protectors got burnt. Curiously, the TV was not completely dead afterwards,
just temperamental about turning on when warm.)


I witnessed potentially expensive neutral problems twice, once while
living in Hawaii, and once at my present location
in North Carolina. In Hawaii the house I was staying in had to be
fumigated and while the workers were tenting the house,
they managed to break a partially corroded-thru neutral wire coming
from the power pole, which no one noticed. Upon moving back into the
house, the recently-new refrigerator died a quick death upon being
plugged back in, upon which an electrician was called in, who quickly
located the broken neutral.

The second time was when I'd been living where I am now, and I'd
recently bought a new fridge - after a few months having it
working fine I noticed it was sounding like it was struggling to start
and at the same time some of the lights would get brighter (I guess
they were on the other half of the 240V supply). Not wanting to have
to deal with a dead fridge again, I investigated the incoming power
panel and found the neutral to be rather lose, so I coated it and the
other 2 incoming wires with some Noalox (an anti-aluminum oxidation
compound) and tightened 'em all goot-n-tite. That was about 7 years
ago, no more problems so far.

Mike

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 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" wrote in message
...
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