Power through water pipes - Dangerous?

[Barry]

I didn't know where to post it, so moderators feel free to relocate.

This morning the power in my house was doing funny things.
Lights were going dim then bright again.
Machines were turning on and off.
Wireless phone base kept blinking its lights....etc...

My mum called Western Power.
Whoever she talked to said to reset safety breakers if we have any, which
she did. That didn't do anything, so they said they'd send someone over.

A little while later my mum reached for the tap on the kitchen sink and got
zapped. Almost at the same time, my brother had the unlucky idea to take a
shower and got zapped too when he reached for the tap.

So my mum called Western Power again, and told them they were getting
electric shocks from the water taps. She demanded that they send someone
right away.

The Western power dude showed up. He looked at our switchboard and said
everything was fine there. He 'tested" the taps and confirmed that there
current running through them. I don't know how he tested, my mum told me he
had some electronic device.

Then he called more people from western power who brought a truck with a
crane/ladder thing to reach power poles.

Now at my house, the power cable come off one of those power poles in the
street, and connect to the top of a shorter pole in our garden, then
disappears under ground.

The power guy said the problem was with the connection to the little pole.
He 'cleaned' it and added extra isolation around the connection.

The guy told my mum:
-that it's common that current 'gets' into water pipes
-that it's the fault of salty breeze, due to living close to the sea (we're
about 1.5km)
-that we were never under any danger because it was only a low voltage going
through water pipes

Unfortunately I wasn't there. My mum isn't very clued on about electricity &
power, so she didn't question what he said, and didn't ask many questions.

But when I heard this I thought it made no sense whatsoever, and I'm certain
the western power guy must have been bullshitting. Of course he would say we
were never under any danger, like he'd say anything else...

Any advice?

 

[Palindr☻me]

I didn't know where to post it, so moderators feel free to relocate.

This morning the power in my house was doing funny things.
Lights were going dim then bright again.
Machines were turning on and off.
Wireless phone base kept blinking its lights....etc...

My mum called Western Power.
Whoever she talked to said to reset safety breakers if we have any, which
she did. That didn't do anything, so they said they'd send someone over.

A little while later my mum reached for the tap on the kitchen sink and got
zapped. Almost at the same time, my brother had the unlucky idea to take a
shower and got zapped too when he reached for the tap.

So my mum called Western Power again, and told them they were getting
electric shocks from the water taps. She demanded that they send someone
right away.

The Western power dude showed up. He looked at our switchboard and said
everything was fine there. He 'tested" the taps and confirmed that there
current running through them. I don't know how he tested, my mum told me he
had some electronic device.

Then he called more people from western power who brought a truck with a
crane/ladder thing to reach power poles.

Now at my house, the power cable come off one of those power poles in the
street, and connect to the top of a shorter pole in our garden, then
disappears under ground.

The power guy said the problem was with the connection to the little pole.
He 'cleaned' it and added extra isolation around the connection.

The guy told my mum:
-that it's common that current 'gets' into water pipes
-that it's the fault of salty breeze, due to living close to the sea (we're
about 1.5km)
-that we were never under any danger because it was only a low voltage going
through water pipes

Unfortunately I wasn't there. My mum isn't very clued on about electricity &
power, so she didn't question what he said, and didn't ask many questions.

But when I heard this I thought it made no sense whatsoever, and I'm certain
the western power guy must have been bullshitting. Of course he would say we
were never under any danger, like he'd say anything else...

Any advice?

It sounds like you had a break in the power "return" line on the pole.

The salt air probably got at the joint on the pole and corroded it until
it broke or made a bad connection- hence breaking the return path. When
repairing it, the electrician added extra "isolation" to keep the salt
air out, not to keep the electricity in.

If the house electrics had all been installed and set up properly and is
in perfect working order, you were in next to no danger. It is
worthwhile getting this checked once every few years, just to make sure
that nothing else has corroded that could make you less safe. An
electrician checking your "earth and bonding" should be able to do the
tests needed in 30 minutes or less. That you actually got shocks off the
taps could indicate that there is a problem as proper bonding should
make this very unlikely.

If you are interested in the technical aspects of this, here is a simple
explanation for the British systems:

http://www.diyfaq.org.uk/electrical/electrical.html

It can happen that a bonding wire going to a pipe gets broken - there
will be no obvious effect until there is another fault. It is also
possible that a clamp can become loose and I have seen one that was
removed and then put back on a painted, rather than bare metal, pipe -
which makes it useless. You may also have a ground "spike" - a
copper-coated pointed steel rod hammered into the ground near the house,
with a wire on. It is very common for that wire to become broken or the
connection corroded - again, until there is another fault, there is
nothing to show that this has happened.

Although it is easy to take the house wiring for granted - it is worth
having it checked out now and again.

 

[Lzmain]

I didn't know where to post it, so moderators feel free to relocate.

This morning the power in my house was doing funny things.
Lights were going dim then bright again.
Machines were turning on and off.
Wireless phone base kept blinking its lights....etc...

My mum called Western Power.
Whoever she talked to said to reset safety breakers if we have any, which
she did. That didn't do anything, so they said they'd send someone over.

A little while later my mum reached for the tap on the kitchen sink and got
zapped. Almost at the same time, my brother had the unlucky idea to take a
shower and got zapped too when he reached for the tap.

So my mum called Western Power again, and told them they were getting
electric shocks from the water taps. She demanded that they send someone
right away.

The Western power dude showed up. He looked at our switchboard and said
everything was fine there. He 'tested" the taps and confirmed that there
current running through them. I don't know how he tested, my mum told me he
had some electronic device.

Then he called more people from western power who brought a truck with a
crane/ladder thing to reach power poles.

Now at my house, the power cable come off one of those power poles in the
street, and connect to the top of a shorter pole in our garden, then
disappears under ground.

The power guy said the problem was with the connection to the little pole.
He 'cleaned' it and added extra isolation around the connection.

The guy told my mum:
-that it's common that current 'gets' into water pipes
-that it's the fault of salty breeze, due to living close to the sea (we're
about 1.5km)
-that we were never under any danger because it was only a low voltage going
through water pipes

Unfortunately I wasn't there. My mum isn't very clued on about electricity &
power, so she didn't question what he said, and didn't ask many questions.

But when I heard this I thought it made no sense whatsoever, and I'm certain
the western power guy must have been bullshitting. Of course he would say we
were never under any danger, like he'd say anything else...

Any advice?

Sounds like you have two problems. The first is a poor ground return via
the powerlines, and the second is someone tied the power return to the water
pipes, which is illegal in most US areas. That was an old way (back in the
30's)of getting a cheap ground when waterpipes were iron, but the
connections get very poor with age (corrosion) and plastic is being used
everywhere now.

The Tech is wrong in three places (he is the power company guy, different
skill set from home electrician)
*Adding "extra insulation" to it does nothing at all for the shock problem.
*Low voltage going through pipes is really high voltage, after all she got
shocked by it. It was probably 120 volts, and can kill. That is why the code
was changed back in the 40's to not attach ground returns to water pipes,
and run a separate ground wire for all circuits.
*current doesn't "get into waterpipes" if the today's wiring code is
followed.

You should have an electrician come out and check the house. The power
company is responsible for the lines up to your house, not what goes on
inside. Some of the really older homes (70 years or more) have poor
degrading wiring which is inherently unsafe and can start fires. (the old 2
wire system) and should be rewired.

 

[Beachcomber]

It can happen that a bonding wire going to a pipe gets broken - there
will be no obvious effect until there is another fault. It is also
possible that a clamp can become loose and I have seen one that was
removed and then put back on a painted, rather than bare metal, pipe -
which makes it useless. You may also have a ground "spike" - a
copper-coated pointed steel rod hammered into the ground near the house,
with a wire on. It is very common for that wire to become broken or the
connection corroded - again, until there is another fault, there is
nothing to show that this has happened.

Could this be one of those SWER (single wire earth return) systems?

To the original poster: How many wires from your power company are
going into the transfomer nearest your house?

Beachcomber

 

[Beachcomber]

Sounds like you have two problems. The first is a poor ground return via
the powerlines, and the second is someone tied the power return to the water
pipes, which is illegal in most US areas. That was an old way (back in the
30's)of getting a cheap ground when waterpipes were iron, but the
connections get very poor with age (corrosion) and plastic is being used
everywhere now.

The Tech is wrong in three places (he is the power company guy, different
skill set from home electrician)
*Adding "extra insulation" to it does nothing at all for the shock problem.
*Low voltage going through pipes is really high voltage, after all she got
shocked by it. It was probably 120 volts, and can kill. That is why the code
was changed back in the 40's to not attach ground returns to water pipes,
and run a separate ground wire for all circuits.
*current doesn't "get into waterpipes" if the today's wiring code is
followed.

You should have an electrician come out and check the house. The power
company is responsible for the lines up to your house, not what goes on
inside. Some of the really older homes (70 years or more) have poor
degrading wiring which is inherently unsafe and can start fires. (the old 2
wire system) and should be rewired.

That's odd. My house was built in 1991 and has a bare ground wire
attached to the cold water piper. As far as I know, it meets all the
NEC Codes. I think that it is still proper to do this. There is
also a driven ground rod outside under the meter. This is probably
considered the real ground reference point and everything else is just
electrically bonded to it.

In the older house, (built 1958), there was no outside ground rod,
just the cold water connection. There was also a stiff wire jumper
across the electric meter as well.

Beachcomber

 

[Palindr☻me]

It is not illegal in the US. In fact, it is mandatory.




Nowadays, you cannot rely on the water pipes to be the sole ground
reference for the reasons stated. You have to drive a ground rod to
be the ground reference point. But you still must bond the water piping
to the ground for safety reasons.

The original poster seems to have two problems: An open return/neutral
and an insufficient ground at the panel/service entrance. (I don't know
the grounding requirements in the UK) Electricity was trying to flow
from the hot through the lights/appliances to the return, and because the
return to the service was open, it then flowed to the ground reference/water
pipes, and because the ground was poor, through the poor guy's mum.

That is how I saw it- but you put it better

Two minor points:

The OP is in Australia, not the UK. I would imagine that the code is
similar to the UK, but am not sure about it. Equipotential bonding of
all exposed metalwork does seem to make sense in any language though.

Secondly, the OP mentioned that the visiting electrician checked out the
distribution panel. Now I can't see how he could have done this without
checking the local earth - bearing in mind the fault that was notified.
So it sounded like the local earth wasn't properly bonded to the water
pipes..Hence the need to check out the bonding.

 

[w_tom]

Lzmain is posting the correct attitude. All other posters
are strongly encouraged to comprehend what he has posted.

No matter what happens to AC electric, electricity must not
exist in pipes. Furthermore connecting to pipes to dump
electricity there is dangerous - and now illegal in many
countries. A connection from breaker box to cold water pipe
is only to remove electricity from those pipes. It is no
longer valid as an earth ground connection.

A probably missing connection that may have prevented severe
human safety threat is the earth ground rod. Every building
must connect one wire of AC electric to earth ground. Every
incoming electrical utility must also make a dedicated
connection to this ground rod. With failure of one AC
electric wire, the earth ground rod could have 'taken up the
load' - protected human life.

In a parallel example, the home had no earth ground. When
an AC neutral wire disconnected from utility transformer, then
household electricity had to find other paths. It used the
gas meter until a gasket finally failed. Fortunately no one
was home when it exploded.

Find your building's earth ground connection. It should be a
rather heavy copper wire from mains board to an earth ground
rod (again, water pipes are no longer acceptable for this
function). Wire should be about 4mm (or about 6 AWG). If
earth ground does not exist, then definitely get an
electrician to immediately upgrade or restore that all so
essential earthing.

Getting shocked in the shower is never an acceptable failure
- anywhere. To happen, multiple failures must exist. They
found and fixed one. Did they fix the others? Bottom line -
it remains the homeowner's responsibility to fix.

 

[daestrom]

Could this be one of those SWER (single wire earth return) systems?

To the original poster: How many wires from your power company are
going into the transfomer nearest your house?

I'll bet the answer *must* be two. The question you meant to ask is, "How
many of the wires going into the transformer connect to overhead lines
coming to the pole?"

(SWER still has two wires on the transformer, just that one leads to local
ground instead of coming from the overhead)

daestrom

 

[factoride]

I'll bet the answer *must* be two. The question you meant to ask is, "How
many of the wires going into the transformer connect to overhead lines
coming to the pole?"

(SWER still has two wires on the transformer, just that one leads to local
ground instead of coming from the overhead)

daestrom

Should be 3, one ground and two phases.

 

[factoride]

Has anybody considered a ground loop? I have found these from time to time.
It's easy to correct and I haven't had any problems since.

Electrical wiring and the Water pipes should never be connected for any
reason. Someone could get killed.

 

[Eric Tappert]

Sounds like you have two problems. The first is a poor ground return via
the powerlines, and the second is someone tied the power return to the water
pipes, which is illegal in most US areas.

It is not illegal in the US. In fact, it is mandatory.

That was an old way (back in the
30's)of getting a cheap ground when waterpipes were iron, but the
connections get very poor with age (corrosion) and plastic is being used
everywhere now.

Nowadays, you cannot rely on the water pipes to be the sole ground
reference for the reasons stated. You have to drive a ground rod to
be the ground reference point. But you still must bond the water piping
to the ground for safety reasons.

The original poster seems to have two problems: An open return/neutral
and an insufficient ground at the panel/service entrance. (I don't know
the grounding requirements in the UK) Electricity was trying to flow
from the hot through the lights/appliances to the return, and because the
return to the service was open, it then flowed to the ground reference/water
pipes, and because the ground was poor, through the poor guy's mum.[/QUOTE]


I agree the real problem was the open neutral/return lead, but before
we decide the ground was "poor", let's consider Ohm's Law. It is very
difficult to achieve, in most soil conditions, a ground connection
with a low impedance. Usually a single ground rod will have an
impedance higher than 10 Ohms. In fact, the US NEC clearly requires a
second ground rod if the first measures in excess of 25 Ohms. Usually
the installer just puts in two instead of measuring the first. In
some soil conditions, the impedance will be well above 50 Ohms. It is
easy to see how a large voltage can be developed if the grounding
system is the only return conductor.

I had the same problem (open neutral between the distribution
transformer and the house) a few years back and have a ground system
that far exceeds the typical residence. My ground system has three 10
foot (3 meter) ground rods (well spaced) and a Ufer ground in a 20' by
40' in-ground pool. When I lost the neutral back to the distribution
transfomer, the house neutral moved about 70 volts or so with a 10 amp
unbalanced load. With the plumbing tied to the ground system
(required by the NEC for other reasons), that would leave a bit of a
voltage on the plumbing fixtures.

Where there are "good ground systems" they are extensive, with
multiple rings, Ufer grounds, multiple rods and even counterpoises or
"ground mats". These are usually found in power distribution
substations, telephone exchanges and large industrial plants. The
typical residence rarely has a ground system with only a few Ohms of
impedance, as achieving that level is a bit impractical and/or
uneconomical. With good neutral/return connections, the multiplicity
of grounds in the distribution system and all the residences feed by
that system works rather well.

Tell Mum not to touch the plumbing if the lights dim...

E. Tappert

 

[ssparling]

Has anybody considered a ground loop? I have found these from time to time.
It's easy to correct and I haven't had any problems since.

 

[w_tom]

If voltage exists relative to some mythical force, then this
analysis is correct. But this is reality. There must be no
voltage difference between bathtub and water spout even if
earth ground voltage rises 10,000 volts. Problem eliminated
because everything must connect to a single point earth ground
AND everything must be interconnected. Furthermore if the
'hot' wire shorted to plumbing and bathtub was connected to
earth, then circuit breaker should trip. Tripping circuit
breakers is why we interconnect grounds - and then connect
that interconnected network to earth ground. Soil
conductivity would not cause a problem - and be apparent in
light intensity variations.

To have a shock in the shower, multiple failures had to
exist - no matter whether that soil resistance was 50 ohms or
0.25 ohms. To be shocked in a shower, a voltage difference
had to exist. In a properly wired house (no matter what
failure was out at the pole), that voltage difference could
not exist. With the same house properly earthed means even
less voltage difference could exist.

Multiple failures in wiring must exist to have someone
shocked in the shower. For example bathtub and fresh water
pipes had to be connected to different and separated grounds.
Just not possible if house is properly wired. If multiple
problems were not identified and repaired, then human safety
issues still exist.

 

[w_tom]

Ground loops would exist if the wiring was in violation of
what I had posted previously (Monday). Ground loops should
not be a problem. Again, to have someone shocked in the
shower, then multiple failures must exist. Electricity in a
shower or bath is that dangerous that we have long since made
these grounding requirements AND upgraded them over the
decades.

Electric shock in a shower *must* be considered a most
extreme of dangers. Just because no one died is not
sufficient. Multiple problems. Were multiple problems
identified and corrected. If not, then serious human safety
issues still exist.