I am visiting my retired parents in Mexico and have been taked to try
and figure out why their and their friends appliances keep failing
after very limited use. They have experienced numerous failures of
kitchen appliances, with microwaves and refrigerators having the most
problems. These are new relatively good quality brands that seem to
fail in 6 to 12 months. I don't have my multimeter with me but I have
been told that someone else has measured voltages from the wall outlets
as high as 129v. So I don't know if Mexico has a voltage regulation
problem with their grid? The house wiring I have observed is pretty
bad, espite being a new construction with 3 prong outlets. So I can't
confirm if the grounding has been adequately done or if there are
ground loops, et. al.
Does anyone have ideas as where to proceed? Voltage
stabilizers/regulators maybe? thanks, rick

semidemiurge wrote:

I am visiting my retired parents in Mexico and have been taked to try
and figure out why their and their friends appliances keep failing
after very limited use. They have experienced numerous failures of
kitchen appliances, with microwaves and refrigerators having the most
problems. These are new relatively good quality brands that seem to
fail in 6 to 12 months. I don't have my multimeter with me but I have
been told that someone else has measured voltages from the wall outlets
as high as 129v. So I don't know if Mexico has a voltage regulation
problem with their grid? The house wiring I have observed is pretty
bad, espite being a new construction with 3 prong outlets. So I can't
confirm if the grounding has been adequately done or if there are
ground loops, et. al.
Does anyone have ideas as where to proceed? Voltage
stabilizers/regulators maybe? thanks, rick

Mexico's 'official' voltage is 127V.

So yes it causes trouble. A bucking transformer or two might help you.

Graham

"Eeyore" wrote in message
...


semidemiurge wrote:

I am visiting my retired parents in Mexico and have been taked to try
and figure out why their and their friends appliances keep failing
after very limited use. They have experienced numerous failures of
kitchen appliances, with microwaves and refrigerators having the most
problems. These are new relatively good quality brands that seem to
fail in 6 to 12 months. I don't have my multimeter with me but I have
been told that someone else has measured voltages from the wall outlets
as high as 129v. So I don't know if Mexico has a voltage regulation
problem with their grid? The house wiring I have observed is pretty
bad, espite being a new construction with 3 prong outlets. So I can't
confirm if the grounding has been adequately done or if there are
ground loops, et. al.
Does anyone have ideas as where to proceed? Voltage
stabilizers/regulators maybe? thanks, rick

Mexico's 'official' voltage is 127V.

So yes it causes trouble. A bucking transformer or two might help you.

Graham


A friend of mine worked for the local water authority many years ago, and he
had a similar problem at a remote pumping station, where light bulbs and
pump motors would fail in short order. Turned out that there was an
intermittent neutral connection at the pole transformer half a field away,
which was allowing the line voltage to come up to the three phase level
intermittently - over here that's up to 415v from 240v. I've probably
explained that wrong, I'm not an electricity distribution expert, but the
gist of it in terms of levels and the cause is right, so I'm sure someone
who is au fait with the subject can pick it up and know what I'm trying to
say.

Arfa

Arfa Daily wrote:

"Eeyore" wrote in message
semidemiurge wrote:

I am visiting my retired parents in Mexico and have been taked to try
and figure out why their and their friends appliances keep failing
after very limited use. They have experienced numerous failures of
kitchen appliances, with microwaves and refrigerators having the most
problems. These are new relatively good quality brands that seem to
fail in 6 to 12 months. I don't have my multimeter with me but I have
been told that someone else has measured voltages from the wall outlets
as high as 129v. So I don't know if Mexico has a voltage regulation
problem with their grid? The house wiring I have observed is pretty
bad, espite being a new construction with 3 prong outlets. So I can't
confirm if the grounding has been adequately done or if there are
ground loops, et. al.
Does anyone have ideas as where to proceed? Voltage
stabilizers/regulators maybe? thanks, rick

Mexico's 'official' voltage is 127V.

So yes it causes trouble. A bucking transformer or two might help you.

Graham


A friend of mine worked for the local water authority many years ago, and he
had a similar problem at a remote pumping station, where light bulbs and
pump motors would fail in short order. Turned out that there was an
intermittent neutral connection at the pole transformer half a field away,
which was allowing the line voltage to come up to the three phase level
intermittently - over here that's up to 415v from 240v. I've probably
explained that wrong, I'm not an electricity distribution expert, but the
gist of it in terms of levels and the cause is right, so I'm sure someone
who is au fait with the subject can pick it up and know what I'm trying to
say.

Arfa

Yup, I know exactly the scenario you mean.

In the USA a similar thing can happen with their ( I'm the UK too btw )
'centre-tapped' 2 phase 240V too. The 120V single phase supply can go soaring.

Graham

Arfa Daily wrote in message
...

"Eeyore" wrote in message
...


semidemiurge wrote:

I am visiting my retired parents in Mexico and have been taked to try
and figure out why their and their friends appliances keep failing
after very limited use. They have experienced numerous failures of
kitchen appliances, with microwaves and refrigerators having the most
problems. These are new relatively good quality brands that seem to
fail in 6 to 12 months. I don't have my multimeter with me but I have
been told that someone else has measured voltages from the wall outlets
as high as 129v. So I don't know if Mexico has a voltage regulation
problem with their grid? The house wiring I have observed is pretty
bad, espite being a new construction with 3 prong outlets. So I can't
confirm if the grounding has been adequately done or if there are
ground loops, et. al.
Does anyone have ideas as where to proceed? Voltage
stabilizers/regulators maybe? thanks, rick

Mexico's 'official' voltage is 127V.

So yes it causes trouble. A bucking transformer or two might help you.

Graham


A friend of mine worked for the local water authority many years ago, and
he
had a similar problem at a remote pumping station, where light bulbs and
pump motors would fail in short order. Turned out that there was an
intermittent neutral connection at the pole transformer half a field away,
which was allowing the line voltage to come up to the three phase level
intermittently - over here that's up to 415v from 240v. I've probably
explained that wrong, I'm not an electricity distribution expert, but the
gist of it in terms of levels and the cause is right, so I'm sure someone
who is au fait with the subject can pick it up and know what I'm trying to
say.

Arfa



But with that fault, for the UK does not that just mean the same usable
supply stays at 240V but instead of neutral being a nominal near ground it
goes up 150 V or whatever, which should not blow equipment.
Isn't it more a problem of very low loading or heavy inductive loading /
unbalanced loading that shifts the supply up in voltage range to dreate
surge/oversupply to equipment problems.

N Cook wrote:
Arfa Daily wrote in message
...

A friend of mine worked for the local water authority many years ago, and
he
had a similar problem at a remote pumping station, where light bulbs and
pump motors would fail in short order. Turned out that there was an
intermittent neutral connection at the pole transformer half a field away,
which was allowing the line voltage to come up to the three phase level
intermittently - over here that's up to 415v from 240v. I've probably
explained that wrong, I'm not an electricity distribution expert, but the
gist of it in terms of levels and the cause is right, so I'm sure someone
who is au fait with the subject can pick it up and know what I'm trying to
say.

Arfa



But with that fault, for the UK does not that just mean the same usable
supply stays at 240V but instead of neutral being a nominal near ground it
goes up 150 V or whatever, which should not blow equipment.


The voltage can fluctuate according to the appliances connected within
each property/dwelling supplied from that transformer. I posted an
explanation of this a little while ago.

http://groups.google.co.uk/group/sci...8153f55808c325


--
Tim Phipps

replace "invalid" with "uk" to reply by email

"N Cook" wrote in message
...
Arfa Daily wrote in message
...

"Eeyore" wrote in message
...


semidemiurge wrote:

I am visiting my retired parents in Mexico and have been taked to try
and figure out why their and their friends appliances keep failing
after very limited use. They have experienced numerous failures of
kitchen appliances, with microwaves and refrigerators having the most
problems. These are new relatively good quality brands that seem to
fail in 6 to 12 months. I don't have my multimeter with me but I have
been told that someone else has measured voltages from the wall
outlets
as high as 129v. So I don't know if Mexico has a voltage regulation
problem with their grid? The house wiring I have observed is pretty
bad, espite being a new construction with 3 prong outlets. So I can't
confirm if the grounding has been adequately done or if there are
ground loops, et. al.
Does anyone have ideas as where to proceed? Voltage
stabilizers/regulators maybe? thanks, rick

Mexico's 'official' voltage is 127V.

So yes it causes trouble. A bucking transformer or two might help you.

Graham


A friend of mine worked for the local water authority many years ago, and
he
had a similar problem at a remote pumping station, where light bulbs and
pump motors would fail in short order. Turned out that there was an
intermittent neutral connection at the pole transformer half a field
away,
which was allowing the line voltage to come up to the three phase level
intermittently - over here that's up to 415v from 240v. I've probably
explained that wrong, I'm not an electricity distribution expert, but the
gist of it in terms of levels and the cause is right, so I'm sure someone
who is au fait with the subject can pick it up and know what I'm trying
to
say.

Arfa



But with that fault, for the UK does not that just mean the same usable
supply stays at 240V but instead of neutral being a nominal near ground it
goes up 150 V or whatever, which should not blow equipment.
Isn't it more a problem of very low loading or heavy inductive loading /
unbalanced loading that shifts the supply up in voltage range to dreate
surge/oversupply to equipment problems.


As I said, I'm no expert on electricity distribution, but this problem
causing the voltage to shoot up to interphase level was something to do with
the PME overhead distribution system that is still around in some UK rural
areas, and was the system that this pumping station was fed from. Although
it was a long time ago, I can quite clearly remember him installing a
voltage recorder in the station, which gave the clue to what was happening.
He then met the supply company lineman on site, and that guy pinned it to an
intermittent neutral connection at the transformer. It just seemed to me
that this sounded like just the sort of thing that the OP was describing,
and given that he said the wiring looked pretty dodgy to him, and much of
the North American continent is fed via overhead pole transformer systems, I
thought that it was an idea worth considering.

Arfa

Arfa Daily wrote in message
...

"N Cook" wrote in message
...
Arfa Daily wrote in message
...

"Eeyore" wrote in message
...


semidemiurge wrote:

I am visiting my retired parents in Mexico and have been taked to
try
and figure out why their and their friends appliances keep failing
after very limited use. They have experienced numerous failures of
kitchen appliances, with microwaves and refrigerators having the
most
problems. These are new relatively good quality brands that seem to
fail in 6 to 12 months. I don't have my multimeter with me but I
have
been told that someone else has measured voltages from the wall
outlets
as high as 129v. So I don't know if Mexico has a voltage regulation
problem with their grid? The house wiring I have observed is pretty
bad, espite being a new construction with 3 prong outlets. So I
can't
confirm if the grounding has been adequately done or if there are
ground loops, et. al.
Does anyone have ideas as where to proceed? Voltage
stabilizers/regulators maybe? thanks, rick

Mexico's 'official' voltage is 127V.

So yes it causes trouble. A bucking transformer or two might help
you.

Graham


A friend of mine worked for the local water authority many years ago,
and
he
had a similar problem at a remote pumping station, where light bulbs
and
pump motors would fail in short order. Turned out that there was an
intermittent neutral connection at the pole transformer half a field
away,
which was allowing the line voltage to come up to the three phase level
intermittently - over here that's up to 415v from 240v. I've probably
explained that wrong, I'm not an electricity distribution expert, but
the
gist of it in terms of levels and the cause is right, so I'm sure
someone
who is au fait with the subject can pick it up and know what I'm trying
to
say.

Arfa



But with that fault, for the UK does not that just mean the same usable
supply stays at 240V but instead of neutral being a nominal near ground
it
goes up 150 V or whatever, which should not blow equipment.
Isn't it more a problem of very low loading or heavy inductive loading /
unbalanced loading that shifts the supply up in voltage range to dreate
surge/oversupply to equipment problems.


As I said, I'm no expert on electricity distribution, but this problem
causing the voltage to shoot up to interphase level was something to do
with
the PME overhead distribution system that is still around in some UK rural
areas, and was the system that this pumping station was fed from. Although
it was a long time ago, I can quite clearly remember him installing a
voltage recorder in the station, which gave the clue to what was
happening.
He then met the supply company lineman on site, and that guy pinned it to
an
intermittent neutral connection at the transformer. It just seemed to me
that this sounded like just the sort of thing that the OP was describing,
and given that he said the wiring looked pretty dodgy to him, and much of
the North American continent is fed via overhead pole transformer systems,
I
thought that it was an idea worth considering.

Arfa



Here is witnessed similar surge, urban setting.
Someone , non technical, I know, retuned from abroad about 3 or 4 in the
morning. Sitting down unwinding, with the lights on, he noticed the room
light was getting noticeably brighter and brighter over 10 seconds or so
until it popped , quickly followed by a sidelight. Next day he discovered
VCR blown and a couple of other items blown.
Could he get compensation from the utility - no?
How would you get a slow increase with that transformer fault condition,
intermittant or instantaneous but not gradual increase.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

I'm joing this late, but here's some more practical suggestions:

1. Buy a REAL surge protector such as a Trip Lite ISOBAR. Around $100.
There are clones made by someone else for Hi-Fi's for about $250,
IMHO not any different except in marketing.

2. Buy one from Trans-Tector. A lot more money, but they make them for
use in air traffic control centers, hospitals, etc where you can't
turn off or unplug equipment during a lightening storm.

3. Make one out of a small (rating) fast blow fuse and a 150 volt MOV.
When you get a big surge, the MOV fails, which causes it to short and
the fuse blows. Possible put this in front of the surge protector,

4. Buy a commercial grade UPS.

Geoff.
--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 Fax ONLY: 972-2-648-1443 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

"Geoffrey S. Mendelson" wrote:

I'm joing this late, but here's some more practical suggestions:

1. Buy a REAL surge protector such as a Trip Lite ISOBAR. Around $100.
There are clones made by someone else for Hi-Fi's for about $250,
IMHO not any different except in marketing.

Surges are very unlikely to be the problem.

More likely is long term modest overvoltage.

Graham

Eeyore wrote:
More likely is long term modest overvoltage.

Exactly how modest? When I lived in the U.S. (Philly, until 1996), the
line voltage was always 127 volts. If you figure a range of 10% is ok,
than that would be 133 volts as the top limit for a 120 volt device.

More likely it's 15% which would take it up to 138 volts.

That's why Israel chose 230 volts, people could bring applicances from
Europe and the rest of the world that was 220, or the U.K., where it
was 240 volts and they generaly would work ok. The E.U. (which AFAIK
includes the U.K.) has switched to 230 volts as part of their "normalization
program".

My expectations are that the cheap appliances are burning out because
they are cheap appliances. Things are not built like they used to be.

For example, if he wants to get them a mixer, either buy them a Sunbeam
at a garage sale, or a new Kenwood if he can get one. I bought one here
(in 230 volts) because after a lot of research I found that they were far
more relaiable and better made than the current Kitchen Aid ones.

For example, my mixer, which is a mid range model, is 1000w 2-3 times the
power of anything Kitchen Aid sells.

Geoff.
--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 Fax ONLY: 972-2-648-1443 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

In a case like that nothing but a UPS will work. Surge protectors
are made for higher spikes. A good UPS will switch on during the
overvoltage condition.

N Cook wrote:

Here is witnessed similar surge, urban setting.
Someone , non technical, I know, retuned from abroad about 3 or 4 in the
morning. Sitting down unwinding, with the lights on, he noticed the room
light was getting noticeably brighter and brighter over 10 seconds or so
until it popped , quickly followed by a sidelight. Next day he discovered
VCR blown and a couple of other items blown.
Could he get compensation from the utility - no?
How would you get a slow increase with that transformer fault condition,
intermittant or instantaneous but not gradual increase.

(Geoffrey S. Mendelson) wrote in
:

Buy a REAL surge protector such as a Trip Lite ISOBAR. Around $100.
There are clones made by someone else for Hi-Fi's for about $250,
IMHO not any different except in marketing.


Trip Lite Isobar surge protectors come in several models, some including
protection for phone line, coax cable, etc.

Although their list prices are high, street prices are surprisingly
affordable, $43 and up.

http://tinyurl.com/yays84 [amazon.com]

Here is witnessed similar surge, urban setting.
Someone , non technical, I know, retuned from abroad about 3 or 4 in the
morning. Sitting down unwinding, with the lights on, he noticed the room
light was getting noticeably brighter and brighter over 10 seconds or so
until it popped , quickly followed by a sidelight. Next day he discovered
VCR blown and a couple of other items blown.
Could he get compensation from the utility - no?
How would you get a slow increase with that transformer fault condition,
intermittant or instantaneous but not gradual increase.



Loose neutral, probably within his own home, not the power company's
problem.

Geoffrey S. Mendelson wrote:
I'm joing this late, but here's some more practical suggestions:

1. Buy a REAL surge protector such as a Trip Lite ISOBAR. Around $100.
There are clones made by someone else for Hi-Fi's for about $250,
IMHO not any different except in marketing.

2. Buy one from Trans-Tector. A lot more money, but they make them for
use in air traffic control centers, hospitals, etc where you can't
turn off or unplug equipment during a lightening storm.

3. Make one out of a small (rating) fast blow fuse and a 150 volt MOV.
When you get a big surge, the MOV fails, which causes it to short and
the fuse blows. Possible put this in front of the surge protector,

4. Buy a commercial grade UPS.



A surge protector won't do anything to prevent damage from high line
voltage, the voltage has to get *really* high before they even kick in,
like 400-600V. A constant voltage (ferro-resonant) transformer would do
the trick but those are big, heavy, inneficient, and therefor run hot
and tend to hum as well.