Power Quality Problem

J

John Miller

Guest
Hello,

This question is more to do with electricity than electronics per se - I
hope that's okay!

The quality of the electricity supply to my house is terrible (North
Carolina, standard single phase). For *ages*, light bulbs have been popping
very prematurely. Last week, I bought a used 'scope from eBay and, looking
for a quick signal to test it with, stuck a x10 probe into an power outlet.
I did not see a nice sine wave but a very distorted one - like you'd get if
you over drive a vacuum tube. This also explained why an old NAD amplifier
I was testing was consistently yielding DC rail voltages approx. 20% higher
than specified.

Although the peak line voltage is about right (153V which would be approx.
108V rms), the true rms value is about 130V). I've reported this to the
local utility company. The person in the Power Quality section didn't
understand the concept of peak vs. rms and also stated that an engineer
would come out to run some tests on the neutral bonding but that they don't
have the means to look at the shape of the incoming waveform (surely not!).

Anyway, I grew up in the UK and so I don't know the regulations in the US
specifying the quality of power supply (given the never ending brown-outs
etc, I suspect they are not as strict).

So - the question: what's the right way to get this seen to and does anyone
have a link to the corresponding NFPB/NEC regulations?

Thanks,

John.
 
"John Miller" <me@nowhere.com> wrote in message
news:10e527fmchhbb2c@corp.supernews.com...
Hello,

This question is more to do with electricity than electronics per se - I
hope that's okay!

The quality of the electricity supply to my house is terrible (North
Carolina, standard single phase). For *ages*, light bulbs have been popping
very prematurely. Last week, I bought a used 'scope from eBay and, looking
for a quick signal to test it with, stuck a x10 probe into an power outlet.
I did not see a nice sine wave but a very distorted one - like you'd get if
you over drive a vacuum tube. This also explained why an old NAD amplifier
I was testing was consistently yielding DC rail voltages approx. 20% higher
than specified.

Although the peak line voltage is about right (153V which would be approx.
108V rms), the true rms value is about 130V). I've reported this to the
local utility company. The person in the Power Quality section didn't
understand the concept of peak vs. rms and also stated that an engineer
would come out to run some tests on the neutral bonding but that they don't
have the means to look at the shape of the incoming waveform (surely not!).

Anyway, I grew up in the UK and so I don't know the regulations in the US
specifying the quality of power supply (given the never ending brown-outs
etc, I suspect they are not as strict).

So - the question: what's the right way to get this seen to and does anyone
have a link to the corresponding NFPB/NEC regulations?

Thanks,

John.
Click to expand...
As far as the process, I would first ask if any of my neighbors were
experiencing similar problems (if yes, that will give you more clout) then
call the Public Utility Commission (should be in the phone book) to complain
and follow it up with a letter. Be sure to get a name. They will probably pass
you back to the power company, but they will probably give you more attention.
When you write to them in the future you can cc the person in the PUC.

I should think they should be able to understand that the voltage is too
high - 130 - however.

Bill
 
On Wed, 30 Jun 2004 10:24:40 GMT, "Bill" <xxx@yy.zz> wrote:

"John Miller" <me@nowhere.com> wrote in message
news:10e527fmchhbb2c@corp.supernews.com...
Hello,

This question is more to do with electricity than electronics per se - I
hope that's okay!

The quality of the electricity supply to my house is terrible (North
Carolina, standard single phase). For *ages*, light bulbs have been popping
very prematurely. Last week, I bought a used 'scope from eBay and, looking
for a quick signal to test it with, stuck a x10 probe into an power outlet.
I did not see a nice sine wave but a very distorted one - like you'd get if
you over drive a vacuum tube. This also explained why an old NAD amplifier
I was testing was consistently yielding DC rail voltages approx. 20% higher
than specified.

Although the peak line voltage is about right (153V which would be approx.
108V rms), the true rms value is about 130V). I've reported this to the
local utility company. The person in the Power Quality section didn't
understand the concept of peak vs. rms and also stated that an engineer
would come out to run some tests on the neutral bonding but that they don't
have the means to look at the shape of the incoming waveform (surely not!).

Anyway, I grew up in the UK and so I don't know the regulations in the US
specifying the quality of power supply (given the never ending brown-outs
etc, I suspect they are not as strict).

So - the question: what's the right way to get this seen to and does anyone
have a link to the corresponding NFPB/NEC regulations?

Thanks,

John.



As far as the process, I would first ask if any of my neighbors were
experiencing similar problems (if yes, that will give you more clout) then
call the Public Utility Commission (should be in the phone book) to complain
and follow it up with a letter. Be sure to get a name. They will probably pass
you back to the power company, but they will probably give you more attention.
When you write to them in the future you can cc the person in the PUC.

I should think they should be able to understand that the voltage is too
high - 130 - however.
Click to expand...
---
Also, while you're waiting for the process to work (good luck!) you
might want to take matters into your own hands and check out constant
voltage (ferroresonant) transformers. Good for curing lots of power
quality problems, and here's a link to start you off:

http://www.sola-hevi-duty.com/products/powerconditioning/pdfs/cvs.pdf

--
John Fields
 
Thanks for the suggestion.

John.

"John Fields" <jfields@austininstruments.com> wrote in message
news:vnr5e0dpmpit2aumnosq3ncgv0lvqhoc6o@4ax.com...
On Wed, 30 Jun 2004 10:24:40 GMT, "Bill" <xxx@yy.zz> wrote:


"John Miller" <me@nowhere.com> wrote in message
news:10e527fmchhbb2c@corp.supernews.com...
Hello,

This question is more to do with electricity than electronics per se -
I
hope that's okay!

The quality of the electricity supply to my house is terrible (North
Carolina, standard single phase). For *ages*, light bulbs have been
popping
very prematurely. Last week, I bought a used 'scope from eBay and,
looking
for a quick signal to test it with, stuck a x10 probe into an power
outlet.
I did not see a nice sine wave but a very distorted one - like you'd
get if
you over drive a vacuum tube. This also explained why an old NAD
amplifier
I was testing was consistently yielding DC rail voltages approx. 20%
higher
than specified.

Although the peak line voltage is about right (153V which would be
approx.
108V rms), the true rms value is about 130V). I've reported this to
the
local utility company. The person in the Power Quality section didn't
understand the concept of peak vs. rms and also stated that an engineer
would come out to run some tests on the neutral bonding but that they
don't
have the means to look at the shape of the incoming waveform (surely
not!).

Anyway, I grew up in the UK and so I don't know the regulations in the
US
specifying the quality of power supply (given the never ending
brown-outs
etc, I suspect they are not as strict).

So - the question: what's the right way to get this seen to and does
anyone
have a link to the corresponding NFPB/NEC regulations?

Thanks,

John.



As far as the process, I would first ask if any of my neighbors were
experiencing similar problems (if yes, that will give you more clout)
then
call the Public Utility Commission (should be in the phone book) to
complain
and follow it up with a letter. Be sure to get a name. They will probably
pass
you back to the power company, but they will probably give you more
attention.
When you write to them in the future you can cc the person in the PUC.

I should think they should be able to understand that the voltage is too
high - 130 - however.

---
Also, while you're waiting for the process to work (good luck!) you
might want to take matters into your own hands and check out constant
voltage (ferroresonant) transformers. Good for curing lots of power
quality problems, and here's a link to start you off:

http://www.sola-hevi-duty.com/products/powerconditioning/pdfs/cvs.pdf

--
John Fields
Click to expand...
 
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