My house has been plagued by dimming lights for quite a while and
finally yesterday I decided to explore the situation and came up with
some results that have me stymied. I put a voltmeter into the various
outlets throughout the house and saw that the voltage would read at
118v for a while and then would suddenly shift to reading 127v. When
this happened the lights in the room would either brighten or dim.
This would alternate every few minutes.. I then went to my breaker
panel and shut off my main breaker and checked the voltage situation on
the lead in wires and saw that it was a steady 240 between tge two
lead-ins but that the same instability occured between the individual
leads and the ground/neutral.. (It would be 118 to ground and then
shift to being 127 to ground every few minutes with the other wire
reading the opposite at the same time). I went to a neighbor who comes
off of the same transformer and asked him if he had the same light
dimming problems and he said he hadn't noticed it but he said that his
light bulbs were always burning out after just a short while... Anyway
I am assuming that the problem is with the utility transformer but
just wanted to know if this fluctuating current is typical of a bad
transformer or could my ground connection possibly be causing this to
happen... Thanks for your help. David
That sounds like a floating ground. It may well be in your home. Do
you, by chance, have aluminum wires? If you have aluminum wire, it is
likely your neighbor also does. You don't need aluminum wire to cause the
problem, but it is often the problem. I suggest you consider this
possibility first. Next step would be to contact the utility company.
This is usually an intermittent neutral problem. When the voltage
goes up on one side of the line, the voltage dips on the other. The
voltage changes as loads vary if the neutral is disconnected, high
resistance or intermittent and can't carry the neutral current.
You can check this with two meters. Connect one meter to one side of
the incoming power and neutral and the other meter to the other
incoming line and neutral. Then turn on and off 120 volt loads around
the house, the larger the better. If one meter goes up and the other
goes down, then the neutral is bad somewhere.
You need to get this checked right away, as when the neutral finally
opens up completely, destructively high voltage will appear on the
lightly loaded side of the box. Poofed appliances and even fire is
The problem is usually with the utility equipment so I'd place an
immediate call to the utility and report the problem. Utilities tend
to jump on these kinds of problems quickly because of the potential
liability. If their bad hardware causes a fire, especially after it's
been reported, they get to pay. I bet they'll have someone out within
an hour or two of you calling it in.
John, retired utility dude
John De Armond
See my website for my current email address
you probably have have a bad connection on the ground (nuetral)
wire. ive seen it many times. i bet your getting shocked quite a bit to
touching metal things in your house too. usually the electric company
will disgnose and fix that for you. lucas
Sounds like the neutral (not ground) between the the utility companay
transformer and your breaker panel has a poor connection. Check it at
your panel and if that's ok if it is call the power company to check at
their transformer. The fluctuations come when the load within your
house isn't equal on the two 120 volt phases. That's likely to happen
when a load changes, such as your refrigerator turning on and off
automatically. This needs to be fixed immediately as devices on the
more lightly loaded side can by damaged by the overvoltage.
Your tests were good. Without knowing the 240 was stable at entrance
panel there would be other possibilities. I'd repeat the tests at the
te breaker panel and confirm with the voltmeter that phase A to neutral
plus phase B to neutural voltage is approximately equal in magnitude to
phase A to phase B voltage withing two volts and that Phase A to Ground
minus phase B to ground is larger than about 2 volts. If that's true it
confirmes the above suspicion of a loose or open neutral. By code both
the neutral at your entrance and the neutral at the transformer are
grounded, but if there's not a good metallic conductor (the third wire)
between them any current unbalaance will show up as a difference in
phase voltages. Earth grounds usually have several ohms of resistance,
possibly a lot more depending on soil conditions.
I'll vote along with Neon John based on the information you have
provided. The problem could be on either side of the meter. (Yours
or the utility company.) One thing that is almost necessary to
isolate this problem is a solenoid operated voltmeter (Wiggy). The
high impedance of a conventional VOM (analog or digital) can
really lead you down the wrong path.
: > Don't play with high voltage unless you have an ugly wife or
: > dick.
: Fortunately, there are no high voltages in house wiring.
And unfortunately some "leprotic" dicks in this group.
I'm pretty sure most people have never heard them called solenoid
operated voltmeters. .If you want people to understand, I'd either
explain what I meant, or call them mechanical voltmeters, (or
electromechanical, or wire coil, or moving needle VOMs)
What is Wiggy?
Remove NOPSAM to email me. Please let
me know if you have posted also.
"Solenoid meter" is the only thing I've ever heard it called besides a
Wiggy. Wiggy is (I think) Square D's brand name for a solenoid meter.
A solenoid meter does not have a needle. It has a plunger that gets
sucked into a solenoid, the depth of which depends on the voltage. A
real Wiggy also has a polarity indicating magnet on top. Some other
brands have neon bulbs mounted on the plunger to aid in seeing it. It
is a low impedance device that does not respond to leakage current.
Instead of sowing confusion, why not google it?
John De Armond
See my website for my current email address
You'd think so, but it isn't true. Digital meters are fine for accurate
measurement of a stable voltage but lousy for fluctuations where you can
get an inkling of what's happening with an analog meter, wiggie or
otherwise, but not with a digital readout. The way things are, analog
meters will remain useful for the foreseeable future. I have both digital
and analog meters. I usually prefer using the analog meter.
Watch someone come along and suggest using an oscilloscope for this
do you remember LPs, music on vinyl? they were the means for
storage of an analog representation of sound on a media capable
of containing the entire full linear spectrum of a line.
with the correct components comprising the system: i.e. pre amp,
amp, turntable and speakers music sure did sound much better back
then. a fuller more complete sound with harmonics.
with analog to digital conversions, line sampling by picking points
on the line in order to reproduce the analog signal in a digital format
leaves a lot of information out of the reconstructed information stream.
all has to do with mathematically speaking of how a line is actually an
infinite series of points with there always being a point in-between any
two picked points that is being left out.
CD - half the music and dog gone near twice the price. if the industry
had said, CDs for people who can not hear well and vinyl will still be
pressed for those who can hear, but we're going to charge twice the price
for vinyl, I'd paid it. oh well, that did not work out.
reminds me of how industry sold everyone VCR machines and then made those
obsolete by moving the format to DVD machines. one thing is for sure and
that's how getting caught up in materialism leads one to chase and spend
money in pursuit of satisfaction that just can't quite seem to be retained.
thank you God for setting me free of satan and his thievery.
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