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Power Brownouts

10/25/2017 12:25 PM

I have a problem and wonder where to look.

Standard USA power system 240 volts main and 120 distribution panel with Breakers. typical stuff 99.9999% of the country.

But On one circut of the system, Power has been dropping from the nominal 120 to 130 volts, 90% of the time 126. Down to 90 volts or so.

But for short periods of time like ohhh 5 to 10 seconds in dutration, but doing these down to 90 or so for 5 to 10 seconds then back up to nominal voltage for 5 to 10 and then down for 5 up for 2- down for 10 up for 5 etc. It will keep doing this for a while, then go away, and not do it for hours.

No breakers ever trip

Now whats even weirder, is on a totally different breaker circut, is a set of altec lansing powered amplified computer speakers.

And whenever that brownout is happening, a 60 hz hum comes out from the speakers,

anyone have any ideas as to what might be going on?

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#1

Re: Power Brownouts

10/25/2017 12:33 PM

Well the first thing to do is shut off your main breaker and see if the problem is coming from the service or is something in the house causing it...If it's the service, then call your utility and inform them of this problem....If it's something in the house I would suspect a seized compressor in the AC unit trying to start...

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#2
In reply to #1

Re: Power Brownouts

10/25/2017 12:37 PM

Ummm...if the service is off, how can he test the house side?

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#3
In reply to #2

Re: Power Brownouts

10/25/2017 12:49 PM

Test the service first with the main off....if it's not the main incomer, then it's in the house, so turn the breaker back on and find it....

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#4

Re: Power Brownouts

10/25/2017 1:01 PM

Does the other phase go up when this side goes down. A neighbor had neutral break at the pole. When the washer kicked on one phase dropped by 40-50 VAC and the other phase went up. They figured it out about an hour after the fire department showed up.

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#8
In reply to #4

Re: Power Brownouts

10/25/2017 1:27 PM

Fire Department?

What happened?

I'm gonna go in and tighten all the connections in the breaker panel first and see what happens.

Odd thing, it hasn't done it at all ever since I posted this question.

As far as any high power stuff, that was the first thng I thought of.

No AC here, so that's not it, any other medium current stuff not running.

soo odd.

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#5

Re: Power Brownouts

10/25/2017 1:03 PM

Sounds like *something* designed for two-phase operation possibly has a phasing problem somewhere...probably at an outlet. Time to get/use a 220-240 version of this:

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#6

Re: Power Brownouts

10/25/2017 1:17 PM

As SE says, it's probably a motor with overcurrent protection trying to start up. It's drawing a lot of current, but apparently not enough to trip the breaker.

I would go to the breaker box and find the circuits for Air Conditioning, etc. (big loads) and attach a clamp-on meter. You should notice when you have the voltage drop if you have lights on, or use your computer speakers.

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#7

Re: Power Brownouts

10/25/2017 1:24 PM

It sounds like a bad connection is overheating on that circuit between the effected outlet and your distribution panel. You might even have a bad breaker if the whole circuit is effected. If you are lucky a FLIR imagery scanner during a failure might reveal the source of the problem without extensive sheet rock removal.

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#9

Re: Power Brownouts

10/25/2017 1:53 PM

Romex cable nicked by a nail?

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#10
In reply to #9

Re: Power Brownouts

10/25/2017 1:56 PM

Nope,

No new construction or wiring has been done.

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#12
In reply to #10

Re: Power Brownouts

10/25/2017 2:19 PM

I bet you also believe that not a single new picture has been hung either.

Nothing has changed but something is changing.

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#21
In reply to #9

Re: Power Brownouts

10/26/2017 8:35 AM

My father built houses over 50 years ago. That actually happened to him. Drove him bonkers till he found that nail driven through the Romex in one of the bedrooms.

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#34
In reply to #21

Re: Power Brownouts

10/30/2017 11:42 AM

Ugh, that must have been frustrating.

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#11

Re: Power Brownouts

10/25/2017 2:14 PM

It could have been a short in the power lines somewhere in the neighborhood that has now been fixed....

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#23
In reply to #11

Re: Power Brownouts

10/26/2017 11:20 AM

Wow. You sure come up with the weirdest stuff. That was funny.

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#13

Re: Power Brownouts

10/25/2017 2:36 PM

Ok, I think I have found it.

I took off the breaker panel cover, And started tightening the screws on the outputs of each breaker.

All allowed at least 1/4 turn. to snug them tight, a few were even 1/2 a turn.

Then saw what was obviously hot wires on the neutral connection row. as seen in the image.

The wire with the green dot you could even wiggle! All allowed at least 1/2 a turn to snug down a few even a full turn. I plan on cutting them all back and re installing them.

Now I have two problems tho, Being the neutral, do I have to kill the main breaker to re do them? or can I re do them one at a time with power applied, since being the neutrals it will be nearly impossible to tell what breaker is associated with it.

Now an even more questionable and worrisome issue.

The screw with the Green dot,, When tightening it up, I accidentally got near the bare wire to it's right that goes to the row above it, both being neutrals I was not too careful about touching them together but I was very surprised quite surprised when a decent sized spark happened.

A DVM placed across the two rows should be zero volts of course. But I am measuring 7 to 8 volts. Not a lot, But should be NONE, and it must be a LOT of current for the size of the spark, The spark was think like jumper cables and a car jumping one with a dead battery.

Now why would there be a voltage differential between these two rows,

My Guess is hat jumper strap (red arrow) Is not making a good connection,

So, My Plan is to take as many of the toasty lower level ones, Clean them up and connect them to the upper row,

And, place as heavy of a jumper as possible between the two rows using the locations with the red dots.

The embedded picture is kind of small so it is view-able here too.

http://i64.tinypic.com/d9lw6.jpg

Thoughts>?

Joe

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#14
In reply to #13

Re: Power Brownouts

10/25/2017 3:30 PM

Can a seasoned, knowable individual with all of the correct PPE work hot?

Yes, but only if there is a very good reason for working hot. I'm feeling lazy is not a good reason.

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#15
In reply to #13

Re: Power Brownouts

10/25/2017 3:48 PM

If you have the breaker on for a circuit and you remove the neutral wire return, the neutral wire becomes hot through the load. Open the main.

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#17
In reply to #15

Re: Power Brownouts

10/25/2017 4:50 PM

Thats what I also thought.

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#16
In reply to #13

Re: Power Brownouts

10/25/2017 4:12 PM

Don't confuse your neutral terminal bus with the ground terminal bus....I would start tracing out these circuits and labelling the breakers, if this has not been done....You might have to isolate each circuit and test for continuity if you keep having problems....Always shut off the main if you can, while working in the distribution box, especially if you suspect a short someplace....A spark like you saw sounds like line voltage to me, what you measured is the potential between 2 points, isolate the neutral and ground buses from each other for a good reading....remember both lines could be 120v of the same phase, and you would read "0" voltage...check the potential from both incoming legs to the wire that sparked, and see if they read the same....you might get a surprise...

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#18
In reply to #16

Re: Power Brownouts

10/25/2017 4:58 PM

But as you see, all the neutrals and grounds are tied together.

Measured between that bare wire, and both line

123.1

123.3

Close enough.

BUT

Just as I was walking away from the panel. ( I was not even touching it )

But just as I was backing away a bzzzt spark was seen and heard coming from where that jumper strap goes behind the lower track of connection points.

So it's not a good joint there I'm pretty sure, so making the better connection should fix this.

Thoughts?

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#19
In reply to #18

Re: Power Brownouts

10/25/2017 5:35 PM

You should not have that much current on the neutral, I suspect a short...It sounds like you have a live wire touching the neutral...

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#20
In reply to #19

Re: Power Brownouts

10/25/2017 6:19 PM

What we get a lot of down here is the ceiling fan motors shorting, people don't notice because the motor continues to run, but when you yank the chain to change the speed or turn the light on, it gets you, if you happen to be grounded....

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#22
In reply to #13

Re: Power Brownouts

10/26/2017 11:07 AM

You need to get an electrician. Is this the 1st point of disconnect or a sub panel? Do I see other than white connected to the neutral buss without being phase taped or are they actually hots. I see arc damage near the neutral and ground busses. It would appear this panel has been wired by other than an individual with appropriate electrical knowledge. A fire waiting to happen.

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#28
In reply to #13

Re: Power Brownouts

10/26/2017 2:08 PM

The blackness on the left side of the bottom row of terminals looks like it got hot. Is that where the "buzzt" came from? You may need a new breaker box, or at least the insides of one. The fix you have described may not meet code. Red wires are not necessarily hot, but black wires are. Find out why a black wire is going to the neutral or ground!

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#29
In reply to #13

Re: Power Brownouts

10/26/2017 2:46 PM

By looking at the picture, is this breaker box in Disneyland ? Cuz, all of that wiring sure looks Mickey Mouse.

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#32
In reply to #13

Re: Power Brownouts

10/29/2017 9:09 PM

Dirty..dirty job they got you there. I don't like to see such wiring. The "just put it on" style in wiring. Lazy job with no art, at all.

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#24

Re: Power Brownouts

10/26/2017 11:44 AM

Something else to consider: I saw a place that had the water heater and the clothes dryer on the same breaker. Usually they did not run at the same time, and no problem developed. But if you did more than one load of laundry, the dryer and heater could be on at the same time and trip the breaker. Those 240V breakers don't always trip both sides. This one tripped only one side and left 120V still hot. The problem was not obvious, because everything still seemed to "work", and the tripped breaker still looked "on". If you have a 2-pole breaker going out, or tripped on only one side, it could produce excessive current in the neutral line. I'd check to make sure all the breakers are still working properly with good connections, before going to the more expensive repairs.

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#25

Re: Power Brownouts

10/26/2017 11:59 AM

Yeah this is the main panel. ( the only panel )
What appears to be the "MAIN" problem, that started this whole thing is two Items.
1- The wire under the green dot was sooo loose it actually could wiggle under the set screw! And all others could at least accept between 1/4 and 1/2 turn.
2- The jumper between the rows, ( Red Arrow ) Is Bad. It is not making a good connection between the rows. Yesterday after taking some measurements, as I was backing away from the panel, I heard and saw a good sized spark come from the area where that jumper strap goes behind ( under ) the lower contact row. How it is fastened to the lower row is not obvious.
Plan of attack,
Move as many wires to the upper level, ( 3 are not even being used. )
Make a better connection between the rows, By adding a #4 wire ( max that will fit in the wire hole ) Between the location with the Green dot, and the one above it. So to again have a solid connection between the two rows.
Thoughts?

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#26
In reply to #25

Re: Power Brownouts

10/26/2017 12:13 PM

When you start having more than one problem, especially loose/bad connections that produce heat, collateral damage can occur and could also be a symptom of old age. It would be a good idea to check everything (even if it looks good) to make sure impending problems are prevented. Heat can cause bad connections to get worse and need to to be cleaned. Old breakers need to be checked to ensure nothing is missed. You might have to clean/fix every connection in the box. Even if everything seems to work properly, a high resistance connection could be a fire hazard. I wouldn't take any chances.

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#27
In reply to #26

Re: Power Brownouts

10/26/2017 12:17 PM

Thats what I plan on doing, all the wires will be cut back to non heat deteriorated areas clean bright copper, and re connected. The set screws will be pulled all the way out and wire brushed if needed. to get them back to clean state.

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#30

Re: Power Brownouts

10/27/2017 3:19 PM

Yup killed the Main and started pulling wires.

Wow the bottom terminal strip was still warm even.

Some of the set screws got sooo hot they are seized in and can not be removed.

Cleaned everything, Put in new jumper strap to connect top and bottom rows.

Cut wires back to non heat distorted and clean copper.

Put all back together.

Not only is voltage dead steady to within 0.1 volts regardless of load.

Even after four hours with electric dryer running and 4 110 volt 1200/1500 watt electric heaters ( turned them on to make massive 110 draw.)

after 4 hours neutral buss Ice cold still.

Good deal.

Hey heres a question? Would bad connections like this cause you to use more KWh's?

Sounds logical.

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#31

Re: Power Brownouts

10/29/2017 2:38 PM

Oh, its an RLC circuit, don't you think? By the time you pull off the power of it, it will still vibrate by itself until the electrical energy is totally spent or dissipated.

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#33

Re: Power Brownouts

10/30/2017 7:40 AM

Poor neutral connection, upstream of the distribution board, and probably in the utility supplier's domain.

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