Multiple transformers buzzing

[OVerLoRDI]

Mods: feel free to move this to anywhere else, but I was unsure of where would be a good place to ask this question.

I recently moved into a new place and noticed some buzzing coming from my old CRT. My first thought was that the transformer is finally on its way out. This morning I climbed down to plug some stuff into the back of my tower and noticed a buzzing coming from the PSU as well. I then checked the rest of my electronics, my LCD was also buzzing in a similar way (although much more faint than the CRT) as is my laptop charger. Pretty much anything that has a transformer is buzzing in my room to varying degrees.

Googling around has lead me to believe it might be a grounding problem with the wiring in my room. My room was a recent addition to the house, converting part of the garage into a room. So perhaps the electrical wiring wasn't done correctly.

So ATOT, what say you? Am I correct in my diagnosis? What steps can I take to narrow down the problem? Is there any danger to my electronics?

Edit: The buzzing in my laptop charger is is much higher pitched and very difficult to hear if plugged into a different circuit. So it appears the buzzing might be related to one particular circuit in the house.

 

[Squisher]

Do you have a multi-meter? If so, I'd be interested to know what voltage you're getting out of your outlets. I've heard buzzing like that during brown outs.

 

[OVerLoRDI]

Do you have a multi-meter? If so, I'd be interested to know what voltage you're getting out of your outlets. I've heard buzzing like that during brown outs.

I do not have one on hand. I used to have one, I'll go pick one up and see what voltage I'm getting.

 

[mk]

Oh, n/m. I thought this was about something else.

 

[OVerLoRDI]

I remembered my Kill-a-watt. Voltage is 120-122 depending on load. Hz looks like 60 consistently. PF (no idea what this is) is .096-.97.

 

[KGB]

You need to check if the ground lug in the outlets is truly connected to ground.

 

[OVerLoRDI]

You need to check if the ground lug in the outlets is truly connected to ground.

I'll pull a socket cover off and take a look.

 

[KGB]

I'll pull a socket cover off and take a look.

You might wanna throw the breaker first.

 

[BoomerD]

You might wanna throw the breaker first.

You really know how to spoil a fucking party...

 

[OVerLoRDI]

You really know how to spoil a fucking party...

Ha I did throw the breaker before checking.

The wiring to the outlet I checked looked fine. 2 white wires, 2 black ones, and a 5th bare copper wire that I would assume is ground.

If it is a grounding issue it doesn't look to be outlet specific. Is there a way I can test to see if the ground wire isn't grounded? (nevermind I googled, Looks like I'll be snagging a multimeter)

 

[dud]

OP, save yourself the time/aggravation and go to Home Depot and buy one of these:

http://www.homedepot.com/h_d1/N-5yc1...atalogId=10053

"Sperry 3-Wire Circuit Analyzer Voltage Tester tests for faulty wiring in standard 120-volt, 3-wire outlets. The device tests for 7 common wiring errors and indicates the wiring status by matching the color of the illuminated lamps with the color-coded status chart.

Tests for 7 common wiring errors in standard 120-volt, 3-wire outlets
Color-coded lamps and chart indicate status of circuit wiring for quick, easy-to-read circuit testing
Compact size for handheld testing
UL listed for peace of mind
MFG Brand Name : Sperry
MFG Model # : HCA300
MFG Part # : HCA300"




For $3.98 you can't beat it for the utility of being able to check your outlets SIMPLY, without having to turn the power off. I'd lend you mine if you were local. Good luck and let us know how it goes ...

 

[SpatiallyAware]

+1 on the outlet tester... Just because the outlet looks ok doesn't mean something isn't swapped or disconnected down the line.


I would also go through and unplug *everything* in the house, then plugin one 'buzzing' thing just in case one device is acting up and causing this.

 

[KGB]

You really know how to spoil a fucking party...

:carradine:

 

[OVerLoRDI]

Got the outlet tester. Things look fine. However, I came home and discovered none of my devices buzzing like they were this morning... Everything is silent and back to normal.

I guess if the buzzing starts happening again I'll swap in the outlet tester and see if there is a fault then. Apparently the problem is intermittent.. yay

Thanks for your advice guys.

 

[SpatiallyAware]

Got the outlet tester. Things look fine. However, I came home and discovered none of my devices buzzing like they were this morning... Everything is silent and back to normal.

I guess if the buzzing starts happening again I'll swap in the outlet tester and see if there is a fault then. Apparently the problem is intermittent.. yay

Thanks for your advice guys.

Very probably the fridge, a/c, bathroom fan etc with a compressor or motor causing issues.

 

[OVerLoRDI]

Very probably the fridge, a/c, bathroom fan etc with a compressor or motor causing issues.

I'll further troubleshoot when the buzzing returns.

Is this a symptom of bad wiring in the house? Basically, should I be worried?

 

[Rubycon]

Excessive harmonic distortion (interference) likely. No consumer "tester" is going to show this unfortunately.

 

[OVerLoRDI]

Excessive harmonic distortion (interference) likely. No consumer "tester" is going to show this unfortunately.

Googling shows me that this will shorten the life of my electrical equipment. Most of the links I found related to industrial applications and not home electronics. I'll have to track down what is causing it.

 

[hanoverphist]

You need to check if the ground lug in the outlets is truly connected to ground.

and the correct ground. i work for an electrical contractor, had field guys wire a new office addition. damn monitors and computers are noisy as hell. did some digging in the wiring, found they crossed over the dedicated computer circuit and the regular circuit grounds, causing the issues. had my shop manager fix it, been good since.

 

[GoodRevrnd]

Sounds like an infestation of bumble bees.

 

[OVerLoRDI]

I discovered the cause. There is a dimmer switch in a different room on a separate circuit that causes all the transformers in my room to buzz. Tomorrow I'll check and see if it is house wide, or isolated to that 1 dimmer switch, but it is 3:30 in the morning now and it is bedtime.

 

[Mark R]

I discovered the cause. There is a dimmer switch in a different room on a separate circuit that causes all the transformers in my room to buzz. Tomorrow I'll check and see if it is house wide, or isolated to that 1 dimmer switch, but it is 3:30 in the morning now and it is bedtime.

Harmonic distortion in action. A faulty dimmer, or a dimmer driving an incorrect type of load (e.g. someone has connected CFLs, or wire-wound low-voltage transformer powere lamps to a regular dimmer), could on a poor wiring system, cause sufficient harmonic distortion to cause audible buzzing on loads. In particular, capacitative loads (such as EMC filters) are extremely sensitive to harmonic distortion, and when coupled with an inductor (e.g. in an EMC filter) the current surges produced by the distortion can cause audible buzzing of the inductor winding.

Harmonic distortion is a pain to detect. You simply don't get consumer level distortion meters - they are strictly pro-industrial level and cost $$$$.

Didn't stop me from building one out of some electronic scrap I had lying around though.


You can see an example of harmonic distortion recorded by my device. Note that the distortion here is exaggerated in this example, as I screwed up the commentary (the commentary says voltage, it isn't) and was measuring the current through a capacitor, not the actual voltage. The waveform shown demonstrated what a capacitor in a mains filter/PSU would see.

 

[BrokenVisage]

Sounds like an infestation of bumble bees.

Awesome.

 

[marvdmartian]

Sounds like an infestation of bumble bees.

Could be Decepticons nearby! :sneaky:

 

[OVerLoRDI]

Harmonic distortion in action. A faulty dimmer, or a dimmer driving an incorrect type of load (e.g. someone has connected CFLs, or wire-wound low-voltage transformer powere lamps to a regular dimmer), could on a poor wiring system, cause sufficient harmonic distortion to cause audible buzzing on loads. In particular, capacitative loads (such as EMC filters) are extremely sensitive to harmonic distortion, and when coupled with an inductor (e.g. in an EMC filter) the current surges produced by the distortion can cause audible buzzing of the inductor winding.

Harmonic distortion is a pain to detect. You simply don't get consumer level distortion meters - they are strictly pro-industrial level and cost $$$$.

Didn't stop me from building one out of some electronic scrap I had lying around though.


You can see an example of harmonic distortion recorded by my device. Note that the distortion here is exaggerated in this example, as I screwed up the commentary (the commentary says voltage, it isn't) and was measuring the current through a capacitor, not the actual voltage. The waveform shown demonstrated what a capacitor in a mains filter/PSU would see.

Thank you for the information. I believe the problem is dimmer switch combined with CFLs. I'm just surprised it is causing a problem across circuits. So my question is, should I be worried about this? What course of action should I take? I'm renting this place for the next year (at least) and I could probably get by without using the dimmer switch. The harmonic distortion is not present when the dimmer switch isn't... "dimming" (not sure if that is the right word)