Is the grounding in my house normal?

[PCBONEZ]

Re: Is the grounding in my house normal?

The "vibrating sensation" is called an "electric shock".

I suggest you fix the problem you've blown off for 20 years that MIGHT KILL YOU and worry about noisy speakers after that's fixed.

.

[Krankshaft]

Re: Is the grounding in my house normal?

Sounds like branch circuit grounding issues.

It seems like the coax cable which should be grounded at the service entrance is acting as an impromptu ground for your outlet which is not grounded.

You'll need a DMM to troubleshoot further. There's probably a difference in potential from hot to neutral and hot to ground. This can only be checked with a DMM. From H to N and from H to G the voltage read should be the same if it isn't you have an abnormal resistance in the line. If you don't get a reading at one path you have an open circuit.

If there is resistance in the ground wire when you touch the case of something grounded your body is a lower resistance path and the current takes it.

Neon testers are all but useless I had a grounding issue in my basement (corrosion issues) years back a neon checker said the ground was all good. My DMM said otherwise.

[delaware74b]

Re: Is the grounding in my house normal?

In my line of work as an electrician, I've seen a lot of violations of NEC (National Electrical Code) concerning grounding, or the lack of. Here in the US, we have 'grandfathered' policies concerning grounds. It can be a bad situation.

Example - Houses built prior to 1960 were not required to have a ground wire in branch circuits. As a result, the original outlets were allowed to be 2-prong, non-grounding type. Joe Homeowner goes in and replaces all of them with the now required 3-prong, grounding type. Now all of the new receptacles have NO means of grounding.
NEC now requires a GFCI placed either in the panel or the first device from the panel. Additional labels are required at all 'downstream' receptacles to state 'No Equipment Ground Available'

To the OP, it looks like you have an open ground on that circuit that is presently feeding your computer equipment and the coax is acting as a ground.

[Krankshaft]

Re: Is the grounding in my house normal?

The OP isn't in the US so we have no clue about what type of receptacles he has.

On the three prong upgrade grounding issue that would apply to 2 wire non metallic sheath cable like knob and tube wiring or cloth embedded tar romex for example.

In older houses with BX the outer sheath would act as the ground conductor since the metal ears of three prong receptacles are connected to the receptacle ground prong. The ground path would be from the receptacle mounting screws to the box from the box to the metal sheathing.

As long as the sheathing is properly clamped to the box (and all other boxes in the circuit back to the service panel) you would technically be grounded. I'm sure the NEC would get into a hissy fit over this because it's not a legitimate green insulated or bare copper ground conductor but it's better than nothing.

[ratdude747]

Re: Is the grounding in my house normal?

i hope not the tarred cloth romex... my house has it... PITA to work with.

[delaware74b]

Re: Is the grounding in my house normal?

I've run into the 'first generation' of grounded romex cable. It is the tarred cloth that ratdude is referring. It was introduced in the late 50's. Generally the jacket is silver, white, or brown in color. Technically, it's not considered a grounded cable but one with a bonding wire.
The bonding wire is usually 16 gauge and it is hard to find in an outlet box due to the wiring methods in the 50's and 60's. The bonding wire was folded back and wrapped around the outer jacket. The wrapped wire was then secured to the box by the cable clamp.
A sure-fire way is to use a voltmeter at the outlet in question, reading from the box or the plate mounting screw to the hot side of the outlet. If you get 120 volts, chances are good you have a decent ground.

[PCBONEZ]

Re: Is the grounding in my house normal?

Or in this case 220v.

[ratdude747]

Re: Is the grounding in my house normal?

I've run into the 'first generation' of grounded romex cable. It is the tarred cloth that ratdude is referring. It was introduced in the late 50's. Generally the jacket is silver, white, or brown in color. Technically, it's not considered a grounded cable but one with a bonding wire.
The bonding wire is usually 16 gauge and it is hard to find in an outlet box due to the wiring methods in the 50's and 60's. The bonding wire was folded back and wrapped around the outer jacket. The wrapped wire was then secured to the box by the cable clamp.
A sure-fire way is to use a voltmeter at the outlet in question, reading from the box or the plate mounting screw to the hot side of the outlet. If you get 120 volts, chances are good you have a decent ground.

my house was built in 1941 and it has all of the original wiring as tarred romex. then again, i found a shred of steel k&t wire and a few knobs on a basement ceiling joist. since the walls are old drywall, maybe it was renovated in the 50's... it has been built on to many times...

[Searinox]

Re: Is the grounding in my house normal?

I would like to note the difference between the vibration, tingling sensation of an electric shock like when I touch case and ground, and that of when I'm touching the comp case or fridge without touching a ground such as the radiator. The sensation I get when touching only the case is ONLY felt when I move my hand against its surface. I feel nothing when I hold still but as I move a sort of vibration different from that of shock can be felt. It's like something is moving inside my fingers and completly painless.

Until I can get the proper test gear tell me -- I've had this problem for a very long time now but it's never affected audio output. Is there a mechanism somewhere that's supposed to prevent such stray currents from causing noise, and if so what is it? Lifting the ground doesn't kill the buzz btw.

Another question, this current in my computer case, is it AC or DC? I know the power input is AC, but I wanna make sure about the leak.

[Scenic]

Re: Is the grounding in my house normal?

that sounds exactly like what i felt when a computer was plugged into a specific wall outlet in my room..

as soon as you move your fingers across any exposed metal surface of the computer (or whatever was connected to that outlet), it kinda "vibrates" in your finger/hand. hold your finger or hand still and there's nothing to be felt.
really hard to describe it properly.

the cause in my case was the wall outlet.
i took it out just to find out the ground wire wasn't connected at all
it was snipped off too short to connect it up directly, so the guy who lived here before simply wrapped electrical tape around it and tucked it away unconnected.. omg..

i would really get a professional electrician to look at your setup if i were you. this sounds like there are some serious issues with the (ground-) wiring..
this could not only damage electronic devices, but also be a health hazard..

as for the speakers.. maybe the grounding issue is caused by a flaky connection somewhere and it didn't affect the computer/ups/speaker outlet before.. (?!)
(brittle grounding wire snapped, giving you problems on that outlet which you didn't have before for example)

where are you located btw..?

[japlytic]

Re: Is the grounding in my house normal?

Whenever you rent or buy a house, check the outlets with a tester.
The majority of wiring problems in the US are related to the ground pin.
Also, I've seen some UPS units (and some computer power supplies as well) with a Site Wiring Fault light.

[Searinox]

Re: Is the grounding in my house normal?

I was not born when my parents moved here, got no clue who lived here before nor could I get it outta my dad exactly how they checked and set up the wiring. This was some 25 years ago.

Scenic: I live in Romania, East Europe in the capital Bucharest. The outlets around here look like this.



The hot and neutral are the two holes. The upper and lower yellow metal connectors are the ground.

[Scenic]

Re: Is the grounding in my house normal?

classic "SchuKo" (from "SchutzKontakt" -> protective contact)

http://en.wikipedia.org/wiki/Schuko

your description fits for the no-grounding-at-all scenario i've experienced with one outlet in my room (see post #30)..
I would take a look at the outlet to see if the ground wire is actually attached..
if this affects more than one outlet, there seems to be a general wiring fault.. -> get an electrician. preferably one with a good reputation. too many DIY guys out there who think they're electricians cause they can put an outlet into a wall or install a ceiling lamp

or the installation is just waaay too old and doesn't have grounding, but someone slapped schuko outlets in there anyways... (which, over here in germany, would be illegal)

[Searinox]

Re: Is the grounding in my house normal?

I got my hands on an AC volt measurement tool and put one contact on the case and another on a portion of chipped metal on the radiator! I could detect 24V of current(no clue how many amps, tool's quite primitive). When I plug the TV cable in, that voltage disappears and nothing can be measured. I should prolly run yet another test, with the UPS unpligged, which effectively lifts the ground completly while still keeping the PC running. If I get the same reading does that mean that my PC has no grounding at all?

Sadly, it's unlikely I'll be able to check if there is indeed a ground connected to the schuko or not -- not only would I have to rip it out of the wall, but there's a biiiiiiiiiiig wardrobe right in front of it and only an extension cord provides my access to it.

Is it a rule that non-grounded computers will result in speaker buzz?

I've dealt with computers which didn't seem to have proper ground in the past, because they gave the same hand sensation, and none of them had this noise.

[Scenic]

Re: Is the grounding in my house normal?

if i understood that right, then yes.

seems like the TV coax cable is the only ground source on your computer setup.
(the outer shield is connected to the computer case through the TV card)

[Searinox]

Re: Is the grounding in my house normal?

Let me make sure one last time - every computer that would, for any reason, have a leakage of current onto their case, but proper socket grounding, would NEVER feel in this way to the touch, shock while touching it grounded, or read current vs ground like mine does. Yes?

[Pyr0Beast]

Re: Is the grounding in my house normal?

yup - if it is grounded, laptops sometimes aren't.

Move it to a different socket.

[Searinox]

Re: Is the grounding in my house normal?

Okay we've got a clear verdict on the grounding now: there is bad or no ground. Now for the issue at hand: is it normal for speakers to buzz without a ground? I think I've seen several ungrounded PCs none of them buzzed.

[Pyr0Beast]

Re: Is the grounding in my house normal?

Some speaker buzz for no reason.

[Searinox]

Re: Is the grounding in my house normal?

I know the problems of reviving an old thread but I use google for my problems A LOT and I know many others do, so I'd like to leave this here for whoever has similar issues in the future, especially with a problem as odd and cryptical as mine.

I finally bought a new power supply. And the buzzing disappeared. Forever. No more TV tuner acting as ground, nothing. Back to normal as it's always been.

Conclusion: My issue was a combination of old PSU current filter and lack of grounding. Fixing ANY of the two will fix the problem.