Hello, my house had no eletrical grounding, and I was kinda tired of getting shocks whenever I touch my interface or the golden plated cables, so I decided to ground only one of my room outlets, the one that I plug my computer, monitor, audio receiver and router, but after grounding my outlet I noticed that my audio receiver had no ground pin on the plug, so I checked on the back of the receiver and it had an ground thing, that I could cut an wire and attach on it, and the other end I could attach on the ground wire (from my outlet).


So thats what I did, I connected it and when I plugged it on (without any other thing connected on the outlet I pluged it) I noticed that the old "hum" noise it had when I had nothing connected to it (yes, as soons as I connect my receiver on my interface the hum disappears).
So I tought: well it should be cool now, right? Well, I was wrong. As soon as I plugged my computer in the outlet it immediately started hummin way louder than ever (like 4x the volume of the hum it did when not connected to anything).

When I take the ground thing off the receiver, it stops humming, but it returns to shock me if I touch the audio interface or the golden plug (even though the computer is still grounded) also shocks when I touch my mic.

Any idea of how to solve it? I cant use balanced cables because my receiver output is RCA

 

heres is a photo of the "ground" thing

 

how exactly do you have grounded your room outlet, when the house itself is not grounded?

 

You can use a cable wired to connect an unbalanced device to a balanced device in either direction.

Questions?
what voltage is the mains power. 120, 230 or 240?
is the ground an earth ground from the mains panel?
is any other AC outlet shared with the computer outlet?
is there a cable TV box connected to the receiver?

Without being there to see your setup, it is hard, but not impossible to guess at a solution.

Here is the link to the Rane wiring guide:

Sound System Interconnection
Rane Technical Staff
RaneNote 110 written 1985; last revised 11/15

There is a link at the bottom of the page to download a PDF version.

 

It's best to have an electrician look at it, who can assess it more precisely/better. Let the landlord know about it. The landlord is responsible for calling the electrician and must usually also pay for the costs.

1.) GND means GrouND, i.e. ground.
The screw terminal is not coincidentally located next to the PHONO inputs for a turntable.
Older record player models have an extra ground wire next to the audio cables, which must be connected to a stereo system to avoid hum (mains hum).

2.) Grounding in existing buildings
Some older buildings do not yet have grounding or have poorly functioning grounding. It is not possible to install a ground loop here. Fortunately there is another solution. You can get one or more grounding rods (at least 3m between the grounding rods). These metal spikes are driven 80 cm into the ground and connected to the electrical installation using the ground wire. The earth wire connects the earth electrode to the earth breaker and the main earth terminal. The section of this conductor is a minimum of 16mm² if fitted with a yellow-green insulator, or 25mm² if uninsulated.

More bottoms
In addition to the ground loop or ground electrodes, you also need a ground wire that connects everything to the main ground bar. This has a diameter of at least 16 mm². Also get a ground breaker so the resistance can be checked. This resistance should be a maximum of 30 ohms.


Example of an earth breaker. image source

What then has to be “grounded”?
There are various elements in your home that need grounding. For example, think of sockets and points of light in the first place. You can recognize the protective conductor by the yellow-green insulation. It must have the same diameter as the phase conductor.

In addition, some metal bases are protected against dangerous voltage. Potential connections are needed for this purpose. We distinguish two types here:

1. The main potential connections : for the main gas and water pipes and central heating. You need yellow-green wire that is at least 6 mm² wide.
2. Additional potential connections : for the metal structures of a bathroom (bathtub, drain, etc.). This connection, insulated by yellow-green wire, has a minimum diameter of 2.5 mm² when placed in a pipe. If this is not the case, a diameter of 4 mm² is required.

In our webshop you can find clamps with which you can attach the basic cables to other elements.

Source: www.dmlights.de/blog/ist-eine-erdung-und-warum-ist-sie-unerlasslich/

 

Last edited: Feb 23, 2022

Where do you live? I understand if you don't want to share here, but I'm just interested since most developed countries have grounded buildings by now.

 

It's best to have an electrician look at it, who can assess it more precisely/better. Let the landlord know about it. The landlord is responsible for calling the electrician and must usually also pay for the costs.

1.) Most better-quality audio components have a (conductive) screw on the chassis. It may be labelled — “GND” or “Ground”, sometimes “Earth” (EU and UK). You should connect an insulated copper wire from each “Source” component (Tape drives, CD, GEq, TV, mixer, computer audio interface, etc.) to the Grounding Screw on the receiver.

A more “Component” system would have separate Tuner, Pre-amp and Power Amp, and they would be centrally grounded, as well.

PLEASE Note — Audio Components should be grounded chassis to chassis as described, but NOT grounded to the Safety Ground “Green Wire” electrical ground in ANY unit. The purpose of component grounding is to reduce noise, interference and “Ground Loops”. Safety (electrical) ground could actually add introduce noise from local devices sharing that safety ground.

www.quora.com/How-do-you-ground-a-turntable-to-a-receiver

 

Last edited: Feb 23, 2022

Of course it made it worse. Let me explain in short how electrical grounding works.

You usually have one grounding per house. If you live in a big house, when a neighbour turns on a washing machine it's grounded to the same ground and its hum leaks to all the residents of the house through this common grounding. That's why a lot of audio devices have "ground lift" button, or a screw. Depending on the voltage this device works at, it is not recommended to lift the grounding because it can shock you [not to say electrocute you] and the "shock" depends on what voltage the device is working on. Some devices use the infamous power adapters which are not grounded, like guitar pedals for instance, or Alesis 6830 compressor. Those are safe from ground hum devices.

That's why there are genius devices like Furman PL-8C that not just provide you with separate grounding, but also clean up the current, filter out peaks, stabilise it. I highly recommend acquiring one if you have more audio hardware than just laptop, speakers, audio interface, and a MIDI keyboard. Hell, even if you have only that, I can still recommend it to protect your devices from voltage fluctuations, voltage spikes, lightning, anything peculiar in the powerline, and neighbour's washing machines, of course!

Cheers!

 

It's best to have an electrician look at it, who can assess it more precisely/better. Let the landlord know about it. The landlord is responsible for calling the electrician and must usually also pay for the costs.

Hifi receiver without grounding?

a,
That depends on the protection class. A protective conductor (PE) is required
for protection class SKI .
With protection class SKII , no protective conductor is required and none may be connected.
The protection class is on the rating plate (SK II has 2 squares one inside the other).

b.
These old American devices from the 70s often had these grounding screws on the back of the housing (GRD)
. My Marantz had that too at the time.
Since the devices were not exactly immune to interference from harmonics, this additional housing grounding was used to prevent hum circuits in the loudspeaker boxes and also so that the CB radio operators in the neighborhood were not disturbed, but this was not always of any use.

c.
In the old stereo systems made up of individual components, the grounding screw on the amplifier was usually intended for the turntable in order to connect the turntable chassis to the amplifier ground using the separate ground wire.

d.
A teacher once told me during my training
that the electronics in receivers are often cast in plastic so that the housing corresponds to the SkII
despite the sheet metal and no protective conductor is required.
It is also clear why this is done this way (ground loops, etc...)

e.
On the old receiver, the marking of the protection class is actually completely missing. But since I now know what the grounding screw is for (turntable), I assume that the device is "protectively insulated".
Ps: Not much is cast in plastic. I had it open to change a fuse. The 230V cables are simply plugged onto the connections with clamps. I hope it holds up and doesn't fall off on the case at some point....

f.
This is also not a grounding screw but a potential equalization.
I always find the protective insulation of these amplifiers a little questionable, because at the latest when the house antenna is attached, the housing is inevitably grounded.

g.
I don't know which one is the "old one" for you and which one isn't and how old it is.
In the past , "SKI" devices (with a metal housing) only had a 2-wire connection cable, although nothing was double insulated (cast) on the inside. There was just no protective conductor, neither in the devices nor in the system.
If you have such an old device, I would replace the connecting cable with a safety plug and PE connection .

h.
If there is a risk of an active conductor shorting to ground, then I have already written: "... I would replace the connecting cable with a safety plug and PE connection ."

i.
Nothing has to be shed. You have a suitable transformer inside and the connection line for the 230V must be double insulated up to there. The wires must not only be simply soldered to the circuit board, but there is also a cable tie that, if the soldering point does not hold, the loose wire cannot cause any damage. And just like that, a device made of metal becomes a SKII device.

j.
However, the danger does not exist with devices with protective insulation, even in metal housings.
Nobody in the DKE/K 735 committee knows anymore why, according to IEC 60728-11, the housing of antenna components with a docked power supply unit has to be included in the PA, whereas the cable shields of the PA components fed by remote or receiver are sufficient.
Those who are privileged to have access to standards should take a look at Supplement 1 of DIN EN 50083 (VDE 0855):2002-01, which is still valid and was once created as a joint effort by 9 (!) DKE committees. The supplementary sheet is also a reference work with explanations on the subjects of protection classes, harmonics, potential differences and leakage currents.

k.
That's right. But if the TE already finds out that the connection cable can easily fall on the housing, then the device is definitely not protectively insulated.

l.
But the TE also wrote that he didn't find any SKII symbol. Then it's not SKII either.
And if I professionally turn it into a SKI - what's the problem?

m.
If there was no Schuko plug on it, it is not an SKI and if you connect a Schuko plug properly, you may only have problems with ground loops if you maybe want to feed the music from the PC or from the television or or.

www.elektrikforum.de/threads/hifi-receiver-ohne-erdung.29726/
https://www-elektrikforum-de.transl...l=auto&_x_tr_tl=en&_x_tr_hl=de&_x_tr_pto=wapp

 

Last edited: Feb 23, 2022

It's best to have an electrician look at it, who can assess it more precisely/better. Let the landlord know about it. The landlord is responsible for calling the electrician and must usually also pay for the costs.

How dangerous are sockets without grounding?

Today I removed, cleaned and reinstalled the socket covers in the new rental apartment. When this was finished, my father (former electrical engineer) measured the sockets to see if everything was working properly and found to his horror that about 3/4 of the sockets were not grounded.
https://www-finanzfrage-net.transla...l=auto&_x_tr_tl=en&_x_tr_hl=de&_x_tr_pto=wapp

If house built before 1973:

In old installations, instead of a protective conductor and a neutral conductor, a combined neutral conductor (both functions combined in one "PEN" wire) can be used. In 99.99% of cases, there is no indication that it is one of these.

Accordingly, this neutral conductor must be clamped twice to the socket (bridge the neutral conductor from the wall to PE of the socket, from there to N using a short piece of wire).

They were probably replaced by amateurs because whoever replaced them didn't know that.

Be careful with wire colors in old buildings! Zeroing may only be carried out if you are sure that it has to be and you are sure which is the neutral conductor. Mistakes are unforgivable here! You can't do it yourself anyway!

If the house is newer, then it has actually been botched and it is impossible to operate Schuko sockets on 2-wire lines.

• What can happen?

If a device has an insulation fault, you will get an electric shock.

• What should I avoid doing?

Do not insert a Schuko plug into the affected sockets (those are the thick, round ones). The flat Euro plugs don't care. Otherwise see text.

• What needs to be done to ensure safety?

See text

• Does the landlord have to make improvements or do I have to bear the costs?

The landlord is responsible for ensuring that the installation is in a safe condition. So he has to make sure that zeroing bridges get into the sockets.

 

I tried to draw how I connected everything, its on the attached file

"Is the ground an earth ground from the mains panel?"
No, I called an eletrician and asked if he could ground only this outlet (because my house is really old so it would be really expensive to ground everything from zero), he said he could and he did it, only grounded this outlet

"Is any other AC outlet shared with the computer outlet?"
No, as shown in the image

"Is there a cable TV box connected to the receiver?"
No, I only connected my interface, which is connected to my computer, which is connected only to the router

 

Brazil

 

Ooooh I see, so that may be my mistake, I was connecting this ground to my house grounding rod , let me test if it works.
Wait, should I connect it to my audio interface or to my computer? and how should I connect it? like, theres no place to connect it in my computer or my interface, should I just stick it anywhere?

 

The question is: is your receiver powered ? Where do you get the electric shocks from ? I can't give you any advice because it's about life-threatening electricity. We must first find out the source, some device is defective.

This GND on your receiver is for ground loops from the speakers or the turntable. If you get electric shocks, there must be a defective device. The defective device must be replaced and repaired. Tell the story to the electrician.

 

I would unplug the fan from that power strip.

Also you main panel is probably grounded to earth since you are on AC.

The third conductor is generally a duplicate of the neutral conductor that provides a low resistance path to earth in case of a neutral fault. Could you get IMD from a separate ground? Yes, but I think I would check for something on the circuit or use an outlet tester first. In old houses like that it's highly likely that creative wiring especially on 3 way switches and lighting circuits is causing problems. Getting the entire house on 3 wires is more a question of wiring than electrical supply.

A 2.5M earthing rod into solid soil shouldn't cause feedback unless something is not right. Check the unit in question as well. Get a good digital volt meter and check current stability from the carrier wire to the neutral, from the carrier wire to the ground. They should be the same +/- the tolerances for your local codes and supply but you shouldn't get modulation over .5v on 220V or .15 on 110V. Check from neutral to ground you should get zero.

No magic, just measure and check.

 

I get eletric shocks from touching those while im barefoot, but if I disconnect the cables from the back of the interface, the shocking stops

 

Oooh, so where exactly should I put the other end of the grounding wire in my system? in the audio interface? or in the computer? and how should I plug it?

 

ayy im counfused trying to understand this
I think my house as no grounding at all, only 2 wires in the entire house, this is 50-60 years old or more

 

In my opinion, you don't need a GND. Just ignore it.

...................
1.) Most better-quality audio components have a (conductive) screw on the chassis. It may be labelled — “GND” or “Ground”, sometimes “Earth” (EU and UK). You should connect an insulated copper wire from each “Source” component (Tape drives, CD, GEq, TV, mixer, computer audio interface, etc.) to the Grounding Screw on the receiver.

A more “Component” system would have separate Tuner, Pre-amp and Power Amp, and they would be centrally grounded, as well.

PLEASE Note — Audio Components should be grounded chassis to chassis as described, but NOT grounded to the Safety Ground “Green Wire” electrical ground in ANY unit. The purpose of component grounding is to reduce noise, interference and “Ground Loops”. Safety (electrical) ground could actually add introduce noise from local devices sharing that safety ground.

www.quora.com/How-do-you-ground-a-turntable-to-a-receiver

 

Last edited: Feb 23, 2022

Your outlets are not grounded because you only have two wires. Your panel where electricity comes in is connected to earth (ground), if you had three wires coming out of your panel to every outlet and switch your house's electrical system would considered grounded even though the ground (green or bare copper) are connected to the same earth.



Either way it doesn't change anything, you need to measure across all the conductors in your outlet and check for modulation and leakage. It's much easier to work off numbers so you can eliminate issues that trying to use divination.

My money is on either the fan connected to the outlet or a 3 way switch leaking feedback into the neutral.