Interference or Electrical ground loop

Hi @Shinto

I did the pending test today. I pulled 3 extension cords from another room to my system. Then I tried to play with tube light and fan switches in the listening room. Boom there was no interference. So now I am thinking to get a dedicated line from the mains (16 Amps) that terminates on a board with 3 to 4 outlets.

I was reading through some Surge Protector posts on the forum, and saw some Surge protectors cum MCB from Schneider. (RCCBs) residual current circuit breaker. I am not sure what are these. They seem to be not very cheap. Could be around 7 to 8k. Is it worth investing in that kind of MCB over normal MCB?

What else I should be doing while getting the dedicated line?

Any suggestion on wire gauge and switches are welcome.

Thanks

Regards
Vivek
Hi Vivek,

Wire size

2.5 mm2 is normally used to wire power points and should be enough and more for 16 A .But better use 4 mm2 .
This is strictly from electrical point of view.(i.e carry the current with minimal voltage drop).

Surge diverter and RCCB are totally different things.

RCCB
is residual current circuit beaker which in simple terms protects humans from shock by detecting the smallest leakage current.based on ratings of 10mA,30 mA.etc..)RCCB is a combined version of ELCB and MCB.

Existing lines
If your switch board doesn't have a main RCCB /ELCB or individual RCCB/ELCB's for all existing circuits , you should install a main or individual RCCB /ELCB for all existing circuits.The point is, RCCB has nothing to do with protection of your equipment,it is all about protecting lives.
May be standards would require individual ELCBs ,please check with your local electrician.

New dedicated line
For your new line, if there is no main ELCB in your switchboards , you should install a main or individual ELCB + MCB or RCCB .May be standards would require individual ELCBs ,please check with your local electrician.
But this will be installed in the switch board.
I don't see any requirement for ELCB or circuit breakers in the power point near your equipments.

Surge diverter
It provides protection from surges.
It is a good idea to have one in your switchboard.But this is not a mandatory requirement.This can installed in the switch board to protect all your equipment's or a dedicated one can be installed for your most important ones(audio).You might find it cheaper to get a dedicated surge protection for your switch board.Get a generic cheap normal product installed in your switchboard.Local Electricians can help.

3 phase vs single phase

Since your house is 3 phase, you 2 options for your dedicated line.

Option 1:You can use a 3 phase cable from your switch board to near your equipment's and install 3 power points all from different phases.
Option 2: Use a single phase cable from your switch board to near your equipment's and install 3 power points all from the same phase.

As your house wiring is an existing one, 3 phases are already wired through out the house,it may not be an easy task to have a phase completely dedicated for Audio.The best you can do is option 1.But I am not sure if this will have any benefit on audio.
Option 1 will be expensive than option 2 considering the cable price and price of the breakers etc for 3 phase.But the price difference might not be significant.

Hope this helps.
 
Hi @Shinto

I did the pending test today. I pulled 3 extension cords from another room to my system. Then I tried to play with tube light and fan switches in the listening room. Boom there was no interference. So now I am thinking to get a dedicated line from the mains (16 Amps) that terminates on a board with 3 to 4 outlets.

I was reading through some Surge Protector posts on the forum, and saw some Surge protectors cum MCB from Schneider. (RCCBs) residual current circuit breaker. I am not sure what are these. They seem to be not very cheap. Could be around 7 to 8k. Is it worth investing in that kind of MCB over normal MCB?

What else I should be doing while getting the dedicated line?

Any suggestion on wire gauge and switches are welcome.

Thanks

Regards
Vivek
Nothing to do with Audio but a good RCCB is an absolute must have.
Actually your primary distributor should have all 3 separate viz single surge protector (1 for each phase or a single 3 phase) -> RCCB (1 for each phase or a single 3 phase) ->.MCB for each distribution line

MCBs protect against shorts/ overloads but RCCBs do something very important too - if it detects any imbalance between the current on the Live and neutral, it trips
In other words, any leakage (including someone accidentally touching a live wire) will cause thE RCCB TO disconnect the powert
 
Hi Vivek,

Wire size

2.5 mm2 is normally used to wire power points and should be enough and more for 16 A .But better use 4 mm2 .
This is strictly from electrical point of view.(i.e carry the current with minimal voltage drop).

Surge diverter and RCCB are totally different things.

RCCB
is residual current circuit beaker which in simple terms protects humans from shock by detecting the smallest leakage current.based on ratings of 10mA,30 mA.etc..)RCCB is a combined version of ELCB and MCB.

Existing lines
If your switch board doesn't have a main RCCB /ELCB or individual RCCB/ELCB's for all existing circuits , you should install a main or individual RCCB /ELCB for all existing circuits.The point is, RCCB has nothing to do with protection of your equipment,it is all about protecting lives.
May be standards would require individual ELCBs ,please check with your local electrician.

New dedicated line
For your new line, if there is no main ELCB in your switchboards , you should install a main or individual ELCB + MCB or RCCB .May be standards would require individual ELCBs ,please check with your local electrician.
But this will be installed in the switch board.
I don't see any requirement for ELCB or circuit breakers in the power point near your equipments.

Surge diverter
It provides protection from surges.
It is a good idea to have one in your switchboard.But this is not a mandatory requirement.This can installed in the switch board to protect all your equipment's or a dedicated one can be installed for your most important ones(audio).You might find it cheaper to get a dedicated surge protection for your switch board.Get a generic cheap normal product installed in your switchboard.Local Electricians can help.

3 phase vs single phase

Since your house is 3 phase, you 2 options for your dedicated line.

Option 1:You can use a 3 phase cable from your switch board to near your equipment's and install 3 power points all from different phases.
Option 2: Use a single phase cable from your switch board to near your equipment's and install 3 power points all from the same phase.

As your house wiring is an existing one, 3 phases are already wired through out the house,it may not be an easy task to have a phase completely dedicated for Audio.The best you can do is option 1.But I am not sure if this will have any benefit on audio.
Option 1 will be expensive than option 2 considering the cable price and price of the breakers etc for 3 phase.But the price difference might not be significant.

Hope this helps.
Hi Shinto

Thanks for the detailed explanation. Below is what I have understood from you. Please correct me if I am wrong or missing something in the chain.



Dedicated-Line.png

It is a good exercise to get the electrician to test the grounding starting from main meter box to all the sockets in the house for leaks.
If possible, you can even draw a separate ground & mains from the meter to AV plug point. It is laborious task to draw a new uncut line but did make difference in my case. I also found that the there were two rooms where earthing line was dead as the wire was too thin and joins got worn of due to heat.

Electrician & his helper took about 4-5 hours to replace the entire line by and paid him about 3K (including other ground checking/ petty work) + two 4 sq mm coils of Finolex ~2300Rs per coil (I still have about 50M cable per coil left).

If I were to redo the exercise, I would have done two things differently. One - draw a separate earth line from the panel to the switchboard. Use Lapp cables instead of Finolex. Probably would have costed another 3-5K extra but would have had solved the issue once for all.
Hi @arunkvivek

As you have suggested to use Lapp cables instead of Finolex or others. Anything special about Lapp cables? It has to run overhead say around 20 meters.

Regards
Vivek
 
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Isn’t this noise caused by airborne electromagnetic waves from the devices reaching your audio devices since they aren’t physically too far apart ? Or is it coming through the wiring ?this always baffled me. I had usb dacs in the past for phones which use to make this grainy noise when a electric train is passed near by.

From what I understand your amps power cable can act like an antenna to pick up these waves and add noise to amp.

again,unless you identify which scenario is causing this noise, there is no one way to solve it all.
 
Hi Shinto

Thanks for the detailed explanation. Below is what I have understood from you. Please correct me if I am wrong or missing something in the chain.

View attachment 46016
Yes .but the termination is on the wall.is it??

Nothing to do with Audio but a good RCCB is an absolute must have.
Actually your primary distributor should have all 3 separate viz single surge protector (1 for each phase or a single 3 phase) -> RCCB (1 for each phase or a single 3 phase) ->.MCB for each distribution line

MCBs protect against shorts/ overloads but RCCBs do something very important too - if it detects any imbalance between the current on the Live and neutral, it trips. In other words, any leakage (including someone accidentally touching a live wire) will cause thE RCCB TO disconnect the powert
Please don't get offended But I would like to clarify that my whole point was how important is an ELCB ,that it needs to be installed even on his existing circuits.please read carefully before quoting parts of it which gives a different idea.Please see below"Existing lines.

If your switch board doesn't have a main RCCB /ELCB or individual RCCB/ELCB's for all existing circuits , you should install a main or individual RCCB /ELCB for all existing circuits.The point is, RCCB has nothing to do with protection of your equipment,it is all about protecting lives.

May be standards would require individual ELCBs ,please check with your local electrician"
 
Last edited by a moderator:
Yes .but the termination is on the wall.is it??
Hi @Shinto

No termination will not be in the wall box. That would be quite a work to run the cable through the old iron conduits. I want to keep the new line as much isolated as possible. Does my drwaing makes any sense? Am I missing any component?

Isn’t this noise caused by airborne electromagnetic waves from the devices reaching your audio devices since they aren’t physically too far apart ? Or is it coming through the wiring ?this always baffled me. I had usb dacs in the past for phones which use to make this grainy noise when a electric train is passed near by.

From what I understand your amps power cable can act like an antenna to pick up these waves and add noise to amp.

again,unless you identify which scenario is causing this noise, there is no one way to solve it all.
I somehow found the problem. Its some wiring issue most likely. Going to solve it by isolated line for music system. If the power cable were acting as an antena, then it would pick the noise no matter from where the system is powered. But this is not the case. The noise comes only when the lights/fans on the same circuit as of the system are operated. When turned OFF. No noise when turned ON.
 
Please don't get offended But I would like to clarify that my whole point was how important is an ELCB ,that it needs to be installed even on his existing circuits.please read carefully before quoting parts of it which gives a different idea.Please see below"Existing lines
If your switch board doesn't have a main RCCB /ELCB or individual RCCB/ELCB's for all existing circuits , you should install a main or individual RCCB /ELCB for all existing circuits.The point is, RCCB has nothing to do with protection of your equipment,it is all about protecting lives.
May be standards would require individual ELCBs ,please check with your local electrician"
Hi @Shinto

No termination will not be in the wall box. That would be quite a work to run the cable through the old iron conduits. I want to keep the new line as much isolated as possible. Does my drwaing makes any sense? Am I missing any component?
The wiring should only be done by a qualified Electrician.The drawing makes sense.
 
The wiring should only be done by a qualified Electrician.The drawing makes sense.
Ok. Yeah I am not going to do it myself. So I guess ELCB or a good quality MCB with 4 sq mm wire is all I need and on termination end, a board with few sockets.

Thanks
 
Do I really need ELCB since my equipment do not have earthing pins?
ElCB is a must have as you power sockets will have earth.and the cable path also needs protection from leakages.A 16 A MCB will trip only at 16 A which will only occur if there is an overload at the power points or a phase to phase or earth fault.
A 30 mA ElCB trips at 30 mA protecting precious lives.In a way it also protect s from fire as it trip s at small leakages where as an MCB will wait for 16 A which will never happen in a small leakage, but there will be hazardous voltages in the vicinity.
 
ElCB is a must have as you power sockets will have earth.and the cable path also needs protection from leakages.A 16 A MCB will trip only at 16 A which will only occur if there is an overload at the power points or a phase to phase or earth fault.
A 30 mA ElCB trips at 30 mA protecting precious lives.In a way it also protect s from fire as it trip s at small leakages where as an MCB will wait for 16 A which will never happen in a small leakage, but there will be hazardous voltages in the vicinity.
Thanks a lot for all the help. I will get it as well.
 
Hi @arunkvivek

As you have suggested to use Lapp cables instead of Finolex or others. Anything special about Lapp cables? It has to run overhead say around 20 meters.

Regards
Vivek
Finolex is good enough. I heard from and electrical vendor in wholesale market that Lapp is extremely strict on quality control in raw materials used .the guy mentioned that copper quality was better. They are almost double the cost of finolex and are available online in India.
 
Finolex is good enough. I heard from and electrical vendor in wholesale market that Lapp is extremely strict on quality control in raw materials used .the guy mentioned that copper quality was better. They are almost double the cost of finolex and are available online in India.
Thanks for inside information Arun. :)
 
Please don't get offended But I would like to clarify that my whole point was how important is an ELCB ,that it needs to be installed even on his existing circuits.please read carefully before quoting parts of it which gives a different idea.Please see below"Existing lines
If your switch board doesn't have a main RCCB /ELCB or individual RCCB/ELCB's for all existing circuits , you should install a main or individual RCCB /ELCB for all existing circuits.The point is, RCCB has nothing to do with protection of your equipment,it is all about protecting lives.
May be standards would require individual ELCBs ,please check with your local electrician"
None taken
I had anyway clarified upfront that my post has nothing to do with audio :)
 
Update on dedicated line

I still get disturbance when I switch on/off tube lights, when the washing machine is being used and the door bell rings. So the deciated line didn't help much. Its for the people who are trying to sort similar problem by installing a dedicated line. Well its not that simple I guess. There is something more in to this.
 
Update on dedicated line

I still get disturbance when I switch on/off tube lights, when the washing machine is being used and the door bell rings. So the deciated line didn't help much. Its for the people who are trying to sort similar problem by installing a dedicated line. Well its not that simple I guess. There is something more in to this.
Yes it is complicated.Your only easy option is trial and error using different circuits etc via extension codes etc, unless you want to use an Electrical consultancy service to do a power quality analysis etc.. which may or may not be an economically feasible option here.It all boils down to the quality of power in your area i.e how strong/weak the network is in your area .
 
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