I am building a mains extension block for use in my hi fi system.
I have six MK individual sockets mounted in an alloy housing and I would be interested to hear recommendations on the best way to wire these together.
The earth/ground wiring is clear to me in that this should be "star earthed",i.e each earth socket terminal is wired individually to a single point which is then connected to the incoming earth terminal on the IEC plug.
However should I connect the live and negative terminals on the sockets in a similar manner with an individual connection/wire from each to a single point and then to the IEC ? Or alternatively should I "daisy chain" these (live/neg separately of course !)connections where each socket is connected to the next and on to the next and so on until final connection to the IEC ?
Obviously there are safety considerations here and these must be observed,but do these conflict or run in line with any sonic benefits which may be gained from either format of wiring ?
The unit will be fused and fitted with appropriate MOVs at the IEC plug terminals.
I have six MK individual sockets mounted in an alloy housing and I would be interested to hear recommendations on the best way to wire these together.
The earth/ground wiring is clear to me in that this should be "star earthed",i.e each earth socket terminal is wired individually to a single point which is then connected to the incoming earth terminal on the IEC plug.
However should I connect the live and negative terminals on the sockets in a similar manner with an individual connection/wire from each to a single point and then to the IEC ? Or alternatively should I "daisy chain" these (live/neg separately of course !)connections where each socket is connected to the next and on to the next and so on until final connection to the IEC ?
Obviously there are safety considerations here and these must be observed,but do these conflict or run in line with any sonic benefits which may be gained from either format of wiring ?
The unit will be fused and fitted with appropriate MOVs at the IEC plug terminals.
Each output socket will have a <=13A plug top fuse after it.
The wiring to the group of six should be sufficient for the total load of all six sockets. The fuse before that wiring must be rated lower than the wiring that follows.
I would daisy chain the Lives and Neutrals using offcuts of insulated wire from 2 core + earth. 2.5mm² is enough. I would then "Ring" wire from the last socket back to the input. This way the daisy chain is fed from both ends (in the Live and in the Neutral).
I would do the Earth wire differently.
Get a continuous length of uninsulated copper (2.5mm²). Have sufficient green/yellow sleeving for insulating all exposed earthing wire.
From the Input, run to the first socket. Cut a sleeve and insulate. Fold the earth wire and insert the exposed "fold" into the earth terminal. Now run that earth wire to the second socket. Cut and sleeve. Fold and insert. Keep going until all Earth terminals are connected using that ONE CONTINUOUS copper wire. Now connect back to the input Earth. Again you have a "ring". Add a sleeved earthing wire from input to "alloy box" chassis. This last could be part of that same continuous earthing wire if you plan it that way.
The idea of the continuous earthing wire is to reduce the risk if one terminal screw comes loose. This same idea is applied to other "external" earthing around the house. It's a belt and braces that is common to UK practice.
The wiring to the group of six should be sufficient for the total load of all six sockets. The fuse before that wiring must be rated lower than the wiring that follows.
I would daisy chain the Lives and Neutrals using offcuts of insulated wire from 2 core + earth. 2.5mm² is enough. I would then "Ring" wire from the last socket back to the input. This way the daisy chain is fed from both ends (in the Live and in the Neutral).
I would do the Earth wire differently.
Get a continuous length of uninsulated copper (2.5mm²). Have sufficient green/yellow sleeving for insulating all exposed earthing wire.
From the Input, run to the first socket. Cut a sleeve and insulate. Fold the earth wire and insert the exposed "fold" into the earth terminal. Now run that earth wire to the second socket. Cut and sleeve. Fold and insert. Keep going until all Earth terminals are connected using that ONE CONTINUOUS copper wire. Now connect back to the input Earth. Again you have a "ring". Add a sleeved earthing wire from input to "alloy box" chassis. This last could be part of that same continuous earthing wire if you plan it that way.
The idea of the continuous earthing wire is to reduce the risk if one terminal screw comes loose. This same idea is applied to other "external" earthing around the house. It's a belt and braces that is common to UK practice.
You could fit a mains interference filter at the input to the distribution box. "catching" the interference early is better than waiting until the last input. You still need all your equipment to be fitted with input filters to "catch" interference that gets past the first and also any air borne interference that gets added in to the cabling after that first filter.
Forgive my ignorance, but what's wrong with just star wiring L, N & E wires for each socket back to the input?
Marce
How is it any more dangerous than the usual 'daisy chaining' method described by AndrewT for the L & N lines? If one of the links in the live chain comes out of its terminal, it can still make the metal box live, as can star wiring.
What's the difference?
How is it any more dangerous than the usual 'daisy chaining' method described by AndrewT for the L & N lines? If one of the links in the live chain comes out of its terminal, it can still make the metal box live, as can star wiring.
What's the difference?
L and N probably no problem, but as I said I am not up on the new rules and regulations, I was mainly referring to protective earth.
Again though how much if any benefit would it provide, apart from adding more wiring (and thus the possibility of RF pick up to the equation.
In the past I have had a dedicated spur with its own fuse etc for my gear, with some decently thick cable.
Again though how much if any benefit would it provide, apart from adding more wiring (and thus the possibility of RF pick up to the equation.
In the past I have had a dedicated spur with its own fuse etc for my gear, with some decently thick cable.
The metal box is grounded so any live wire touching it will blow a fuse or trip a breaker.
My guess is that the wiring details will have no effect on audio, but can affect safety. As far as possible you don't want one connection depending on a chain of soldered or screw connections, especially earth. The ground connection to the box should be the first in the chain so it has the lowest impedance.
My guess is that the wiring details will have no effect on audio, but can affect safety. As far as possible you don't want one connection depending on a chain of soldered or screw connections, especially earth. The ground connection to the box should be the first in the chain so it has the lowest impedance.
insulated solid core copper is used for the daisy chaining.
If one terminal screw becomes loose, then the solid core will stay in approximately the same location. It should not spring out to touch any other component. The worst that is likely to happen is that the connection goes open circuit. All your equipment downstream of that open circuit stops working.
Can you see how this has not created a hazard?
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Thank you all for your input,I shall follow these recommendations,as I suspected Safety is the most important issue here and sonic benefits are difficult to define.
Andrew
How would solid core wire spring out of the terminal exactly?
My experience of it is that once you have set it in position it
stays there and would just go open circuit if the terminal screw loosened. Remember that all house wiring used to be radial,not ring at one time
How would solid core wire spring out of the terminal exactly?
My experience of it is that once you have set it in position it
stays there and would just go open circuit if the terminal screw loosened. Remember that all house wiring used to be radial,not ring at one time
Andrew
No I didn't misread it. I meant that the solid core wire is just as (un)likely to spring out of the socket terminal if star wired as if ring wired, so I don't see how star wiring is any less safe than ring wiring.
Whether star wiring has any audible benefits over ring wiring is another matter. Possibly, so if there's no added danger, why not star wire?
No I didn't misread it. I meant that the solid core wire is just as (un)likely to spring out of the socket terminal if star wired as if ring wired, so I don't see how star wiring is any less safe than ring wiring.
Whether star wiring has any audible benefits over ring wiring is another matter. Possibly, so if there's no added danger, why not star wire?
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What terminal size is required to fit in 6off 2.5mm² wires?
I doubt a 16mm² terminal will take that. But maybe one could deform the 6 wires sufficiently to fit.
I doubt a 16mm² terminal will take that. But maybe one could deform the 6 wires sufficiently to fit.
Don't forget that eric's talking about building a mains extension block. So you'd have 6 sockets on the top of the block with 3 off 6+ way brass common blocks at the input end of the block to which the incoming L, N, E also connect. Might be a bit bulky but so what?
There is no sonic benefits of staring the wiring, if anything you will add more problems, and more loops to the equation. If you have a system the best method is to hang all the equipment of one ring, not have separate feeds to each component of the system.
When people complain about mains hum (ground loops) one of the first bits of advice given is to check that your wiring is from one point to minimise the loop area...
When people complain about mains hum (ground loops) one of the first bits of advice given is to check that your wiring is from one point to minimise the loop area...
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