Installing DEDICATED power line to 2 channel system

[robbee]

A dedicated power circuit from the switchboard to your hi fi equipment is not necessary.

Check the power consumption rating on the back of your gear and add it all up.

 General purpose outlets(GPO's) are rated at 10Amp so your good for 2400 watt @ 240 volt on a single outlet before a dedicated circuit is required .( W=V x I)

Most power circuits in new homes with 2.5mm2 TPS cable feeding the GPO's have 20amp circuit breakers protecting the cable and RCD's protecting you. 

You won't hear any difference on a dedicated circuit verses one which feeds other electrical appliances around the home. Dedicated circuits are only installed generally for single appliances that draw more than 10A such as an air con or stove.

[Jones99]

8 minutes ago, robbee said:

A dedicated power circuit from the switchboard to your hi fi equipment is not necessary.

Check the power consumption rating on the back of your gear and add it all up.

 General purpose outlets(GPO's) are rated at 10Amp so your good for 2400 watt @ 240 volt on a single outlet before a dedicated circuit is required .( W=V x I)

Most power circuits in new homes with 2.5mm2 TPS cable feeding the GPO's have 20amp circuit breakers protecting the cable and RCD's protecting you. 

You won't hear any difference on a dedicated circuit verses one which feeds other electrical appliances around the home. Dedicated circuits are only installed generally for single appliances that draw more than 10A such as an air con or stove.

Mine far exceeds 10A......hence the multiple circuits but dedicated circuits are more about removing other appliances/devices from circuits  than about loading.

As for seperate circuits making a difference tough one to prove ...for me and my system I think it has. 

 

[Red MacKay]

9 hours ago, Marc said:

 

Probably getting beyond my electrical knowledge now, but I don't believe so. Single phase here?

100% tested and repeatable - as soon as projector power point was moved from a normal household circuit, onto my dedicated circuit, hum disappeared. Ground loop resolved.

 

I have exactly the same experience in my music room with my projector..

[Red MacKay]

30 minutes ago, robbee said:

A dedicated power circuit from the switchboard to your hi fi equipment is not necessary.

Check the power consumption rating on the back of your gear and add it all up.

 

You won't hear any difference on a dedicated circuit verses one which feeds other electrical appliances around the home. 

 

Sorry - I totally disagree here.  With a dedicated line - you chop a lot of the electrical crud from lights and other things like switch mode power supplies to the computer, tv, fridge etc which are pollution city.

 

And yes - go big with your cable - it's all about current capability, not what you are drawing, rather but the instantaneous rise time for current demand.

 

I am about to get a sparkie to put a dedicated line into my room too.  I will be using 6mmsq orange circular to a Black Art 5000va balanced transformer, with a separate earth stake.  I am going to terminate it to a single 32A Clipsal 56 Series socket on the wall.  Why 32A?  By Law, I am only allowed one socket per 32A line.  This socket must also be switched.  Have you ever pulled a 10 or 15A switch from a standard power point apart?  The contact area is complete rubbish, absolutely miniscule!  The 32A one on the other hand, is about 6mm dia switching area.   the round pins for contact are around 6mm dia too, and the contact clench is far greater meaning better contact, better current capability and less heat.  From there into a diy 9 way board with no switches.

 

The only battle I have, is my original 1958 circuit board on the house isn't up to it.  I have to spend $1200 there to get it replaced before I can even start.  I might even need the SEC (or whatever they are called now) to run new mains from the street as my current capacity from the new switchboard might exceed the feed line from the street that I already have.

 

But I am still a couple of months away and keen to hear what happens here.  Things like that Gigawatt not being legal in Vic - gold!  A pity, but great to learn now.

 

Ahhh, ...but then I can have the capability to run some AC in there too!

[Dirkgerman]

8 hours ago, Red MacKay said:

with a separate earth stake.

Tap onto the site earth stake is a better idea with your Iso Tx, keep all the main grounds common to one another.

I hope you know that what you suggest is a total, utter and overkill with regard to the 32A56 Series stuff. Good old ugly Clipsal double pole GPO is the go. BTW that miniscule contact will run a welder/kettle, so unless your stereo is operated in the +3Kw region miniscule would do nicely. Have a nice day Red.

 

[Red MacKay]

Yes, you are totally correct Dirk.  I do realise it is total overkill.

 

I'm curious what you say re the common earth, as this is all a bit of a mystery to me.

Can you elaborate any here?

 

The cost is absolute peanuts compared to the other money I have wasted on this hobby over the years.

Orange circ is like $5/m, Clipsal 56 outlet $100, plug, $100, inside switchbox $150, sparkie $400.  (all an estimate)

 

But as long as it is all to AUSNZ code, and all done by a registered sparkie that knows what he is doing, all good.

[Assisi]

Earlier this year I had a separate circuit run from the Switch Board to my system mainly because I needed additional sockets.  I decided to be serious with cable and used Gigawatt.  The interesting and surprising outcome is that the voltage on the Gigawatt is approx. 4 volts higher than the other circuits to other parts of the house.  Right now, the audio system is getting 230 volts and the computer that I am working on is getting approx. 226 volts.

[Dirkgerman]

55 minutes ago, Red MacKay said:

the common earth

With a new switchboard, earth stake/conductor, new mains, new point of attachment + all the other outlandish stuff will keep a Sparky busy for more than a day., I would estimate a couple of grand easy, the chicken comes before the egg in this case.

 

A common ground will keep the earth potential resistances to one another lowest as possible in event of any fault. If you do not run a second multiple earth neutral on the secondary of the iso transformer I think you will find you "must use the site main earth link" via the regs. 

Keep thinking that if there is any current flowing down to earth, at the chassis of the iso tranny the last thing you want is a second earth stake as there may be gobs of resistance (dangerous potential voltages) between the 1, chassis, 2, main earth link/stake, 3, other earth stake.  Earth Star point in a power amplifier ring any bells, Red, similar theory here.  Not a good idea and never a done thing in field, from a Senior Sparky who has "done $hit" built many off grid power stations, EHV Switchyard earth mats and the like over 35 years. 

An example, you have seen this system personally and heard the results although you may have forgotten, was a couple of years ago.

An off grid 8 Kva Inverter, with literally an 8 Kva balanced iso transformer output main earth is derived from the main earth link within the switchboard 6mm2 in this case. It has 2 circuits, with 4mm2 conductor (A and E) to a dedicated sound lounge. It has it's own M.E.N. and main switchboard.

 

The second earth stake is not a good idea. If the circuit is over 50m long, then maybe it is.  RCBO double pole  protection on the iso tranny  output as a matter of coarse. 

 

Have fun the rabbit hole is deep although from what you say, you are down there already  peace Mate.

Edited January 24, 2021 by Dirkgerman

[aussievintage]

11 hours ago, Red MacKay said:

With a dedicated line - you chop a lot of the electrical crud from lights and other things like switch mode power supplies to the computer, tv, fridge etc which are pollution city.

 

How effective is it at doing this unless you put a power filter between the circuits?  They are all connected together with a very low impedance otherwise.  The thicker and bigger cable you run, the better they are connected, as I am seeing it.

[Dirkgerman]

14 minutes ago, aussievintage said:

very low impedance

Sorry to jump in if I may,

Red is sort of correct, imagine on a single circuit, wired for low impedance by it's very nature a dirty old fridge is plugged into it with a pair of contacts in the thermostat that have worn out, the motor cap is leaking and lost it's Zzaaap a decade ago.  The stereo shares the same circuit and just so happens it is further down the parallel circuit.  Running a separate circuit may alleviate waveform distortion that the stereo equipment power supplies will see as the faulty appliance is then "further away" or on a higher impedance part of the distribution within the dwelling.  THe lesser the impedance to the supply the less distortion it will have, even in an arrangement with the highest resistance of any part of the circuity s 1 ohm.

Edited January 24, 2021 by Dirkgerman

[aussievintage]

5 minutes ago, Dirkgerman said:

Sorry to jump in if I may,

Red is sort of correct, imagine on a single circuit, wired for low impedance by it's very nature a dirty old fridge is plugged into it with a pair of contacts in the thermostat that have worn out, the motor cap is leaking and lost it's Zzaaap a decade ago.  The stereo shares the same circuit and just so happens it is further down the parallel circuit.  Running a separate circuit may alleviate waveform distortion that the stereo equipment power supplies will see as the faulty appliance is then "further away" or on a higher impedance part of the distribution within the dwelling.  THe lesser the impedance to the supply the less distortion it will have, even in an arrangement with the highest resistance of any part of the circuity s 1 ohm.

 

I see what you are getting at.   

 

The best move however, for noisy switching and old caps,  has always been to fix the problem at the source.  Bypass the noise making devices with a good mains rated cap, as close to the source as possible.  One of the reasons is the noise, may cross over to other circuits purely due to proximity in the walls, which can't be avoided as they all have to end up back at the same distribution board. 

 

It does bring up another thing, if running a dedicated circuit, shield it well, and run it via as different a route as is possible.

 

[Assisi]

13 minutes ago, aussievintage said:

It does bring up another thing, if running a dedicated circuit, shield it well, and run it via as different a route as is possible.

I think that in my case the above was achieved.

 

The gigawatt is well shielded.  The cable had to go through the slab into the cellar across the cellar ceiling, outside through a vent pipe, then through 30cms of stone wall back into the house.

John

[Guest]

13 hours ago, robbee said:

A dedicated power circuit from the switchboard to your hi fi equipment is not necessary.

Check the power consumption rating on the back of your gear and add it all up.

 General purpose outlets(GPO's) are rated at 10Amp so your good for 2400 watt @ 240 volt on a single outlet before a dedicated circuit is required .( W=V x I)

Most power circuits in new homes with 2.5mm2 TPS cable feeding the GPO's have 20amp circuit breakers protecting the cable and RCD's protecting you. 

You won't hear any difference on a dedicated circuit verses one which feeds other electrical appliances around the home. Dedicated circuits are only installed generally for single appliances that draw more than 10A such as an air con or stove.

 

It's got zero to do with circuit capacity, and everything to do with noise and interference. 

[robbee]

2 minutes ago, Marc said:

 

It's got zero to do with circuit capacity, and everything to do with noise and interference. 

Yep l get it but if there's no noise or interference to start with then it's unnecessary to run a dedicated power circuit from the main switchboard. 

[Guest rmpfyf]

4 hours ago, Dirkgerman said:

Tap onto the site earth stake is a better idea with your Iso Tx, keep all the main grounds common to one another.

 

Permissible under AS3000 to use a separate ground downstream of a trans, as you know, and as you suggest, context dependent as to whether or not it's best practice. I'm continually surprised the number of audiophools that get this far and then don't put RCBO's (or more) on the output because of some percieved noise issue with Clipsal/Hager/whatever.

 

13 hours ago, Red MacKay said:

The only battle I have, is my original 1958 circuit board on the house isn't up to it.  I have to spend $1200 there to get it replaced before I can even start.  I might even need the SEC (or whatever they are called now) to run new mains from the street as my current capacity from the new switchboard might exceed the feed line from the street that I already have.

 

Order it though your retailer - costs are then fixed depending on your DNSP (you can look up what's what on their website). If you really need to up your incoming and you're overhead reticulated, go three phase if you can. Cost is not so different and down the road you're covered for all sorts of hijinks. 

 

Whatever you end up doing for earth... you can have some fun and paralell 'em up, dig nicely and insert a bentonite slurry, etc. Your sparkie will take a Very Dim View of being asked to hammer in multiple stakes so if it's something you can do and they wire, so be it.

 

Black Art makes a beautiful trans though on prices... damn... Airlink's looking competitive (<50%), they have legitimate studio chops and they'll build to whatever configuration for safety's sake if you ask nicely. 

 

See what you can do for wire with ESD cable. Cost won't be so different and you get some nice shielding.

Just now, robbee said:

Yep l get it but if there's no noise or interference to start with then it's unnecessary to run a dedicated power circuit from the main switchboard. 

 

Really depends what's perceivable, whether you do, whether you want to protect against any in future and whether you just want it. 

 

In most cases from a pure demand perspective then no it's usually unecessary, though that's an incomplete thesis with regards to 'is it a good idea'. 

[Dirkgerman]

5 minutes ago, robbee said:

Yep l get it but if there's no noise or interference to start with then it's unnecessary

Agree in a perfect World  .

Sometimes though you may be at the end of a long L.V. run from the local distribution transformer (20 houses full of noisy crap on your supply upstream of you) , with that in mind, deriving a supply via an isolation transformer/filter/waveform re constructor thingo becomes viable, but that's off the topic  

[Wimbo]

6 hours ago, Marc said:

It's got zero to do with circuit capacity, and everything to do with noise and interference. 

You can use the speaker outputs of Levison 20.5's to arc weld.

[Wimbo]

Back in the early 90's, I asked my boss if we could put 40amp circuits in for the Krell's to drive The Duntech Sovereigns. Our electrician thought I was a Madman. (I am a bit). He kept fighting until my the boss told him to do it. Just to see. After doing it and letting everything warm up, we played that Harry Conick Junior album that was popular at the time {which we played before the work began as well) and the electrician fell off his chair. My boss is still following this procedure AFAIK as I havent worked for 5 years.

 

[Red MacKay]

Instantanous current capability and lack of sag in voltage.  That's where it is at.

[robbee]

6 hours ago, Dirkgerman said:

Agree in a perfect World  .

Sometimes though you may be at the end of a long L.V. run from the local distribution transformer (20 houses full of noisy crap on your supply upstream of you) , with that in mind, deriving a supply via an isolation transformer/filter/waveform re constructor thingo becomes viable, but that's off the topic  

True, there could be all sorts of noisy crap on the supply line but if your not hearing it when listening to your system then all good. The power transformer inside your amp and the filtering caps do a great job of  filtering any crud and once it's converted to DC voltage inside your amp it is clean with no noise.

[robbee]

40 minutes ago, Red MacKay said:

Instantanous current capability and lack of sag in voltage.  That's where it is at.

How much current are you talking about here Red? What is sag voltage?

[BATMAQN]

26 minutes ago, robbee said:

How much current are you talking about here Red? What is sag voltage?

 

 

https://www.elspec-ltd.com/what-are-voltage-sags-and-swells/

[andyr]

54 minutes ago, robbee said:

True, there could be all sorts of noisy crap on the supply line but if your not hearing it when listening to your system then all good. The power transformer inside your amp and the filtering caps do a great job of  filtering any crud and once it's converted to DC voltage inside your amp it is clean with no noise.

 

I suspect you must be a (licenced) electrician, robbee?

 

IOW, you work from written standards (developed by those who are interested (hopefully!) in safety) ... not SQ.

 

If you have a toroid as the power traffo inside your component ... then it filters nothing!  'Crud' on the primary gets passed thru to the output - and into the regulators.

 

(If you have an EI power traffo ... this does filter hash.)

 

And as for "if you're not hearing it when listening to your system then all is good " ... it's a matter of relativity.  You may think that what you have is fine (noise free) ... then you make a change - and suddenly, the noise floor drops ... and you can hear an absence of what you heard before.  

 

Andy

 

[Assisi]

53 minutes ago, robbee said:

True, there could be all sorts of noisy crap on the supply line but if your not hearing it when listening to your system then all good.

How do you know that you have a noise problem via the supply power until you do something about mitigating the crap.  Ignorance is bliss.  A while back SNA was littered with posts saying that there were no power issues on the East Coast.  It may not be as bad as the west but there are problems.  As well many of the posts said what you are saying below.  I do not know the technical matters.  I dealt with the power in various ways and as a consequence my system sounded better.  Many people say it it is the room the room the room. To me power is very important also.

 

1 hour ago, robbee said:

The power transformer inside your amp and the filtering caps do a great job of  filtering any crud and once it's converted to DC voltage inside your amp it is clean with no noise.

John

[Red MacKay]

1 hour ago, robbee said:

How much current are you talking about here Red? What is sag voltage?

 

I have no electrical qualifications, so please treat what I think with that in mind...

 

Sorry - 'voltage drop' is better terminology, like mentioned before when the member said he had 4v more on his dedicated line than the rest of his house.  Less impedance.

 

...And yes Andy - Rob does know what he is talking about.