Weird electric question about solid bare wire

[RayM77]

Ok so please read the whole thing as I’m trying to figure this one out. This is on an out door project and not on mains power in any way and will be in a place that no human can touch the wires while power is running through them. Here are the variables,
50-150 volts “voltage changes”.
50-150 amps “amperage changes but opposite of voltage, so when 150v it is 50a”.
20hz-60hz “frequency does not collate to power in any measurable way”
The longest run will be 12’, each run has it own power supply.

So here is the Questions
What size solid bare wire can I use?

Will polishing the wire i.e. make it pretty hurt the electrical conductivity?

Would copper or aluminum work better?
Maximum space allows for a .4” conductor diameter.

Would it hurt to copper on line and aluminum on the neutral?

Vibration won’t be an issues as I will be laser cutting acrylic channels and brackets.
This is actually going to be the speaker wire in a large audio build where each pair of conductors will see roughly 5kw of ac power, there will be 12 15” 100lbs subwoofers on 12 10kw amplifiers and would lover the look of beautifully bent bare wire. Most people in the car audio industry will use very small undersized wire “like 8 gauge stranded wire on a 200a plus load” and well I like overkill.

If you have any other questions please ask.
If you are able to help please do and I thank you for your time and help.

 

[rambojoe]

I have a question, are you making a rig to kill birds and stray cats or just doing audio?
Why not good ol' fashion insulated speaker cable? Bare or not it will make zero difference. Just size appropriatly...

 

[LarryFine]

Welcome to the forum.

50-150 volts “voltage changes”.
50-150 amps “amperage changes but opposite of voltage, so when 150v it is 50a”.

That's mathematically correct that current varies inversely with voltage for a given power, but:

This is only true when the load is altered to produce the same power on a different voltage.

But current varies proportionately with voltage when applied to a constant (resistive) load.

So here is the Questions
What size solid bare wire can I use?

For 150 amps? See NEC 310.

Will polishing the wire i.e. make it pretty hurt the electrical conductivity?

No measurable effect.

Would copper or aluminum work better?

Copper for a given size and most environments, depending on your definition of "better".

Maximum space allows for a .4” conductor diameter.

I'm not sure of conductor diameters.

Would it hurt to copper on line and aluminum on the neutral?

Not at all.

This is actually going to be the speaker wire in a large audio build where each pair of conductors will see roughly 5kw of ac power, there will be 12 15” 100lbs subwoofers on 12 10kw amplifiers and would lover the look of beautifully bent bare wire. Most people in the car audio industry will use very small undersized wire “like 8 gauge stranded wire on a 200a plus load” and well I like overkill.

I want to see this! I've been into car (and home and commercial) audio since 8-tracks.

An automotive brake-line bender should give you pretty bends.

 

[ggunn]

Would it hurt to copper on line and aluminum on the neutral?

Neutral in speaker wires?

 

[RayM77]

I have a question, are you making a rig to kill birds and stray cats or just doing audio?
Why not good ol' fashion insulated speaker cable? Bare or not it will make zero difference. Just size appropriatly...

so if I go by electrical code it would be huge wire for a 150a load old fashion speaker wire is 8 gauge wire that get so hot it starts to melt the insulation off of it

 

[LarryFine]

Neutral in speaker wires?

Maybe he meant + and -.

 

[RayM77]

Welcome to the forum.


That's mathematically correct that current varies inversely with voltage for a given power, but:

This is only true when the load is altered to produce the same power on a different voltage.

But current varies proportionately with voltage when applied to a constant (resistive) load.


For 150 amps? See NEC 310.


No measurable effect.


Copper for a given size and most environments, depending on your definition of "better".


I'm not sure of conductor diameters.


Not at all.


I want to see this! I've been into car (and home and commercial) audio since 8-tracks.

An automotive brake-line bender should give you pretty bends.

So on a speaker the resistance changes as the coil moves in and out of the magnetic gap. When I look at basic charts for 150a loads it say I need 2/0 wire but my runs are very short so wasn’t sure if I could go smaller on the conductor size
As soon as I figure out how to share pics on here from my iPhone I will, but it currently has 4 400a alts “going to 6 of them” have 900ah of lithium to put in with a additional 500ah in the future. 8 runs of 4/0 welding cable, 4 positive 4 ground. In a 2004 Yukon xl, only has the 2 front seats

 

[RayM77]

Neutral in speaker wires?

So yes Neutral is probably a poor choice on words but half bridge amplifiers have a +v rail a 0v rail in them, full bridge amplifiers have a +v, 0v and a -v rail in them. So in a way a neutral rail that carries no potential across it.

 

[RayM77]

Maybe he meant + and -.

I gave a explanation below as neutral may have been a poor choice of words lol

 

[Speedskater]

With 50,000 Watts of low frequency audio, we all will be able to hear it.
Widely spaced conductors will need lots of bracing or they will vibrate at low frequencies.
Seems like something that they built to test ICBM's.

 

[jim dungar]

You are unlikely to find a good NEC compliant answer to your sizing question.
The NEC tables do not address conductors installed into 'channels cut into acrylic'.
You may need to ask a 'conductor' manufacturer or a place like copper.org, as thus is more of a product design question. Maybe UL can help.
Of concern will be the length of time the conductors are exposed to the different current levels.

 

[Speedskater]

Just use copper water pipes.

 

[RayM77]

With 50,000 Watts of low frequency audio, we all will be able to hear it.
Widely spaced conductors will need lots of bracing or they will vibrate at low frequencies.
Seems like something that they built to test ICBM's.

Will be closer to 120kw of power total but about 10kw per sub and 5kw per coil

 

[ggunn]

So yes Neutral is probably a poor choice on words but half bridge amplifiers have a +v rail a 0v rail in them, full bridge amplifiers have a +v, 0v and a -v rail in them. So in a way a neutral rail that carries no potential across it.

I've worked with a few full bridge amps; for the ones I have there was a 0V rail internal to the amp but there were only two conductors in the speaker cables.

 

[RayM77]

You are unlikely to find a good NEC compliant answer to your sizing question.
The NEC tables do not address conductors installed into 'channels cut into acrylic'.
You may need to ask a 'conductor' manufacturer or a place like copper.org, as thus is more of a product design question. Maybe UL can help.
Of concern will be the length of time the conductors are exposed to the different current levels.

So they will be laying in the channel with periodic acrylic straps over to help prevent the conductor from vibrating and keep spacing equal. The people at UL don’t have an actual clue as there compliance says I can use 12awg stranded wire because they load won’t be anywhere near as high as I’m saying. It’s like non of them have ever seen a big show system.

 

[RayM77]

Just use copper water pipes.

Not enough conductor and my maximum diameter is .4”

 

[RayM77]

I've worked with a few full bridge amps; for the ones I have there was a 0V rail internal to the amp but there were only two conductors in the speaker cables.

There are a few full bridge on the market now that can be run as 2 half bridge amps but are internally strapped to a full bridge so you get a full push pull from the amp

 

[Speedskater]

Will this be for continuous test tones or something approaching music?
There are other smaller flexible copper tubing. But looking in Grainger none look like a great match.

 

[RayM77]

Will this be for continuous test tones or something approaching music?
There are other smaller flexible copper tubing. But looking in Grainger none look like a great match.

This will be roughly a 167 db spl demo vehicle playing music for extended periods of time.

 

[RayM77]

Will this be for continuous test tones or something approaching music?
There are other smaller flexible copper tubing. But looking in Grainger none look like a great match.

I can buy 4 gauge bare bright copper wire but just not sure in that is big enough for the power I will be putting across it and I don’t know if polishing it would effect the power handling capacity of it.