2 computer circuits sharing a neutral

[iwire]

480 just didn a pretty good job of it himself right above your post.

That was no voltage drop calculation.

 

[steelersman]

Without double-checking Ed's numbers, I think that's already been done.

agreed....

 

[steelersman]

That was no voltage drop calculation.

the diagram pretty much shows it, at least to me it does, that the mere fact of not having the extra neutral in there reduces not only the voltage drop but also the load on the neutral.

 

[480sparky]

We still disagree and this is my plane.

That's funny. SR71s has what for armaments?

 

[steelersman]

I don't think length is the story, load is. Look at the load on the neutral in Ed's diagrams.

true, length is not the story load is but also the number of neutrals is the story just as well.

 

[iwire]

That's funny. SR71s what what for armaments?

I never said I was shooting anything, that was your game.

I am just flying at the edge of space at Mach 3.

 

[480sparky]

I never said I was shooting anything, that was your game.

I am just flying at the edge of space at Mach 3.

So how do you take out targets in my game? Fly low and fast and hope the sonic boom does some damage?

 

[steelersman]

I am just flying at the edge of space at Mach 3.

space has no edge.

 

[wasasparky]

Anytime you use a multiwire branch circuit you can reduce voltage drop. (Assuming same loads, same size condutors, same length etc.)

From a long ago thread

To be more accurate, shouldn't the load in Watts (not Amps) stay the same from A to B?
Should I find some spare time (and the wife isn't around) maybe i'll remember to crunch the numbers...

 

[480sparky]

space has no edge.

Then I got thinking.... is >mach 1 at tree-top level inside an SR71's flight envelope?

 

[iwire]

space has no edge.

NASA is going to be upset to learn that.

Strange Clouds at the Edge of Space


AIM at the Edge of Space

 

[480sparky]

NASA is going to be upset to learn that.

Strange Clouds at the Edge of Space


AIM at the Edge of Space

NASA has no 'jurisdiction' over the definition. IAU does.

 

[dereckbc]

Ok this is something new to me. I now can understand this concept, however, what dereckbc said makes it sound like you will only reduce the voltage drop if you use the shared neutral on single phase. I don't see how this would make any difference. Another words this concept should also work on 3 phase just the same.

It will work on 3-phase too, just not to the same degree because the currents are 120 degrees out vs 180 of single phase.

However in 3-phase the harmonics can be additive or subtractive, so you don't always know what you get. With single pahse it is all subtractive and harmonics are of no concern.

 

[iwire]

As far as the length vs current discussion 480 you may may be right, it may be both. :smile:

As far as the side topic I am done. You guys can continue to battle for the forums most nit-picky.

 

[steelersman]

NASA is going to be upset to learn that.

Strange Clouds at the Edge of Space


AIM at the Edge of Space

they know nothing!

from space.com: http://www.space.com/scienceastronomy/astronomy/universe_overview_010605-2.html
Does the observable universe have an edge?
No, said Livio.
Argh. First you guys tell us the universe is expanding. Then you say it is finite. Now you say it has no edge! We need a visual here.
Livio is up to the task. He dredges up the old expanding balloon as his prop. "An ant traveling on the surface of a balloon will never reach an edge," Livio explains. "In the worst case it will return to its starting point."
And so too do we return. It is now a few moments later in the same year, 2001, heart of the same Information Age, well after the telescope was invented, and we still don't know how big the big house is nor what, if anything, lies beyond.
But now, perhaps we understand what we don't know a little better.

 

[aftershock]

Ok look, Who has a need to install a service at the edge of the universe? And if so, does the NEC have jurisdiction?

 

[480sparky]

Ok look, Who has a need to install a service at the edge of the universe? And if so, does the NEC have jurisdiction?

The NEC has no jurisdition anywhere. That's the AHJ.

 

[aftershock]

The NEC has no jurisdition anywhere. That's the AHJ.

You got me.


Space helmets for the AHJ's I say.

 

[Speedskater]

I'm not dis-agreeing with the concept in the schematic drawing but:
If the loads are all modern computers with switch mode power supplies (SMPS) then each power supply will self-adjust to compensate for changes in AC input voltage and continue to supply the same amount of load power.

 

[Karl H]

As with any electrical Install just use your education and experience.
I've ran thousands of MWBC's to serve computer loads. I have yet to have a
call back to repair a problem due to my original install. I have many repeat
customers. If you don't have a lot of experience with MWBC's this is the
perfect time to educate yourself on the proper way to install MWBC's.
I don't know your situation, But, I bet it won't be PC's that challenge your
install, it will be space heaters. One tip, do the math and balance the loads
as close as you can.