ACSR FAULT CURRENT

[ptonsparky]

POCO told me a couple days ago that if ACSR overhead cable is involved they give fault current calculations at the transformer secondary. Underground they will give to the meter. Reason being their calculator does not include an option for the ACSR. MHs calculator includes "Aluminum in Nonmetallic Raceway".

Is there a significant difference or close enough? The difference between AL in metallic vs non is a couple hundred amps for the single phase calcs I did to compare.

 

[mbrooke]

Overhead AL will have a higher reactance due to being spaced further apart. I'm surprised a POCO engineer hasn't been able to come up with an equation since ACSR spaced some level apart is universal for MV and HV.

 

[ptonsparky]

Overhead AL will have a higher reactance due to being spaced further apart. I'm surprised a POCO engineer hasn't been able to come up with an equation since ACSR spaced some level apart is universal for MV and HV.

I would think cable of any type would be spaced tighter than any three or four single conductors in any raceway.

 

[mbrooke]

I would think cable of any type would be spaced tighter than any three or four single conductors in any raceway.

You mean aerial bundled cable? In that case I'd think standard spacing in conduit would be a good enough estimate.

Though I am curious by how much twisting reduces X.

 

[ptonsparky]

You mean aerial bundled cable? In that case I'd think standard spacing in conduit would be a good enough estimate.

Though I am curious by how much twisting reduces X.

Yes, that sounds like a good description but, I've never used that term for it.

 

[retirede]

You mean aerial bundled cable?

I’ve always thought ACSR was conductors twisted on a messenger wire. Is there something else?

 

[mbrooke]

I’ve always thought ACSR was conductors twisted on a messenger wire. Is there something else?

https://overheadtransmission.southwire.com/wp-content/uploads/2017/06/acsr.pdf

The messenger is usually ACSR.

But you also have bare AL wire used in T&D which is re-enforced with steal 99% of the time.

 

[mbrooke]

Yes, that sounds like a good description but, I've never used that term for it.

Triplex and quadplex service drop I've heard it called. But I guess it varies by area.

 

[retirede]

https://overheadtransmission.southwire.com/wp-content/uploads/2017/06/acsr.pdf

The messenger is usually ACSR.

But you also have bare AL wire used in T&D which is re-enforced with steal 99% of the time.

Right...I misused the term.

 

[ptonsparky]

Right...I misused the term.

That makes two of us.

 

[kwired]

I’ve always thought ACSR was conductors twisted on a messenger wire. Is there something else?

All the single conductor primary lines are ACSR as well as many single conductor secondary lines where you do run into them.

multiplex assemblies only the messenger is ACSR.

 

[mbrooke]

Right...I misused the term.

you haven't seen me mis-use terms on this forum

That for me is actually a big weakness.

 

[ptonsparky]

Even when I ask for it, I say ACSR triplex or quad. Duh.

 

[mbrooke]

Even when I ask for it, I say ACSR triplex or quad. Duh.

Ask for 1590 ACSR