450kcmil cable

[hhsting]

Anyone know if their is such a size cable? Ampacity tables, table 250.122 don’t show it but plans do??

 

[electrofelon]

There are some specialty cables that come in "odd" sizes. For example DLO cable comes in a 444 KCMIL, and I believe that is usually also dual rated as RHH for NEC use.

 

[hhsting]

There are some specialty cables that come in "odd" sizes. For example DLO cable comes in a 444 KCMIL, and I believe that is usually also dual rated as RHH for NEC use.

This for feeder from breaker used as equipment grounding conductor

 

[electrofelon]

This for feeder from breaker used as equipment grounding conductor

Do they say what type of conductor it is?

 

[hhsting]

Do they say what type of conductor it is?

No


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[electrofelon]

Is the next standard size down from what is shown compliant?

 

[hhsting]

Is the next standard size down from what is shown compliant?

Not sure about that. I have 1200A breaker and phase/neutral conductors have been increased to 6 sets of 4#400kcmil AL due to voltage drop

Its confusing to do 250.122(B) with parallel conductors and see if 400kcmil AL would be ok or 500kcmil be ok?

 

[Rock86]

Not sure about that. I have 1200A breaker and phase/neutral conductors have been increased to 6 sets of 4#400kcmil AL due to voltage drop

Its confusing to do 250.122(B) with parallel conductors and see if 400kcmil AL would be ok or 500kcmil be ok?

Is this a feeder or service entrance. If you are using 250.122 i'm assuming feeder in which case you need a 3/0 copper or 250 al. not sure where you are getting 400 for the equipment grounding conductor.

Also, in Post #1 you mention asking about a cable ampacity, but you're referencing 250.22. Not sure which you are concerned with, equipment grounding conductor size or feeder cable ampacity. Post thread is unclear.

 

[hhsting]

Is this a feeder or service entrance. If you are using 250.122 i'm assuming feeder in which case you need a 3/0 copper or 250 al. not sure where you are getting 400 for the equipment grounding conductor.

Also, in Post #1 you mention asking about a cable ampacity, but you're referencing 250.22. Not sure which you are concerned with, equipment grounding conductor size or feeder cable ampacity. Post thread is unclear.

Its feeder fed from 1200A breaker. Their are 6 sets of 4#600kcmil AL Not 4#400 kcmil.

Feeder cable size is increased due to Voltage drop.

250.122(B) would apply and how did you get 250kcmil Al?

 

[electrofelon]

not sure where you are getting 400 for the equipment grounding conductor.

Me neither, although it does depend what is used for the "normal size". Perhaps OP can show the math.

 

[infinity]

Not sure about that. I have 1200A breaker and phase/neutral conductors have been increased to 6 sets of 4#400kcmil AL due to voltage drop

Its confusing to do 250.122(B) with parallel conductors and see if 400kcmil AL would be ok or 500kcmil be ok?

Is it 450 kcmil (thread title) or 400 kcmil?

 

[hhsting]

Me neither, although it does depend what is used for the "normal size". Perhaps OP can show the math.

Its 6 sets of 4#600kcmil Al NOT 4#400kcmil

 

[electrofelon]

Its feeder fed from 1200A breaker. Their are 6 sets of 4#600kcmil AL Not 4#400 kcmil.

Feeder cable size is increased due to Voltage drop.

250.122(B) would apply and how did you get 250kcmil Al?

Damnit, I want my money back. I just wasted several minutes on incorrect numbers please send guaranteed funds such as money order or certified check....

 

[Rock86]

Its 6 sets of 4#600kcmil Al NOT 4#400kcmil

You dind't tell us the wire size to begin with. Please show us your math and we will help you where you are having the problem.

Unless someone else wants to be nice and do it for you first.

 

[hhsting]

Damnit, I want my money back. I just wasted several minutes on incorrect numbers please send guaranteed funds such as money order or certified check....

??


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[hhsting]

You dind't tell us the wire size to begin with. Please show us your math and we will help you where you are having the problem.

Unless someone else wants to be nice and do it for you first.

I know what the math is. What would be the minimum size conductor for 1200A breaker? How does one determine that to do the math?

 

[Rock86]

I know what the math is. What would be the minimum size conductor for 1200A breaker? How does one determine that to do the math?

Show us your math if you know it. I have an answer for you and will explain, but I want to know how you got what you got.

 

[electrofelon]

I know what the math is. What would be the minimum size conductor for 1200A breaker? How does one determine that to do the math?

10 sets of 1/0 AL...... That would be the minimum. But it's not very realistic. Unfortunately the code doesn't tell us how to determine the original/normal size. You just have to pick what you would have used if it wasn't for voltage drop.

 

[hhsting]

Show us your math if you know it. I have an answer for you and will explain, but I want to know how you got what you got.

Very well but you still dont get my point but this should illustrate i know the equation:

1. Lets say you take 3/0 awg AL at 65C then 130A.

1200/130= 9.2 which means minimum 10 sets of 3/0AL req.

3/0 is approx 163kcmil. 163x10=1630kcmil

Using 6 sets of 600kcmil so thats 3600kcmil

3600/1630*250= 552kcmil

 

[hhsting]

….You just have to pick what you would have used if it wasn't for voltage drop.

See and what would that be?