# Transmission line

Hello

i would like to know what is the different between 300km and 150km in transmission line..
thanks

jim mcnamara
Mentor
What kind of characteristics are you asking about? Line loss? There is a practical limit to the length of a transmission line, substations and ties affect transmission lines as well.

Could you please be a lot more specific? example: How many Kv? What are you trying to learn about?
http://en.wikipedia.org/wiki/Electric_power_transmission

[story]
As a side note: Rio Grande Electric Cooperative has the single longest transmission line in the US (As of 1995).
It was nicknamed 'Old Leaky'. If I remember correctly, it had line losses on the order of 15%. Rio Grande, to my knowledge, has never done well financially. I think the line has something to do with it. With the measurement of customers per mile of line, it was also awful - about .5 customer meters per mile. Most meters were lumped in a few small developments in the Big Bend Park.
[/story]

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okay...

I'm not asking for line loss, I'm asking like what is the main different between both of the lines..
380v...

jim mcnamara
Mentor
None, except increased line loss and side effects like cost of maintenance. Line loss is a function of distance, AC vs DC, conductor types, coronal loss, voltage, etc. Line length(resistance / impedance) is the primary factor after AC/DC and voltage.

So, your question, as asked, makes little sense to me. Unless you are referring to impedance or resistance....

Since you refuse to consider line loss (impedance/resistance, etc), the answer is: no difference.

Is this a homework question of some sort?

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davenn