by David Benton
I presume the Navy follow the color coding of the rest of the world , bar america . black is neutral , not ground . ground would be green , green / yellow , or bare conductor . Neutral may be tied to earth , but the key difference is the neutral is current carrying , the earth only carries current under fault conditions .
the 50 kv / 25 kv system auto transformer system does carry current at 50 kv , and does have less losses consenquently . you posted a link to an article stating the savings at 75 % , yet you say you still dont believe it works ??? . i have explained it to you at least 3 times .
the key disadvantage of the auto transformer is the secondary circuit is not isolated from the primary circuit , under fault conditions (or even open circuit ??? ) all parts of the cirucit can reach the voltage of the highest (primary ) side . you asked why not have a 75kv / 25 kv sysytem , the answer is your potential fault voltage is 100kv in all parts of the cirucit . i dont think many railroad personnel would be keen to have 100 kv floating around their locomotives .
i think the second reason against a bigger voltage differential is that all parts of the circuit carry the same current , so you lose efficency bove a 50 :50 ratio. but im not too sure on that one .
Autotransformers are usually used where a small step up or down in voltage is required . i.e you may have one that is 100:110 volts , to compensate for voltage drop in a domestic circuit .
the 50 kv / 25 kv system auto transformer system does carry current at 50 kv , and does have less losses consenquently . you posted a link to an article stating the savings at 75 % , yet you say you still dont believe it works ??? . i have explained it to you at least 3 times .
the key disadvantage of the auto transformer is the secondary circuit is not isolated from the primary circuit , under fault conditions (or even open circuit ??? ) all parts of the cirucit can reach the voltage of the highest (primary ) side . you asked why not have a 75kv / 25 kv sysytem , the answer is your potential fault voltage is 100kv in all parts of the cirucit . i dont think many railroad personnel would be keen to have 100 kv floating around their locomotives .
i think the second reason against a bigger voltage differential is that all parts of the circuit carry the same current , so you lose efficency bove a 50 :50 ratio. but im not too sure on that one .
Autotransformers are usually used where a small step up or down in voltage is required . i.e you may have one that is 100:110 volts , to compensate for voltage drop in a domestic circuit .
Moderator worldwide railfan , Rail travel & trip reports
The only train trips I regret are the ones I didn't take.
The only train trips I regret are the ones I didn't take.