Thread: Upgrading sub surface tube lines to 750V
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Old April 12th 10, 02:32 PM posted to uk.transport.london,uk.railway
Denis McMahon[_2_] Denis McMahon[_2_] is offline
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Default Upgrading sub surface tube lines to 750V
Basil Jet wrote:
On 12/04/2010 14:56, d wrote:

Raising the voltage does seem an odd thing to do not least because
they dropped
the voltage from 640V years ago citing power saving reasons (which
sounds like
rubbish TBH , lower voltages are less efficient , not more).

... unless the lower voltages leak less.

Lower voltage means a higher current draw for the same power, and
transmission losses are proportional to I^2.

Rgds

Denis McMahon
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