Current carrying capacity

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FMurtz
Guest

Sun Dec 02, 2018 2:45 pm

No, it is *not* the same at different voltages, not by a long chalk.

The voltage drop for a given current at a given length *is* the same.
Neglecting the issue of waste heat, this means that the voltage drops
to zero at a much shorter distance with a lower voltage.

Example : 60A through 65mm^2, you are down to zero before 400m at 12V
(ie 100% wasted as heat in the cable), at 220kv, you are less than 3%
down at 200 km with the same cable.

Quote:
the current will be higher at 12 volt but still much much less than
20 amps

2.5mm^2 is unacceptable if someone is paying you to do the job.... The
loss exceeds the 3% maximum allowable loss. But it is unlikely to be
hazardous.
--
Cheers,
Paul Saccani
Perth, Western Australia.

FMurtz
Guest

Sun Dec 02, 2018 2:45 pm

FMurtz wrote:
Quote:

No, it is *not* the same at different voltages, not by a long chalk.

The voltage drop for a given current at a given length *is* the same.
Neglecting the issue of waste heat, this means that the voltage drops
to zero at a much shorter distance with a lower voltage.

Example : 60A through 65mm^2, you are down to zero before 400m at 12V
(ie 100% wasted as heat in the cable), at 220kv, you are less than 3%
down at 200 km with the same cable.

the current will be higher at 12 volt but still much much less than
20 amps

2.5mm^2 is unacceptable if someone is paying you to do the job.... The
loss exceeds the 3% maximum allowable loss.   But it is unlikely to be
hazardous.
OOps bits missing

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