Background of Members Here

[JimB]

apparently there are undersea power cables from the Continent to the UK, and these have to be DC because they are under sea water?.

I think that the idea is to reduce the capacitive current to earth.

There are some high voltage, long distance overhead power lines which use DC for the same reasons.

Look here:

Benefits of High-Voltage Direct Current Transmission Systems

High-voltage direct current (HVDC) technology offers more efficient bulk power transfer over long distances compared to alternating current (AC) systems.

www.powermag.com

and:

High-voltage direct current - Wikipedia

en.wikipedia.org

JimB

 

[Grossel]

I asked further, and apparently there are undersea power cables from the Continent to the UK, and these have to be DC because they are under sea water?

Yes exactly. AC cables have limitations when it comes to length because of extreme power factors over long distances, and DC cables is usually a better choice.

Another thing about long distances DC cables in sea bottom is that you need only one conductor, the sea water itself works as a huge earth conductor. Not without any losses of course - in each end of such cables there is huge underwater electrodes, and when running full capacity it may look like the sea just outside land/beach are boiling.

 

[ClydeCrashKop]

Yes exactly. AC cables have limitations when it comes to length because of extreme power factors over long distances, and DC cables is usually a better choice.

Why then, if someone wants to operate a 12 volt light bulb at 100 yards, they are advised to use 00 battery cable?

 

[Pommie]

Another thing about long distances DC cables in sea bottom is that you need only one conductor, the sea water itself works as a huge earth conductor. Not without any losses of course - in each end of such cables there is huge underwater electrodes, and when running full capacity it may look like the sea just outside land/beach are boiling.

What happens to anything lving in the vacinity?

Mike.

 

[Nigel Goodwin]

Why then, if someone wants to operate a 12 volt light bulb at 100 yards, they are advised to use 00 battery cable?

What has 12V got to do with AC or DC?.

 

[ClydeCrashKop]

I asked further, and apparently there are undersea power cables from the Continent to the UK, and these have to be DC because they are under sea water?.

What has 12V got to do with AC or DC?.

Why then, if someone wants to operate a 12 volt light bulb at 100 yards, they are advised to use 00 battery cable?

Not so much AC vs DC but that is the advice given for DC wiring.
How many miles of what size DC cable do they use to transfer worth while amount of current from the Continent to the UK?

 

[Nigel Goodwin]

Not so much AC vs DC but that is the advice given for DC wiring.

No, that's the advice given for LOW VOLTAGE/HIGH CURRENT wiring - nothing to do with DC.

 

[Grossel]

Why then, if someone wants to operate a 12 volt light bulb at 100 yards, they are advised to use 00 battery cable?

I believe that cable rating is US standard, at least I haven't heard about that term before. How does it translate into square millimeters ?

What happens to anything lving in the vacinity?

Mike.

Where? I don't live in Netherlands.

Lving

www.google.com

[edit while writing] Figured you means "Living". Since I'm not native English I don't pick up on typos just like that.

 

[ClydeCrashKop]

Why then, if someone wants to operate a 12 volt light bulb at 100 yards, they are advised to use 00 battery cable?

I believe that cable rating is US standard, at least I haven't heard about that term before. How does it translate into square millimeters ?

Ha ha, Sorry. That was an exaggeration. “00” battery cable would be plenty to crank a 2000 horse power, 16 cylinder diesel engine. It is just that when people ask about running a light load over a distance, they get advice to use cost prohibitive, overkill wiring.

 

[Nigel Goodwin]

It is just that when people ask about running a light load over a distance, they get advice to use cost prohibitive, overkill wiring.

No, no one gives that kind of crazy advice, the cable specification is simply dependent on the current. It's simple ohms law.