|
|
|
|
|||||
|
||||||
From: Arild Jensen (no email)
Date: Sun Jan 02 2005 - 23:49:33 EST
The January issue of Professional Boat builder has an article by Nigel
Calder on the subject of Hybrid power propulsion.
There is a side bar on regulatory and safety issues. In it he says:
"it is sometimes suggested that 120VDC is more dangerous than 120VAC".
He then goes on to say that he does not know if these fears have any
scientific foundation.
Then he quotes someone from the Glacier Bay company who indicates that DC
power is less dangerous than AC. HUH???
I have worked in electrical and electronic industry all my life.
>From the basic apprentice class, right through to the monthly safety classes
we had a the power utility company I recall exactly the opposite being
taught.
My partner and I were responsible for all the maintenance and service work
in a 2 Megawatt transformer station.
Included in that station was a DC backup power supply consisting of a 120VDC
battery bank with several thousand amp hours of energy. Enough to keep the
station operating for 8 hours even if the main high voltage grid failed.
We were taught that the 120V DC battery was far more dangerous that the
higher voltage AC. We were also taught that this battery room was probably
more dangerous that the 27,600 volt switch gear in terms of injury potential
from shock.
So now I am wondering. Did I get it wrong all these years or is Nigel
Calder quoting incorrect information.
As I recall, several listees have a background in power utility related work
or DC power applications.
Can anyone contribute some safety knowledge on this issue of DC versus AC.
Regards
Arild
_______________________________________________
http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering
To Unsubscribe send email to
Include the word Unsubscribe (and nothing else) in the subject or body of the message.
Trawlers and Trawlering, T and T, TrawlersandTrawlering, and TandT are trademarks of Water World International. Unauthorized use is prohibited.
|