T-Pain Is On A Boat: Re: [Electric Boats] Re: Batteries wired in series

Thursday, April 28, 2016

Re: [Electric Boats] Re: Batteries wired in series

Most welders and plasma systems work around 30-40 volts.
The EU low voltage directive is set at 80V DC for a reason.

And I´m somewhat conversant with electrical stuff, as I build and design (industrial type) CNC systems.
No argument that 62 V is unpleasant.

Just that neither 48, nor 80V, is really dangerous, nor 220V single phase (with RCD and or GFI).

380V 3-phase is not particularly dangerous, unless its high power.

But, 400V DC is dangerous and needs to be tested to make sure its off.

Moral:
High voltage DC is very dangerous.

The commonly accepted and legal limit is 80V DC.

And most especially on these high power devices where power is tens to hundred kW plus, such as boats and cars.

Anecdote:
We connected 380V, 100 amps, live wires, on our extension cords.
With a running 50 kW diesel generator.
It ran upto 4 industrial cnc machines at a time (on lowered accelerations, due to limited total power).
We ran the genset 10 hours a day 3 months straight, and needed to fill the tank once (1000 l iirc).

But yes, we had industrial engineers and technicians, with experience (about 14 of 18 were engineers).
Its not amateur stuff.
I would not connect live 50 kW stuff, myself.

We could not get the power company to turn on the power for 3+ months.
T.I.S. wins, again..

On 28/04/2016 15:43, Chris Hudson clh5_98@yahoo.com [electricboats] wrote:

I work in the electrical field. We have 125 volt battery banks with the center of the bank grounded. Accidentally coming in contact with the +62.5 or the -62.5 volt side to ground gives a wicked shock. A hit across the heart at that voltage could be deadly. Don't underestimate our "low" voltage systems.

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