unless I'm mistaken, what Rich is saying is that if you properly design
the car, isolating the charger isn't really an issue. The reasons for
isolating your battery pack from the frame and body of the car is, of
course, to prevent electric shock of the innocent bystander or
yourself. Your main battery pack should not be connected directly to
the frame of the car, obviously, but in addition to that, there are a
few other ways in which your traction pack could become connected to
your frame, posing a potential issue. The simplest reason is through
faulty wiring, second, battery shmutz makes the connection through your
batt boxes, and third, which Rich was indirectly mentioning, is through
carbon dust buildup in the motor. In a properly designed car, both
sides of your traction pack are disconnected from the drive system (and
hence the motor) when the car is turned off, eliminating the potential
for there to be a connection through the motor. Have dual contactors,
do your wiring well, take care of your batteries (or use sealed ones),
and your pack is completely isolated from the frame of your car, hence
no issue with charging. Am I mostly right here? Personally, I think I
would use a GFI breaker with my future PFC, just in case.
Seth
On Wednesday, October 9, 2002, at 01:01 PM, Mark Dodrill wrote:
>>> For the sake of everyone's safety, including your own: if you elect
>>> to
>> use a
>>> nonisolated charger, such as a BC-20 or one of Rich's high-power PFC
> models,
>>> please add an isolation transformer. Or wait until Rich develops an
>>> isolated model.
>>>
>
>> Isolate the Damn CAR!!
>> It's easier, and cheaper and should be done anyways with more than 96
>> volts of battery on board.
>> Do the car right.... and the charger is a NON issue.
>> Adding in a Neg side contactor to your Motor negative is all you have
>> to
>> do on most EVs to keep the motor from becoming the ground fault.
>
> Rich, could you give more details for us less educated EV people (like
> me)
> on exactly what this would mean, and what needs to be done?
>
> Thanks.
>
> Mark Dodrill
>
>
>
>
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