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Discussion Starter #1
Hi Folks,

I've been having problems with my PFC-20B tripping GFCI. The typical
way to cause the trip is to set the current to zero, turn off the
charger, plug in the charger, turn on the charger, and then start
turning the current up. My home circuit is now tripping when the PFC is
using 7A at 110v. It used to work up to 16A and is on a 20A circuit.

Any thoughts?

Cheers,
Peter

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Discussion Starter #2
Hello Peter,

Turn off the charger as you been doing, by turning down the current knob and
then turn off the charger and unplug the AC.

Take a continuity reading from the charger case to the frame of vehicle. If
you bolted the charger directly to any metal of the vehicle, you should read
close to 0 ohms.

Now is you could unplug the charger from the incoming AC plug and do the
continuity test from a metal shell of the receptacle to the frame. If you
have continuity, then you receptacle is a self grounding from the ground
terminal to the metal case of the receptacle.

If the receptacle is a totally enclose plastic or nylon shell, then this is
a isolated plug and receptacle device that will not self ground to the metal
body of a EV.

Next, connect a volt meter from the most positive post of the main battery
pack to a metal surface of the EV. Then plug in main AC plug, turn on
charger circuit breaker. Only turn up the current knob a bit, but not over
the ampere you trip the GFCI.

If you see any voltage between the main battery pack and the frame of the
EV, then the it may be the following results:

The PFC charger case and/or the AC input receptacle is grounded to the EV.
This voltage reading is normal, because the this type of charger is not
isolated which allows a current return through the ground system which is
then connected to the neutral either at the main service entrance switch
and/or meter.

Now if you remove the meter leads which causes in it self a shunt path to
the grounded EV frame, there could be still some current leakage from any of
the battery terminals across the battery case to either a battery hold down
or to the battery box itself.

To test this, turn off the charger and unplug it. Then adjust the voltmeter
to the same voltage as one battery and put one lead on the battery post and
one on the battery plastic top next to the other post, but not touching it.
If you see any voltage, then the battery case is conducting some current.
Now slide the test lead across the top of the battery, and you see it will
vary in voltage.

If you batteries are in a enclose battery box or just a holding frame, than
keep sliding the voltmeter test lead unto the battery box surfaces and/or
any tie down devices. If you still see any voltages, then it is time to
clean the batteries, battery box and ties downs.

I had even seen this continuity path along the main battery cables that came
off the battery.

Another path for this current to travel while the charger is on, is the
battery feeder cables that go up to the main contactor and to the controller
which is just a straight feed throw to the motor. If your motor is a DC
type with brushes, then the brush dust can track from the commentator down
to the motor shaft which is another AC ground return through a grounded
frame.

To prevent on having the charging current on these devices, I had to install
two more contactors on battery feeder lines to isolated the charging current
from the controller and motor.

One time while I was charging the EV, it was dark, and I saw arcing in the
motor. Some times if you have a very bad leaking damp battery, you can see
this arcing between a battery case and a grounded conductive surface. It is
time to clean the batteries.

To prevent any of these ground fault problems, I built a isolation system
where the batteries are in a epoxy coated fiber glass battery boxes which
are seal. I use a totally enclose arc proof exhaust blower on the battery
boxes that bring in clean fresh air.

I then made the charger a double insulated type, where the metal frame of
the charger is also setting in a epoxy coated fiber glass enclosure which is
also seal and have another blower fan apply positive pressure to this
enclosure. Only the charger case is ground. it like having a charger
setting out of the vehicle with only the two battery leads going to a DC
input plug.

This method is ok, if you only charge at home inside a building and have the
EV setting on a insulated floor and no body is touching the EV and some
other electrical ground device. To use a outboard GFIC, some Anderson
Connectors, have a small pin that is use for grounding.

If you carry your charger on board as I do, I install a 2 pole 50 amps GFI
circuit breaker which is wire between the main AC input plug and charger.
The ground lead of this charger is then connected to the ground connection
in the main AC input. This allows me to plug in any where they might not
have a GFI system.

Any time I have any leakage, I spray the battery surfaces, battery boxes,
cables, or other surfaces with Windex with Ammonia. The ammonia is what
neutralizes any battery acid.

Roland






----- Original Message -----
From: "Peter C. Thompson" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Monday, September 27, 2010 9:58 AM
Subject: [EVDL] Manzanita PFC-20B tripping GFCI


> Hi Folks,
>
> I've been having problems with my PFC-20B tripping GFCI. The typical
> way to cause the trip is to set the current to zero, turn off the
> charger, plug in the charger, turn on the charger, and then start
> turning the current up. My home circuit is now tripping when the PFC is
> using 7A at 110v. It used to work up to 16A and is on a 20A circuit.
>
> Any thoughts?
>
> Cheers,
> Peter
>
> _______________________________________________
> | REPLYING: address your message to [email protected] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>

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Discussion Starter #3
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Discussion Starter #4
On 10 Oct 2010 at 21:07, Peter C. Thompson wrote:

> She also made an interesting observation - there are no
> noise-rejection chokes in the charger - something that she says should
> be in ANY charger or inverter (she should know - she designs power
> supplies for my company).

The PFC chargers are not consumer items. They were designed by an EV
hobbyist for EV hobbyists. The lowest possible cost per watt of output in a
limited-production charger was the primary goal, trumping everything else,
including safety.

Noise suppression isn't the only omission. They are not galvanically
isolated from the power mains, and yet they don't include GFI protection
(though they say you should connect it to a GFI). To my knowledge they have
never been tested to ensure they will survive high voltage surges without,
say, catching fire. At least when I last checked, they had not been tested
or approved by UL, CSA, FCC, or any other regulatory agency.

I worry a bit about Rich sometimes. Most likely nothing untoward will ever
happen, given the numbers in which the PFC chargers sell. But if anybody
with a PFC-equipped EV should ever have his kid be electrocuted, or have his
garage burn down, or have his heart pacemaker interfered with, and decide to
come after Rich brandishing a large, keenly-sharpened attorney, Rich stands
to lose a LOT. I hope he carries a good and very generous liability
insurance policy.

David Roden - Akron, Ohio, USA
EVDL Administrator

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Discussion Starter #5
On 11 Oct 2010 at 3:52, EVDL Administrator wrote:

> They were designed by an EV hobbyist for EV hobbyists.

On second thought (and second reading), the first part of that sentence
isn't really accurate, and it carries a connotation I don't mean at all.

But I think it's fair to say he designed the PFC for hobbyists - in fact the
process involved consultation with this list.

David Roden - Akron, Ohio, USA
EVDL Administrator

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