EV Digest 6614
Topics covered in this issue include:
1) UNSUBSCRIBE
by Michael Wong <[EMAIL PROTECTED]>
2) Re: ADC v.s. ImPulse9
by <[EMAIL PROTECTED]>
3) RE: Quick PFC20 question
by "Roger Stockton" <[EMAIL PROTECTED]>
4) Re: Motor temp
by "Ryan Stotts" <[EMAIL PROTECTED]>
5) Slightly lower cost A123's
by "Ryan Stotts" <[EMAIL PROTECTED]>
6) Re: Quick PFC20 question
by "Evan Tuer" <[EMAIL PROTECTED]>
7) Re: practical grounding (RE: Quick PFC20 question)
by "Rich Rudman" <[EMAIL PROTECTED]>
8) Re: Slightly lower cost A123's
by [EMAIL PROTECTED]
9) Re: Quick PFC20 question
by "Rich Rudman" <[EMAIL PROTECTED]>
10) Re: Quick PFC20 question
by "Evan Tuer" <[EMAIL PROTECTED]>
11) Re: Quick PFC20 question
by "Rich Rudman" <[EMAIL PROTECTED]>
12) Re: Quick PFC20 question
by "Joe Smalley" <[EMAIL PROTECTED]>
13) Re: May C&D Article on White Zombie
by "Paul G." <[EMAIL PROTECTED]>
14) RE: Quick PFC20 question
by "Roger Stockton" <[EMAIL PROTECTED]>
15) Re: Quick PFC20 question
by "Rich Rudman" <[EMAIL PROTECTED]>
16) RE: Quick PFC20 question
by "Roger Stockton" <[EMAIL PROTECTED]>
17) Re: Quick PFC20 question
by "Roland Wiench" <[EMAIL PROTECTED]>
18) Motor problems
by [EMAIL PROTECTED]
19) More Killacycle press
by "Ryan Stotts" <[EMAIL PROTECTED]>
20) Re: Motor problems
by Jim Husted <[EMAIL PROTECTED]>
21) Re: ADC v.s. ImPulse9
by Jim Husted <[EMAIL PROTECTED]>
22) Re: EV converter in North Carolina
by David Brandt <[EMAIL PROTECTED]>
--- Begin Message ---
UNSUBSCRIBE
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--- Begin Message ---
Hi Jim The Idea behind the implus was I beleave to have a shorter motor that
would fit where a 8 was and a 9 wouldn't go ,,, but taking a few inches off the
length gave it less toqure , and therefor more rpm for the same power out ...
It has the same burshes and com as the 9 , which are about 20% bigger the the
8. . >
> From: Jim Husted <[EMAIL PROTECTED]>
> Date: 2007/03/30 Fri AM 08:57:19 EDT
> To: [email protected]
> Subject: Re: ADC v.s. ImPulse9
>
> Hey all
>
> I've yet to see an Impulse9 and is the reason I didn't
> chime in on this thread. Sorry but I have no imput
> yet 8^(
>
> Just wanted to say I wasn't ignoring this topic.
>
> Cya
> Jim Husted
> Hi-Torque Electric
>
> --- [EMAIL PROTECTED] wrote:
>
> > I have both of these motors in me shop ,,,Toqure per
> > amp ( no volt :-) they both look close , the Implus
> > is about 20 lbs heaver but has the bigger brushes
> > by about %20 , like the 9 " the com is bigger round
> > ... amybody running two impluse 9's might this be
> > the new ticket , not to big not to small ?
> > steve clunn .
> > >
> > > From: "Roger Daisley @ R J Ranch"
> > <[EMAIL PROTECTED]>
> > > Date: 2007/03/28 Wed PM 07:12:42 EDT
> > > To: <[email protected]>
> > > Subject: ADC v.s. ImPulse9
> > >
> > > Any comments on the Advanced D.C. 8" motor
> > (#203-06-4001) vs.. the ImPulse 9
> > > motor?
> > >
> > >
> >
> >
>
>
>
>
> ____________________________________________________________________________________
> Now that's room service! Choose from over 150,000 hotels
> in 45,000 destinations on Yahoo! Travel to find your fit.
> http://farechase.yahoo.com/promo-generic-14795097
>
>
--- End Message ---
--- Begin Message ---
Rich Rudman wrote:
> GET 50 amp HOT tub GFI breaker..
> They are about $105 each.
Fine for home use and a PFC50, but doesn't really help you when charging
elsewhere and is a bit overkill for a PFC20 or 30, isn't it?
Also, Rich may have deliberately intended to state "GFI", but note that
a GFI and GFCI are tow different animals: a GFCI device is intended to
protect personnel and so trips for leakage current of >4-6mA; a GFI
device is intended to protect equipment only and so trips for leakages
>30mA. Hot tub/spa breakers are actually GFCI devices.
Here's a suggestion: instead of installing that breaker in your home
panel, install it in a box onboard the EV between the charge inlet and
charger. This way you always have a GFCI inline where ever you charge,
and you don't have to pay an electrician to install a breaker in your
house panel.
You can buy the breaker complete with a suitable enclosure, such as this
unit from Cutler-Hammer:
<http://eatonelectrical.ca/lcb/docs/SA3113CSK.pdf>
$108 here, which is the enclosure *and* 2-pole 50A GFCI breaker:
<http://www.cpostores.com/source4data/browse.cfm/4,390.htm>
For 120VAC input only chargers, a convenient option may be to use one of
the readily available extension cords with built-in GFCI to plug in your
charger:
12/3, 50 foot with GFCI $65: <http://www.rewci.com/50grfaciinge.html>
Same thing, but 25 foot $55: <http://www.rewci.com/25grfaciinex.html>
Or, for a bit less cost ($46), just put a 15A or 20A plug with built-in
GFCI on your charger's cord:
<http://www.twacomm.com/catalog/model_6593.htm?sid=FF00244675D65D94C3937
155741BDB6F>
Here's an interesting one for Rich:
<http://www.twacomm.com/catalog/model_8895.htm?sid=FF00244675D65D94C3937
155741BDB6F>
20A 125V GFCI, 80A @ 240VAC when used with an appropriate relay. $53.
> Ok.. from the real world of EVers.. GFI won't stay in..Darn!!
> remove it I am not walking home...
Right. So how do we address this?
Having a GFCI breaker inline provides a couple of safety features:
- when you plug in, you can press the 'test' button to see if the
outlet's ground connection is present.
- if your vehicle develops a significant level of ground leakage, the
GFCI will trip and alert you to the situation.
If the GFCI trips, it is telling you that you've got an undesired
leakage path to ground and need to address it. I can't think of a
simpler, more foolproof way to be notified that it is time to clean the
batteries, etc.
Now, what conditions might cause it to trip?
- a leakage path to chassis through the motor (which will happen due to
brush dust and other normal contamination in the motor). Solution: use
contactors in *both* traction lines so the pack is completely
disconnected from the motor (and electronics) when the key is off and
the charger is connected. As a bonus, this can allow everything under
the hood to be compeltely disconnected from the traction pack when
parked with the hood up, so no need for extra plastic covers and "danger
- high voltage" type warnings to scare the public into thinking EVs are
too dangerous.
- a leakage path to chassis from one or more battery terminals due to
acid mist. This is primarily a concern with floodies, and will
eventually happen in normal use. Solution: keep the batteries clean
(reality: this can be labour intensive and human nature is such that
routine maintenance will be neglected until the GFCI prevents charging,
which will only happen when you *really* need to charge and aren't in a
position to troubleshoot/clean the pack ;^). Place the batteries in
non-conductive boxes and use non-conductive hold-downs or at least
design the hold-downs so that they don't provide an easier leakage path
to ground and/or trap electrolyte between them and the battery case such
that it is difficult or impossible to clean the leakage path away.
Design the boxes to make routine cleaning easy (e.g. design in drains so
that the batteries can be hosed down, etc.). Use a charger that doesn't
gas the batteries excessively to start with. Use sealed batteries (AGM,
gel) to greatly reduce this problem, and place them in non-conductive
boxes to virtually eliminate it.
> Ev listers are Not going to pay a Buck a watt for a EV
> charger..
It isn't that expensive to build in the safeties. You are about
$0.50/watt, right? If you built a $100 50A GFCI breaker into every
unit, let's assume $200 added cost (should be more than generous since
you won't be paying retail for those breakers anyway); that's a 10% hit
on a $2000 charger and doesn't push you anywhere near $1/watt. In fact,
the hit would be less since you would be replacing the existing breaker
with the GFCI.
Likewise, isolation doesn't have to push the cost up much.
> Iso and GFIs are bandaids...
I've tried to address GFCI above, so let's look at isolation now.
The output of an isolated charger is isolated with respect to the AC
line, so even if the vehicle is ungrounded and a leakage path to chassis
exists one cannot get shocked by touching the vehicle and earth ground.
So far so good. Now, what if the isolation fails? If the chassis is
ungrounded, then there is a good chance the fault will go undetected
until someone touches the chassis and provides a path to earth ground.
If the chassis is grounded, the fault might still go undetected, but one
can't get shocked by touching the chassis and earth ground. A GFCI on
the AC input *might* trip and reveal the fault if the isolation fails
and the chassis is grounded; I'm not certain. A GFCI on the AC input is
still a very good idea anyway since it will reveal and prevent any
leakage of the AC line to ground after the GFCI device (e.g. a fault on
the input side of the charger).
I wonder if it would add value (or violate some code) to provide a
connection (direct or through some highish impedance) between the
negative side of the isolated charger's output and earth ground (at
least while charging)? This would seem to be a way to ensure that the
GFCI would trip in the unlikely event of an isolation failure.
I don't understand the reference to isolation being a bandaid since it
reduces the risk of shock hazard whether the chassis is grounded or not,
and so I would suggest that if one is using floodies, which are prone to
leakage to chassis, an isolated charger is a wise choice since it would
result in a reduced shock hazard and reduced likelihood of GFCI nuisance
tripping.
> All of us racers and real EV runners almost to a fault don't
> have GFI or even chassis grounds hooked up while we are charing.
> In racing ... it gets in the way.
Can you explain why that would be? If racers are so diligent to ensure
that there isn't any leakage paths to chassis from the pack, then how
can a GFCI possibly get in the way?
> I think one of the points is that we specifically don't run a
> Grid ground to a race car.. that way you can't get shocked
> unless the fault is to the track from the battery post and wires.
> Adding in the grounded chassis adjacent to the pack and
> charge port just puts both sides of circuit within hands reach.
This is an interesting observation, but it implies three things: first
you are assuming a non-isolated charger; second, you are assuming that a
GFCI is NOT being used (since it would protect against an unsafe leakage
between charger output and the grounded chassis); and third, that either
there is exposed traction wiring or that someone is foolish enough to be
removing the covers and working on the traction electrical while it is
charging (a fundamental safety no-no). If normal (race) charging of the
vehicle requires exposing the traction pack connections, then it
probably hasn't been designed safely to start with (e.g. a lexan cover
with holes for DMM probes at the appropriate places is inherently safer
than pulling the cover to monitor module voltages, and a proper BMS to
do it automatically is even better).
> If you really want a safe EV build it that way to start.
> Then Iso.NON iso GFI etc is a moot point.
Designing safety in from the start is definitely wise advice. Isolation
and/or GFCI don't become moot points because designing the EV to be safe
doesn't ensure that it will remain safe. The GFCI is your friend: every
time you plug in it verifies that the EV is still as safe as you
intended it to be, without any extra effort on your part. If you've
designed the EV to be safe, then the GFCI should never trip, but when
the unthinkable happens and that wire abrades to the chassis, etc. it
will catch it.
Cheers,
Roger.
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--- Begin Message ---
Doug wrote:
But seriously, a display labeled "AMP TEMP" is a deal-killer for me.
Life's too short to put up with bad user interfaces.
I think it was referring to car audio amplifiers?
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--- Begin Message ---
See the price here for the four pack:
http://www.a123racing.com/html/rcdevkits.html
And then here for the same(different price):
http://www.maxamps.com/products.php?cat=62
The question though is: how much did THEY pay for the four pack? And
a further question on top of that would be: How much profit does A123
make off the sale of the four pack?
Just what amount of markup are we dealing with here?
There has got to be some ingenious was to string ~6,000+ batteries together...
What if they made the cases so they could be threaded together? Then
have threaded "bus bars" to hook parallel rows together with?
--- End Message ---
--- Begin Message ---
On 3/30/07, Rich Rudman <[EMAIL PROTECTED]> wrote:
Look EVAN
All of us racers and real EV runners almost to a fault don't have GFI or
even chassis grounds hooked up while we are charing. In racing ... it gets
in the way.
The Story to be learned here is that we don't have shocks and ground faluts
or any of the ...Oh Gee we gonna die issues.
Like I said, that's all perfectly fine as far as I'm concerned. My
point was only that you are encouraging random people on an internet
mailing list to follow suit, who in all likelihood don't understand
the risks. I'm just trying to challenge that to at least make people
aware that it's a bad idea for a daily driver EV, if you don't want to
get a nasty shock one day.
Are you a safe Ev driver or are you a fool that needs the added protection??
Excuse me? I have an EV to drive, not to "look for and solve leaks
and potential fail points on a minute by minute bassis" - in fact my
girlfriend drives it, and we put 20,000 miles on it each year. Number
of times it's tripped the RCD? None. Number of times I've felt the
need to poke about the battery box with a multimeter, just to see if
it's likely to kill one of us next time we open the door? None. Do
we worry if it's charging at the side of the street and people walk
past and brush against it? No. And neither should we have to.
Rich, I was not attacking you, but you are being totally irrational on
this issue.
I'll continue to point it out if I see anyone advising dangerous
courses of action, without any other explanation.
Good luck
Evan
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--- Begin Message ---
Use the ground pin on your Charger to affect the ground for the charger.
If your charger has a Green ground wire on the DC side..
PFC chargers do.. connect this to your chassis.
You get the chassis grounded as per code.
Warnings.. you really need a ground close to your EV.. having the ground rod
too far away , can give you a Ground lift effect if and when there is a
need. The point is you need a ground at the EV site. Not 300 yards away.
I think the rules are 50 ft from a out door recepticle. It's not far.
lots of us have the EV plug really close to the breaker box, That has a
ground pin right under it. This is good.
Again. I succesfully charged Goldie with no Grounds from 240 VAC.. brushed
against her.. touched and adjusted the Regs and controls..
I am quite a live.. not even shocked. Not even tingled.
The charger case is VERY grounded I might add. The EV chassis is not.
Rich Rudman
Manzanita Micro
----- Original Message -----
From: "Randy Burleson" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, March 30, 2007 10:47 AM
Subject: practical grounding (RE: Quick PFC20 question)
> > > And never let the neibour Kids mess with your EV while it's
> charging.
> > Easier said than done, that one. Never charge anywhere except in
> > your closed garage? Never let anyone touch it in case they get a
> > shock?
>
> So let's take this discussion in a different way... how do you ground a
> vehicle best? Using fully grounded equipment makes sense, but is there
> an easy way to do supplemental grounding to actual earth?
>
> Reason I ask is that I have a big pine tree that is slowly tearing up my
> slab sidewalk, and have an 'opportunity' to replace it -- should I run a
> Ufer ground (concrete encased electrode) simultaneously and provide a
> secondary ground where I'll be charging? BTW, I had to check the
> spelling of that, and Googled up a nice history on Herbert G. Ufer:
> http://www.scott-inc.com/html/ufer.htm
>
> I'm running a sizable underground conduit from the shop for later use,
> as well.
>
> Comments, advice? Laughter? ;)
>
> Randii
>
--- End Message ---
--- Begin Message ---
Ryan> See the price here for the four pack:
Ryan> http://www.a123racing.com/html/rcdevkits.html
Ryan> And then here for the same(different price):
Ryan> http://www.maxamps.com/products.php?cat=62
Someone else pointed out that these require welding or soldering which is
expensive, infeasible or both, depending what connection technology you're
dealing with and your access to fancy schmancy welding gear. They aren't
dual tab batteries as are contained in the more expensive kit on the A123
site.
--
Skip Montanaro - [EMAIL PROTECTED] - http://www.webfast.com/~skip/
"The hippies and the hipsters did some great stuff in the sixties,
but the geeks pulled their weight too." -- Billy Bragg
--- End Message ---
--- Begin Message ---
Roger yer out winding me...
And that takes some effort!
Madman
--- End Message ---
--- Begin Message ---
On 3/30/07, Roger Stockton <[EMAIL PROTECTED]> wrote:
Also, Rich may have deliberately intended to state "GFI", but note that
a GFI and GFCI are tow different animals: a GFCI device is intended to
protect personnel and so trips for leakage current of >4-6mA; a GFI
device is intended to protect equipment only and so trips for leakages
>30mA. Hot tub/spa breakers are actually GFCI devices.
Hi Roger,
In the US, do you have different current classes of RCD / GFCI available?
I believe that at least with non-isolated chargers, the most likely
fault current (pack leakage to ground) suggests a class A, rather than
the normal AC variety.
From this page http://www.tlc-direct.co.uk/Book/5.9.2.htm :
[..]
There are currently four basic types of RCD. Class AC devices are used
where the residual current is sinusoidal - this is the normal type
which is in the most wide use. Class A types are used where the
residual current is sinusoidal and/or includes pulsating direct
currents - this type is applied in special situations where electronic
equipment is used. Class B is for specialist operation on pure direct
current or on impulse direct or alternating current. Class S RCDs have
a built-in time delay to provide discrimination (see below).
[..]
I think the point is that the AC type might fail to trip at its rated
current (or perhaps be damaged by) a DC component.
It's worth a thought anyway.
Regards
Evan
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--- Begin Message ---
Please do so.
> Rich, I was not attacking you, but you are being totally irrational on
> this issue.
>
> I'll continue to point it out if I see anyone advising dangerous
> courses of action, without any other explanation.
>
> Good luck
> Evan
>
I know the rules as well as any of you do...
I also know that they are over whelming and knee jerk reactions.
I am clearly pointing out... that you are not going to get killed by
disregarding most if not all the "Code" requirements. It takes a special set
of faults to make a lethal event happen.
Know what they are and learn from them.
EVs won't reach out and grab you the way the safety folks would have you
believe. You should read the safety requirements to work on a Hybrid Ford..
3 ft of clear air.. rubber gloves...
restricted personal... for 330 DC mind you... Yawn!! 480 VAC still scares
the hell out of me though.
I am being irrational just because I am arguing the other side of the
coin..... Most folks with GFCI and GFI devices on thier EVs.. are. Well
kinda strange to me. Most are wired in a way to make them useless. And most
folks ignore them if they get in the way. So what's the use????
There is nothing worse that standing around while somebody has to go reset a
GFI or figure out why the little charger won't play games....
And I have not looked too hard at Goldie in years... oH since the last
Battery swap... fired up and ran fine.. chassis was not hot to the touch...
I was standing on damp ground and in wet tenny shoes... 240 Line to line..
Grounded charger..floating chassis.
The PFC 30 is on a Lexan sheet covering the rear battery box.
I will run and charge like this But I will not work on the chassis with the
charger powered up.
Maybe that is the whole story.. Not grounded but not enough leakage to
notice, And the smarts not to get caught under the EV where you are a MUCH
better grounding rod, and can't get away from it.
The point is not to trash my product but learn from my hands on experiece at
surviving.
If my chassis goes hot to line.. Believe me I will be the first to notice
and the first to wring the necks of those who expose this hazzard to the
General public.
Mean while I will use the contractors measuring stick.. If it blows a
breaker turn it down.
That's what protected circuit means.
When somebody pays for a Code charger.. then they get to pay for all the
specs and saftey tests.
I think most folks are pretty happy with 25 cents watt and PFC with Breaker
and fuses and voltage and current control, timers and BMS feedbacks.
Oh I keep forgetting.. You want to meet the %125 over design, and the not
more than %80 of branch rating?????
Trun it down!!!, funny I have always had that feature on my chargers.. You
can always turn it down.
That leaves the customer to make the decision as to how much needs to be
drawn and can be utilized.
I have been back logged for about a year now...
My customers seam to be pretty happy with my feature set..
Iso will cost about %40, and I doubt that I can stuff 9600 watts from a 1/2
a cubic foot box with Iso. That would be a real challenge. Water cooled
is just about the only option, With spiffy heatsinks and such. Heck doing
that single stage is hard enough.
So.. are we going to let this thread die??? or are we going to gain
something from it?
While all you safety guys are going for isolation transformers and GFCI.. I
will be cleaning up my battery tops and checking Regs for the hotter
weather. Maybe a shot of air to kick out the Graphite dust that is the ONLY
AC leak I am concerned about.
Madman
--- End Message ---
--- Begin Message ---
Yes, You did get that right.
Joe Smalley
----- Original Message -----
From: "Bill Dennis" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, March 30, 2007 11:44 AM
Subject: Re: Quick PFC20 question
If I understand correctly, the connection to ground on Rich's PFC
chargers is made back at the utility box, not inside the charger
itself. That is to say, inside the charger, the green and white AC
wires are not connected. The green wire is the only one that's
connected to the charger case, so the charger case gets connected to
ground only when the charger is actually plugged into an AC outlet.
Therefore, when the charger is unplugged from AC, there is no electrical
connection between the traction pack and the charger case (and thus the
car chassis). Did I get that right?
Thanks.
Bill Dennis
--- End Message ---
--- Begin Message ---
On Mar 30, 2007, at 6:21 AM, Jim Husted wrote:
You know my wife tells me all the time I could use a
good ass kicking EVery now and then! FWIW I hope you
all don't think I'm above a good spanking so let em
rip if you see me stuffing my face full of foot 8^)
You know, a closed mouth gather no feet! Please don't quit talking
though, I'm always looking for a chance to feed you feet LMAO.
More seriously, we need your wisdom too :-)
Paul "neon" G.
--- End Message ---
--- Begin Message ---
Rich Rudman wrote:
> Roger yer out winding me...
>
> And that takes some effort!
Yeah, that message did get a little long ;^>
The important question is are we providing the sort of information that
newbies (and not-so-newbies) need in order to be able to build safe EVs
and keep them safe?
> The point is not to trash my product but learn from my hands
> on experiece at surviving.
Right. Non-iso chargers, whether yours or someone else's (or a homebrew
badboy, etc.) are going to be used. So will isolated ones
(low-frequency and high). So let's understand what design precautions
and safety practices are essential for a long and uneventful
relationship with our chosen poison. Let's especially understand if
there is something that improves safety with one type of charger but
compromises it with another.
You provided a good set of safety practices associated with working on
an EV, but I'm not sure that we've really established a clear list of
safety-related best practices for design and ordinary operation. As
Evan says, an Ever shouldn't have to constantly wonder/worry about/test
if their EV poses a shock hazard every time they plug in. Can we come
up with any clear list of best practices to achieve this goal with
either isolated or non-isolated chargers?
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
We Bond the Green ground wire to the chassis of the Charger.
The Green Ground on the DC cable is also bonded to the charger case.
We do not use the White Neutral wire in a 4 wire plug.
OK.... now what are you talking about here...?? NO AC plugged in...
There is no connection from the charger case to traction pack at any time!!
That would be a short!.
The point is to keep the traction pack Both sides of it away from Chassis
and earth ground.
The chassis grounding to earth eliminates the risk of a chassis to person
shock.. But increased the risk of charger damage, and single point faults.
Single point faults are when you close the gap from cable or battery to
chassis ground. Yea your kids don't get a shock... You do when you get your
finger in the wrong place or drop a tool.
Madman
----- Original Message -----
From: "Bill Dennis" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, March 30, 2007 11:44 AM
Subject: Re: Quick PFC20 question
> If I understand correctly, the connection to ground on Rich's PFC
> chargers is made back at the utility box, not inside the charger
> itself. That is to say, inside the charger, the green and white AC
> wires are not connected. The green wire is the only one that's
> connected to the charger case, so the charger case gets connected to
> ground only when the charger is actually plugged into an AC outlet.
> Therefore, when the charger is unplugged from AC, there is no electrical
> connection between the traction pack and the charger case (and thus the
> car chassis). Did I get that right?
>
> Thanks.
>
> Bill Dennis
>
--- End Message ---
--- Begin Message ---
Evan Tuer wrote:
> In the US, do you have different current classes of RCD /
> GFCI available?
> I believe that at least with non-isolated chargers, the
> most likely fault current (pack leakage to ground)
> suggests a class A, rather than the normal AC variety.
I don't know. I've seen references to 'Class A' GFCI devices, but
nothing to describe how they might differ from any other class of GFCI
(nor any reference to any other class of GFCI). The only clear
reference I've seen is the distinction between "GFI" and "GFCI" devices.
Everywhere a GFCI device is required, the Class A type seems to be
specified, but I've no idea if our Class A is the same as yours!
GFCI devices tend to be based on inductive sensing of current imbalance,
and so ordinarily wouldn't seem to be able to detect a DC leakage,
however the (Class A?) GFCI devices are apparently able to detect
leakage between neutral and earth even without any (other) load current,
so perhaps they might. In any event, if there was a leakage path, then
as soon as AC is applied, there will be an AC component to the leakage
current and presumably the device will trip if the leakage current is
significant enough.
I will note that GFCIs have different sensitivity to high-frequency
noise, and some models are much more sensitive to high-frequency leakage
than to line frequency (i.e. will trip for currents much less than their
4-6mA spec). Be sure to test the GFCI with your particular charger/load
to ensure compatibility before assuming you have a ground fault just
because it trips.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
My EV has a built in chassis mounted circuit breaker between the a isolated
50 amp 4 wire nylon cover connecter and plug. This connector is not self
grounding to the metal housing.
There is a AC magnetic contactor that is between this circuit breaker and
charger that is held close by a normally close contact of a small glass plug
in relay that is rated at 250 volts with a 12 volt coil that I control with
a 3 position selector switch. The AC magnetic contactor has a extra power
pole on it that turns off the ignition 12 volt circuit while the AC plug is
connected to the EV.
The 12 volt coil is to be connected to a ground detection device, which I
did not install yet. Normally these take a AC circuit and A battery DC
current to chassis ground does not work. A dc current relay may work.
The circuit breaker is Square D 60 amp 2 pole 250 VAC that is use in
commercial frame panels. It uses set screw line and load lugs. Using a
chassis mounted kit, it can be mount on a flat chassis board.
Square D, General Electric, Westinghouse, Cutler Hammer and others make the
same type of circuit breaker. You can only replace these 2 pole or 3 pole
breakers 250 and 480 volt circuits breakers with a GFI type only.
Roland
----- Original Message -----
From: "Roger Stockton" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, March 30, 2007 3:21 PM
Subject: RE: Quick PFC20 question
> Rich Rudman wrote:
>
> > GET 50 amp HOT tub GFI breaker..
> > They are about $105 each.
>
> Fine for home use and a PFC50, but doesn't really help you when charging
> elsewhere and is a bit overkill for a PFC20 or 30, isn't it?
>
> Also, Rich may have deliberately intended to state "GFI", but note that
> a GFI and GFCI are tow different animals: a GFCI device is intended to
> protect personnel and so trips for leakage current of >4-6mA; a GFI
> device is intended to protect equipment only and so trips for leakages
> >30mA. Hot tub/spa breakers are actually GFCI devices.
>
> Here's a suggestion: instead of installing that breaker in your home
> panel, install it in a box onboard the EV between the charge inlet and
> charger. This way you always have a GFCI inline where ever you charge,
> and you don't have to pay an electrician to install a breaker in your
> house panel.
>
> You can buy the breaker complete with a suitable enclosure, such as this
> unit from Cutler-Hammer:
>
> <http://eatonelectrical.ca/lcb/docs/SA3113CSK.pdf>
>
> $108 here, which is the enclosure *and* 2-pole 50A GFCI breaker:
>
> <http://www.cpostores.com/source4data/browse.cfm/4,390.htm>
>
> For 120VAC input only chargers, a convenient option may be to use one of
> the readily available extension cords with built-in GFCI to plug in your
> charger:
>
> 12/3, 50 foot with GFCI $65: <http://www.rewci.com/50grfaciinge.html>
>
> Same thing, but 25 foot $55: <http://www.rewci.com/25grfaciinex.html>
>
> Or, for a bit less cost ($46), just put a 15A or 20A plug with built-in
> GFCI on your charger's cord:
>
> <http://www.twacomm.com/catalog/model_6593.htm?sid=FF00244675D65D94C3937
> 155741BDB6F>
>
> Here's an interesting one for Rich:
>
> <http://www.twacomm.com/catalog/model_8895.htm?sid=FF00244675D65D94C3937
> 155741BDB6F>
>
> 20A 125V GFCI, 80A @ 240VAC when used with an appropriate relay. $53.
>
> > Ok.. from the real world of EVers.. GFI won't stay in..Darn!!
> > remove it I am not walking home...
>
> Right. So how do we address this?
>
> Having a GFCI breaker inline provides a couple of safety features:
>
> - when you plug in, you can press the 'test' button to see if the
> outlet's ground connection is present.
>
> - if your vehicle develops a significant level of ground leakage, the
> GFCI will trip and alert you to the situation.
>
> If the GFCI trips, it is telling you that you've got an undesired
> leakage path to ground and need to address it. I can't think of a
> simpler, more foolproof way to be notified that it is time to clean the
> batteries, etc.
>
> Now, what conditions might cause it to trip?
>
> - a leakage path to chassis through the motor (which will happen due to
> brush dust and other normal contamination in the motor). Solution: use
> contactors in *both* traction lines so the pack is completely
> disconnected from the motor (and electronics) when the key is off and
> the charger is connected. As a bonus, this can allow everything under
> the hood to be compeltely disconnected from the traction pack when
> parked with the hood up, so no need for extra plastic covers and "danger
> - high voltage" type warnings to scare the public into thinking EVs are
> too dangerous.
>
> - a leakage path to chassis from one or more battery terminals due to
> acid mist. This is primarily a concern with floodies, and will
> eventually happen in normal use. Solution: keep the batteries clean
> (reality: this can be labour intensive and human nature is such that
> routine maintenance will be neglected until the GFCI prevents charging,
> which will only happen when you *really* need to charge and aren't in a
> position to troubleshoot/clean the pack ;^). Place the batteries in
> non-conductive boxes and use non-conductive hold-downs or at least
> design the hold-downs so that they don't provide an easier leakage path
> to ground and/or trap electrolyte between them and the battery case such
> that it is difficult or impossible to clean the leakage path away.
> Design the boxes to make routine cleaning easy (e.g. design in drains so
> that the batteries can be hosed down, etc.). Use a charger that doesn't
> gas the batteries excessively to start with. Use sealed batteries (AGM,
> gel) to greatly reduce this problem, and place them in non-conductive
> boxes to virtually eliminate it.
>
> > Ev listers are Not going to pay a Buck a watt for a EV
> > charger..
>
> It isn't that expensive to build in the safeties. You are about
> $0.50/watt, right? If you built a $100 50A GFCI breaker into every
> unit, let's assume $200 added cost (should be more than generous since
> you won't be paying retail for those breakers anyway); that's a 10% hit
> on a $2000 charger and doesn't push you anywhere near $1/watt. In fact,
> the hit would be less since you would be replacing the existing breaker
> with the GFCI.
>
> Likewise, isolation doesn't have to push the cost up much.
>
> > Iso and GFIs are bandaids...
>
> I've tried to address GFCI above, so let's look at isolation now.
>
> The output of an isolated charger is isolated with respect to the AC
> line, so even if the vehicle is ungrounded and a leakage path to chassis
> exists one cannot get shocked by touching the vehicle and earth ground.
> So far so good. Now, what if the isolation fails? If the chassis is
> ungrounded, then there is a good chance the fault will go undetected
> until someone touches the chassis and provides a path to earth ground.
> If the chassis is grounded, the fault might still go undetected, but one
> can't get shocked by touching the chassis and earth ground. A GFCI on
> the AC input *might* trip and reveal the fault if the isolation fails
> and the chassis is grounded; I'm not certain. A GFCI on the AC input is
> still a very good idea anyway since it will reveal and prevent any
> leakage of the AC line to ground after the GFCI device (e.g. a fault on
> the input side of the charger).
>
> I wonder if it would add value (or violate some code) to provide a
> connection (direct or through some highish impedance) between the
> negative side of the isolated charger's output and earth ground (at
> least while charging)? This would seem to be a way to ensure that the
> GFCI would trip in the unlikely event of an isolation failure.
>
> I don't understand the reference to isolation being a bandaid since it
> reduces the risk of shock hazard whether the chassis is grounded or not,
> and so I would suggest that if one is using floodies, which are prone to
> leakage to chassis, an isolated charger is a wise choice since it would
> result in a reduced shock hazard and reduced likelihood of GFCI nuisance
> tripping.
>
> > All of us racers and real EV runners almost to a fault don't
> > have GFI or even chassis grounds hooked up while we are charing.
> > In racing ... it gets in the way.
>
> Can you explain why that would be? If racers are so diligent to ensure
> that there isn't any leakage paths to chassis from the pack, then how
> can a GFCI possibly get in the way?
>
> > I think one of the points is that we specifically don't run a
> > Grid ground to a race car.. that way you can't get shocked
> > unless the fault is to the track from the battery post and wires.
> > Adding in the grounded chassis adjacent to the pack and
> > charge port just puts both sides of circuit within hands reach.
>
> This is an interesting observation, but it implies three things: first
> you are assuming a non-isolated charger; second, you are assuming that a
> GFCI is NOT being used (since it would protect against an unsafe leakage
> between charger output and the grounded chassis); and third, that either
> there is exposed traction wiring or that someone is foolish enough to be
> removing the covers and working on the traction electrical while it is
> charging (a fundamental safety no-no). If normal (race) charging of the
> vehicle requires exposing the traction pack connections, then it
> probably hasn't been designed safely to start with (e.g. a lexan cover
> with holes for DMM probes at the appropriate places is inherently safer
> than pulling the cover to monitor module voltages, and a proper BMS to
> do it automatically is even better).
>
> > If you really want a safe EV build it that way to start.
> > Then Iso.NON iso GFI etc is a moot point.
>
> Designing safety in from the start is definitely wise advice. Isolation
> and/or GFCI don't become moot points because designing the EV to be safe
> doesn't ensure that it will remain safe. The GFCI is your friend: every
> time you plug in it verifies that the EV is still as safe as you
> intended it to be, without any extra effort on your part. If you've
> designed the EV to be safe, then the GFCI should never trip, but when
> the unthinkable happens and that wire abrades to the chassis, etc. it
> will catch it.
>
> Cheers,
>
> Roger.
>
>
--- End Message ---
--- Begin Message ---
The brusheson my 9" 4001 dc motor went out. It was sgrinding so much I
thought the transmission was gone. Anyone know about how much it will cost to
have the motor repaired? I am sure the comutateris in bad shape.I live in
Calabasas which is only 30 miles from los angeles.Looking for a good moter
shop.
Larry Cronk
72 Datsun Elec tk
--- End Message ---
--- Begin Message ---
Sure is getting around:
http://www.autobloggreen.com/2007/03/30/edmunds-editor-karl-brauer-offers-a-brief-opinion-on-batteries-f/
The RC mag and the Hot Rod mag. I'm surprised the Sport Bike mags
haven't ran an article.
Pick up a Sport Bike and put an A123 pack, Zilla, and some motor in
it? Race ~8 second Busa's with it and drive it on the streets? That
might rock the sport bike world? Maybe one of the big OEM's would
duplicate your efforts? How's the math look on range? I could see
gone green Honda building a performance electric sport bike.
--- End Message ---
--- Begin Message ---
Hey Larry
I'm a good motor shop! 8^) Maybe farther than you want
to go though 8^(
You probably just need a turn and cut and some new
brushes that is unless this grindings been an ongoing
issue 8^P
If you'd like and are up to it I can walk you through
removing the armature before having it worked on as
it'll save you money. I'd advise getting the bearings
changed while it's out. Take some pics and I should
be able to check it out and help make sure you don't
get milked locally 8^)
Start looking for electric motor shops
Hope this helps
Jim Husted
Hi-Torque Electric
http://www.hitorqueelectric.com
--- [EMAIL PROTECTED] wrote:
> The brusheson my 9" 4001 dc motor went out. It
> was sgrinding so much I
> thought the transmission was gone. Anyone know about
> how much it will cost to
> have the motor repaired? I am sure the comutateris
> in bad shape.I live in
> Calabasas which is only 30 miles from los
> angeles.Looking for a good moter shop.
>
> Larry Cronk
> 72 Datsun Elec tk
>
>
____________________________________________________________________________________
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with the Yahoo! Search weather shortcut.
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--- End Message ---
--- Begin Message ---
Hey Steve
Thanks for the info, I have seen pics and stuff on
them though 8^P
Let me rephrase, I've never touched, tasted, and
breathed one yet 8^o Pics I've seen, but I need the
whole brail touchy thing before I feel I can comment
other than in general terms 8^)
Cya
Jim Husted
Hi-Torque Electric
--- [EMAIL PROTECTED] wrote:
> Hi Jim The Idea behind the implus was I beleave
> to have a shorter motor that would fit where a 8 was
> and a 9 wouldn't go <snip>
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--- End Message ---
--- Begin Message ---
Hey, Steve, I'm in between you two in Savannah, GA. If he wants to take a day
trip or weekend trip to see an EV, then you can send him this way...
I could also do a conversion for him if he wants.
David Brandt
----- Original Message ----
From: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
To: [email protected]
Sent: Friday, March 30, 2007 1:54:54 AM
Subject: EV converter in North Carolina
James E mailed me about getting a EV , or a conversion done on his car .. he
is in N.C
Also sombody else e mailed me about advertixing there conversion servise on
grassrootsev.com and I lost there mail before replying .
steve clunn
Hi Steve,
I'm James, from North Carolina. I'd like to have an electric but I'd
like to learn all there is to know from a consumer's standpoint before I
buy anything. If you post my email, put up the [EMAIL PROTECTED] address.
Thanks!
James
____________________________________________________________________________________
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--- End Message ---
