# [EVDL] traction pack voltage leakage



## EVDL List (Jul 27, 2007)

I'm measuring about 80v from my 153v (48 CALB cells) traction pack (+) to m=
y chassis. The charger is isolated (mounted on plywood, output disconnec=
ted when not charging). There is an Iota DC/DC that is only on with the =
ignition. The controller is a Synkromotive which is fully isolated. M=
otor is a Warp9. I have no continuity between traction pack (-) and chas=
sis ground.

>From my initial internets research, I'm suspecting corrosion in the motor i=
s causing a voltage leak. Is this reasonable? How can I verify this? =
What do I do about it? The car used to have a Logisystems controller =
for a few years, I just installed the Synkro, but I don't know if this leak=
was there before.

Thanks,
David.
http://www.evalbum.com/4021
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## EVDL List (Jul 27, 2007)

Voltage leaks are like water leaks, they almost always come from the most obvious place even if you cannot see it. In an EV this is almost always from the battery pack. It just takes a bit of conductive dirt in the wrong place and the solution is usually a thorough cleaning of the batteries. This is of course not always the case, but it is where I would start if I were you.
damon

> Date: Tue, 8 Nov 2011 12:43:39 -0800
> From: [email protected]
> To: [email protected]
> Subject: [EVDL] traction pack voltage leakage
> 
> I'm measuring about 80v from my 153v (48 CALB cells) traction pack (+) to my chassis. The charger is isolated (mounted on plywood, output disconnected when not charging). There is an Iota DC/DC that is only on with the ignition. The controller is a Synkromotive which is fully isolated. Motor is a Warp9. I have no continuity between traction pack (-) and chassis ground.
> 
> >From my initial internets research, I'm suspecting corrosion in the motor is causing a voltage leak. Is this reasonable? How can I verify this? What do I do about it? The car used to have a Logisystems controller for a few years, I just installed the Synkro, but I don't know if this leak was there before.
> 
> Thanks,
> David.
> http://www.evalbum.com/4021
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## EVDL List (Jul 27, 2007)

Hello David,

Some controllers pass the main battery (-) right throw the controller to the 
motor. To verify this, see if there is any continuity from the battery (-) 
and the a motor terminal, while the battery charger is off and the main AC 
plug is disconnected from the EV.

If you have another main contactor on the battery (-), then read from this 
contactor to the motor terminal.

If you do not have a another main contactor on the battery (-) then the 
charge current is pass right through the controller and to the motor 
terminal and comes out the other motor terminal to the controller.

To prevent this charge current to be on either the controller and motor, I 
install a contactor on the (-) and another one on the (+) of the main 
battery. This isolates the charger current from any devices that are on 
this circuit. These two contactors must come on first before the main 
contactor comes on, or you may get a controller error which states, NO BAT 
VOLTAGE to Main Contactor.

When I did this, I drop any current flow that was between the main battery 
terminal and chassis ground. The cause for me, was increase inductance in a 
DC motor, that cause brush dust tracking from the communtator down the face 
of the communtator and on to the motor shaft.

I actually saw small arcing between the face of the communtator and the 
motor shaft. I only can see this arcing at night or with the lights off.

You can first test the resistance to the motor frame by reading the 
resistance from any motor terminal to frame. When the motor is new, it 
should read about 20meg ohms. My motor took about 10 years before it got 
down to 30 K ohms. Its time to clean the motor.

After I clean the motor, I pick up some motor enamel spray from a motor 
shop and spray the face of the communtator and down and on the motor shaft 
which prevented this tracking. I was able to run the GE-11 motor from 85 to 
2002 with no problems.

Then you might say, how does the EV frame become grounded while the charger 
is on or even if the AC plug is connected? Look at your main AC receptacle 
and/or plug. Many of these receptacle have a self grounding strap between 
the ground pin and the housing. This grounds your EV frame.

I use a all nylon receptacle and plug that is not self grounding that goes 
to a non-isolated charger, which is place inside a fiberglass air cool 
compartment. The two extra contactors between the main battery and 
controller prevents any charger currents on these lines.

I even have my batteries in a epoxy fiberglass battery boxes, but when the 
charger is on, I get some type of capacitance action between the battery 
terminals and battery cases or even between the battery terminals and EV 
frame. Here the voltage first start out as 1.75 vdc and floats down to 
below 1.00 vdc which is not critical.

In some of our high voltage work, we actually have to install a metal shield 
around a conductor that is in between two layers of insulation. This is 
call a bleeder shield which bleeds of this induce field which is connected 
to a isolated ground which is not connected to a electrical ground.

Roland






----- Original Message ----- 
From: "David Ladd" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Tuesday, November 08, 2011 1:43 PM
Subject: [EVDL] traction pack voltage leakage


I'm measuring about 80v from my 153v (48 CALB cells) traction pack (+) to my 
chassis. The charger is isolated (mounted on plywood, output disconnected 
when not charging). There is an Iota DC/DC that is only on with the 
ignition. The controller is a Synkromotive which is fully isolated. Motor is 
a Warp9. I have no continuity between traction pack (-) and chassis ground.

>From my initial internets research, I'm suspecting corrosion in the motor 
>is causing a voltage leak. Is this reasonable? How can I verify this? What 
>do I do about it? The car used to have a Logisystems controller for a few 
>years, I just installed the Synkro, but I don't know if this leak was there 
>before.

Thanks,
David.
http://www.evalbum.com/4021
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## EVDL List (Jul 27, 2007)

i did a few more measurements. In the battery pack, I have 0v to chassis=
at the first terminal, and 87v at the last. It goes up about 1.8v for e=
very cell as I move along the pack.

The battery (-) and motor (-) are on the same bar at the controller, so the=
re is continuity there. I only have a single contactor on the (+) side, =
precharge is handled by the controller.

With the traction pack breaker on, but the controller not powered up (thoug=
h it has an always on traction pack signal wire going to it) I measure 87v =
to chassis from the battery side of the contactor, and 47v from the control=
ler side to chassis. Of course 47v also from bat (+) on the controller.

I measure zero volts from either motor terminal to chassis.

I don't know how to measure the resistance from a motor terminal to chassis=
, I got nothing but probably am not doing it right. 

charger is not even in the car during this measuring.

i do have a shunt with an ammeter on the (-) side, could this be affecting =
anything? Voltmeter is off when ignition is off.

doing the best I can! But I still have a LOT to learn about this stuff. =
I'm more on the mechanical side of things...
david.
http://www.evalbum.com/4021



________________________________
From: Roland Wiench <[email protected]>
To: David Ladd <[email protected]>; Electric Vehicle Discussion List <ev=
@lists.sjsu.edu>
Sent: Tuesday, November 8, 2011 1:50 PM
Subject: Re: [EVDL] traction pack voltage leakage

Hello David,

Some controllers pass the main battery (-) right throw the controller to th=
e =

motor. To verify this, see if there is any continuity from the battery (=
-) =

and the a motor terminal, while the battery charger is off and the main AC =

plug is disconnected from the EV.

If you have another main contactor on the battery (-), then read from this =

contactor to the motor terminal.

If you do not have a another main contactor on the battery (-) then the =

charge current is pass right through the controller and to the motor =

terminal and comes out the other motor terminal to the controller.

To prevent this charge current to be on either the controller and motor, I =

install a contactor on the (-) and another one on the (+) of the main =

battery. This isolates the charger current from any devices that are on =

this circuit. These two contactors must come on first before the main =

contactor comes on, or you may get a controller error which states, NO BAT =

VOLTAGE to Main Contactor.

When I did this, I drop any current flow that was between the main battery =

terminal and chassis ground. The cause for me, was increase inductance i=
n a =

DC motor, that cause brush dust tracking from the communtator down the face =

of the communtator and on to the motor shaft.

I actually saw small arcing between the face of the communtator and the =

motor shaft. I only can see this arcing at night or with the lights off.

You can first test the resistance to the motor frame by reading the =

resistance from any motor terminal to frame. When the motor is new, it =

should read about 20meg ohms. My motor took about 10 years before it got =

down to 30 K ohms. Its time to clean the motor.

After I clean the motor, I pick up some motor enamel spray from a motor =

shop and spray the face of the communtator and down and on the motor shaft =

which prevented this tracking. I was able to run the GE-11 motor from 85=
to =

2002 with no problems.

Then you might say, how does the EV frame become grounded while the charger =

is on or even if the AC plug is connected? Look at your main AC receptac=
le =

and/or plug. Many of these receptacle have a self grounding strap betwee=
n =

the ground pin and the housing. This grounds your EV frame.

I use a all nylon receptacle and plug that is not self grounding that goes =

to a non-isolated charger, which is place inside a fiberglass air cool =

compartment. The two extra contactors between the main battery and =

controller prevents any charger currents on these lines.

I even have my batteries in a epoxy fiberglass battery boxes, but when the =

charger is on, I get some type of capacitance action between the battery =

terminals and battery cases or even between the battery terminals and EV =

frame. Here the voltage first start out as 1.75 vdc and floats down to =

below 1.00 vdc which is not critical.

In some of our high voltage work, we actually have to install a metal shiel=
d =

around a conductor that is in between two layers of insulation. This is =

call a bleeder shield which bleeds of this induce field which is connected =

to a isolated ground which is not connected to a electrical ground.

Roland






----- Original Message ----- =

From: "David Ladd" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Tuesday, November 08, 2011 1:43 PM
Subject: [EVDL] traction pack voltage leakage


I'm measuring about 80v from my 153v (48 CALB cells) traction pack (+) to m=
y =

chassis. The charger is isolated (mounted on plywood, output disconnected =

when not charging). There is an Iota DC/DC that is only on with the =

ignition. The controller is a Synkromotive which is fully isolated. Motor i=
s =

a Warp9. I have no continuity between traction pack (-) and chassis ground.

>From my initial internets research, I'm suspecting corrosion in the motor =

>is causing a voltage leak. Is this reasonable? How can I verify this? What =

>do I do about it? The car used to have a Logisystems controller for a few =

>years, I just installed the Synkro, but I don't know if this leak was ther=
e =

>before.

Thanks,
David.
http://www.evalbum.com/4021
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|
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| Multiple-address or CCed messages may be rejected.
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## EVDL List (Jul 27, 2007)

Hello David,

To measure ohms, you have to use a multi-meter with a ohms scale on it. Set 
it to the highest scale there is which should be 20 megohms which is 20 
million ohms. Take a reading and if it barely reads anything, then move 
down the scale to 10 meg, 1 meg, 100k, and so on until you start to read 
something. Record that reading and save if for future reference so you can 
compare it to another reading several years later.

The sense wires from the shunt to the meter should not cause this problem, 
unless the sense wire is shorted inside the meter or the wires are shorted 
to the EV frame.

In installing any sense wires from a shunt, I always install fuses on this 
line right at the shunt. You can get a spade type fuse that will slip under 
the sense screws. Remember you have the full current potential on these 
sense wires. It may not be a problem if one of these wires short to ground, 
but if any of the pos + wires from the main battery shorted like the ones 
going to a volt meter, you could have these wires have a melt down and burn 
up your EV.

I also install fuses on my volt meter leads as close to a battery pos and 
neg source too. The fuses can be about a 0.5 amp rating.

You should not read any voltage from the motor terminals to frame while the 
charger is off, because you may be reading the same conductor that could be 
shorting to ground.

When you are set up with a ohm meter, see if there is continuity from the 
motor terminal to frame. If there is, it should be reading about 0 ohms. 
If there is some type of conductance, it could be reading a very high 
resistance cause by brush dust.

Remember when doing this resistance test on the motor, disconnect the 
controller leads to the motor or the controller can effect this reading.

Roland


----- Original Message ----- 
From: "David Ladd" <[email protected]>
To: <[email protected]>
Sent: Tuesday, November 08, 2011 4:29 PM
Subject: Re: [EVDL] traction pack voltage leakage


i did a few more measurements. In the battery pack, I have 0v to chassis at 
the first terminal, and 87v at the last. It goes up about 1.8v for every 
cell as I move along the pack.

The battery (-) and motor (-) are on the same bar at the controller, so 
there is continuity there. I only have a single contactor on the (+) side, 
precharge is handled by the controller.

With the traction pack breaker on, but the controller not powered up (though 
it has an always on traction pack signal wire going to it) I measure 87v to 
chassis from the battery side of the contactor, and 47v from the controller 
side to chassis. Of course 47v also from bat (+) on the controller.

I measure zero volts from either motor terminal to chassis.

I don't know how to measure the resistance from a motor terminal to chassis, 
I got nothing but probably am not doing it right.

charger is not even in the car during this measuring.

i do have a shunt with an ammeter on the (-) side, could this be affecting 
anything? Voltmeter is off when ignition is off.

doing the best I can! But I still have a LOT to learn about this stuff. I'm 
more on the mechanical side of things...
david.
http://www.evalbum.com/4021



________________________________
From: Roland Wiench <[email protected]>
To: David Ladd <[email protected]>; Electric Vehicle Discussion List 
<[email protected]>
Sent: Tuesday, November 8, 2011 1:50 PM
Subject: Re: [EVDL] traction pack voltage leakage

Hello David,

Some controllers pass the main battery (-) right throw the controller to the
motor. To verify this, see if there is any continuity from the battery (-)
and the a motor terminal, while the battery charger is off and the main AC
plug is disconnected from the EV.

If you have another main contactor on the battery (-), then read from this
contactor to the motor terminal.

If you do not have a another main contactor on the battery (-) then the
charge current is pass right through the controller and to the motor
terminal and comes out the other motor terminal to the controller.

To prevent this charge current to be on either the controller and motor, I
install a contactor on the (-) and another one on the (+) of the main
battery. This isolates the charger current from any devices that are on
this circuit. These two contactors must come on first before the main
contactor comes on, or you may get a controller error which states, NO BAT
VOLTAGE to Main Contactor.

When I did this, I drop any current flow that was between the main battery
terminal and chassis ground. The cause for me, was increase inductance in a
DC motor, that cause brush dust tracking from the communtator down the face
of the communtator and on to the motor shaft.

I actually saw small arcing between the face of the communtator and the
motor shaft. I only can see this arcing at night or with the lights off.

You can first test the resistance to the motor frame by reading the
resistance from any motor terminal to frame. When the motor is new, it
should read about 20meg ohms. My motor took about 10 years before it got
down to 30 K ohms. Its time to clean the motor.

After I clean the motor, I pick up some motor enamel spray from a motor
shop and spray the face of the communtator and down and on the motor shaft
which prevented this tracking. I was able to run the GE-11 motor from 85 to
2002 with no problems.

Then you might say, how does the EV frame become grounded while the charger
is on or even if the AC plug is connected? Look at your main AC receptacle
and/or plug. Many of these receptacle have a self grounding strap between
the ground pin and the housing. This grounds your EV frame.

I use a all nylon receptacle and plug that is not self grounding that goes
to a non-isolated charger, which is place inside a fiberglass air cool
compartment. The two extra contactors between the main battery and
controller prevents any charger currents on these lines.

I even have my batteries in a epoxy fiberglass battery boxes, but when the
charger is on, I get some type of capacitance action between the battery
terminals and battery cases or even between the battery terminals and EV
frame. Here the voltage first start out as 1.75 vdc and floats down to
below 1.00 vdc which is not critical.

In some of our high voltage work, we actually have to install a metal shield
around a conductor that is in between two layers of insulation. This is
call a bleeder shield which bleeds of this induce field which is connected
to a isolated ground which is not connected to a electrical ground.

Roland






----- Original Message ----- 
From: "David Ladd" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Tuesday, November 08, 2011 1:43 PM
Subject: [EVDL] traction pack voltage leakage


I'm measuring about 80v from my 153v (48 CALB cells) traction pack (+) to my
chassis. The charger is isolated (mounted on plywood, output disconnected
when not charging). There is an Iota DC/DC that is only on with the
ignition. The controller is a Synkromotive which is fully isolated. Motor is
a Warp9. I have no continuity between traction pack (-) and chassis ground.

>From my initial internets research, I'm suspecting corrosion in the motor
>is causing a voltage leak. Is this reasonable? How can I verify this? What
>do I do about it? The car used to have a Logisystems controller for a few
>years, I just installed the Synkro, but I don't know if this leak was there
>before.

Thanks,
David.
http://www.evalbum.com/4021
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## EVDL List (Jul 27, 2007)

the light bulb did not light up at all, current read 0. In the 200mA set=
ting it read .2

Is this small enough to ignore, or should I keep going and figure out the c=
ause?

david.
http://www.evalbum.com/4021



________________________________
From: Jay Summet <[email protected]>
To: [email protected]
Sent: Tuesday, November 8, 2011 4:52 PM
Subject: Re: [EVDL] traction pack voltage leakage

...snip...

My suggestion: Get a small 120v light bulb (like a few watt Christmas
tree bulb or nightlight) Use that to connect your multimeter (in 20A
current sensing mode) from the + battery to the chassis. The light bulb
will automatically limit the total mount of current flow to a safe level
if you have a full out short.

If you have a "serious" high current leak, the light bulb will glow (at
80-153v, and only a few watts this will be well less than 20 A of
current...so you can safely measure it with your multimeter). [The amp
meter really isn't needed if the light bulb lights up...if that happens
you have a "serious" short.]

If you have only a capacitive linkage (or a high resistance short)
between your batteries and the frame, the lightbulb won't even light up,
and the 20A scale on your multimeter will read 0....if that is the
case...you may want to risk going down to a 1A scale, or 200 mA scale to
see if you have any amount of current at all.

On my truck I have had both kinds of shorts. After fixing the first, I
spent a good few days trying to fix the 2nd (capacitive linkage between
metal plates in my lead-acid batteries and the metal frame rails of the
truck).....finally I realized that if I kept the volt meter on the frame
and battery pack for longer than 20 seconds, the voltage would slowly
start to drop, until it eventually reached a very low level. This was
because my multi-meter's internal voltage sensing resistor was slowly
discharging the built up charge, because the amount of current was so
low......


Jay
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## EVDL List (Jul 27, 2007)

<snip>
the light bulb did not light up at all, current read 0. In the 200mA
setting it read .2

Is this small enough to ignore, or should I keep going and figure out the
cause?
<snip>

Your voltage measurements: 0 Volts at the bottom of the pack and 87 Volts at
the top indicate that a resistive link exists at the bottom bus and that the
resistance is 3/4 the resistance of your voltmeter : (153-87)/87.
The current measurement indicates a resistance of 153/0.0002 =3D 0.75 Meg O=
hm.
Together that says your meter has a 1 Meg input impedance.
A 750 k Ohm leakage should probably be addressed.
Gerhard



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## EVDL List (Jul 27, 2007)

Your symptoms sound like mine. Try disconnecting your gauges from the pack
and see if it is still there. I've chosen to ignore mine as I haven't had
time to try and understand it, but because there is such a high resistance
on the connection, it's not really dangerous (as I've determined in my case,
yours could be different). Shorting it just makes a bit of sizzling sparks.

--
View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Saturn-glider-available-N-Cal-2-tp3991855p4020088.html
Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com.

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## EVDL List (Jul 27, 2007)

First off, my apologies for even suggesting that I should stop trying to de=
termine the cause of the leak! It's 40 degrees in my garage and I have a=
cold...

So, in the light of a new day I did some more testing. Here's what I got:

1) Traction pack totally disconnected at the front of the car (all batte=
ries are in the back). Measuring voltage across the main B+ and B- cable=
s up at the front of the car (cables just floating, not connected to anythi=
ng. Zip tied safely out of the way of accidental contact) gave 163v. =
B+ to chassis was 0v. Actually it was between 0 and .1, but I'll just ca=
ll it zero. This eliminates corrosion and conductive leakage at the batt=
eries and in the cable run from the back to front, right?

2) Connected B- to the shunt, removed cable from shunt to controller, le=
ft B+ floating. 0v to chassis. This eliminates any leakage at the amm=
eter, right?

3) connect controller to shunt (which connects cable to motor- (A2) also=
since it's on a common bar at the controller). B+ still floating. B+=
to either motor terminal is 163v. B+ to chassis is 80v.

4) Disconnect A2 at the motor. Same result as above, B+ to either mot=
or terminal is 163v, B+ to chassis is 80v.

5) Disconnect S2 at motor. Motor is now totally disconnected, only co=
nnection to controller is B-. B+ still floating. B+ to chassis is 0v.=
B+ to either motor terminal is 163v.

6) I measured the resistance from the motor terminals to the frame. A=
1 and S1 still tied together, does that matter? I got 2.5meg ohms. I =
happen to have another Warp9 in my garage right now (i thought I was going =
to need it, but didn't), it did not register on my ohmmeter at all when I m=
easured it.

so... what would you all conclude from this data?

Thanks!
david.
http://www.evalbum.com/4021
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## EVDL List (Jul 27, 2007)

ack, the below statement should say B+ to either motor CABLE is 163v. Th=
e motor terminals read 0v. The cables are disconnected from the motor, b=
ut are still attached to the controller M+ and M- here.



> 5) Disconnect S2 at motor. Motor is now totally disconnect=
> ed, only connection to controller is B-. B+ still floating. B+ to cha=
> ssis is 0v. B+ to either motor terminal is 163v. [QUOTE/]
> 
> ...


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## EVDL List (Jul 27, 2007)

Hello David,

Ok, you now have determine when the motor is connected to B- through the 
controller and shunt, you still have this 80 volts to chassic. Further 
isolated the motor circuits to see if the problem is in the motor field 
circuit which is connected to S1 and S2 or in the communtator circuit where 
the brushes go to A1 and A2.

Disconnect the jumper from A1 to S1 which connects the Armature to the Field 
in series. Leave the B+ floating and connect the B- from controller to A2 
connected and try your test again. If it reads 80 volts, then connected the 
B- from the controller to S1 or S2 and try again. If the voltage reads 0 
volts to chassis, then the problem is in the A1 and A2 armature circuit.

Sometimes you may get a high resistance reading with power off, but the 
brush dust aligns up, increases the conductance when the power is on.

Try this as a experiment: sprinkle some carbon powder on a piece of paper 
and try to read the resistance from several points of the carbon powder. 
You will find that the resistance can read from less then 0 ohms to over 20 
meg ohms.

Now place the magnet on the bottom of the paper and the carbon powder will 
follow the magnetic field of magnet. Read the resistance of one of these 
carbon tracks while the magnet is place and then read it again when the 
magnet is remove. You will find it will change.

If you find that the A1 and A2 armature circuit is causing this problem and 
not the S1 and S2, I would say it still the brush dust tracking to the 
chassic via the brush dust tracking from the communtator to the motor shaft, 
to the motor shaft bearing and to the motor frame.

Note: If your motor mounts are insulated like it is on a engine, which my 
motor is, the ground path continues through the transmission and drive line 
to the differential. I find while the ohm meter is connected to the motor 
terminals and rotate the motor by hand, the resistance reading will jump 
around to different values.

Try this test and see what happens.

Roland




----- Original Message ----- 
From: "David Ladd" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Wednesday, November 09, 2011 11:34 AM
Subject: Re: [EVDL] traction pack voltage leakage


First off, my apologies for even suggesting that I should stop trying to 
determine the cause of the leak! It's 40 degrees in my garage and I have a 
cold...

So, in the light of a new day I did some more testing. Here's what I got:

1) Traction pack totally disconnected at the front of the car (all batteries 
are in the back). Measuring voltage across the main B+ and B- cables up at 
the front of the car (cables just floating, not connected to anything. Zip 
tied safely out of the way of accidental contact) gave 163v. B+ to chassis 
was 0v. Actually it was between 0 and .1, but I'll just call it zero. This 
eliminates corrosion and conductive leakage at the batteries and in the 
cable run from the back to front, right?

2) Connected B- to the shunt, removed cable from shunt to controller, left 
B+ floating. 0v to chassis. This eliminates any leakage at the ammeter, 
right?

3) connect controller to shunt (which connects cable to motor- (A2) also 
since it's on a common bar at the controller). B+ still floating. B+ to 
either motor terminal is 163v. B+ to chassis is 80v.

4) Disconnect A2 at the motor. Same result as above, B+ to either motor 
terminal is 163v, B+ to chassis is 80v.

5) Disconnect S2 at motor. Motor is now totally disconnected, only 
connection to controller is B-. B+ still floating. B+ to chassis is 0v. B+ 
to either motor terminal is 163v.

6) I measured the resistance from the motor terminals to the frame. A1 and 
S1 still tied together, does that matter? I got 2.5meg ohms. I happen to 
have another Warp9 in my garage right now (i thought I was going to need it, 
but didn't), it did not register on my ohmmeter at all when I measured it.

so... what would you all conclude from this data?

Thanks!
david.
http://www.evalbum.com/4021
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## EVDL List (Jul 27, 2007)

You know, I think this looking for leakage thread is close to madness. Wha=
t needs to be asked and I have not seen, what is the input impedNce of your=
meter? The comment about capacitance is right on. You need to determine cu=
rrent. Maybe use an old simpson analog meter. Is it humid out?

Sent from my Verizon Wireless Phone

-----Original Message-----
From: David Ladd <[email protected]>
Sent: Wednesday, November 09, 2011 1:34 PM
To: Electric Vehicle Discussion List <[email protected]>
Subject: Re: [EVDL] traction pack voltage leakage

First off, my apologies for even suggesting that I should stop trying to de=
termine the cause of the leak! It's 40 degrees in my garage and I have a=
cold...

So, in the light of a new day I did some more testing. Here's what I got:

1) Traction pack totally disconnected at the front of the car (all batte=
ries are in the back). Measuring voltage across the main B+ and B- cable=
s up at the front of the car (cables just floating, not connected to anythi=
ng. Zip tied safely out of the way of accidental contact) gave 163v. =
B+ to chassis was 0v. Actually it was between 0 and .1, but I'll just ca=
ll it zero. This eliminates corrosion and conductive leakage at the batt=
eries and in the cable run from the back to front, right?

2) Connected B- to the shunt, removed cable from shunt to controller, le=
ft B+ floating. 0v to chassis. This eliminates any leakage at the amm=
eter, right?

3) connect controller to shunt (which connects cable to motor- (A2) also=
since it's on a common bar at the controller). B+ still floating. B+=
to either motor terminal is 163v. B+ to chassis is 80v.

4) Disconnect A2 at the motor. Same result as above, B+ to either mot=
or terminal is 163v, B+ to chassis is 80v.

5) Disconnect S2 at motor. Motor is now totally disconnected, only co


[The entire original message is not included]

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## EVDL List (Jul 27, 2007)

That is correct, as long as the controller is connected to the motor I see the 80v.


________________________________
From: Jay Summet <[email protected]>

If I understand you, B- is connected to your controllers M-, and that is
also connected to motor A2.

Motor s2 is connected to controllers M+, and motors A1/S1 are connected
by a big wire (in a twist?).

It sounds like as soon as you connect B- to the controllers M- you get
the ground to frame short happening, is that correct?

Jay
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## EVDL List (Jul 27, 2007)

1) disconnected A1 to S1. B+ floating, B- connected to A2. result:=
B+ to A2 is 163v. B+ to chassis is 80v. B+ to S2 is 1.2v.

2) move B- to S2. result: B to S2 is 163v. B+ to chassis is 1.7=
v. B+ to A2 is 1.6v.

so it's in the armature circuit.


________________________________
From: Roland Wiench <[email protected]>

Disconnect the jumper from A1 to S1 which connects the Armature to the Fiel=
d =

in series. Leave the B+ floating and connect the B- from controller to =
A2 =

connected and try your test again. If it reads 80 volts, then connected =
the =

B- from the controller to S1 or S2 and try again. If the voltage reads 0 =

volts to chassis, then the problem is in the A1 and A2 armature circuit.
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## EVDL List (Jul 27, 2007)

That is the normal indications I get with all my DC brush type motors after 
I run it for about 10,000 miles which is cause by carbon tracking from the 
brushes.

You said you had another WarP 9 motor. If the motor has never been run, 
then take a ohm reading between all motor terminals and record that for 
future reference.

If the motor has been run, than I would take it to a motor shop to have it 
tested for any shorts. They run a high volt current through the motor which 
will pick up any faults which is call a meggar test. Than pick up some 
electric motor spray cleaner and electric motor enamel coating spray. You 
can do this cleaning and coating while the rotor is in the motor frame. You 
must remove the brushes and masking tape the communtator segments where the 
brushes ride on.

You can also remove the rotor from the motor to do this job. Here, you just 
lift the brushes and tape them back so it will clear the communtator. I 
usually pull the rotor out the back or the drive end because of the large 
fan attach to the motor shaft at that end. You do not have to remove the 
front bell housing and remove the brush holders when it's done this way.

I made a motor stand out of two 4 x 4's about 4 foot long and space apart so 
the motor will set stable between the 4 x 4's which is fasten together with 
2 x 4's at the end and sets on a bench.

You will notice when you pull the drive end motor cover off, that there is a 
plastic fan that shaft end. You do not have to remove it, because it must 
be heat shrink on. As you slide the rotor out, be care full that it does 
not drop down. Put some addition wood under the rotor as it slides out.

Also there are two springs washers on the shaft next to the bearing at the 
brush end. Make sure how these springs washer that are curved are install, 
so you install them the same way.

If you do not pull the rotor, then cover and tape over the bearing and the 
brush wear indicators if it has any. Spray the motor enamel on the front 
face of the communtator down to the motor shaft and up to the bearing, but 
not on the bearing or bearing surfaces. Do a light tack coat which you let 
it dry until its tacky and the follow up with one or two more full coats. 
Leave dry for 24 hours.

You can do this same maintenance on the motor you take out of the EV too.

Roland


----- Original Message ----- 
From: "David Ladd" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Wednesday, November 09, 2011 1:18 PM
Subject: Re: [EVDL] traction pack voltage leakage


1) disconnected A1 to S1. B+ floating, B- connected to A2. result: B+ to A2 
is 163v. B+ to chassis is 80v. B+ to S2 is 1.2v.

2) move B- to S2. result: B to S2 is 163v. B+ to chassis is 1.7v. B+ to A2 
is 1.6v.

so it's in the armature circuit.


________________________________
From: Roland Wiench <[email protected]>

Disconnect the jumper from A1 to S1 which connects the Armature to the Field
in series. Leave the B+ floating and connect the B- from controller to A2
connected and try your test again. If it reads 80 volts, then connected the
B- from the controller to S1 or S2 and try again. If the voltage reads 0
volts to chassis, then the problem is in the A1 and A2 armature circuit.
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