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  #1  
Old 04-24-2012, 12:25 AM
EVDL List EVDL List is offline
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Default [EVDL] Strange Wiring Question

Hello everybody,

I'm just finishing some fairly major rearranging of components and rewiring
under the hood. I was just doing the final checkout tonight and something
really strange happened.

My main drive wiring box is pretty simple: 2/0 wire comes in from the most
positive terminal of the pack, through a 400A fuse, through a manual
disconnect, a current meter shunt, the main contactor (with precharge
resistor) and back out the box, to the controller B+ and motor B+.

I also have a tap for a fused line to the low-current accessory box (10
gauge wire) for things like the DC-DC converter, heater, etc. That is
tapped just past the current shunt, but before the contactor. Inside the
low-current accessory box is a DC solid state relay to turn on the DC-DC
converter when the key is turned on. That accessory wire is also how the
charger feeds the pack.

The general idea is that the manual disconnect opens up the positive side of
the pack completely and makes the car safe to work on. It also means I
can't charge the battery pack with the disconnect open, but I'm OK with
that. (This arrangement also lets me see the current draw of the
accessories on my current meter. Another plus.)

Even with that manual disconnect open, it shocked me today. I'm trying to
figure out why.

I had the system fully operational and was checking all the accessories.
Everything checked out fine. I then opened the manual disconnect and
watched the precharge resistor drain the controller caps. I was timing it
because I was curious how long it took so I could put it in the service
manual I'm writing for my mechanic. While doing this, I was measuring
between B+ and B- on the controller. It took 11 minutes to drop from 150V
to 20V.

I then started removing a bolt to remove a box and reroute a wire and my arm
accidentally touched a terminal on the motor and I got a jolt. It was a BIG
jolt!

Taking my meter, I measured 150v (full pack voltage) between B- on the
controller and frame ground! As far as I can tell, my entire chassis was at
battery potential. I also found it curious that it was exactly full pack
voltage; no voltage drop.

The only thing I can think of that could cause this, is that the cable
coming into the box was shorting against the metal box or the conduit clamp
I have at the inlet (and outlet) of the box. However, the cable and its
shrink wrap look fine. I've also checked the fuse mounting and it isn't
grounded to the box either. I've also made sure the manual disconnect isn't
somehow grounded to the box or frame.

When I removed the cable from the pack to the fuse, the potential on the
frame (again, measured relative to B-) quickly dropped to zero (within a few
seconds).

I've reconnected the cable into the box again and this didn't happen again,
but now I'm deeply concerned. I'm going to try and find a plastic clamp or
liner for the cable entrance and exit of the box, just in case, but I'm not
sure what else to do.

Any suggestions? Things to check? Brilliant ideas?

Mike

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to xxx@xxx.xxx.edu only.
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  #2  
Old 04-24-2012, 12:56 AM
EVDL List EVDL List is offline
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Default Re: [EVDL] Strange Wiring Question

Do you have any meters that may be introducing a short?

I found a similar issue on mine and discovered it went away when I
disconnected my meters from the shunt.

--
View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Strange-Wiring-Question-tp4582463p4582517.html
Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com.

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to xxx@xxx.xxx.edu only.
| Multiple-address or CCed messages may be rejected.
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  #3  
Old 04-24-2012, 01:05 AM
EVDL List EVDL List is offline
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Default Re: [EVDL] Strange Wiring Question

You don't need to have a *short* - just a high impedance *leak*
is enough to give you a good jolt and register on your meter.
You did not say what type of batteries you have, but if these
are flooded lead-acid then it is very common - especially in
the final stage of charging - that they emit vapor that can
cover the top (or even side) of the battery enough to give a
leakage path to chassis.
If this happens near the + terminal (one of the "top" batteries)
then you have your source of 150V for the jolt and your meter
and the time that elapsed since you disconnected and reconnected
everything might be enough for the vapor to dry and the leakage
to go away....
I can't say if this is how it happened, but I am quite sure that
you have a leakage from (near) + pack to chassis.
Other suggestions:
- rodent droppings or bugs can cause a (temp) leakage path
- fuse mountings sometimes are not the correct material or
have developed a hairline crack and leak to the back (chassis)
Or any other type of failure - you are already looking in the
right place, it is just a matter of time to find the culprit.....

Success,

Cor van de Water
Chief Scientist
Proxim Wireless Corporation http://www.proxim.com
Email: xxx@xxx.xxx Private: http://www.cvandewater.com
Skype: cor_van_de_water XoIP: +31877841130
Tel: +1 408 383 7626 Tel: +91 (040)23117400 x203

-----Original Message-----
From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On
Behalf Of Mike Nickerson
Sent: Tuesday, April 24, 2012 11:44 AM
To: 'Electric Vehicle Discussion List'
Subject: [EVDL] Strange Wiring Question

Hello everybody,

I'm just finishing some fairly major rearranging of components and
rewiring under the hood. I was just doing the final checkout tonight
and something really strange happened.

My main drive wiring box is pretty simple: 2/0 wire comes in from the
most positive terminal of the pack, through a 400A fuse, through a
manual disconnect, a current meter shunt, the main contactor (with
precharge
resistor) and back out the box, to the controller B+ and motor B+.

I also have a tap for a fused line to the low-current accessory box (10
gauge wire) for things like the DC-DC converter, heater, etc. That is
tapped just past the current shunt, but before the contactor. Inside
the low-current accessory box is a DC solid state relay to turn on the
DC-DC converter when the key is turned on. That accessory wire is also
how the charger feeds the pack.

The general idea is that the manual disconnect opens up the positive
side of the pack completely and makes the car safe to work on. It also
means I can't charge the battery pack with the disconnect open, but I'm
OK with that. (This arrangement also lets me see the current draw of
the accessories on my current meter. Another plus.)

Even with that manual disconnect open, it shocked me today. I'm trying
to figure out why.

I had the system fully operational and was checking all the accessories.
Everything checked out fine. I then opened the manual disconnect and
watched the precharge resistor drain the controller caps. I was timing
it because I was curious how long it took so I could put it in the
service manual I'm writing for my mechanic. While doing this, I was
measuring between B+ and B- on the controller. It took 11 minutes to
drop from 150V to 20V.

I then started removing a bolt to remove a box and reroute a wire and my
arm accidentally touched a terminal on the motor and I got a jolt. It
was a BIG jolt!

Taking my meter, I measured 150v (full pack voltage) between B- on the
controller and frame ground! As far as I can tell, my entire chassis
was at battery potential. I also found it curious that it was exactly
full pack voltage; no voltage drop.

The only thing I can think of that could cause this, is that the cable
coming into the box was shorting against the metal box or the conduit
clamp I have at the inlet (and outlet) of the box. However, the cable
and its shrink wrap look fine. I've also checked the fuse mounting and
it isn't grounded to the box either. I've also made sure the manual
disconnect isn't somehow grounded to the box or frame.

When I removed the cable from the pack to the fuse, the potential on the
frame (again, measured relative to B-) quickly dropped to zero (within a
few seconds).

I've reconnected the cable into the box again and this didn't happen
again, but now I'm deeply concerned. I'm going to try and find a
plastic clamp or liner for the cable entrance and exit of the box, just
in case, but I'm not sure what else to do.

Any suggestions? Things to check? Brilliant ideas?

Mike

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to xxx@xxx.xxx.edu only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to xxx@xxx.xxx.edu only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev
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  #4  
Old 04-24-2012, 01:15 AM
EVDL List EVDL List is offline
EVDL List Bot
 
Join Date: Jul 2007
Posts: 70
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Default Re: [EVDL] Strange Wiring Question

I do have a volt meter and an ammeter, powered off the pack, but they're
supposed to be disconnected by the manual disconnect as well as the SSR that
turns on the DC-DC converter when the ignition is turned on.

I currently have the accessory box disconnected. I'll watch as I plug each
circuit into it to see if the issue resurfaces.

Mike

> -----Original Message-----
> From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On
> Behalf Of Voltswagon
> Sent: Tuesday, April 24, 2012 12:48 AM
> To: xxx@xxx.xxx.edu
> Subject: Re: [EVDL] Strange Wiring Question
>
> Do you have any meters that may be introducing a short?
>
> I found a similar issue on mine and discovered it went away when I
> disconnected my meters from the shunt.
>
> --
> View this message in context: http://electric-vehicle-discussion-
> list.413529.n4.nabble.com/Strange-Wiring-Question-
> tp4582463p4582517.html
> Sent from the Electric Vehicle Discussion List mailing list archive at
> Nabble.com.
>
> _______________________________________________
> | Moratorium on drag racing discussion is in effect.
> | Please take those discussions elsewhere. Thanks.
> |
> | REPLYING: address your message to xxx@xxx.xxx.edu only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to xxx@xxx.xxx.edu only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev
Reply With Quote
  #5  
Old 04-24-2012, 01:28 AM
EVDL List EVDL List is offline
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Join Date: Jul 2007
Posts: 70
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Default Re: [EVDL] Strange Wiring Question

Hi Cor,

I'm running 45 Thundersky LiFePO4 cells. I just finished putting them in
boxes. The boxes are made of foam and plywood, but have aluminum "C"
channel to hold the sides together. The top is acrylic screwed to the
aluminum channel. There is a 2/0 cable coming from the most positive box,
into the fuse box. I'll disassemble all that area and look for any issues.
I need to make sure I don't have a path to the aluminum channel. It isn't
completely grounded, but could certainly be connected to ground if a cell is
leaking onto the aluminum. I think I'll also double-check the fuse holder.

I also have my accessory box removed temporarily. I guess it's possible
that having that removed is related, but that seems strange when its power
comes from after the manual disconnect. However, I'll measure chassis
voltage after every part I put back and connection I make to see if I can
pinpoint when it returns.

I'll keep looking. Thanks for the help.

Mike

> -----Original Message-----
> From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On
> Behalf Of Cor van de Water
> Sent: Tuesday, April 24, 2012 12:58 AM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] Strange Wiring Question
>
> You don't need to have a *short* - just a high impedance *leak* is enough
to
> give you a good jolt and register on your meter.
> You did not say what type of batteries you have, but if these are flooded
> lead-acid then it is very common - especially in the final stage of
charging -
> that they emit vapor that can cover the top (or even side) of the battery
> enough to give a leakage path to chassis.
> If this happens near the + terminal (one of the "top" batteries) then you
> have your source of 150V for the jolt and your meter and the time that
> elapsed since you disconnected and reconnected everything might be
> enough for the vapor to dry and the leakage to go away....
> I can't say if this is how it happened, but I am quite sure that you have
a
> leakage from (near) + pack to chassis.
> Other suggestions:
> - rodent droppings or bugs can cause a (temp) leakage path
> - fuse mountings sometimes are not the correct material or
> have developed a hairline crack and leak to the back (chassis) Or any
other
> type of failure - you are already looking in the right place, it is just a
matter of
> time to find the culprit.....
>
> Success,
>
> Cor van de Water
> Chief Scientist
> Proxim Wireless Corporation http://www.proxim.com
> Email: xxx@xxx.xxx Private: http://www.cvandewater.com
> Skype: cor_van_de_water XoIP: +31877841130
> Tel: +1 408 383 7626 Tel: +91 (040)23117400 x203
>
> -----Original Message-----
> From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On
> Behalf Of Mike Nickerson
> Sent: Tuesday, April 24, 2012 11:44 AM
> To: 'Electric Vehicle Discussion List'
> Subject: [EVDL] Strange Wiring Question
>
> Hello everybody,
>
> I'm just finishing some fairly major rearranging of components and
rewiring
> under the hood. I was just doing the final checkout tonight and something
> really strange happened.
>
> My main drive wiring box is pretty simple: 2/0 wire comes in from the
most
> positive terminal of the pack, through a 400A fuse, through a manual
> disconnect, a current meter shunt, the main contactor (with precharge
> resistor) and back out the box, to the controller B+ and motor B+.
>
> I also have a tap for a fused line to the low-current accessory box (10
gauge
> wire) for things like the DC-DC converter, heater, etc. That is tapped
just
> past the current shunt, but before the contactor. Inside the low-current
> accessory box is a DC solid state relay to turn on the DC-DC converter
when
> the key is turned on. That accessory wire is also how the charger feeds
the
> pack.
>
> The general idea is that the manual disconnect opens up the positive side
of
> the pack completely and makes the car safe to work on. It also means I
can't
> charge the battery pack with the disconnect open, but I'm OK with that.
(This
> arrangement also lets me see the current draw of the accessories on my
> current meter. Another plus.)
>
> Even with that manual disconnect open, it shocked me today. I'm trying to
> figure out why.
>
> I had the system fully operational and was checking all the accessories.
> Everything checked out fine. I then opened the manual disconnect and
> watched the precharge resistor drain the controller caps. I was timing it
> because I was curious how long it took so I could put it in the service
manual
> I'm writing for my mechanic. While doing this, I was measuring between B+
> and B- on the controller. It took 11 minutes to drop from 150V to 20V.
>
> I then started removing a bolt to remove a box and reroute a wire and my
> arm accidentally touched a terminal on the motor and I got a jolt. It was
a BIG
> jolt!
>
> Taking my meter, I measured 150v (full pack voltage) between B- on the
> controller and frame ground! As far as I can tell, my entire chassis was
at
> battery potential. I also found it curious that it was exactly full pack
voltage;
> no voltage drop.
>
> The only thing I can think of that could cause this, is that the cable
coming
> into the box was shorting against the metal box or the conduit clamp I
have
> at the inlet (and outlet) of the box. However, the cable and its shrink
wrap
> look fine. I've also checked the fuse mounting and it isn't grounded to
the
> box either. I've also made sure the manual disconnect isn't somehow
> grounded to the box or frame.
>
> When I removed the cable from the pack to the fuse, the potential on the
> frame (again, measured relative to B-) quickly dropped to zero (within a
few
> seconds).
>
> I've reconnected the cable into the box again and this didn't happen
again,
> but now I'm deeply concerned. I'm going to try and find a plastic clamp
or
> liner for the cable entrance and exit of the box, just in case, but I'm
not sure
> what else to do.
>
> Any suggestions? Things to check? Brilliant ideas?
>
> Mike
>
> _______________________________________________
> | Moratorium on drag racing discussion is in effect.
> | Please take those discussions elsewhere. Thanks.
> |
> | REPLYING: address your message to xxx@xxx.xxx.edu only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev
>
> _______________________________________________
> | Moratorium on drag racing discussion is in effect.
> | Please take those discussions elsewhere. Thanks.
> |
> | REPLYING: address your message to xxx@xxx.xxx.edu only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to xxx@xxx.xxx.edu only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev
Reply With Quote
  #6  
Old 04-24-2012, 11:35 AM
EVDL List EVDL List is offline
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Join Date: Jul 2007
Posts: 70
EVDL List is on a distinguished road
Default Re: [EVDL] Strange Wiring Question

Hello Mike,

It is best to not only disconnect the battery positive lead, but also the
negative battery lead from the main contactor and motor controller.

In my first EV which was design by electronics engineers and electronics
technicians, did not follow the safety rules that electrical engineers and
electrical technicians do.

There was only one contactor on the positive side of the battery connected
to the motor controller. A precharge lead came off the input side of the
main contactor.

The battery negative ran directly from the battery through the motor
controller and to the motor.

The battery charger was always connected to the batteries while the EV was
in operation. The AC main plug which was adapted to a 50 amp 3 wire 240 vac
and ground. The battery charger housing was AC ground which also grounded
the body of the vehicle when the charger was bolted to it.

The ground wire path is from the AC service entrance where the ground wire
and neutral is tie together either at the meter or ground rod.

This is were the battery negative and motor frame which was grounded,
provided the battery negative path to the motor frame. I did not notice
this until one day I was charging the batteries and had little minute arcs
between the communtator and the motor shaft which may have only 1/16 inch
spacing between the front of the communtator and the motor shaft.

This provided a path of the battery negative to the vehicle body where I
could read some battery voltage and later full battery voltage between the
vehicle frame and the main battery positive.

This path become carbonize and brush dust also provided conductance between
the front of the communtator and the motor shaft.

To prevent arc over, I had a mica tube place over the motor shaft and the
front of the communtator coated with motor enamel. I still had a leakage to
ground with my rotating DC-DC converter which was a motor generator made by
Honey Well.

This DC-DC converter was only control by the battery positive and the
battery negative was connected right through it. When I charge the
batteries, I also had arc over to the converter shaft.

To solve this problem, I install two more contactors between the main
battery positive and negative to the main contactor, motor controller and
any other devices that uses the main battery power.

The motor resistance readings went from 30K ohms to 20 Meg ohms to motor
frame when I did this modifications. The voltage of the main battery pack
went from the full charging voltage of 233 volts to 1.75 volts when the
batteries are clean that where in a aluminum case.

I change the battery cases to epoxy coated fiber glass battery box and also
install the battery charger and all other electrical components in another
fiber glass housing. Only the battery charger is grounded and not the
frame.

Now the leakage voltage is below 0.1 volt when charging, which is cause by
some type of capacitance reactance between the batteries and the vehicle
frame.

After all the above mods, I still had one more issue. I had the charger
unplug and the two safety contactors disconnected the batteries from the
main contactor. When I lifted up a battery link, it spark, which would not
be good when using lead acid batteries that may have fumes.

I found that the PFC-50B charger has a capacitor bank in it, that cause
this. So I ended up installing a 2 pole contactor between the charger and
main battery pack which solve this arcing problem.

I also install a interlock circuit, where I first must turn on a explosive
proof exhaust fan for the battery box to purge any fumes that may be there.
The exhaust fan activates a pressure switch that turns on the control
circuit to the 2 pole contactor between the battery charger and the main
batteries. After this 2 pole contactor comes on, it turns on a 2 pole AC
magnetic contactor that is between the main AC plug in and a onboard 2 pole
50 amp 250 vac GFIC circuit breaker that is connected to the battery
charger.

This interlock systems prevents the charger to come on while the charger is
not connected to the battery.

Roland






----- Original Message -----
From: "Mike Nickerson" <xxx@xxx.xxx>
To: "'Electric Vehicle Discussion List'" <xxx@xxx.xxx.edu>
Sent: Tuesday, April 24, 2012 12:13 AM
Subject: [EVDL] Strange Wiring Question


> Hello everybody,
>
> I'm just finishing some fairly major rearranging of components and
> rewiring
> under the hood. I was just doing the final checkout tonight and something
> really strange happened.
>
> My main drive wiring box is pretty simple: 2/0 wire comes in from the
> most
> positive terminal of the pack, through a 400A fuse, through a manual
> disconnect, a current meter shunt, the main contactor (with precharge
> resistor) and back out the box, to the controller B+ and motor B+.
>
> I also have a tap for a fused line to the low-current accessory box (10
> gauge wire) for things like the DC-DC converter, heater, etc. That is
> tapped just past the current shunt, but before the contactor. Inside the
> low-current accessory box is a DC solid state relay to turn on the DC-DC
> converter when the key is turned on. That accessory wire is also how the
> charger feeds the pack.
>
> The general idea is that the manual disconnect opens up the positive side
> of
> the pack completely and makes the car safe to work on. It also means I
> can't charge the battery pack with the disconnect open, but I'm OK with
> that. (This arrangement also lets me see the current draw of the
> accessories on my current meter. Another plus.)
>
> Even with that manual disconnect open, it shocked me today. I'm trying to
> figure out why.
>
> I had the system fully operational and was checking all the accessories.
> Everything checked out fine. I then opened the manual disconnect and
> watched the precharge resistor drain the controller caps. I was timing it
> because I was curious how long it took so I could put it in the service
> manual I'm writing for my mechanic. While doing this, I was measuring
> between B+ and B- on the controller. It took 11 minutes to drop from 150V
> to 20V.
>
> I then started removing a bolt to remove a box and reroute a wire and my
> arm
> accidentally touched a terminal on the motor and I got a jolt. It was a
> BIG
> jolt!
>
> Taking my meter, I measured 150v (full pack voltage) between B- on the
> controller and frame ground! As far as I can tell, my entire chassis was
> at
> battery potential. I also found it curious that it was exactly full pack
> voltage; no voltage drop.
>
> The only thing I can think of that could cause this, is that the cable
> coming into the box was shorting against the metal box or the conduit
> clamp
> I have at the inlet (and outlet) of the box. However, the cable and its
> shrink wrap look fine. I've also checked the fuse mounting and it isn't
> grounded to the box either. I've also made sure the manual disconnect
> isn't
> somehow grounded to the box or frame.
>
> When I removed the cable from the pack to the fuse, the potential on the
> frame (again, measured relative to B-) quickly dropped to zero (within a
> few
> seconds).
>
> I've reconnected the cable into the box again and this didn't happen
> again,
> but now I'm deeply concerned. I'm going to try and find a plastic clamp
> or
> liner for the cable entrance and exit of the box, just in case, but I'm
> not
> sure what else to do.
>
> Any suggestions? Things to check? Brilliant ideas?
>
> Mike
>
> _______________________________________________
> | Moratorium on drag racing discussion is in effect.
> | Please take those discussions elsewhere. Thanks.
> |
> | REPLYING: address your message to xxx@xxx.xxx.edu only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev
>

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to xxx@xxx.xxx.edu only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev
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  #7  
Old 04-25-2012, 08:45 AM
EVDL List EVDL List is offline
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Default Re: [EVDL] Strange Wiring Question

Hi Roland,

The Kelly controllers have a warning I've previously interpreted as
discouraging a contactor on B-. In its entirety, it says:

" Caution: Make sure all connections are correct before applying power.
Otherwise it may
damage the controller! Please securely wire B- before applying power. It's
preferred to place
contactor or breaker on B+. Don't connect RTN to B-. Please place
precharge resistor on any
breaker! It can cause damage without it!!!"

I'm not sure why they state that B- should be securely wired before applying
power and contactors are preferred on B+ instead of B-.

I have an update to my situation:

I believe the problem was where the B+ wire enters my fuse / contactor box.
The box edge and metal conduit clamp happen to hit just behind the lug on
the cable. To make it worse, the mechanical arrangement of the parts is
pressing the cable pretty firmly into the top of the conduit surface. The
shrink tubing looked OK, but seemed to be conducting. I'm not sure why. I
do suspect that I might have only had shrink tubing and not insulation in
that area since it was the transition from cable to lug.

I never liked having this be metal, but I was always facing a problem when
trying to install plastic in its place. I have 2/0 cable which is about
1/2", but the cable lugs are about 3/4". The hole in the electrical box is
1". A 3/4" waterproof plastic conduit box connector is just the right size
for the cable, but the lug won't fit through it. A 1" plastic conduit box
connector just fits the lug, but won't fit in the hole.

I came up with a solution last night that I think will work OK. I took a
hacksaw and cut the 3/4" plastic conduit box connector lengthwise. I just
cut a slit on one side. This let me create a gap big enough to fit the lug
through. The plastic then snapped back into place and I was able to thread
the nut to secure the connector into the electrical box.

After doing this, I only measure 1V between frame and B-. After that
initial reading, the voltmeter drain is enough to quickly drain to 0.1V. I
will obviously be keeping a close eye on this!

Mike

> -----Original Message-----
> From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On
> Behalf Of Roland Wiench
> Sent: Tuesday, April 24, 2012 11:27 AM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] Strange Wiring Question
>
> Hello Mike,
>
> It is best to not only disconnect the battery positive lead, but also the
> negative battery lead from the main contactor and motor controller.
>
> In my first EV which was design by electronics engineers and electronics
> technicians, did not follow the safety rules that electrical engineers and
> electrical technicians do.
>
> There was only one contactor on the positive side of the battery connected
> to the motor controller. A precharge lead came off the input side of the
main
> contactor.
>
> The battery negative ran directly from the battery through the motor
> controller and to the motor.
>

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to xxx@xxx.xxx.edu only.
| Multiple-address or CCed messages may be rejected.
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  #8  
Old 04-25-2012, 10:55 AM
EVDL List EVDL List is offline
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Join Date: Jul 2007
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Default Re: [EVDL] Strange Wiring Question

Hello Mike,

I am running a Zilla controller where there must be B- to the controller and
B+ to the input side of the main contactor before the main contactor comes
on.

The two safety contactors which is on the negative and positive power leads
between the main battery come on first by the ignition on key which
activates a 12 volt relay that first turns on the safety contactors.

The Start position then turns on the main contactor and motor controller.

If you turn on a negative battery contactor at the same time that the main
positive contactor comes on, sometimes the main contactor may come on a
micro second before the negative contactor comes on, and you may received a
fault. This is why I use the Ignition on switch to first turn on the safety
contactors first before the main contactor comes on.

Another info note:

I do not use 12 volt coils in my contactors. I use line voltage coils,
meaning they use the same voltage of the battery pack. The contactors are
made by Cable Form which is a industrial contactor design to run off the
main battery pack.

A 12 volt contactor coil pulls about 4 amps and a line voltage coil for my
180 volt battery pack about 0.3 amps. These contactors are design to work
even if the voltage drops to 12 volts and up to 250 volts using a 180 volt
contactor coil.

Lets say the voltage drops to 11 volts, then the contactor will open and
will not close until the voltage reaches 160 volts which is the Low Voltage
Limit I have the motor controller set at anyway.

I use industrial 12 volt coil plug in relays made by Square D Co. that the
contacts are rated for 250 VAC at 10 amp and 80 VDC at 1 amp. This relays
have now been running since 1975 with no problems.

Roland


----- Original Message -----
From: "Mike Nickerson" <xxx@xxx.xxx>
To: "'Electric Vehicle Discussion List'" <xxx@xxx.xxx.edu>
Sent: Wednesday, April 25, 2012 8:37 AM
Subject: Re: [EVDL] Strange Wiring Question


> Hi Roland,
>
> The Kelly controllers have a warning I've previously interpreted as
> discouraging a contactor on B-. In its entirety, it says:
>
> " Caution: Make sure all connections are correct before applying power.
> Otherwise it may
> damage the controller! Please securely wire B- before applying power. It's
> preferred to place
> contactor or breaker on B+. Don't connect RTN to B-. Please place
> precharge resistor on any
> breaker! It can cause damage without it!!!"
>
> I'm not sure why they state that B- should be securely wired before
> applying
> power and contactors are preferred on B+ instead of B-.
>
> I have an update to my situation:
>
> I believe the problem was where the B+ wire enters my fuse / contactor
> box.
> The box edge and metal conduit clamp happen to hit just behind the lug on
> the cable. To make it worse, the mechanical arrangement of the parts is
> pressing the cable pretty firmly into the top of the conduit surface. The
> shrink tubing looked OK, but seemed to be conducting. I'm not sure why.
> I
> do suspect that I might have only had shrink tubing and not insulation in
> that area since it was the transition from cable to lug.
>
> I never liked having this be metal, but I was always facing a problem when
> trying to install plastic in its place. I have 2/0 cable which is about
> 1/2", but the cable lugs are about 3/4". The hole in the electrical box
> is
> 1". A 3/4" waterproof plastic conduit box connector is just the right
> size
> for the cable, but the lug won't fit through it. A 1" plastic conduit box
> connector just fits the lug, but won't fit in the hole.
>
> I came up with a solution last night that I think will work OK. I took a
> hacksaw and cut the 3/4" plastic conduit box connector lengthwise. I just
> cut a slit on one side. This let me create a gap big enough to fit the
> lug
> through. The plastic then snapped back into place and I was able to
> thread
> the nut to secure the connector into the electrical box.
>
> After doing this, I only measure 1V between frame and B-. After that
> initial reading, the voltmeter drain is enough to quickly drain to 0.1V.
> I
> will obviously be keeping a close eye on this!
>
> Mike
>
> > -----Original Message-----
> > From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On
> > Behalf Of Roland Wiench
> > Sent: Tuesday, April 24, 2012 11:27 AM
> > To: Electric Vehicle Discussion List
> > Subject: Re: [EVDL] Strange Wiring Question
> >
> > Hello Mike,
> >
> > It is best to not only disconnect the battery positive lead, but also
> > the
> > negative battery lead from the main contactor and motor controller.
> >
> > In my first EV which was design by electronics engineers and electronics
> > technicians, did not follow the safety rules that electrical engineers
> > and
> > electrical technicians do.
> >
> > There was only one contactor on the positive side of the battery
> > connected
> > to the motor controller. A precharge lead came off the input side of
> > the
> main
> > contactor.
> >
> > The battery negative ran directly from the battery through the motor
> > controller and to the motor.
> >
>
> _______________________________________________
> | Moratorium on drag racing discussion is in effect.
> | Please take those discussions elsewhere. Thanks.
> |
> | REPLYING: address your message to xxx@xxx.xxx.edu only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev
>

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to xxx@xxx.xxx.edu only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev
Reply With Quote
  #9  
Old 04-26-2012, 01:16 AM
EVDL List EVDL List is offline
EVDL List Bot
 
Join Date: Jul 2007
Posts: 70
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Default Re: [EVDL] Strange Wiring Question

Well, the car is back on the road after its extended absence to add battery
insulation and heating cables under each set of cells. I am cutting it way
closer than I would like because we have our Alternative Transportation Fair
at HP tomorrow morning and I'm showing my vehicle. It came off the jack
stands about 10:00 this evening. A quick test drive to the car wash for the
(very little) detailing it's going to get, and off to the show tomorrow.

I thought about the "How To Burn Up Your DC Motor" thread as I as pulling my
car into the car wash and creeping over the ramp that traps your front tire
while in the automatic car wash. Wouldn't want to do that!

I'll have to wait until next winter to see if the battery heaters help as
much as I hope they will.

For now, the car is driving well and has no more stray voltages on the
chassis. I will check it one more time tomorrow before showing. I also
need to get some photos to update my evalbum page. People won't believe all
the stuff packed under the hood of the poor little del Sol. And, yes, the
hood does close; barely!

Mike

> -----Original Message-----
> From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On
> Behalf Of Mike Nickerson
> Sent: Wednesday, April 25, 2012 8:38 AM
> To: 'Electric Vehicle Discussion List'
> Subject: Re: [EVDL] Strange Wiring Question
>
> Hi Roland,
>
> The Kelly controllers have a warning I've previously interpreted as
> discouraging a contactor on B-. In its entirety, it says:
>
> " Caution: Make sure all connections are correct before applying power.
> Otherwise it may
> damage the controller! Please securely wire B- before applying power. It's
> preferred to place contactor or breaker on B+. Don't connect RTN to B-.
> Please place precharge resistor on any breaker! It can cause damage
without
> it!!!"
>
> I'm not sure why they state that B- should be securely wired before
applying
> power and contactors are preferred on B+ instead of B-.
>
> I have an update to my situation:
>
> I believe the problem was where the B+ wire enters my fuse / contactor
box.
> The box edge and metal conduit clamp happen to hit just behind the lug on
> the cable. To make it worse, the mechanical arrangement of the parts is
> pressing the cable pretty firmly into the top of the conduit surface. The
> shrink tubing looked OK, but seemed to be conducting. I'm not sure why.
I
> do suspect that I might have only had shrink tubing and not insulation in
that
> area since it was the transition from cable to lug.
>
> I never liked having this be metal, but I was always facing a problem when
> trying to install plastic in its place. I have 2/0 cable which is about
> 1/2", but the cable lugs are about 3/4". The hole in the electrical box
is 1". A
> 3/4" waterproof plastic conduit box connector is just the right size for
the
> cable, but the lug won't fit through it. A 1" plastic conduit box
connector just
> fits the lug, but won't fit in the hole.
>
> I came up with a solution last night that I think will work OK. I took a
hacksaw
> and cut the 3/4" plastic conduit box connector lengthwise. I just cut a
slit on
> one side. This let me create a gap big enough to fit the lug through.
The
> plastic then snapped back into place and I was able to thread the nut to
> secure the connector into the electrical box.
>
> After doing this, I only measure 1V between frame and B-. After that
initial
> reading, the voltmeter drain is enough to quickly drain to 0.1V. I will
> obviously be keeping a close eye on this!
>
> Mike
>
> > -----Original Message-----
> > From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On
> > Behalf Of Roland Wiench
> > Sent: Tuesday, April 24, 2012 11:27 AM
> > To: Electric Vehicle Discussion List
> > Subject: Re: [EVDL] Strange Wiring Question
> >
> > Hello Mike,
> >
> > It is best to not only disconnect the battery positive lead, but also
> > the negative battery lead from the main contactor and motor controller.
> >
> > In my first EV which was design by electronics engineers and
> > electronics technicians, did not follow the safety rules that
> > electrical engineers and electrical technicians do.
> >
> > There was only one contactor on the positive side of the battery
> > connected to the motor controller. A precharge lead came off the
> > input side of the
> main
> > contactor.
> >
> > The battery negative ran directly from the battery through the motor
> > controller and to the motor.
> >
>
> _______________________________________________
> | Moratorium on drag racing discussion is in effect.
> | Please take those discussions elsewhere. Thanks.
> |
> | REPLYING: address your message to xxx@xxx.xxx.edu only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to xxx@xxx.xxx.edu only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev
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