[EVDL List]

Maybe this is common knowledge for this group, but I recently learned how to burn up my motor.

I was returning home, thinking about the prospect of working on the car and bumping the accelerator. I was working under the dash recently, on the heater core. If it were in gear and on, who would win: the motor or the parking brake? Some of you see where this is headed. I parked the car in the garage, set the brake and pressed the accelerator for at least 2 seconds, probably 4 or 5 seconds. The battery delivered 25A during this. The brake won, I turned everything off and went inside. The next day, as the car began to roll, there was a tick-tick sound. I'd overheated the commutators and lifted 4 bars. A LOT of motor amps had heated it when it wasn't turning.

The Zilla has stall protection; my Soliton apparently does not.

Lesson learned. :-\

BTW, Steve and Audrey from Green Shed Conversions drove up from Florida on short notice and brought a spare motor so I could show the car for Earth Day. Wow! Kudos and a big thank you!

Bruce

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[EVDL List]

I'm glad my Zilla has stall detect. its kicked in a couple times pulling
onto a trailer :-)
[quote] "Bruce Lawton" <xxx@xxx.xxx> wrote:

> Maybe this is common knowledge for this group, but I recently learned how
> to burn up my motor.
>
> I was returning home, thinking about the prospect of working on the car
> and bumping the accelerator. I was working under the dash recently, on the
> heater core. If it were in gear and on, who would win: the motor or the
> parking brake? Some of you see where this is headed. I parked the car in
> the garage, set the brake and pressed the accelerator for at least 2
> seconds, probably 4 or 5 seconds. The battery delivered 25A during this.
> The brake won, I turned everything off and went inside. The next day, as
> the car began to roll, there was a tick-tick sound. I'd overheated the
> commutators and lifted 4 bars. A LOT of motor amps had heated it when it
> wasn't turning.
>
> The Zilla has stall protection; my Soliton apparently does not.
>
> Lesson learned. :-\
>
> BTW, Steve and Audrey from Green Shed Conversions drove up from Florida on
> short notice and brought a spare motor so I could show the car for Earth
> Day. Wow! Kudos and a big thank you!
>
> Bruce
>
> _______________________________________________
> | Moratorium on drag racing discussion is in effect.
> | Please take those discussions elsewhere. Thanks.
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[EVDL List]

Bummer. Does your EV still have the tranny or are you direct drive?

BTW the parking brake went overcenter on my EV once -- I couldn't get the p=
arking brake to release. I was able to drive it off the trailer and into my=
garage against the parking brake without drama. That was with 48V on my Ko=
stov sepex, the "controller" was just a switch... No Amp limit! Since there=
was no PWM there was no current multiplication, though.



________________________________
From: Bruce Lawton <xxx@xxx.xxx>
To: xxx@xxx.xxx.edu =

Sent: Saturday, April 21, 2012 4:50 PM
Subject: [EVDL] How To Burn Up Your DC Motor

[top]

Maybe this is common knowledge for this group, but I recently learned how t

o burn up my motor.

I was returning home, thinking about the prospect of working on the car and=
bumping the accelerator. I was working under the dash recently, on the hea=
ter core. If it were in gear and on, who would win: the motor or the parkin=
g brake? Some of you see where this is headed. I parked the car in the gara=
ge, set the brake and pressed the accelerator for at least 2 seconds, proba=
bly 4 or 5 seconds. The battery delivered 25A during this. The brake won, I=
turned everything off and went inside. The next day, as the car began to r=
oll, there was a tick-tick sound. I'd overheated the commutators and lifted=
4 bars. A LOT of motor amps had heated it when it wasn't turning.

The Zilla has stall protection; my Soliton apparently does not.

Lesson learned. :-\

BTW, Steve and Audrey from Green Shed Conversions drove up from Florida on =
short notice and brought a spare motor so I could show the car for Earth Da=
y. Wow! Kudos and a big thank you!

Bruce

_______________________________________________
| 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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[EVDL List]

Bruce,
Wow, that is indeed fast - are you sure it was only 2 sec that you used
full throttle? 25A from the batteries can easily turn into about 500A
motor current if the impedance of the loop controller - motor is low enough.
I have occasionally tested my EV pack by loading the motor while on parking =

brake - apparently the fact that I had an AC (induction) motor saved me
because I just heard a swishing sound of a slow rotating (slipping)
magnetic field at full power, but no harm was done to the field windings
(this AC motor was also water cooled - still I did not dare to run the
test longer than half a minute at a time with cooling periods)

In your case it sounds like the brushes and especially the contact area wit=
h the comm
heated up (that is one place where there is resistance and thus voltage dro=
p)
which managed to over-heat the comm bars due to the absence of cooling,
I take it that your motor has only an internal fan, not an external blower?

Indeed - lesson learned. I expect that the old motor is salvageable,
if needed by installing a new comm but probably by repairing the
damage that was done to the comm and rebanding it.

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 Behal=
f Of David Dymaxion
Sent: Sunday, April 22, 2012 12:57 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] How To Burn Up Your DC Motor

Bummer. Does your EV still have the tranny or are you direct drive?

BTW the parking brake went overcenter on my EV once -- I couldn't get the p=
arking brake to release. I was able to drive it off the trailer and into my=
garage against the parking brake without drama. That was with 48V on my Ko=
stov sepex, the "controller" was just a switch... No Amp limit! Since there=
was no PWM there was no current multiplication, though.



________________________________
From: Bruce Lawton <xxx@xxx.xxx>
To: xxx@xxx.xxx.edu
Sent: Saturday, April 21, 2012 4:50 PM
Subject: [EVDL] How To Burn Up Your DC Motor

[top]

Maybe this is common knowledge for this group, but I recently learned how t

o burn up my motor.

I was returning home, thinking about the prospect of working on the car and=
bumping the accelerator. I was working under the dash recently, on the hea=
ter core. If it were in gear and on, who would win: the motor or the parkin=
g brake? Some of you see where this is headed. I parked the car in the gara=
ge, set the brake and pressed the accelerator for at least 2 seconds, proba=
bly 4 or 5 seconds. The battery delivered 25A during this. The brake won, I=
turned everything off and went inside. The next day, as the car began to r=
oll, there was a tick-tick sound. I'd overheated the commutators and lifted=
4 bars. A LOT of motor amps had heated it when it wasn't turning.

The Zilla has stall protection; my Soliton apparently does not.

Lesson learned. :-\

BTW, Steve and Audrey from Green Shed Conversions drove up from Florida on =
short notice and brought a spare motor so I could show the car for Earth Da=
y. Wow! Kudos and a big thank you!

Bruce

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| 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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[EVDL List]

Bruce Lawton wrote
> ... I parked the car in the garage, set the brake and pressed the
> accelerator for at least 2 seconds, probably 4 or 5 seconds. The battery
> delivered 25A during this. The brake won, I turned everything off and went
> inside. The next day, as the car began to roll, there was a tick-tick
> sound. I'd overheated the commutators and lifted 4 bars. A LOT of motor
> amps had heated it when it wasn't turning.
>
> The Zilla has stall protection; my Soliton apparently does not....
>

As of version 1.5.1 of the Soliton code that is correct - we do not prevent
you from pushing current through the motor even when stalled.

We did contemplate adding this function at one time but did not because it
has a high annoyance potential (ie - stall detect triggering while trying to
drive up onto a trailer would infuriate me - I certainly wouldn't be
"thanking my controller" for its overzealousness), and, frankly, we feel it
is the motor manufacturer's responsibility to provide adequate
specifications and warnings for their products, rather than it be entirely
up to use to protect their products from abuse.

I should also point out that you are the only person I am aware of that has
damaged a motor by stalling it in the 3.5 years we've been selling Soliton
controllers, so I'd say this is a very rare problem. In contrast, we have
destroyed 7 motors ourselves by pushing too much current through them for
too long but I rather suspect that no one wants us to lower our current
ratings or otherwise thermally-cripple our controllers to protect against
that kind of abuse...

But if protecting against a stall seems really important to people -
particularly people that already own our controllers - then we'll add it to
the 1.6 release of the code.

We are about to roll out an intermediate version, 1.5.2, to correct the bug
in the start button function (failing to idle the motor) and add a couple of
minor functions: block throttle when signal is above calibrated range and a
somewhat convoluted reverse switch function to protect against reversing the
field polarity when the motor is already spinning. Coincidentally, both
functions are being added because someone did something dumb with their
controllers.



--
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_______________________________________________
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| Please take those discussions elsewhere. Thanks.
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[EVDL List]

Can the stall protection be configurable,
so you have it default "off" but if someone
needs it, it can be configured "on" and that
person must take care when loading the car on
a trailer that he may instantly lose traction
and catapult backwards due to this feature?
(the safe way would be to use a winch or at least
a protection that can be ratcheted so the car
does not uncontrolledly leave the trailer...)

I deal with products being deployed in a
wide variety of environments with conflicting
needs on a daily basis, so this is one of the
escapes - keep it compatible (default = old behavior)
and allow it to be "upgraded" to the new feature...

Regards,

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 Jeffrey Jenkins
Sent: Monday, April 23, 2012 5:23 PM
To: xxx@xxx.xxx.edu
Subject: Re: [EVDL] How To Burn Up Your DC Motor


Bruce Lawton wrote
> ... I parked the car in the garage, set the brake and pressed the
> accelerator for at least 2 seconds, probably 4 or 5 seconds. The
> battery delivered 25A during this. The brake won, I turned everything
> off and went inside. The next day, as the car began to roll, there was

> a tick-tick sound. I'd overheated the commutators and lifted 4 bars. A

> LOT of motor amps had heated it when it wasn't turning.
>
> The Zilla has stall protection; my Soliton apparently does not....
>

As of version 1.5.1 of the Soliton code that is correct - we do not
prevent you from pushing current through the motor even when stalled.

We did contemplate adding this function at one time but did not because
it has a high annoyance potential (ie - stall detect triggering while
trying to drive up onto a trailer would infuriate me - I certainly
wouldn't be "thanking my controller" for its overzealousness), and,
frankly, we feel it is the motor manufacturer's responsibility to
provide adequate specifications and warnings for their products, rather
than it be entirely up to use to protect their products from abuse.

I should also point out that you are the only person I am aware of that
has damaged a motor by stalling it in the 3.5 years we've been selling
Soliton controllers, so I'd say this is a very rare problem. In
contrast, we have destroyed 7 motors ourselves by pushing too much
current through them for too long but I rather suspect that no one wants
us to lower our current ratings or otherwise thermally-cripple our
controllers to protect against that kind of abuse...

But if protecting against a stall seems really important to people -
particularly people that already own our controllers - then we'll add it
to the 1.6 release of the code.

We are about to roll out an intermediate version, 1.5.2, to correct the
bug in the start button function (failing to idle the motor) and add a
couple of minor functions: block throttle when signal is above
calibrated range and a somewhat convoluted reverse switch function to
protect against reversing the field polarity when the motor is already
spinning. Coincidentally, both functions are being added because someone
did something dumb with their controllers.



--
View this message in context:
http://electric-vehicle-discussion-list.413529.n4.nabble.com/How-To-Burn
-Up-Your-DC-Motor-tp4577309p4580199.html
Sent from the Electric Vehicle Discussion List mailing list archive at
Nabble.com.

_______________________________________________
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| Please take those discussions elsewhere. Thanks.
|
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[EVDL List]

I would suggest an "override" feature that could be triggered by a
momentary switch that the operator has to push if he wants to do something
out of the norm, like drive the EV up onto a trailer. During normal
operation, there would be normal stall protection. Voila, the best of both
worlds.


[quote] Cor van de Water <xxx@xxx.xxx> wrote:

> Can the stall protection be configurable,
> so you have it default "off" but if someone
> needs it, it can be configured "on" and that
> person must take care when loading the car on
> a trailer that he may instantly lose traction
> and catapult backwards due to this feature?
> (the safe way would be to use a winch or at least
> a protection that can be ratcheted so the car
> does not uncontrolledly leave the trailer...)
>
> I deal with products being deployed in a
> wide variety of environments with conflicting
> needs on a daily basis, so this is one of the
> escapes - keep it compatible (default = old behavior)
> and allow it to be "upgraded" to the new feature...
>
> Regards,
>
> 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 Jeffrey Jenkins
> Sent: Monday, April 23, 2012 5:23 PM
> To: xxx@xxx.xxx.edu
> Subject: Re: [EVDL] How To Burn Up Your DC Motor
>
>
> Bruce Lawton wrote
> > ... I parked the car in the garage, set the brake and pressed the
> > accelerator for at least 2 seconds, probably 4 or 5 seconds. The
> > battery delivered 25A during this. The brake won, I turned everything
> > off and went inside. The next day, as the car began to roll, there was
>
> > a tick-tick sound. I'd overheated the commutators and lifted 4 bars. A
>
> > LOT of motor amps had heated it when it wasn't turning.
> >
> > The Zilla has stall protection; my Soliton apparently does not....
> >
>
> As of version 1.5.1 of the Soliton code that is correct - we do not
> prevent you from pushing current through the motor even when stalled.
>
> We did contemplate adding this function at one time but did not because
> it has a high annoyance potential (ie - stall detect triggering while
> trying to drive up onto a trailer would infuriate me - I certainly
> wouldn't be "thanking my controller" for its overzealousness), and,
> frankly, we feel it is the motor manufacturer's responsibility to
> provide adequate specifications and warnings for their products, rather
> than it be entirely up to use to protect their products from abuse.
>
> I should also point out that you are the only person I am aware of that
> has damaged a motor by stalling it in the 3.5 years we've been selling
> Soliton controllers, so I'd say this is a very rare problem. In
> contrast, we have destroyed 7 motors ourselves by pushing too much
> current through them for too long but I rather suspect that no one wants
> us to lower our current ratings or otherwise thermally-cripple our
> controllers to protect against that kind of abuse...
>
> But if protecting against a stall seems really important to people -
> particularly people that already own our controllers - then we'll add it
> to the 1.6 release of the code.
>
> We are about to roll out an intermediate version, 1.5.2, to correct the
> bug in the start button function (failing to idle the motor) and add a
> couple of minor functions: block throttle when signal is above
> calibrated range and a somewhat convoluted reverse switch function to
> protect against reversing the field polarity when the motor is already
> spinning. Coincidentally, both functions are being added because someone
> did something dumb with their controllers.
>
>
>
> --
> View this message in context:
> http://electric-vehicle-discussion-list.413529.n4.nabble.com/How-To-Burn
> -Up-Your-DC-Motor-tp4577309p4580199.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
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>
> _______________________________________________
> | Moratorium on drag racing discussion is in effect.
> | Please take those discussions elsewhere. Thanks.
> |
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> | Multiple-address or CCed messages may be rejected.
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[EVDL List]

Mark Warner wrote
>
> I would suggest an "override" feature that could be triggered by a
> momentary switch that the operator has to push if he wants to do something
> out of the norm, like drive the EV up onto a trailer. During normal
> operation, there would be normal stall protection. Voila, the best of both
> worlds.
>

This isn't practical because the owner would have to 1) foresee the need to
override stall detection in the first place; 2) install a switch to do so;
3) remember to use the switch when the motor is inadvertently stalled!

Also, this still wouldn't have protected the OP from damaging his motor, as
he *intentionally* stalled it.






--
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_______________________________________________
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[EVDL List]

The Leaf seems to have a bit of this problem. If parallel parking on a
hill, and you're using the brake, I think it's ignoring the accelerator
pedal till you take you foot off the brake. This results in a small surge
causing a small bump into the vehicle in front (or back). Not sure of the
best way to solve this, but something to think about.

Peri

-----Original Message-----
From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On Behalf
Of Mark Warner
Sent: 23 April, 2012 7:02 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] How To Burn Up Your DC Motor

I would suggest an "override" feature that could be triggered by a momentary
switch that the operator has to push if he wants to do something out of the
norm, like drive the EV up onto a trailer. During normal operation, there
would be normal stall protection. Voila, the best of both worlds.


[quote] Cor van de Water <xxx@xxx.xxx> wrote:

> Can the stall protection be configurable, so you have it default "off"
> but if someone needs it, it can be configured "on" and that person
> must take care when loading the car on a trailer that he may instantly
> lose traction and catapult backwards due to this feature?
> (the safe way would be to use a winch or at least a protection that
> can be ratcheted so the car does not uncontrolledly leave the
> trailer...)
>
> I deal with products being deployed in a wide variety of environments
> with conflicting needs on a daily basis, so this is one of the escapes
> - keep it compatible (default = old behavior) and allow it to be
> "upgraded" to the new feature...
>
> Regards,
>
> 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 Jeffrey Jenkins
> Sent: Monday, April 23, 2012 5:23 PM
> To: xxx@xxx.xxx.edu
> Subject: Re: [EVDL] How To Burn Up Your DC Motor
>
>
> Bruce Lawton wrote
> > ... I parked the car in the garage, set the brake and pressed the
> > accelerator for at least 2 seconds, probably 4 or 5 seconds. The
> > battery delivered 25A during this. The brake won, I turned
> > everything off and went inside. The next day, as the car began to
> > roll, there was
>
> > a tick-tick sound. I'd overheated the commutators and lifted 4 bars.
> > A
>
> > LOT of motor amps had heated it when it wasn't turning.
> >
> > The Zilla has stall protection; my Soliton apparently does not....
> >
>
> As of version 1.5.1 of the Soliton code that is correct - we do not
> prevent you from pushing current through the motor even when stalled.
>
> We did contemplate adding this function at one time but did not
> because it has a high annoyance potential (ie - stall detect
> triggering while trying to drive up onto a trailer would infuriate me
> - I certainly wouldn't be "thanking my controller" for its
> overzealousness), and, frankly, we feel it is the motor manufacturer's
> responsibility to provide adequate specifications and warnings for
> their products, rather than it be entirely up to use to protect their
products from abuse.
>
> I should also point out that you are the only person I am aware of
> that has damaged a motor by stalling it in the 3.5 years we've been
> selling Soliton controllers, so I'd say this is a very rare problem.
> In contrast, we have destroyed 7 motors ourselves by pushing too much
> current through them for too long but I rather suspect that no one
> wants us to lower our current ratings or otherwise thermally-cripple
> our controllers to protect against that kind of abuse...
>
> But if protecting against a stall seems really important to people -
> particularly people that already own our controllers - then we'll add
> it to the 1.6 release of the code.
>
> We are about to roll out an intermediate version, 1.5.2, to correct
> the bug in the start button function (failing to idle the motor) and
> add a couple of minor functions: block throttle when signal is above
> calibrated range and a somewhat convoluted reverse switch function to
> protect against reversing the field polarity when the motor is already
> spinning. Coincidentally, both functions are being added because
> someone did something dumb with their controllers.
>
>
>
> --
> View this message in context:
> http://electric-vehicle-discussion-list.413529.n4.nabble.com/How-To-Bu
> rn -Up-Your-DC-Motor-tp4577309p4580199.html
> Sent from the Electric Vehicle Discussion List mailing list archive at
> Nabble.com.
>
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[EVDL List]

[quote]Jeffrey Jenkins wrote:

> This isn't practical because the owner would have to
> 1) foresee the need to override stall detection in the first place;
> 2) install a switch to do so;

It seems these could be handled by an appropriate section in the controller owner's/installation manual.

> 3) remember to use the switch when the motor is inadvertently stalled!

The suggestion was that stall protection is active by default and the switch/button is an override to temporarily defeat it. It seems to me that if I had read the manual and installed the switch, that I would probably remember it reasonably soon after the stall protection interfered with my loading or unloading my EV from the trailer ;^>

It is the converse that is an issue: i.e. only motor damage will remind the user to turn off the switch should they neglect to re-enable stall protection.

Some SW intelligence could certainly help here, for instance rather than considering the open or closed position as enabling or disabling stall protection, instead consider a transition between the two states as disabling the protection for a short time. At the very least, the SW should re-enable the protection after a fixed amount of time, regardless of the switch position, and perhaps indicate a warning.

> Also, this still wouldn't have protected the OP from damaging his motor,
> as he *intentionally* stalled it.

True, but is there really anything you can do to protect the motor from intentional abuse?

Cheers,

Roger.


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