# [EVDL] Motor Overheat (additional info)



## EVDL List (Jul 27, 2007)

For a few months, I have been troubleshooting an ongoing motor overheat problem in the Citicar. Since I had done a number of changes around the time it started to overheat while driving, I went back to version 1.0 to test how it compared. The results were rather inconclusive.

for reference, about a year ago I tested the range remaining on my aging lead acid battery pack, and noted that the motor heated up at about 7 degrees F for every mile driven. This is with a stock 48v traction pack. The motor is modified slightly to advance the brushes about 5 degrees. Since the motor is rated at Class F, it should be able to operate at up to 260F. At 7 degrees rise per mile, I should be able to go about 27 miles without overheating - about the range of the Citicar. Indeed, I have driven a couple of 20 mile drives in the past, and not overheated the motor.

Back to the present: This afternoon, the motor heated to 204F after nine miles of driving - a rise of about 14F per mile. This is with the same motor (5 degrees advance), but operating at 64v. 

Before we blame it on the slightly higher voltage, I tested the Citicar a week or so ago with a stock motor (zero advance) and 48v. The stock motor was a bit cooler at 12.6 degrees rise per mile. The difference is slight, and may have been simply driving style. Both motors are GE series wound 6.8".

I've tested with various permutations of advance, pack voltage, brush styles (single-carbon stock, Helwig Carbon Red Top) different motors, different gear oils, different motor shaft seals, higher and lower brush spring tension - Just about everything I can think of. Regardless of combination, the rise per mile is still from 12.5 to 14.1 - It has not even tried to run as cool as it used to.

Watt-hours per mile is still about what it always has been - roughly 240 wh/mi measured at the wall outlet, so it doesn't seem like anything mechanical is dragging.

The main source of heat seems to be at the brush end - on any of the motor configurations I've tested. 

Could there be some esoteric problem with the controller (it is an Alltrax 7245)? Could the brush holder be offset incorrectly compared to the commutator? (would .010" to .030" make a difference?) Something obvious I am missing? (Citicar jokes aside...)

Thanks in advance for any hints/suggestions...

Tom Keenan

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


----------



## EVDL List (Jul 27, 2007)

Is there air being blown through the motor?
Is the blower still working at the same capacity?
What is the terrain and speed you are driving,
did that change from the original tests you did? 


Cor van de Water
Chief Scientist
Proxim Wireless Corporation http://www.proxim.com
Email: [email protected] 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: [email protected] [mailto:[email protected]] On
Behalf Of Tom Keenan
Sent: Tuesday, May 08, 2012 8:26 PM
To: EVDL
Subject: [EVDL] Motor Overheat (additional info)

For a few months, I have been troubleshooting an ongoing motor overheat
problem in the Citicar. Since I had done a number of changes around the
time it started to overheat while driving, I went back to version 1.0 to
test how it compared. The results were rather inconclusive.

for reference, about a year ago I tested the range remaining on my aging
lead acid battery pack, and noted that the motor heated up at about 7
degrees F for every mile driven. This is with a stock 48v traction
pack. The motor is modified slightly to advance the brushes about 5
degrees. Since the motor is rated at Class F, it should be able to
operate at up to 260F. At 7 degrees rise per mile, I should be able to
go about 27 miles without overheating - about the range of the Citicar.
Indeed, I have driven a couple of 20 mile drives in the past, and not
overheated the motor.

Back to the present: This afternoon, the motor heated to 204F after
nine miles of driving - a rise of about 14F per mile. This is with the
same motor (5 degrees advance), but operating at 64v. 

Before we blame it on the slightly higher voltage, I tested the Citicar
a week or so ago with a stock motor (zero advance) and 48v. The stock
motor was a bit cooler at 12.6 degrees rise per mile. The difference is
slight, and may have been simply driving style. Both motors are GE
series wound 6.8".

I've tested with various permutations of advance, pack voltage, brush
styles (single-carbon stock, Helwig Carbon Red Top) different motors,
different gear oils, different motor shaft seals, higher and lower brush
spring tension - Just about everything I can think of. Regardless of
combination, the rise per mile is still from 12.5 to 14.1 - It has not
even tried to run as cool as it used to.

Watt-hours per mile is still about what it always has been - roughly 240
wh/mi measured at the wall outlet, so it doesn't seem like anything
mechanical is dragging.

The main source of heat seems to be at the brush end - on any of the
motor configurations I've tested. 

Could there be some esoteric problem with the controller (it is an
Alltrax 7245)? Could the brush holder be offset incorrectly compared to
the commutator? (would .010" to .030" make a difference?) Something
obvious I am missing? (Citicar jokes aside...)

Thanks in advance for any hints/suggestions...

Tom Keenan

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


----------



## EVDL List (Jul 27, 2007)

Was there a significant difference in ambient temperature between the two
runs? That can make quite a difference for an air-cooled motor.

Also, for a fixed resistance, power goes up as the square of the voltage.
However, I would expect you to see that difference in your Wh/mile. Your
pack voltage is now 33% higher, so any resistive losses could be 77% higher.

Mike

> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
> Behalf Of Cor van de Water
> Sent: Wednesday, May 09, 2012 12:33 AM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] Motor Overheat (additional info)
> 
> Is there air being blown through the motor?
> Is the blower still working at the same capacity?
> What is the terrain and speed you are driving, did that change from the
> original tests you did?
> 
> 


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


----------



## EVDL List (Jul 27, 2007)

If the driving speed was the same then the motor voltage and current
should have been the same, independent from pack voltage.... 


Cor van de Water
Chief Scientist
Proxim Wireless Corporation http://www.proxim.com
Email: [email protected]xx.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: [email protected] [mailto:[email protected]] On
Behalf Of Mike Nickerson
Sent: Wednesday, May 09, 2012 12:35 AM
To: 'Electric Vehicle Discussion List'
Subject: Re: [EVDL] Motor Overheat (additional info)

Was there a significant difference in ambient temperature between the
two runs? That can make quite a difference for an air-cooled motor.

Also, for a fixed resistance, power goes up as the square of the
voltage.
However, I would expect you to see that difference in your Wh/mile.
Your pack voltage is now 33% higher, so any resistive losses could be
77% higher.

Mike

> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On 
> Behalf Of Cor van de Water
> Sent: Wednesday, May 09, 2012 12:33 AM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] Motor Overheat (additional info)
> 
> Is there air being blown through the motor?
> Is the blower still working at the same capacity?
> What is the terrain and speed you are driving, did that change from 
> the original tests you did?
> 
> 


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


----------



## EVDL List (Jul 27, 2007)

Tom Keenan wrote
> 
> For a few months, I have been troubleshooting an ongoing motor overheat
> problem

So...around since winter ended? I've noticed mine getting toastier lately,
may need to hook the forced air blower back on even though I'm only using
2nd.

--
View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Motor-Overheat-additional-info-tp4619321p4620011.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 [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

It doesn't appear to be voltage or ambient temp related. For several years,
I drove it as a 48v car and did not have an issue with overheating, no
matter the ambient temp. To check if it was a voltage problem, I went back
to the 48v setup, and still have an overheat problem - it does heat up a
little more slowly compared to 64v, but not much.

The motor is not ventilated (never has been...) 

Tom Keenan

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Voltswagon
Sent: Wednesday, May 09, 2012 3:36 AM
To: [email protected]
Subject: Re: [EVDL] Motor Overheat (additional info)


Tom Keenan wrote
> 
> For a few months, I have been troubleshooting an ongoing motor 
> overheat problem

So...around since winter ended? I've noticed mine getting toastier lately,
may need to hook the forced air blower back on even though I'm only using
2nd.

--

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


----------



## EVDL List (Jul 27, 2007)

If the setup is the same as before (no fan)
and you use approx the same amount of energy
(so it is not something dragging causing higher
current through the motor) and there are not
other obvious things like change of timing of
the brushes or some other change to the motor,
the only other thing I can think of is the
airflow - did you change the way air is flowing
over the motor or add a bellypan/splash shield
that may cause the air around the motor to stall
and remove cooling from the motor?

It sounds like you *need* to add a fan to that motor now!

Regards,

Cor van de Water
Chief Scientist
Proxim Wireless Corporation http://www.proxim.com
Email: [email protected] 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: [email protected] [mailto:[email protected]] On
Behalf Of Tom Keenan
Sent: Wednesday, May 09, 2012 5:17 AM
To: 'Electric Vehicle Discussion List'
Subject: Re: [EVDL] Motor Overheat (additional info)

It doesn't appear to be voltage or ambient temp related. For several
years, I drove it as a 48v car and did not have an issue with
overheating, no matter the ambient temp. To check if it was a voltage
problem, I went back to the 48v setup, and still have an overheat
problem - it does heat up a little more slowly compared to 64v, but not
much.

The motor is not ventilated (never has been...) 

Tom Keenan

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Voltswagon
Sent: Wednesday, May 09, 2012 3:36 AM
To: [email protected]
Subject: Re: [EVDL] Motor Overheat (additional info)


Tom Keenan wrote
> 
> For a few months, I have been troubleshooting an ongoing motor 
> overheat problem

So...around since winter ended? I've noticed mine getting toastier
lately, may need to hook the forced air blower back on even though I'm
only using 2nd.

--

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


----------



## EVDL List (Jul 27, 2007)

By swapping motors, you've eliminated the motor from contention. If the
watthours/mile figure remains the same, then the only remaining variables
seem to be ambient air temperature and airflow around the motor. 

Is the terrain identical? The rate of heating goes up quickly with higher
amperage, so you could (possibly) have a similar average Wh/mile figure but
increased heating from hills, with the temperature not able to fall off
between hills. 

I can't think of anything in the controller that would cause this in a
series motor. 

Hot to the touch after only 4 miles is way too hot. 





-----
Think Big.
Drive Small. 
--
View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Motor-Overheat-additional-info-tp4619321p4621183.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 [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Airflow could even be changed dramatically by raising or lowering the
suspension at one end of the car or both.


Sincerely,
Mark Grasser


-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Cor van de Water
Sent: Wednesday, May 09, 2012 12:16 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Motor Overheat (additional info)

If the setup is the same as before (no fan) and you use approx the same
amount of energy (so it is not something dragging causing higher current
through the motor) and there are not other obvious things like change of
timing of the brushes or some other change to the motor, the only other
thing I can think of is the airflow - did you change the way air is flowing
over the motor or add a bellypan/splash shield that may cause the air around
the motor to stall and remove cooling from the motor?

It sounds like you *need* to add a fan to that motor now!

Regards,

Cor van de Water
Chief Scientist
Proxim Wireless Corporation http://www.proxim.com
Email: [email protected] 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: [email protected] [mailto:[email protected]] On Behalf
Of Tom Keenan
Sent: Wednesday, May 09, 2012 5:17 AM
To: 'Electric Vehicle Discussion List'
Subject: Re: [EVDL] Motor Overheat (additional info)

It doesn't appear to be voltage or ambient temp related. For several years,
I drove it as a 48v car and did not have an issue with overheating, no
matter the ambient temp. To check if it was a voltage problem, I went back
to the 48v setup, and still have an overheat problem - it does heat up a
little more slowly compared to 64v, but not much.

The motor is not ventilated (never has been...) 

Tom Keenan

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Voltswagon
Sent: Wednesday, May 09, 2012 3:36 AM
To: [email protected]
Subject: Re: [EVDL] Motor Overheat (additional info)


Tom Keenan wrote
> 
> For a few months, I have been troubleshooting an ongoing motor 
> overheat problem

So...around since winter ended? I've noticed mine getting toastier lately,
may need to hook the forced air blower back on even though I'm only using
2nd.

--

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


----------



## EVDL List (Jul 27, 2007)

I just got done yesterday testing out the different heights of the EV. Rear 
vs. Front from even heights, lower front end height or lower rear end 
heights.

Replace the existing air suspension that was install back in 1980 with Shock 
Wave units for the front which replaces the springs. Replace the rear air 
shocks and install a air bag into the springs.

Instead of 100 psi air pressure it took to level a 7000 lb vehicle, it now 
only takes 30 psi.

The old geezer at the auto shop, said if you raise the rear end higher than 
the front, you will use less energy to move the vehicle, because you are 
coasting down hill all the time. Back in the old days, wagons had larger 
wheels than the front.

I said, that will make the vehicle body at a angle which will cause more 
front area which will included the top of the hood and roof area. So we 
tested out this theory to see what happens.

Drove the EV exactly for 2.5 miles at 35 mph on level grade with no wind and 
the E-meter read 10 AH with the rear jack all the way up looking like a 
dragster. Lower the EV to exact level and this time it took 11.5 AH!

He said, see it takes less energy. I said, the first leg was west and we 
are going against the rotation of the earth. The second leg was with the 
rotation of the earth.

Actually, the motor ampere was more, because the battery voltage was less on 
the return trip. If I would let the EV set for about a hour and let the 
batteries defuse for a while, it will be closer in the 10 AH range.

Roland






----- Original Message ----- 
From: "Mark Grasser" <[email protected]>
To: "'Electric Vehicle Discussion List'" <[email protected]>
Sent: Wednesday, May 09, 2012 11:57 AM
Subject: Re: [EVDL] Motor Overheat (additional info)


> Airflow could even be changed dramatically by raising or lowering the
> suspension at one end of the car or both.
>
>
> Sincerely,
> Mark Grasser
>
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On 
> Behalf
> Of Cor van de Water
> Sent: Wednesday, May 09, 2012 12:16 PM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] Motor Overheat (additional info)
>
> If the setup is the same as before (no fan) and you use approx the same
> amount of energy (so it is not something dragging causing higher current
> through the motor) and there are not other obvious things like change of
> timing of the brushes or some other change to the motor, the only other
> thing I can think of is the airflow - did you change the way air is 
> flowing
> over the motor or add a bellypan/splash shield that may cause the air 
> around
> the motor to stall and remove cooling from the motor?
>
> It sounds like you *need* to add a fan to that motor now!
>
> Regards,
>
> Cor van de Water
> Chief Scientist
> Proxim Wireless Corporation http://www.proxim.com
> Email: [email protected] 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: [email protected] [mailto:[email protected]] On 
> Behalf
> Of Tom Keenan
> Sent: Wednesday, May 09, 2012 5:17 AM
> To: 'Electric Vehicle Discussion List'
> Subject: Re: [EVDL] Motor Overheat (additional info)
>
> It doesn't appear to be voltage or ambient temp related. For several 
> years,
> I drove it as a 48v car and did not have an issue with overheating, no
> matter the ambient temp. To check if it was a voltage problem, I went 
> back
> to the 48v setup, and still have an overheat problem - it does heat up a
> little more slowly compared to 64v, but not much.
>
> The motor is not ventilated (never has been...)
>
> Tom Keenan
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On 
> Behalf
> Of Voltswagon
> Sent: Wednesday, May 09, 2012 3:36 AM
> To: [email protected]
> Subject: Re: [EVDL] Motor Overheat (additional info)
>
>
> Tom Keenan wrote
> >
> > For a few months, I have been troubleshooting an ongoing motor
> > overheat problem
>
> So...around since winter ended? I've noticed mine getting toastier 
> lately,
> may need to hook the forced air blower back on even though I'm only using
> 2nd.
>
> --
>
> _______________________________________________
> | Moratorium on drag racing discussion is in effect.
> | Please take those discussions elsewhere. Thanks.
> |
> | REPLYING: address your message to [email protected] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | 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 [email protected] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | 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 [email protected] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | 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 [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

At only 25 mph what is your motor rpm? a 4.5mile trip at only 2,000 rpm
will overheat. the efficiency is increased at higher rpm and the internal
fan will be more effective. shift grars to low and raise the rpm to keep
the motor cooler.!.
Regards,
*Dennis Lee Miles*
+++++++++++++++++++++++++++++++++++++++++++++


> Tom Keenan <[email protected]> wrote:
> 
> > One of those quandaries... the ambient temp varies somewhat here, but it
> > has not overheated during the past four years of (somewhat) variable temps.
> ...


----------



## EVDL List (Jul 27, 2007)

> Tom Keenan wrote:
> > Adding a cooling blower would probably help, but it feels like it
> > would be similar to adding an electric radiator fan to a car with a
> > bad radiator - nothing but a band-aid...
> ...


----------



## EVDL List (Jul 27, 2007)

I'd considered that the motor might be aging, and I have a recently
overhauled 'stock' motor that I swapped in for a test. During a several day
test, the motor averaged about the same as the 'old' motor - from 12 to 14
degrees F per mile.

Yesterday's reading on the 'old' motor was 14.3 F per mile. Today it was
12.3. Today's ambient temp is a bit hotter than yesterday, but traffic
(such as it is) was a little slower today - perhaps an average of 23 mph
compared to 27 mph. For reference, about two years ago the 'old' motor did
a 23 mile drive with about a 6 degree F per mile rise, averaging about 30
MPH.

I may end up putting in a cooling fan so I can drive it longer than a few
miles, but whatever the problem is probably won't go away on its own...

Tom Keenan

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Lee Hart
Sent: Thursday, May 10, 2012 9:56 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Motor Overheat (additional info)



> Tom Keenan wrote:
> > Adding a cooling blower would probably help, but it feels like it
> > would be similar to adding an electric radiator fan to a car with a
> > bad radiator - nothing but a band-aid...
> ...


----------



## EVDL List (Jul 27, 2007)

Hi Tom,

I was thinking about this today as I was watching my temperature gauge and
driving home. If you are pulling the same power overall as before, but the
temperature is going up, it has to be something with the cooling airflow. I
can only think of: 

- Internal Fan
- External ducting or cowling
- Ambient temperature

Since you mentioned this happens across a wide range of ambient
temperatures, I think we could rule that out. 

Have you changed the body, front grill or belly pan in the past so that the
motor is now in a "wind shadow?" If not, the next thing that comes to mind
is the internal fan of the motor. Is it working as well as it used to?
Since you've tried two different motors, it sounds like that isn't it,
though.

In my case, one of my battery boxes creates a wind shadow for the motor, so
I have ducting from the front grill to the motor air intake to try and
combat that. Since much of my drive is at 55 mph, that works pretty well.

Other than that, I'm pretty well stumped!

Mike

> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
> Behalf Of Tom Keenan
> Sent: Thursday, May 10, 2012 5:41 PM
> To: 'Electric Vehicle Discussion List'
> Subject: Re: [EVDL] Motor Overheat (additional info)
> 
> I'd considered that the motor might be aging, and I have a recently
> overhauled 'stock' motor that I swapped in for a test. During a several
day
> test, the motor averaged about the same as the 'old' motor - from 12 to 14
> degrees F per mile.
> 
> Yesterday's reading on the 'old' motor was 14.3 F per mile. Today it was
12.3.
> Today's ambient temp is a bit hotter than yesterday, but traffic (such as
it is)
> was a little slower today - perhaps an average of 23 mph compared to 27
> mph. For reference, about two years ago the 'old' motor did a 23 mile
drive
> with about a 6 degree F per mile rise, averaging about 30 MPH.
> 
> I may end up putting in a cooling fan so I can drive it longer than a few
miles,
> but whatever the problem is probably won't go away on its own...
> 
> Tom Keenan
> 

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


----------



## EVDL List (Jul 27, 2007)

> Lee Hart <[email protected]> wrote:
> 
> > On 5/9/2012 1:57 PM, Roland Wiench wrote:
> > > I just got done yesterday testing out the different heights of the EV...
> ...


----------

