DIY Electric Car Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
70 Posts
Discussion Starter #1
Hi -

I have an electric motorcycle I built. The base system is as follows:

48vdc
Altrax AXE 4844 controller
Etek permanent magnet brush motor

I have burned up three controllers now. All have lasted a number of
miles before failing. The first lasted about 2000 miles. The second
about 600 miles and the last one about 2,400 miles.

The vehicle's wiring was questionable on the first two failures. I was
using one of the four batteries for my 12 vdc lighting requirements and
had a common ground to the frame of the bike. The motor casing was
grounded to the frame as well.

Also, I went through a set of brushes on the Etek after about 2000
miles. I attributed that to the fact that the AXE 4844 is a 400 amp
controller. So when I installed the second replacement I cranked it
down to 220 amps which seems to work fine in my application until it
burned up in about 600 miles.

When I got the third replacement Altrax I decided that perhaps some
sort of anomalous ground-loop was occurring in my system which was
causing the controllers to fail. So I made some wiring changes before
hooking up the third controller.

Altrax happen, at the same time, to post some suggested wiring
schematics to their website which I followed prior to installing the
third unit. I used the schematic titled: "AXE to Permanent Magnet Wire
Diagram" <http://tinyurl.com/2w4u49>. I added a contactor, a pre-charge
resistor, a diode across the contactor's coil, and a 48vdc to 12vdc
converter. I also eliminated all grounds to the chassis, including
lighting grounds. I triple checked diode polarity and all other wiring
prior to heating up the new controller.

Well, that one lasted about 2,400 miles before it burned up. I had it
set to default settings except it was turned down to 220 amps.

Any ideas about what may be happening? Could there be some timing issue
with the motor?

For more details about my bike check here:
http://www.austinev.org/evalbum/971

Thanks!

Be well,
Bob




____________________________________________________________________________________
Yahoo! oneSearch: Finally, mobile search
that gives answers, not web links.
http://mobile.yahoo.com/mobileweb/onesearch?refer=1ONXIC

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #2
The Etek is a very low impeadance motor, this can create problems with many
controllers, especially with software-based current limiting that cannot
respond fast enough.

One thing that is important to do is to place some low-esr capacitors
(ceramic) across the brushgear. This can help deal with the high dV/dt
spikes that come off the commutator. Just one of those spikes can get
through to the MOSFETs in the controller and blow them!

Another thing that will help is to place a large inductor in series with the
motor. There were some posts on the list a while ago where someone was
describing making one out of an old microwave oven transformer core.

This is providing you also have your wiring done right. Use heavy wiring
and be sure that the battery to controller wiring is as low inductance as
possible. Here are some excellent articles and tips from 4QD:

Wiring Practice:
http://www.4qd.co.uk/serv/appnotes/machinewire.html

Failure Modes:
http://www.4qd.co.uk/serv/MOSFETfail.html

-Phil
----- Original Message -----
From: "Bob Tregilus" <[email protected]>
To: <[email protected]>
Sent: Friday, October 12, 2007 9:42 AM
Subject: [EVDL] Etek / Altrax problem


> Hi -
>
> I have an electric motorcycle I built. The base system is as follows:
>
> 48vdc
> Altrax AXE 4844 controller
> Etek permanent magnet brush motor
>
> I have burned up three controllers now. All have lasted a number of
> miles before failing. The first lasted about 2000 miles. The second
> about 600 miles and the last one about 2,400 miles.
>
> The vehicle's wiring was questionable on the first two failures. I was
> using one of the four batteries for my 12 vdc lighting requirements and
> had a common ground to the frame of the bike. The motor casing was
> grounded to the frame as well.
>
> Also, I went through a set of brushes on the Etek after about 2000
> miles. I attributed that to the fact that the AXE 4844 is a 400 amp
> controller. So when I installed the second replacement I cranked it
> down to 220 amps which seems to work fine in my application until it
> burned up in about 600 miles.
>
> When I got the third replacement Altrax I decided that perhaps some
> sort of anomalous ground-loop was occurring in my system which was
> causing the controllers to fail. So I made some wiring changes before
> hooking up the third controller.
>
> Altrax happen, at the same time, to post some suggested wiring
> schematics to their website which I followed prior to installing the
> third unit. I used the schematic titled: "AXE to Permanent Magnet Wire
> Diagram" <http://tinyurl.com/2w4u49>. I added a contactor, a pre-charge
> resistor, a diode across the contactor's coil, and a 48vdc to 12vdc
> converter. I also eliminated all grounds to the chassis, including
> lighting grounds. I triple checked diode polarity and all other wiring
> prior to heating up the new controller.
>
> Well, that one lasted about 2,400 miles before it burned up. I had it
> set to default settings except it was turned down to 220 amps.
>
> Any ideas about what may be happening? Could there be some timing issue
> with the motor?
>
> For more details about my bike check here:
> http://www.austinev.org/evalbum/971
>
> Thanks!
>
> Be well,
> Bob
>
>
>
>
> ____________________________________________________________________________________
> Yahoo! oneSearch: Finally, mobile search
> that gives answers, not web links.
> http://mobile.yahoo.com/mobileweb/onesearch?refer=1ONXIC
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #3
How hot is the controller getting? Have you tried to
monitor the controller data with a laptop? It probably
would be a trick on a bike, but could help shed some
light on the problem. I'd capture some data, and look
that over with a fine tooth comb. This is how, I
learned my field wasn't being powered properly in my
EV, and causing the controller to go into current
overload/limit, when the car wouldn't drive over a
pebble in the road at a stop sign. =



--- (=A4Phil=A4) <[email protected]> wrote:

> The Etek is a very low impeadance motor, this can
> create problems with many =

> controllers, especially with software-based current
> limiting that cannot =

> respond fast enough.
> =

> One thing that is important to do is to place some
> low-esr capacitors =

> (ceramic) across the brushgear. This can help deal
> with the high dV/dt =

> spikes that come off the commutator. Just one of
> those spikes can get =

> through to the MOSFETs in the controller and blow
> them!
> =

> Another thing that will help is to place a large
> inductor in series with the =

> motor. There were some posts on the list a while
> ago where someone was =

> describing making one out of an old microwave oven
> transformer core.
> =

> This is providing you also have your wiring done
> right. Use heavy wiring =

> and be sure that the battery to controller wiring is
> as low inductance as =

> possible. Here are some excellent articles and
> tips from 4QD:
> =

> Wiring Practice:
> http://www.4qd.co.uk/serv/appnotes/machinewire.html
> =

> Failure Modes:
> http://www.4qd.co.uk/serv/MOSFETfail.html
> =

> -Phil
> ----- Original Message ----- =

> From: "Bob Tregilus" <[email protected]>
> To: <[email protected]>
> Sent: Friday, October 12, 2007 9:42 AM
> Subject: [EVDL] Etek / Altrax problem
> =

> =

> > Hi -
> >
> > I have an electric motorcycle I built. The base
> system is as follows:
> >
> > 48vdc
> > Altrax AXE 4844 controller
> > Etek permanent magnet brush motor
> >
> > I have burned up three controllers now. All have
> lasted a number of
> > miles before failing. The first lasted about 2000
> miles. The second
> > about 600 miles and the last one about 2,400
> miles.
> >
> > The vehicle's wiring was questionable on the first
> two failures. I was
> > using one of the four batteries for my 12 vdc
> lighting requirements and
> > had a common ground to the frame of the bike. The
> motor casing was
> > grounded to the frame as well.
> >
> > Also, I went through a set of brushes on the Etek
> after about 2000
> > miles. I attributed that to the fact that the AXE
> 4844 is a 400 amp
> > controller. So when I installed the second
> replacement I cranked it
> > down to 220 amps which seems to work fine in my
> application until it
> > burned up in about 600 miles.
> >
> > When I got the third replacement Altrax I decided
> that perhaps some
> > sort of anomalous ground-loop was occurring in my
> system which was
> > causing the controllers to fail. So I made some
> wiring changes before
> > hooking up the third controller.
> >
> > Altrax happen, at the same time, to post some
> suggested wiring
> > schematics to their website which I followed prior
> to installing the
> > third unit. I used the schematic titled: "AXE to
> Permanent Magnet Wire
> > Diagram" <http://tinyurl.com/2w4u49>. I added a
> contactor, a pre-charge
> > resistor, a diode across the contactor's coil, and
> a 48vdc to 12vdc
> > converter. I also eliminated all grounds to the
> chassis, including
> > lighting grounds. I triple checked diode polarity
> and all other wiring
> > prior to heating up the new controller.
> >
> > Well, that one lasted about 2,400 miles before it
> burned up. I had it
> > set to default settings except it was turned down
> to 220 amps.
> >
> > Any ideas about what may be happening? Could there
> be some timing issue
> > with the motor?
> >
> > For more details about my bike check here:
> > http://www.austinev.org/evalbum/971
> >
> > Thanks!
> >
> > Be well,
> > Bob
> >
> >
> >
> >
> >
>
___________________________________________________________________________=
_________
> > Yahoo! oneSearch: Finally, mobile search
> > that gives answers, not web links.
> >
>
http://mobile.yahoo.com/mobileweb/onesearch?refer=3D1ONXIC
> >
> > _______________________________________________
> > For subscription options, see
> > http://lists.sjsu.edu/mailman/listinfo/ev
> > =

> =

> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
> =



_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #4
Hey Bob, Sounds like exactly what I've been thru with my bike. 48 v Altrax,
Etek. I'm on my third controller too. I found out about the precharge
resistor after the first failure. Altrax only provides golfcart replacement
installation instructions with their controllers and they don't give any
clue that alternate schematics exist in their 'Document Depot'. there is no
reference to alternate instructions at all. I thought maybe I should inform
them about the oversite. The second failure was a mystery to me ,but I
figured that I had an intermittent enable sw. I was using the old
handlebar-mounted Honda kill sw. and it's a real crappy sw.(intermittent).
So since I replaced that I detuned my 400 amp controller to 80% and have had
no probs. for 500 mi. I did replace brushes at 1200 mi. so far so good,
knock on wood! I'm in Petaluma, 50 mi north of SF. My bike is #914 on the EV
Album. Later, Bobcat (PS, Check out ElectricMotorcycles.net)
----- Original Message -----
From: "Bob Tregilus" <[email protected]>
To: <[email protected]>
Sent: Thursday, October 11, 2007 4:42 PM
Subject: [EVDL] Etek / Altrax problem


> Hi -
>
> I have an electric motorcycle I built. The base system is as follows:
>
> 48vdc
> Altrax AXE 4844 controller
> Etek permanent magnet brush motor
>
> I have burned up three controllers now. All have lasted a number of
> miles before failing. The first lasted about 2000 miles. The second
> about 600 miles and the last one about 2,400 miles.
>
> The vehicle's wiring was questionable on the first two failures. I was
> using one of the four batteries for my 12 vdc lighting requirements and
> had a common ground to the frame of the bike. The motor casing was
> grounded to the frame as well.
>
> Also, I went through a set of brushes on the Etek after about 2000
> miles. I attributed that to the fact that the AXE 4844 is a 400 amp
> controller. So when I installed the second replacement I cranked it
> down to 220 amps which seems to work fine in my application until it
> burned up in about 600 miles.
>
> When I got the third replacement Altrax I decided that perhaps some
> sort of anomalous ground-loop was occurring in my system which was
> causing the controllers to fail. So I made some wiring changes before
> hooking up the third controller.
>
> Altrax happen, at the same time, to post some suggested wiring
> schematics to their website which I followed prior to installing the
> third unit. I used the schematic titled: "AXE to Permanent Magnet Wire
> Diagram" <http://tinyurl.com/2w4u49>. I added a contactor, a pre-charge
> resistor, a diode across the contactor's coil, and a 48vdc to 12vdc
> converter. I also eliminated all grounds to the chassis, including
> lighting grounds. I triple checked diode polarity and all other wiring
> prior to heating up the new controller.
>
> Well, that one lasted about 2,400 miles before it burned up. I had it
> set to default settings except it was turned down to 220 amps.
>
> Any ideas about what may be happening? Could there be some timing issue
> with the motor?
>
> For more details about my bike check here:
> http://www.austinev.org/evalbum/971
>
> Thanks!
>
> Be well,
> Bob
>
>
>
>
> ____________________________________________________________________________________
> Yahoo! oneSearch: Finally, mobile search
> that gives answers, not web links.
> http://mobile.yahoo.com/mobileweb/onesearch?refer=1ONXIC
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #5
I took a look at your bike on the photoalbum & it looks like you have no
heat sink. Even worse it looks like you have insulation on the bottom. I
ran Curtis controllers on my bikes & used a heatsink. Maybe your problem is
heat disapation. Lawrence Rhodes....

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #6
I have a big heat sink on my Alltrax 4844, but in all honesty, I don't thin=
k it is doing anything. I've never felt the controller warmup. My Curtis =
on the same bike with the same heatsink would go into thermal limit on hill=
s. I have also warranty replaced two Alltraxes, but I am not using an Etek=
, I am using an ADC, so it might not be the motor either. I have always us=
ed a precharge resistor, and I've never used a main contactor (just a switc=
h) so there has not been any inductive kickback, yet I have had two failure=
s.

damon


> From: [email protected]
> To: [email protected]
> Date: Fri, 12 Oct 2007 09:19:15 -0700
> Subject: Re: [EVDL] Etek / Altrax problem
>
> I took a look at your bike on the photoalbum & it looks like you have no
> heat sink. Even worse it looks like you have insulation on the bottom. I
> ran Curtis controllers on my bikes & used a heatsink. Maybe your problem =
is
> heat disapation. Lawrence Rhodes....
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev

_________________________________________________________________
Help yourself to FREE treats served up daily at the Messenger Caf=E9. Stop =
by today.
http://www.cafemessenger.com/info/info_sweetstuff2.html?ocid=3DTXT_TAGLM_Oc=
tWLtagline
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #7
(=A4Phil=A4) wrote:
> The Etek is a very low impeadance motor, this can create problems =

> with many controllers, especially with software-based current =

> limiting that cannot respond fast enough... place a large inductor in
> series with the motor.

This would be my guess as to the source of the problem; too low a motor
inductance.

> One thing that is important to do is to place some low-esr capacitors
> (ceramic) across the brushgear.

Do *not* do this with a PM motor that is directly connected to a PWM
controller! The capacitors will wind up right across the PWM output, and
cause very high peak currents when the controller tries to switch on/off.

Capacitors across the armature may help with a *series* motor, where the
field inductance is between these capacitors and the controller.
-- =

Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #8
Bob Tregilus wrote:
> I have an electric motorcycle I built. The base system is as follows:
> 48vdc
> Altrax AXE 4844 controller
> Etek permanent magnet brush motor
>
> I have burned up three controllers now...

My first thought is that the Etek motor has too little inductance for
the Alltrax controller's current limit circuit to work properly. These
controllers are intended for series motors, whose series field provides
the necessary inductance.

You could try adding a physical inductor in series with the motor and
see if this solves the problem.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #9
Lee, we are talking very low capacitance, say .01uF ceramic capacitors.

If you have dirty or worn brushgear, this will help more than it will =

hinder. It can also be combined with the series inductor.

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

From: "Lee Hart" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Tuesday, October 16, 2007 6:36 AM
Subject: Re: [EVDL] Etek / Altrax problem


(=A4Phil=A4) wrote:
> The Etek is a very low impeadance motor, this can create problems
> with many controllers, especially with software-based current
> limiting that cannot respond fast enough... place a large inductor in
> series with the motor.

This would be my guess as to the source of the problem; too low a motor
inductance.

> One thing that is important to do is to place some low-esr capacitors
> (ceramic) across the brushgear.

Do *not* do this with a PM motor that is directly connected to a PWM
controller! The capacitors will wind up right across the PWM output, and
cause very high peak currents when the controller tries to switch on/off.

Capacitors across the armature may help with a *series* motor, where the
field inductance is between these capacitors and the controller.
-- =

Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #10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 

·
Registered
Joined
·
70 Posts
Discussion Starter #11
Alltrax say since 2006 their controller can take PM motors without problems
but to test difference without/with i would like to know how to calculate
such inductor please ?

philippe


2007/10/17, Lee Hart <[email protected]>:
>
> From: (=A4Phil=A4)
> > Lee, we are talking very low capacitance, say .01uF ceramic
> > capacitors.
>
> 0.01uF is not all that low a capacitance.
>
> Let's say you have a 144v pack. The controller's output is switching
> between 0v and 144v. Let's say the rise/fall times are 500 nsec (typical =
for
> MOSFETs). How much current does it take to charge/discharge a 0.01uFcapac=
itor across the controller output?
>
> I =3D C dv/dt
> =3D 0.01uF x 144v / 500ns
> =3D 2.88 amps
>
> This is several percent of the normal battery current, and adds a
> proportionate amount to the controller's switching and I^2R losses.
> And, do you really want this kind of current flowing in a tiny ceramic
> capacitor?
>
>
> --
> "Excellence does not require perfection." -- Henry James
> --
> Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart-at-earthlink.net
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 
1 - 11 of 11 Posts
Top