# What is my EV's problem?



## gdirwin (Apr 7, 2009)

Hi Pete:

I am not a Soliton user, but sounds like the controller is limiting power to protect itself... For example, do you have a speed sensor into the controller (ie under over-speed the controller would reduce power) and the wires are possibly loose? I would check all wired connections, looking for anything loose...


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## PTCruisin (Nov 19, 2009)

My Soliton Jr is arriving today but I've read the manual several times and would suggest you record a log file on your next drive. This would help isolate the problem I think. What type of throttle position sensor are you using? A pot box with a cheap or defective potentiometer could cause that behavior. An erratic tach input could force the controller to reduce motor rpm. Setting the minimum voltage parameters (for zero current and max current) in the controller could also cause the problem I think.

Also check the 12v input. Are you operating with an aux battery? You might also want to upgrade the firmware in the controller.

That's all I have. Good luck.


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## Tesseract (Sep 27, 2008)

PeterH said:


> ...
> The Soliton Jr. isn't throwing any errors and I still have the slowly blinking green light on the side that suggests all is well.


If this is correct - as in, you are 100% sure that the controller is not throwing any errors - then the likely culprits are intermittent motor connection (warning - this can be fatal to controllers; not when the connection opens up, rather, when it recloses) or an erratic throttle signal. A log file will probably pinpoint the issue quickly.


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## palmer_md (Jul 22, 2011)

Glad to see Tesseract jump in so quickly. I was going to also suggest looking at a log file from the Jr. It should be able to point you in the right direction. My thoughts are also with the throttle signal wiring, but the motor connection would be a scary possibility. Also the tach sensor giving a high rpm signal to cut power, but not sure how this might be occurring.


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## PeterH (Mar 20, 2009)

Thanks everyone for your input. Just a few notes:

1. I'm using the Evnetics throttle assembly.

2. I don't have a tach output from the motor to drive the data input on the Soliton. I hope to fix that later in the Fall when I stop driving for the winter. The Kostov motor has a 'poor' design for the tach output and I need to tear everything apart to correct the gap to generate the proper signal.

Things I'll look at next:

1. I'll record a data log when I test the EV next and verify that the Soliton Jr. isn't throwing an error and my dash "Check Engine" light hasn't burnt out.

2. The loose connection on the motor is a possibility and check that ASAP.

3. I was wondering if a low 12vdc input might be a problem but I see almost 14vdc on the aux battery when the system is swited on because the DC/DC is working as it should.

I hope to be able to post an update on the situation later tonight.

Thanks,
Pete


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## Tesseract (Sep 27, 2008)

Yes, there are lots of possible causes for a sudden loss of power, but most of them will result in the error light blinking. We can eliminate thermal causes right off the bat because they cause a slow reduction in output current, not a sudden loss. Usually the same is true for pack voltage sag until the pack is so depleted that pulling any meaningful current causes the voltage to collapse, but that invariably trips a "pack voltage too low" critical error (ie - opens up the main contactor).

You don't have a tach connected, so that eliminates another one of the prime suspects (ie - a noisy tach signal). As a side note, the internal tach sender in the Kostov motors often doesn't work with our controllers at all, even when the gap is adjusted correctly. I don't know why that is (haven't actually looked at one) so the only advice I can offer whenever this issue pops up is to spend the $25 at Automation Direct for the inductive prox we recommend.

So that pretty much just leaves a 12V supply problem (low enough to inhibit PWM (ie - below 11V) but high enough to not cause a critical error shutdown (ie - above 10V), an intermittent connection on either the throttle S5V or THROT wires, or an intermittent connection in the motor and/or associated wiring (which could be from many different things, including an open brush pigtail, raised commutator bar, weak/bouncing spot weld between the field windings, etc...).

But all of this is speculation; a log file will tell the tale immediately.


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## PeterH (Mar 20, 2009)

I have a new piece of information to share. I haven't tried running the EV yet. I put it on the lift and checked the motor power cable connections. The connections on the Soliton Jr. are nice and tight. The cable connections on the motor terminals are also nice and tight. HOWEVER... the terminals themselves on the Kostov motor are loose. Loose enough to twist a couple of degrees with just a little pressure. Additionally, all four terminals on the motor are equally loose.

Could this be the cause of an intermittent connection issue?

I'm hesitant to run the EV again until I have some better idea if the motor terminals are a problem or not.

Thanks,
Peter


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## Tesseract (Sep 27, 2008)

PeterH said:


> ...the terminals themselves on the Kostov motor are loose. Loose enough to twist a couple of degrees with just a little pressure. Additionally, all four terminals on the motor are equally loose.
> 
> Could this be the cause of an intermittent connection issue?
> 
> I'm hesitant to run the EV again until I have some better idea if the motor terminals are a problem or not...


Yes, of course this is a problem! Whether it is *the* problem is not yet known (though it certainly a prime suspect) but it is *a* problem regardless. Loose electrical connections in high power circuits often result in fires, so definitely tighten them up (and mark the bolts/nuts with paint, nail polish, etc., to make it easy to spot any movement later on).

EDIT: wait... I just remembered that the studs inside the terminal box on the later Kostov motors do "float" somewhat. That is to say, it is possible that the connection between the motor cable and internal motor wiring - via these "floating" studs - is tight, it's just that the studs, themselves, are somewhat loose. If this is the situation you were describing then it is not likely the problem. So we are back to collecting a log file. I don't really see a way around that unless you want to send both the motor and controller back to be checked. I can't speak for Kostov here, but there will be a charge for shop-time and shipping in the case of the controller (our warranty is good, but it is not unlimited!).


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## Duncan (Dec 8, 2008)

Hi PeterH

Do you lose power a bit or completely?

I have just had an intermittent glitch on my car - driving normally then no power

It appears to have been the switch I had on the brake pedal - I checked and the brakes-on switch was on the point of switching with the pedal up

I adjusted so I had to definitely move the pedal to have the switch operate and the fault went away - nearly two weeks now
So I think I have fixed it

May be worth checking your brake switch


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## CrazyAl (May 9, 2011)

I've had intermittent problems like power loss happen to me and I ended up cleaning up the little bit of corrosion and also burn marks from arcing from each connection. Then retightened each connection. Sometimes the corrosion and burn marks are not easy to see. On another occasion, I had to replace the big relay/contactor.

Just wondering if you had a circuit diagram for your traction circuit?


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## PeterH (Mar 20, 2009)

Hello everyone and thanks for the input. 

CrazyAl: I went through everything and all of my connections are still tight and appear to be clean of any indication of arcing. Circuit diagram? Good idea... and you'd think I'd come up with one because by day, I pretend to be a technical writer... so, no diagram at this time.

Duncan: Good thought but In my situation, I seem to be suffering from a general loss across all throttle positions. I just conducted a short test to collect a log file from the Soliton Jr., by driving out of my garage and 30 feet up the drive way. Long enough to demonstrate the problem is consistent and collect some data. I hesitate to take it on the road at the moment... confidence is low at the moment. 

Tesseract: I also visited the Soliton's interface IP address and noted nothing unusual. No errors were recorded in the interface. I have a log file and reviewed it briefly. I don't see anything unusual but I'm far from an expert on interpeting that stream of data. Would you like to see that log file?

If nothing is obvious in the log file, I would be glad to box up the controller and ship it to Florida for a professional exam. I'd rather pay the shipping and shop fees and remove the controller from the list of suspects. 

I communicated with my local vendor who provided the Kostov motor and we are waiting to hear from his contact at Kostov regarding the terminals. But based on your edit to your last post on this thread, I'm willing to consider a problem with the controller as a more likely problem.

Thanks,
Pete


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## Siwastaja (Aug 1, 2012)

Don't underestimate the possibility of a brush problem in the motor. EV DC motors are generally of high quality, but it still seems relatively common that there are problems with brushes, and it can cause exactly the behavior you describe. I'd expect it to show in the controller logs however, but maybe not if the problem is not severe enough.

So I'd vote for motor brush problem over the controller problem, but just guessing.


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## Tesseract (Sep 27, 2008)

PeterH said:


> ...
> Tesseract: I also visited the Soliton's interface IP address and noted nothing unusual. No errors were recorded in the interface. I have a log file and reviewed it briefly. I don't see anything unusual but I'm far from an expert on interpeting that stream of data. Would you like to see that log file?


Mail the log file to our support address. What we are looking for here are entries where Throttle Current and Motor Current are tracking each other then all of sudden motor current starts dropping - perhaps all the way to 0 - then shooting back up again.


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## mora (Nov 11, 2009)

My Kostov has "floating" terminals too. Those are actually pretty loose. I opened it up once and noticed it is "normal". I thought there was something missing inside. Its been so for two years and no problems. I drum for brush inspection too. Should be easy to confirm if brushes move freely and surfaces don't have any cracks or chips missing.


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## PeterH (Mar 20, 2009)

I've sent a copy of the log file to the support email address.

I'll accept the fact that the terminals tend to "float" on the motor side of things. If others have observed this "feature" then I souldn't be surprised to see it on my motor also.

After reading one of the suggestions about brushes, I'm wondering if mine haven't worn out already. I have just over 7500 miles on the motor. I was told to expect a lot more than 7500 miles before needing to replace the brushes but I have heard of others that got a lot less than 7500 miles on their brushes. I wish I had a picture of the "before" condition of the brushes that I could compare with what I see today.

I have often wondered how to tell that the brushes need to be replaced. Is this sort of loss of power the major indication I've been looking for?

I think I'll be replacing the brushes anyway... why? I had to remove the band around the outside of the motors that protects the brushes and just as I was thinking "don't let that little nut fall into the motor" it fell into the motor. 

Just spent 20 minutes with an inspection scope looking around inside the motor as best I could and can't find that darn nut. I'll try again later but if I don't find it, the motor has to come out just to clear out that nut. If it comes out, I'll change the brushes and fix my tachometer problem at the same time.

Thanks,
Pete


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## Tesseract (Sep 27, 2008)

I just replied to your email. For the benefit of those following along, there was nothing obviously amiss in the log file, but I did notice that the brake input is enabled and this will block motor output whenever it is active. None of the log entries showing the brake input active were in the middle of entries showing motor current above 0A, though, so no smoking gun there.


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## Siwastaja (Aug 1, 2012)

PeterH said:


> I have often wondered how to tell that the brushes need to be replaced. Is this sort of loss of power the major indication I've been looking for?


Sudden loss of power, jerky operation, sudden stopping and starting again. Usually a burning smell, but not necessarily. It can seem to be fixed on its own, but then it will get worse again. So, many different symptoms. (I have not used EV size DC motors, but smaller ones; but the principle is the same.)

Brush lifetime can vary a lot, depending on how well the brushes were installed in the first place and how well did they seat during burn-in. Material quality is also important.

The springs holding the brushes must also be inspected, as well as the commutator surface. But I'm sure there are experts on this topic who can chime in.

Anyways, I remember seeing a few topics like this here with similar symptoms and the cause being the brushes. That's why I'm mentioning the possibility. Another usual cause is a poor connection somewhere but that was already covered.

(Even though a properly manufactured DC motor has a very good brush lifetime, this is still one of the reasons I prefer AC.)


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## Joey (Oct 12, 2007)

Tesseract said:


> I just replied to your email. For the benefit of those following along, there was nothing obviously amiss in the log file, but I did notice that the brake input is enabled and this will block motor output whenever it is active. None of the log entries showing the brake input active were in the middle of entries showing motor current above 0A, though, so no smoking gun there.


Thanks for keeping this thread up to date with the results.

Is an intermittent internal short in the motor a possible cause, or would that have a noisy signature in the log file?

I once had a problem where the throttle wasn't returning to the min position after letting off. After hitting the brake pedal, the throttle would remain locked out. But as you said, it was easy to see in the log file. I fixed it with a second spring on the throttle linkage.


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## CrazyAl (May 9, 2011)

PeterH said:


> I've sent a copy of the log file to the support email address.
> 
> I have often wondered how to tell that the brushes need to be replaced. Is this sort of loss of power the major indication I've been looking for?
> 
> ...


Do you have a flexi magnet tool - very handy for fishing for lost nuts (provided there are not stronger magnets around).

Also, since you mentioned the brushes, what do the commutators look like? Do they look burnt or dirty OR are they nice and clean?

I know of someone who had a brand new motor and one of the internal connections inside the motor had a crack or break - can't remember exactly.


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## PeterH (Mar 20, 2009)

Yesterday I gave up looking for the nut with my inspection camera and tonight I don't have time. But I'll try again.

I'll probably go ahead and pull the drive line just so I can take care of my tach sender also.

So I need to:

1. Find a reliable sensor of some sort for this motor and my Soliton Jr.

2. Find a new set of brushes.

The commutator looks nice and clean but I'm thinking my brushes need to be replaced. At this point, I also think the brushes are behind the whole loss of power issue I had/have.

I can say for certain that the current set of brushes weren't properly 'run in' to start with. It might have spun for 6 or 7 hours on 12v to set them but once I got the rig all together, I was off and running. So, lesson learned the hard way. 

Do I need to have the commutator turned before I set new brushes? I've got to take the motor apart anyway... just to find the nut (if I don't find it before), and replace that crappy tach signal sender.

Brushes seem to be my problem and I can't find a source for replacement brushes. I sent out a number of emails yesterday to Kostov dealers but no one has replied yet and I can't find anyone listing brushes on their web site. What gives??

I'd LOVE to go with Helwig brushes but they don't have any for the Kostov motors that I'm aware of.

Thanks,
Pete


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## Tesseract (Sep 27, 2008)

Before you replace the brushes, etc., can you make a short video capturing the loss of power while driving the EV as well as another log file? Make sure the controller is set to performance mode, too (so that the switching will be clearly audible - at least to me, anyway).

My thinking here is that the loss of power might be so brief it happened in between logging intervals (ie - less than ~20ms), and that's why it wasn't captured.


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## PeterH (Mar 20, 2009)

Good news... I found that nut I dropped into the motor and was able to fish it out with a little magnet stuck to a piece of coat hanger!

I slapped everything back together and took it for a test run with my tablet in one hand recording video. Oddly, I had full power during the entire drive of about 2 miles. I was in Peformance mode... I hear the high pitched whine all the time I am asking for power from the Soliton Jr.

I suspect I disturbed whatever brush problem I had/have when I was checking out the brushes and I'll have full power until the problem repeats itself.

Here are 3 pics of the brushes... I couldn't see them all with this camera but my inspection camera showed them to be all in about the same condition.




























To me, everything looks ok. No burn marks, nice patina (sp?) on the commutator... anyone with more experience see something I don't?

So I have a log file and a video clip. The video is useless because I had full power throughout the test. So I won't bother uploading it.

I'm still going to order new brushes... I just won't be standing in my driveway, tapping my foot, waiting for the UPS driver to show up.

Thanks,
Peter H.


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## major (Apr 4, 2008)

Actually the patina or commutator film looks shy to me. I'd prefer to see a uniform color more to the grayish brown. But it is not terrible. And the brushes appear to be plenty long enough nowhere near in need of replacement.

Ref: http://www.remco1.com/Commutator_brochure.pdf


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## Tesseract (Sep 27, 2008)

I agree that your brushes look fine, and so do the pigtails to them. Unless heavily abused, the brushes should last for *years*; it is quite likely you will never have to replace them, actually.

So I think we need to reconsider the problem in more detail. Your initial description was a bit sparse, and I can't help but think the solution is eluding discovery because of that. So, how about filling in a few more details like:

1. How long do the power dropouts last, roughly? Ie - more than a second or less?

2. When power returns does it do so smoothly, or is there an abrupt reapplication of current?

3. What is the motor current slew rate value?

4. Do you use a 12V battery? How is it kept charged up?

5. Are you sure that the ERR light is operating? NB - the error light is blinked during start-up for just this purpose.


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## CrazyAl (May 9, 2011)

PeterH said:


> I suspect I disturbed whatever brush problem I had/have when I was checking out the brushes and I'll have full power until the problem repeats itself.


I'm starting to wonder if the problem you originally had was due to dust from the brushes? In particular, brush dust bridging adjacent segments of the commutator.


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## onegreenev (May 18, 2012)

PeterH,

Glad to hear your motor is running OK for now. As for the terminal issue I can assure you that the Kostov Terminals do wobble a bit. The lower terminal block holds all 4 terminals and each terminal slot is hex shaped to hold the hex shape of the lower portion of the terminal. It does not fit tightly but snug. Leaves enough room to wobble. Then the top portion goes on that and has 4 round holes which the upper portion of the terminal pokes out from. Both the lower block and upper block cap are hard plastic. But both have a bit of play room. I was looking for my lower block to get a picture but could not locate it. I have an extra one kicking around. I did find the upper part. 

Here is a quick video of a terminal and quick explanation. Suffice to say the terminal is most likely not the issue. 

Pete


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## PeterH (Mar 20, 2009)

onegreenev (Pete):

Thanks for sharing that super useful video on the Kostov terminals! It certainly eliminates any question about loose terminals being an issue!

CrazyAl: 

I like the simple cause that is related to a brush problems. Yet, I'm still going to answer Tesseract's questions because we still haven't determined the true cause.  And I'll be ordering a new set because I expect to keep this rig on the road for a lot longer!

Tesseract:

1. When I first experienced a drop-out of this sort, it was a month or so ago on the way to work. The drop out lasted for several minutes and just seemed to be a sudden loss of power, but not a total loss. Perhaps a 40% loss in power. Imagine driving along at 45 when suddenly you feel the car hesitate and slow but continue to move under power. During that first experience power resumed shortly and I was able to continue to the office. It is a 10 mile drive on flat country roads. I had a couple more protracted reductions on that drive to the office but was too far to turn around so I pressed on. Most of the drive was under full or close to full power. On the drive home, I had no problems at all that I was aware of.
That weekend, I opened everything up and checked all of the connections on my pack and everything was tight. From that point on, until last Thursday, I had no trouble at all. During this period the outside air temp was in the 60 to 70 degree range. My Soliton has full time water cooling and never feels hot to the touch.

During this most recent event, I started off with reduce power and by the time I was a mile up the road, I decided it was getting worse and turned around for home. I was barely able to achieve and maintain 35 mph.
During a short test drive that Friday night, before I dropped the nut in the motor, the power reduction was still present throughout my short test drive.

2. It seems to a smooth reduction in output power. The draw on the pack seemed to be normal. I have a meter on the center console that displays pack voltage and current and that was the first thing I looked at when it started. I expected to see a very low voltage pack or a ver low current draw but that wasn't the case. Voltage was normal, about 143 at that part of my drive on a full pack and current was between 70 and 90 amps which is typcial for my 35 to 45 mph cruse on that road.

3. I bumped up the slew rate from 300 to 400 a few months ago. In case the other settings help:
min bat volt at no current: 130
min bat volt at full current: 110
max bat current: 350
max motor voltage: 144
max motor current: 350
max motor power 125

4. I have a 12 starter battery, which is new, as my aux battery. It is charged by a DC/DC that runs when the ignition is switched on. I just checked with the power on and the battery is seeing 13.6 volts. At the time this happened, the aux batt might have been at 12 volts because it hadn't been charged with anything other than the DC/DC in about a week. I usually put it on the 12 charger once a week to keep it fully charged.
5. The dash error light is working. I see it with every start while I wait for the Soliton to close the main contacts. I noticed during a quick test drive I took while working on this email that the green indicator light on the side of the Soliton is blinking rapidly. Normally, or the last time I looked, it was blinking at the slower Cylon rate.

As I found last night, with tonight's quick test, I had full power. I was able to pull out of my driveway, with it's 30 degree grade for the last 20 feet, in second gear with no trouble. During this most recent episode, I felt lucky to get out of the driveway in first gear.

Thanks,
Peter H.


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## Tesseract (Sep 27, 2008)

PeterH said:


> ...The drop out lasted for several minutes and just seemed to be a sudden loss of power, but not a total loss. Perhaps a 40% loss in power.
> ...
> 2. It seems to a smooth reduction in output power. The draw on the pack seemed to be normal.
> ...


You've more or less eliminated the controller, battery pack and both the high and low voltage wiring as the cause with the above statements. The only other thing I can think of that *might* cause this behavior is if one of the two field windings is intermittently dropping out due to a bad spot weld or the like. While I have seen this type of failure before, it was subsequent to pushing 900A through a K9 for 14 seconds; your motor current setting is much more sedate!


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## Duncan (Dec 8, 2008)

Hi Peter


_min bat volt at no current: 130
min bat volt at full current: 110
max bat current: 350
max motor voltage: 144
max motor current: 350
max motor power 125_

These seem incredibly conservative
Are you sure that the controller is not simply cutting power because you have hit the limits 

_min bat volt at full current: 110 - _*I suggest 80*_

max motor current: 350_ *I suggest 500*It is possible that I drive like a hooligan but if I had those settings I would always be hitting the limits

When I had a borrowed Soliton (had to give it back Sob..) and I did hit the minimum full load voltage (on the track) it felt like somebody had stolen half my power

I hit the lower limit after I had used about 60% of my battery - at full battery the current limits stopped me hitting the limit - I think it was 90v
(I didn't use the Soliton to full power because I knew I would have to give it back and I didn't want to be too disappointed when I went back to my OpenRevolt)


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## PeterH (Mar 20, 2009)

Duncan said:


> Hi Peter
> These seem incredibly conservative


Yeah... that's me... my middle name is "conservative" when it comes to my battery pack.

Other times I'm more of a "Paranoid Pete" when it comes to worrying about my battery pack...

You might see a pattern forming here. 

I'm actually very happy with the performance of my EV. But my brother is visiting in a few weeks and he is an old time grease monkey so I'm betting we bump it up a bit further to see what happens. 

I took the EV to work and back today. No problems at all... other than my conservative settings. 

So for the time being, I'm going to work under the theory that my brushes were the problem. So when this happens again, the first thing I will do is put it up on the lift, remove that brush protection band on the motor (the retaining bolt and nut are not on the bottom side!) and just tap the brush holders and see if that restores power.

Thanks everyone for your input on this thread. If/when it happens again, I'll update this thread with the latest information.

Peter H.


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## domosher (Jul 10, 2011)

I rebuild Curtis controls and each time a customer has had this kind of problem I have had them place a 12 volt battery between the plus terminal and the disconnected M terminal leadto make sure the conections through the motor circuit is good and compleat. This has usually found the problem bad cable crimps loose lug nuts oxidized connectors. In looking at the pictures a copper to light brown color is quite accceptable.
Shorted windings will show up as a blackened section on the commutator, badly worn or loose brushes will blacken the whole commutator. In a system running with to much peak current that is saturating the field coils it will blacken the amarture and give a much shortened brush life as well.


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## PeterH (Mar 20, 2009)

I'm baaack...

My EV has been running fine all week. Even pulled a load of firewood home with it yesterday.

Today, Sunday, I drove 12 miles to an auction and everything was ok. Left the auction and within a mile of starting the drive home I felt the hesitation and power loss again. Limped home and fortunately avoided any traffic.

I put the rig on the lift, removed the vented band on the motor that covers the brushes and using my finger, pushed on each of the 8 brush holders to make sure they were all in good contact with the commutator.

Jumped back in and drove down the road a mile and felt full power. On the way out my drive way, with the transmission fully engaged in first gear, I experienced a few seconds of bucking as if the motor was completely cutting out. That quickly passed as I increased speed and shifted into second gear. Made it a mile under full power and no apparent problems. Made my U-turn and in the middle of the U-turn it bucked a bit again, and then on the way back to my garage, I had the hesitation again. Not as bad as before, but still detectable.

I parked, went in and fired up my notebook and grabbed the video camera to collect some hard data. Repeated the same drive test. This time, I detected no hesitation and had full power throughout the entire test.

What would you conclude? Your options are:

1. The brushes aren't being pressed firmly against the commutator enough?

2. The data logger and video camera are influencing the test environment and eliminating the problem so I should run the data logger all the time and keep a video camera trained on my instruments.

3. I should avoid showing off my EV any every opportunity like I did this morning because it seems to jinx the vehicle.

I'm leaning towards the first conclusion. I remember a session with the gentleman from Helwig at last year's EVCCON where he mentioned that he will always add one half of an extra turn on the brush springs to increase the pressure on the brushes.

Anyone care to offer an opinion on the possible utility of my doing the same on my motor?

It certainly won't be an easy operation because I'll have to remove a fair amount of hardware to access 2 of the four sets of brush holders.

Other ideas are certainly welcome!

Thanks,
Peter


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## major (Apr 4, 2008)

I don't think the problem is associated with the motor brushes from what I've read and seen in the photos.


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## PeterH (Mar 20, 2009)

major said:


> I don't think the problem is associated with the motor brushes from what I've read and seen in the photos.


I'm at a loss to explain it any other way. I don't have any loose connections, the Soliton isn't reporting any problems. If not the brushes, what else would you suspect?

At few thoughts I'm having:

If the problem were within the Soliton, would it recognize the problem and indicate a problem and illuminate my check engine light as it does during startup?

If I were hitting some sort of limit, would the Soliton record that on the web interface like it does when it sees a low voltage input from the Aux battery?

As I've tried to share before, the power isn't cut off, it is momentarily reduced. As if something is making only partial contact and 'bouncing' between full contact an partial. If only one brush in the pair, within each brush holder were in contact with the commutator, would I see this effect? If the brushes were causing arching, I'd expect to see evidence on the commutator but it seems to look normal.

Thanks,
Pete


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## kennybobby (Aug 10, 2012)

Weak or low charge on 12v aux battery, loose connection in wiring to main contactor, main contactor weak coil or dirty contacts. Loose connections on the potbox wiring (are you using crimp lug terminals? using crimp lug sliding terminals anywhere?) 

You are either lucky or stupid to be driving around and not get stranded or hurt, knowing that you have an unknown problem-- What if it lays down just as you pull out into a lane with traffic? You have the worst sort of problem to troubleshoot, but it needs to be done before getting back out to play.


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## Tesseract (Sep 27, 2008)

PeterH said:


> I'm at a loss to explain it any other way. I don't have any loose connections, the Soliton isn't reporting any problems. If not the brushes, what else would you suspect?


I suggested the throttle signal as another possibility in my reply to your email yesterday, based on a few dips and pops I saw reported in your latest log file.



PeterH said:


> If the problem were within the Soliton, would it recognize the problem and indicate a problem and illuminate my check engine light as it does during startup?


If the problem is something the Soliton monitors, then yes it will blink or light the error light. 



PeterH said:


> If I were hitting some sort of limit, would the Soliton record that on the web interface like it does when it sees a low voltage input from the Aux battery?


Not necessarily. The only error conditions that get reported on the web interface are ones that cause the controller to shutdown or refuse to start up (pack voltage out of range, 12V out of range, ADC out of range, desaturation, etc.). 



PeterH said:


> As I've tried to share before, the power isn't cut off, it is momentarily reduced. As if something is making only partial contact and 'bouncing' between full contact an partial. ...


Actually, I was getting the distinct impression that there was a total loss of output for very brief periods of time, from, e.g., your statement a couple posts ago: "I experienced a few seconds of bucking as if the motor was completely cutting out."

If the hesitation is more like a dip in output, rather than a complete dropout, then I am much more inclined to think it is a throttle signal issue. That there were both dips and pops reported in your log file further suggests that the proximate cause is noise, and the observation you made that the problem got better after messing around in the engine compartment suggests a physical problem with contacts/wiring. Thus, I suggest checking that no water is trapped inside the weatherproof plug on the throttle (it wouldn't hurt to spray a little WD-40 on the contacts, or dab a bit of dielectric grease on them, before reinserting the plug) and that the crimp terminals on the controller end of the cable are firmly crimped and free of corrosion. Also ensure that the low voltage terminal strip is not getting wet, either from condensation, or spray kicked up by the tires, etc. 

As this has been going on for a while now, if you want to send both the controller and throttle (including the cable) back to us to be checked by me I will tell Aymee waive the shop time charge.


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## PeterH (Mar 20, 2009)

Just a quick update. 

I'm working in checking out all of the throttle connections and linkage connections. As part of this late-night process, I naturally damaged the throttle cable so I'll be replacing that tomorrow after I pick up some new cable on the way home from work.

I'll post more as soon as I have something new to share.

Thanks,
Pete


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## PeterH (Mar 20, 2009)

Update:

I replaced the throttle cable and redesigned the linkage so my 'swing' on the Evnetics throttle assembly is now 55% of full movement rather than the 37% it was previously. The throttle is really stiff now and taking some effort to get used to it.

I drove the EV to work and back yesterday without incident. Today I drove it again to work and had no trouble. However, I felt the hesitation on the way home from work. I happened as I took off from a traffic light and was asking for a lot torque from the motor. As I accelerated away from the light I could feel it suddenly loose some power. Not all power because I was able to maintain my speed in traffic. It didn't last more than a few seconds but recurred again after a few minutes, but again, just briefly and while simply cruising with traffic at 35 mph or so.

It reminded me that on Sunday when I had trouble, it was immediately after I had to pull out of a steep driveway after having to stop at the top to wait for traffic. In that case, I was asking for so much power that the tires actually started to spin before getting traction on the stone driveway.

Does this suggest something about the nature of the problem to anyone or am I just imagining a connection.

Thanks,
Pete


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## Duncan (Dec 8, 2008)

Hesitation just after applying a large load...

Are you sure that it is not just the controller limiting because of your battery voltage?

Your battery will sag under load and your settings are incredibly conservative

Why not reduce your minimum loaded voltage limit to something sensible like 90v and see if that fixes it


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## PeterH (Mar 20, 2009)

Hi Duncan,

I haven't changed my driving habits at all so I'm not asking my EV to do anything it hasn't done frequently in the first 7000 miles on this rig.

I'm certain I'm not hitting any limits because I can watch the pack voltage and current draw and they are acting normally. I can only say that because I have been watching both readings simply form habit. My pack sags to the most 140 volts at this time of the year and the current being pulled from the pack is no more than 200 amps and usually a lot less.

Wish I could watch what voltage and current the Soliton was providing the motor.

I started to think "ok, I'm overheating something...." but I don't think that is the case because on several of my test runs, it was behaving like this from the moment I started out on a totally cold system. Besides, the hesitation went away after a while and the rest of the drive home felt normal, despite my nervous anticipation of a problem. 

I'll be driving it to work again tomorrow. Fortunately, if I see 2 cars on the road at the same time, it seems busy... I take all back roads just in case I have a major problem and have to pull over quickly.

Thanks,
Pete


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## EVfun (Mar 14, 2010)

The brushes need to move smoothly in the brush holders so the spring can enforce good contact. I suggest pulling the springs back with your finger one at a time and make sure the brushes slide back and forth freely by the pigtails. You can also pull the brushes to clean up the sides of the brush and brush holder with an old toothbrush.


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## Duncan (Dec 8, 2008)

Hi Peter

8v sag at 200amps! (148v to 140v)
That is 0.88milliOhms internal resistance per cell!

That is amazing - my Headways are not nearly as good


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## spaceballs3000 (Jun 22, 2012)

After reading these threads, my guess would be the pot box is getting dirty/bad.

I would keep capturing log files until you capture the ongoing issue, and see if your throttle matches your current/voltage output.


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## valerun (Nov 12, 2010)

we had same problem on 2 of our 3 conversions. 0.01uF cap between throttle signal and signal ground fixed the problem. your mileage may vary


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## Tesseract (Sep 27, 2008)

I have yet to receive a response to my email of July 28:



> Hi Peter,
> 
> 
> "Slewrate active" just means that the controller is limiting the rate of rise of motor current in accordance with the slew rate you set in the web interface.
> ...


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## PeterH (Mar 20, 2009)

Tesseract said:


> I have yet to receive a response to my email of July 28:


Guilty as charged... Sorry, just sent it as an attachment to your last email.

Just to bring this thread up to date:

The problem happened again on Sunday while on the way home from a trip to town. Minor hesitation and lack of the normal "pep" I normally enjoy.

Soon as I got home, I put it on the lift and did nothing more than remove the protective band over the brushes, pressed on each brush spring with my finger and replaced the protective band around the motor.

Drove it to work today and home, with no trouble at all. I think this is a "simple" mechanical issue with the brush pressure. 

If the problem occurs again and the same fix works, I will pull the driveline to I have complete access, and add a 180 degree additional turn to the springs. I listened to a lecture last Fall at EVCCON by a gentleman from Helwig Brushes and he recommended this any time he is installing brushes.

Of course, he also said that any time you disturb the brushes at all, you should repeat the original brush break in process of letting it run for a few days on 12 volts. I will admit, that isn't something I've done correctly.

I can't pull anything apart for another couple of weeks. I've been bragging to my brother about this rig for a year now and he is flying across the country next week for a visit. No way can I have my EV off line while he is here! 

I'll update this thread again, soon as I have more info to share.

Thanks
Pete


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## PeterH (Mar 20, 2009)

It has been a while since I posted an update to this thread. Last weekend I removed the motor from my EV.

I've removed all four sets of brushes for examination. Some observations:

1. I've only used about 1/8 inch of brush material on the brushes. That seems normal after 8000 miles of use.

2. One bruch holder seemed to have a much stronger grip on the brushes it held than the other 3 holders. I cleaned out that brush holder and reinstalled the brushes. I did the same to the other 3 holders which is why I think the first holder is the one that had a 'hangup' of some sort.

3. I pulled the back plate off the motor as it stood vertically on the other end. The armature spun freely, quietly, smoothly and for a long time on just a hand spin. That suggests the bearings on the brush end are fine and I have no reason to suspect a problem with the other brushes.

4. I regapped the tach sensor to a MUCH closer clearence than before. I am hoping it makes a difference. But I wonder if anyone can recommend a different sensor I can install while the motor is out. Thoughts anyone?

5. I noticed that my brushes are making a LOT of noise lately. What does that mean? I know the noise is from the brushes because last night when I spun it manually, it was dead quiet and the brushes were out of the holders.

I am off to shop for a new tach sensor...

Thanks,
Peter H.


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## palmer_md (Jul 22, 2011)

Scroll down to "Installation"

http://www.evnetics.com/support/



www.evnetics.com said:


> 1. What type of sensor should I use for the tach input?
> We overwhelmingly prefer industrial inductive proximity sensors from Automation Direct. More specifically, standard and extended sensing distance models with shielded 3-wire cables and PNP outputs (require a 1k pulldown resistor from TACH to SGND - see p9 of the manual).
> Standard sensing distance: AM1-AP-1A
> Extended sensing distance: AM1-AP-3A


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## PeterH (Mar 20, 2009)

Thanks, just ordered one! Glad I checked this before heading off to work in my ICE car.


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## PeterH (Mar 20, 2009)

Hoping the new sensor shows up tomorrow. Meanwhile, do you know the gap specifications for the sensor?

Thanks,
Peter


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## Tesseract (Sep 27, 2008)

PeterH said:


> Hoping the new sensor shows up tomorrow. Meanwhile, do you know the gap specifications for the sensor?


The gap specification is stated right on the Automation Direct website. Ahem.

2mm nominal for AM1-AP-1A
4mm nominal for AM1-AP-3A


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## PeterH (Mar 20, 2009)

My intent was to do something positive about my lack of a good tach signal while I have my motor out. I purchased a new sensor but was unable to squeeze it into the Kostov where the much smaller sensor from the factory sat.

So, still no tach signal. However, I have an idea... why can't I use the exposed end of the drive shaft on the front of the motor? I'll have to machine a piece of aluminum bar stock, 1 inch in diameter, about 1.5 inches long, drill a cavity for a mild steel rod installed perpendicular to the drive shaft, with the ends flush with the surface of the drive shaft 'extension' and then mount the sensor so it detects the movement of the mild steel in the extension?

The end of the motor's drive shaft has a small hole, about 1/8" deep, maybe 1/8" in diameter. I could machine the extension with a nipple to fit in that hole in the shaft. Then I just need to come up with an appropriate adhesive to attach the aluminum to the steel shaft.

Assuming it is perfectly balanced and attached securely, I'd have what I need to monitor motor rpm. Right?

Ok, so start shooting holes in the idea...

By the way, my power loss issue, didn't show up in my first test drive after cleaning the brush holders. But I'll take it for a longer drive tomorrow.

Thanks,
Pete


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