Motor problem diagnosis? Please help

[getzbuzy]

Hi forum,

I'm hoping someone may be able to help me diagnose my ebike problem.

About 2 months ago, I replaced my battery with an em3ev 14s lithium battery, and 12 fet 40A Infineon controller. I'm using a 48 volt 1000 watt brushless motor from yescomusa.com. It's been running great, but yesterday I was riding home in a light rain. going 30 to 32 miles per hour when I heard a slight rubbing or metallic like sound coming from the motor. It was very subtle at first but continued to get worse over the next few miles.

The battery and controller were bone dry in my triangle frame bag. Only wires exposed to the elements are throttle etc because I use a cycle analyst v3.

Today the rubbing sound is extremely loud when the motor tries to turn.

Anybody know what I should do? Did the rain somehow fry the motor?

FYI its only about 9mos old with 1000 miles or so.

Also, I do run 1700 to 1800 watts continuous at times...Paul at em3ev didn't think that would be a problem though unless I was doing 2000 continuous up hills on the 1000w brushless hub....so I'm hoping power didn't fry the motor.

 

[amberwolf]

Rim brakes rubbing on bent rim from broken or loose spoke?

Magnet come loose inside and stuck on stator?

rust in bearings or on stator?

Lots of things it could be; need more specific info on exactly where sound comes from and type of sound.

 

[getzbuzy]

Thanks for responding.

It is definitely something internal...the "grinding" comes from the motor directly. I can eliminate anything along the ideas of bent parts, brakes, or spokes.

I was wondering about a loose magnet stuck on the stator myself...i know nothing about it except what ive read though.

Maybe its coincidental that it was raining. After all it wasn't raining real hard... But then again I was going 30mph so water was kicking up all around me.

Last week I blew the rear tire on a curb...I hit pretty hard. Maybe it loosened up one of these magnets???

I forgot to give a couple details that are important. This is just from spending 5 mins on it this morning... But this is what's happening...

Without load it was hit or miss on the motor in response to the throttle at all. Sometimes it "works" sometimes it doesn't. From the main screen, I know my ca3 is recognizing that throttle is applied. It seems that when there is zero motor response, it will remain that way no matter how many times I try to give throttle. I have to turn the system off and back on to try again. Sometimes the motor starts, sometimes it doesnt.

When it does work, without load the motor grinds only for a few seconds and then seems to fight past it and run smoothly.

With load it is a consistent, horrible grind no matter how much throttle i give.

And finally, I just tried it 5 or 6 times in a row without any response. :x I'm pretty frustrated. I'm going to try it again later but at the moment I'm being pessimistic and thinking it's done for unless I can fix it. All in all I was able to get the motor to respond maybe 10 or 12 times out of the 20 times I turned the system off and on. This is my only mode of transportation.

 

[amberwolf]

Ah, that's a totally different problem, and unlikey to be mechanical.

If you read around the forum for other similar symptoms, you'll see that mostly that sort of thing is hall sensor related, usually connectors.

 

[getzbuzy]

Much thanks. I did read up on similar symptoms and a few people did diagnose hall sensor wires and were able to fix the problem.

Fingers are crossed that its just in the connectors and not a bad hall sensor itself.

 

[wesnewell]

Sounds like a bad hall or phase wire connection.

 

[getzbuzy]

I'll have to take a good look at the connections later this week. I'm really hoping I don't have to order new hall sensors. For some reason I never seem to get online orders in a very timely manner.

Wesnewell, you don't happen to know what hall sensors our 1000w yescomusa motors use do you? I'm also curious how much "short burst" and continuous wattage you have comfortably put through your motor without concern of overheating. Your 100v battery with 40A controller is a LOT more than I thought it would take....but I don't know all that much yet.

I saw Lyen post that the Honeywell SS41 can be used with a lot of brushless motors....

 

[wesnewell]

No, I've never had my 1000W motor open, but hall sensors are pretty common. I see Honeywell sensors mentioned a lot for replacements. As for the motor, I can't put more than 4Kw to the controller which may be close to that to the motor. But one person has run it at 53mph in Florida with an 80A controller. With a 48V battery, you should be able to run it wot until you run out of battery. About 30mph. Mine is over 4 years old now and I've never had a problem with it. I wouldn't go much over 1500W for any length of time, short burst of 6000W should be fine.

 

[Ykick]

@getbuzy - here's my thread and journey sourcing and replacing Hall sensors and wiring for a similar 9C DD motor:

http://endless-sphere.com/forums/viewtopic.php?f=8&t=48114&hilit

It's not particularly difficult but takes some reworking skill and patience to gather everything up and perform the job.

Newer yescom motors may use a PCB mounted Hall sensor setup but they can possibly accept the standard replacement SS41 sensor.

Post up a wanted thread in marketplace and somebody may have a stash of sensors they're willing to sell in small quantity.

 

[getzbuzy]

Thanks everyone.

I found a phase wire almost severed off at the gold bullet connection on a phase wire. I just ordered new connectors, but I picked up these at radio shack for now. I doubt they will carry amps well. Are the OK to use for a week or so and can they somehow do damage??

 

[Ykick]

Avoid those connectors for phase power wires. Solder splice is what I'd do until i could get some 4mm bullets.

 

[getzbuzy]

Glad I asked first. Will do. Thanks.

 

[dnmun]

if you did a twist off and there is a grinding noise as in failure of the controller commutation then you should first test the hall sensors to see if they toggle when you rotate the wheel. the voltage should swing from almost 5V to almost 0V. each hall sensor wire should do that. your controller has to be powered up and the the 5 pin plug connected. measure by sticking the voltmeter probes into the backside of the pin plug. put the black probe on the black wire and the red probe on each of the GBY hall sensor wires as you rotate the tire.

you should solder all of your phase wire connections between controller and motor.

if you have to replace the hall sensors then you can upgrade your phase wires at the same time to 12AWG.

 

[getzbuzy]

Well, I'm back up and running. It was a phase wire....almost completely severed. Not sure how it even happened because everything is very secure in my triangle bag. Does soldering wire make it more brittle? My soldering technique still needs work. Haha.

I was close to missing the problem because my heat shrink tube was covering it.

Anyway, I happened to find a couple spare sets of 4mm gold bullets so I didn't even need to do a temporary solder splice.

All in all a great ebike lesson. I never would have guessed it was an electrical connection problem without all your help. The grinding sounds so mechanical.

So as far as upgrading my phase wires to 12 gauge...is that beneficial to do if I leave the original 16(ish) gauge in the motor?

Wesnewell, what length of time do we generally consider "short bursts"? I limit my Infineon to 33A typically, but with 14s at full charge I have over 58v...which is over 1900 watts when I gun the throttle. That drops as I hit full speed (33 to 35mpg), but I still stay above 1500w a lot of the time. Are all the watts my ca3 shows actually delivered to the motor??

 

[wesnewell]

On level ground the motor will never overheat at wot. That's not to say how long the controller can take it, but it should be able to go more than a few miles before it over heats. Assuming the CA shows the same as other watt meters, it only shows the watts drawn from the battery pack, The power to the motor will be ~10-20% less. The phase wires out of your controller should already be at least 12awg now. Shortening the phase wires to the motor and/or using larger wire will improve efficiency to the motor some, but don't expect anything noticeable.