Author Topic: How to test Hub Motor?  (Read 2274 times)

Just

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How to test Hub Motor?
« on: September 07, 2012, 10:19:40 AM »
Hi All,

I have a geared 48V hub motor with 3 power leads and 5 hall sensor leads.

How can I check that the motor is in a workable condition?

I did the following:
1) span the motor backward (in a reverse direction)
2) verified that when I short between any two power leads of the motor, it stops being spun (brakes).

What's next? How can I check the hall sensors now?

Actually the motor has 5 wires going to the motor's hall sensors: Ha, Hb, Hc, H-(0V) and H+(5V). As for the Ha, Hb, Hc - I guess these are the hall sensor wires. But what about H-(0V) and H+(5V)? Why 5V should be supplied to the 48V motor?

Anyway, if I just supply (without ? controller) 48V to the power leads of the motor, should it turn/spin? Should I apply the power (48V and GND) alternately only to the power leads? What's about the H-(0V) and H+(5V) leads?

Thank you

truly_bent

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Re: How to test Hub Motor?
« Reply #1 on: September 07, 2012, 12:34:21 PM »
dmitryl;

The Hall Effect sensors require a +5V (H+) supply. Naturally, that's what your H-(0V) is for. You'll need to supply the Hall Effect sensors with this supply (almost no current required) to test them. You'll need a meter (DMM) as well.

Having connected the supply, meter between the H- and Ha, Hb, Hc terminals. Rotating the wheel should give you a pulse train from close to the supply level and back to zero.

Trying to run the motor without a controller doesn't strike me as doable... Unless you're incredibly quick with your hands. Getting the motor to actually rotate would mean duplicating the correct firing pulse sequence of a three phase "H bridge". Quickly.

Good luck with that. :)

Jeff


Burley Canto recumbent w/ MP II, Lyen 18FET controller, 48V 20AH LiFeP04, Cycle Analyst, and 4 pounds of zip-ties

Just

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Re: How to test Hub Motor?
« Reply #2 on: September 07, 2012, 05:57:11 PM »
Thank you truly_bent for your comment.
What DMM should I use? Will one shown below be okay? I'm using this one in my measurements.
I've checked the voltages on H- and H+ and they are as expected: 0V and 5V accordingly.
As for Ha, Hb and Hc, they have constant 0V, 5V and 0V and these voltage levels did not changed when I spun the motor. I also tried to spin the motor in different speeds - the voltages on the Hall Sensors stay constant.  Should I measure voltage between hall Sensors and GND or a different voltage between Hall Sensors?
What are the next steps?
Thank you

Kirk

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Re: How to test Hub Motor?
« Reply #3 on: September 09, 2012, 08:12:22 PM »
There are 36 Phase/Hall wire combinations. I have found it easiest to use a cheat sheet to keep track of the wire combinations that I've tried. Try this spreadsheet http://endless-sphere.com/forums/download/file.php?id=11560
I WILL NOT BE RESPONSIBLE FOR DAMAGE TO EQUIPMENT, YOUR EGO, COUNTY  WIDE POWER OUTAGES, BLOWN PARTS, SPONTANEOUSLY GENERATED MINI (OR LARGER) BLACK HOLES, PLANETARY DISRUPTIONS, OR PERSONAL  INJURY THAT MAY RESULT FROM THE USE OF ANYTHING I FIX OR SAY.

Just

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Re: How to test Hub Motor?
« Reply #4 on: September 09, 2012, 08:20:55 PM »
Kirk,
Is your signature copyrighted? Can I use it? :-)
Thanks :-)

Kirk

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Re: How to test Hub Motor?
« Reply #5 on: September 10, 2012, 08:08:52 AM »
Go ahead and use it Dmitryl. I've tried to make my custom harnesses fool proof but the Universe keeps sending me bigger fools. Best of luck to you, hope it works out.
I WILL NOT BE RESPONSIBLE FOR DAMAGE TO EQUIPMENT, YOUR EGO, COUNTY  WIDE POWER OUTAGES, BLOWN PARTS, SPONTANEOUSLY GENERATED MINI (OR LARGER) BLACK HOLES, PLANETARY DISRUPTIONS, OR PERSONAL  INJURY THAT MAY RESULT FROM THE USE OF ANYTHING I FIX OR SAY.

Morgen 3Eman

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Re: How to test Hub Motor?
« Reply #6 on: September 10, 2012, 12:05:25 PM »
Please remember:  Genius has its limits, while stupidity knows no bounds!  :)

(And I should know, I've been on both sides....)

TTFN,
Dennis

Just

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Re: How to test Hub Motor?
« Reply #7 on: September 10, 2012, 12:25:44 PM »
 All in all it depends on the point of view and targets to be achieved :)
« Last Edit: September 10, 2012, 12:30:13 PM by dmitryl »

Just

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Re: How to test Hub Motor?
« Reply #8 on: September 10, 2012, 01:36:18 PM »
Anyway, getting back to the problems...
When I spin the motor, voltage levels on the Ha, Hb and Hc (hall sensor pins in the Controller) should be changed from 0V to 5V and back to 0V (depending on sensor's position).
My question is: "Where these voltage should be measured - between the Ha, Hb and Hc or between each sensor and it's GND ('H-' pin in the Controller) ?
When I spin my motor, voltage on one of the sensors stays constantly 5V and on the rest two 0V and there is no matter how fast I spin the motor... But, when I turn the throttle on, the motor work as expected. So, what's wrong? Am I doing wrong measurements? Why
Thank you

Morgen 3Eman

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Re: How to test Hub Motor?
« Reply #9 on: September 10, 2012, 03:53:59 PM »
Hi Dmitryl

I suggest you slow down:)

To see if your hall sensors are functioning, you have to have 5V and ground supplied to the sensors. (It sounds like you already have that.)   Place your voltmeter leads between ground and each signal lead in turn as you slowly spin the wheel. (It also sounds like your meter connections are correct) Each of the signal should switch from low voltage (about zero) to high voltage (about 5) and back again as the magnets are slowly moved past the sensors.  If you spin the wheel quickly, your meter may not display the voltage correctly due to sampling speed vs signal frequency variations.  Alternatively, you could  slowly move the magnets until the sensor your are metering changes state, then measure the other sensor outputs, move the magnet again, etc., and see that they all change in a pattern.

If the +5V is easier to attach the meter to, you can also measure the signals, with the understanding that the polarity of the signals will seem reversed.  It is the switch from high to low and back again  on each sensor that is important, rather than the meter reference . 

TTFN,
Dennis

Bikemad

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Re: How to test Hub Motor?
« Reply #10 on: September 10, 2012, 04:01:02 PM »
Dmitryl, you need to test the voltage between each of the hall sensor signal connections and H-. If the voltage does not fluctuate between 0 and 5V on all three hall sensors when the wheel is rotated very slowly, then there is a fault with either the respective hall sensor or its wiring.
This would explain why the motor is running in sensorless mode when you spin the wheel with the throttle open.

Alan
 
« Last Edit: September 10, 2012, 07:23:21 PM by Bikemad »

Just

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Re: How to test Hub Motor?
« Reply #11 on: September 10, 2012, 05:10:05 PM »
"need to test the voltage between each of the hall sensor signal connections and H-" - What's exactly that I did

"voltage does not fluctuate between 0 and 5V on all three hall sensors when the wheel is rotated very slowly" - exactly this is the situation

"explain why the motor is running in sensorless mode" - it seems so...

okay, so how is it possible to know what's the current mode of the motor (sensor-ness or sensor-less)? Is there a way to know the motor mode while riding on the bike or only in a garage environment?

While testing the Hall Sensors, should the Power Leads (three thick wires) be connected to the motor? I guess they should not, but asking anyway...

Below I'm attached a picture of DMM, which I use. Is it okay for for the measurements, which I'm doing? Can anyone explain what's the difference between the 10ADC and VOmA inputs in this DMM? I'm using the 'COM' input for a negative polarity and 'VOmA' for the positive one. Is anything wrong?

Thank you!
« Last Edit: September 10, 2012, 05:19:48 PM by dmitryl »

Morgen 3Eman

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Re: How to test Hub Motor?
« Reply #12 on: September 10, 2012, 06:07:18 PM »
Hi Dmitryl
"
The "10ADC" input would only be used when you want to measure current in the few Amp range.  Typical  practice is to place the  black lead in the "COM" (common) input, the red lead in the   "VOma" (Volts, Ohms, Milliamp), and to always connect the black lead to the common or ground level on the device under test.  I probably don't need to tell you, (but I still will) NEVER , NEVER measure a voltage source when you have current measurement  or Ohms measurement selected on your meter.

The motor power leads shouldn't have to be connected to test the Hall devices, but it probably would not have an affect on the readings one way or the other.

I have no idea what your motor looks like, and I have tried to keep out of the way of folks who really know these motors, but I do know how to use test equipment, and troubleshooting techniques.   I would guess that if you simply disconnect the hall sensors entirely, the controller will be in sensorless mode.  But it is just a guess.

TTFN,
Dennis


   

truly_bent

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Re: How to test Hub Motor?
« Reply #13 on: September 10, 2012, 07:17:38 PM »
Dennis, my Main Man! You have the patience of Job! :)
I woulda probably suggested he hit the books... or Google.

No offence dmitryl - I'm just not the hand holding type ;)

Jeff
Burley Canto recumbent w/ MP II, Lyen 18FET controller, 48V 20AH LiFeP04, Cycle Analyst, and 4 pounds of zip-ties

Bikemad

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Re: How to test Hub Motor?
« Reply #14 on: September 10, 2012, 07:54:15 PM »
okay, so how is it possible to know what's the current mode of the motor (sensored or sensor-less)? Is there a way to know the motor mode while riding on the bike or only in a garage environment?

Usually, if there is a problem with one or more of the hall sensors the controller will beep twice and automatically switch to sensorless mode.

In sensorless mode, the motor is unlikely to start turning on its own when the throttle is operated, the wheel will therefore need to be manually rotated until the controller can determine the position of the motor from the inductive pulses coming back through the phase windings as a result of the magnets moving past the segments on the stator.

When my sensors failed on my Magic Pie, it could only run in sensorless mode and I had to start pedalling before the motor would work. The motor also seemed to be slightly noisier and I was aware of a slight delay when the throttle was activated with the wheel already turning.

In conventional mode (sensor controlled), the controller always knows the exact position of the motor from the hall sensor signal voltages and can instantly apply power to the correct windings, even when the motor is stationary.
If the motor operates from a standstill when the throttle is turned, the controller will be functioning normally in sensor controlled mode.

Alan