No drive from brushless motor, please help.

Hey, please forgive me if I'm asking the same questions for the hundredth time but I 'm not finding what I need to know. I really need some help with diagnosis as I'm really not sure how to interpret my tests. The bike is a no name Chinese special with a direct drive motor and brushless controller and wasn't working when I got it. Worse yet, the symptoms keep changing. When I try to activate the throttle, the motor moves momentarily then cuts out. At first it would spin when it was off the ground but cut out when on the ground. Then, the whole system would go dead. I thought I had a BMS issue because I was losing battery voltage. Checked the battery and tightened a couple of connections and now I am not losing power but motor still just pulses momentarily when I use the throttle. Load tested the battery to 8 amps with no problem. If I use the PAS, the motor spins but it is noisy and it seems to cut in and out. Also, if I wiggle the throttle just right, the battery display cuts out. Found some tests on ebikes.ca and on Youtube.
Here's what I've done so far. Bypassed the Keyswitch/display in throttle with a jumper wire, no difference. Checked the throttle output, okay I think. I have 4.3 volts from red to black and a smooth increase from .8v to 3.5v at the green wire as throttle is applied.
On the controller, I have about 10k ohms from neg. to each phase wire and infinity from power wire to phase wires, but only if I test pos. on power lead and neg. on phase wires or use the continuity setting. If I reverse polarity using ohms, my meter starts trying to autorange for some reason.
I checked the motor wiring. Two of the hall sensors switch from 0-5v, but the yellow one switches 0-3v. Also, I checked continuity on motor wires. All phase wires had .1 ohms between them. the green and blue hall wires were open from phase wires but yellow hall wire only had .5 ohms to phase wires. Does this mean I have a bad hall sensor or worse, the motor is fried? Would one bad sensor cause this problem or could I have problems in other components as well? is there anything else I should be testing? I would really appreciate any help as this is my first time working with brushless motors. here are some component pictures.

What's the battery voltage when hooked up to controller? Is there a number etched on the outside ring of the motor on one side? What is it? Do you know what voltage the controller is?

It is a 48 volt system but there is no markings or data that I can find on anything. 48v1000 is written in pencil on top of controller case, that's it. No idea of make or model. I can check motor again though. I have battery voltage now at the controller when on ( 52.8 v).

Looked again where you said and found a # on the motor, missed it before, thanks . it is HBS48V1000W1204120069. Still no name though.

In general, it's always the plugs, the wiring, to the halls or phases.

Low volts on one hall could indicate damage to that hall, or just damage to the wiring or resistors on the halls board inside, if it has them. Open it up, see if everything inside is black, or still golden yellow windings.

Motor got real hot at some point is very possible. Severe resistance to rotation when the motor is unplugged indicates fried windings. If the severe resistance happens only when you plug into the controller, the controller is fried. Those are the really simple indicators of shorted phases.

First thing I'd spend on in your situation, would be a motor, controller, throttle tester. Just makes it easier to test.
http://www.ebay.com/itm/New-24V-36V-48V-60V-Electro-Car-E-bike-Scooter-Brushless-Motor-Controller-Tester-/351119106382?pt=LH_DefaultDomain_0&hash=item51c054614e

puddleglum said:

Looked again where you said and found a # on the motor, missed it before, thanks . it is HBS48V1000W1204120069. Still no name though.

Click to expand...

Same motor I have, but later serial number. Mine is 10120348, which i think was made in the 12th week of 2010. I bought it in Feb. 2011. If it follows the standard date codes, yours was made in the 4th week of 2012. I've got ~15K miles on mine without a problem. It's a Goldenmotor motor or clone since that's a GM part number. Double check all you wiring. If there's a power button, check it too. Other than that, I'd guess a bad fuse or blown controller since you've shunt modded it for 62A.

dogman dan said:

In general, it's always the plugs, the wiring, to the halls or phases.

Low volts on one hall could indicate damage to that hall, or just damage to the wiring or resistors on the halls board inside, if it has them. Open it up, see if everything inside is black, or still golden yellow windings.

Motor got real hot at some point is very possible. Severe resistance to rotation when the motor is unplugged indicates fried windings. If the severe resistance happens only when you plug into the controller, the controller is fried. Those are the really simple indicators of shorted phases.

First thing I'd spend on in your situation, would be a motor, controller, throttle tester. Just makes it easier to test.
http://www.ebay.com/itm/New-24V-36V-48V-60V-Electro-Car-E-bike-Scooter-Brushless-Motor-Controller-Tester-/351119106382?pt=LH_DefaultDomain_0&hash=item51c054614e

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Thanks, that tester looks like a good investment for the future but I'm hoping I won't have to wait another month to diagnose this. I'm okay with pulling the motor apart, I just wanted to make sure that is the problem first. I can certainly recheck connections though. Should the hall wires have continuity to the phase wires or not? Also, what is considered severe resistance? Forgive my ignorance but I have never seen one of these motors before and don't have anything to compare it too. It is easier than my Currie motor bike spins in reverse. It spins almost half a turn with a hard finger flick plugged in or unplugged.

wesnewell said:

It's a Goldenmotor motor or clone since that's a GM part number. Double check all you wiring. If there's a power button, check it too. Other than that, I'd guess a bad fuse or blown controller since you've shunt modded it for 62A.

Click to expand...

Thanks for the ID. I think you're confusing me with kyle201. he is having a similar issue but I haven't done anything to mine. Not even sure what a shunt mod is.

I think I may have found the problem. I opened the motor up to have a look as everything else checked out. Looks really good inside, nothing burnt or broken, thankfully. I am assuming the continuity from the yellow hall wire to the phase wires was the issue. I lifted the signal wire away from the coil and it went open like the others so it was shorted to a winding wire. I haven't been able to test it yet, but I'm hoping that is all it is. There is no insulation between the hall wires and the windings like in pictures I have seen of other motors.
Should I add something? would a piece of that insulating cloth wrap be good?

Hmm, new one for me. I can see how it could happen, the halls prongs very close to touching the steel.

It didn't ground out on the steel it shorted to one wire in the phase windings. It is the middle hall and it shorted to one of the wires that exit the cloth shielding under the left hall. I lifted them and installed another piece of cloth insulation under the center and right hand hall wires. I reassembled and tested the motor last night, just had it clamped in a vice on the bench. It now will start from any position and I can vary the speed nicely with the throttle. So, one problem solved, thanks for the help. You were right, it was wiring to the halls. BUT, now I have another issue. The motor is very noisy when it is running. Rattles really bad. I have always heard that these motors were supposed to be quiet. I can't hear or feel anything when I spin it by hand and there was no sign of anything rubbing inside when I had it apart. I am pretty sure it is electrical noise. I tried all the different phase wire color combinations and color to color is as good as it gets. What would cause it to be so noisy and what else can I test? I am ordering one of those testers but that won't be here for some time.

Well, I still have some issues with this, hopefully someone can verify if I'm on the right track. I changed a bearing and built some spacers to clamp the inner races as they were free to move on the axles so hadn't tested it on the ground but it starts and runs in all positions in the air. I tried a test on the bike today and had the same problem I had last fall. The bike starts to take off then everything goes dead. Only show about 2.5 volts at the power terminals and 34 volts at the charge terminals on the battery charger plug. If I leave it sit with key on throttle off, terminal voltage will climb to the 34 volts but drops off if I turn on the key. If I turn off the key on the battery pack for a few seconds and back on, voltage is back to 52.7 and everything works again. Does that sound like a bad BMS? I checked all the cells earlier and they were even. If the BMS is bad, could I remove it and try the pack without it? I don't mind replacing it if that is the problem, but I hate to do it only to find out something else is wrong. The pack seems small for the motor to me as well. The controller is rated for 30 amps peak and the battery is only 12AH.
I had one other thing happen that concerned me. when I first powered up the bike and turned on the key, the bike lurched ahead. It was against the wall but could have been an issue if it wasn't. It happened twice, both times after having everything disconnected. Is that a indication of a problem or something normal with this system? Could I have a bad throttle or a bad controller? I'm not seeing any voltage drop across the connections for the power but not sure about the throttle. Don't really have a good way to check the amperage when it shuts down. Any advice is appreciated. Sidenote; I found out the bike came from conhismotor. Is their stuff generally okay or is it poor?

I am still fighting with this and keep hitting a brick wall I hope someone will help. I've checked and rechecked connections. Re-did the power supply wires from the battery to the controller. I managed to hook up a 30 amp meter and found the current spikes to 30 amps immediately when I crack the throttle and the BMS shuts down the battery. The motor has very little power. Controller and BMS are both rated for 30 amps from what I can tell.
I got my motor tester today and ran all the tests. The controller and throttle tests showed fine which confirmed the DVOM tests I had ran based on the ebike.ca site. All the hall sensors switched on and off and the motor lights all flash when I spin the motor. I have a question about the phase wire lights though. Are they all supposed to flash all at the same time or in a sequence like the hall wires? Also, I have to spin the wheel Fairly hard to get the lights to flash, It that normal? I'm still wondering if I have shorted wires or phase windings, but if I short the phase windings together there is significantly higher wheel resistance so that doesn't add up. The motor is still quite noisy, even up in the air. Is there anything else I can test? What am I missing?

Al the vibration etc makes me thing that it is a wiring combination issue.

If they were pre made plugs, maybe they were made incorrectly.

Even where you showed a picture of the hall on the phase winding I am not convinced.. The phase winding you can see is covered in an insulated coating, ..so the phase winding are insulated between each other. Unless a bare piece of the hall wiring was actually touching a piece of bare copper or solder from the phase winding I don't see that as much of an issue. the dark windings we can see in the picture are NOT bare copper. they have the semi transparent insulated coating that needs to be removed to get to the much lighter copper colour underneath.

Only way it could have occurred if it was the leg in contact and it happened over time due vibration and wear or damage to the coating.

Either way , I'd replace all three halls, so at least you have a matching set. all putting out the same voltage..

then run through the phase hall sequences..

there are multiple threads on here and in the wiki explaining how it is done. In all there are 36 different possible colour combinations between halls and phases. on a generic motor there 'should be' 6 correct smooth running combinations...3 forward and 3 reverse.


search the forum and wiki for th info..no time to explain ..