burned out my 5kw BLDC, thoughts?

[Jop Amsterdam]

so yeah, very sad update to this thread: https://goldenmotor.com/SMF/index.php?topic=6924.0

I benched the motor, could not figure out the problem but it was clear there was something seriously wrong, send it to the dutch golden motor dealer, just heard that its a total loss as my magnets spools burned out.
so seems I just asked to much from it.

now I have a problem. I guess I could afford a new 5kw motor, that will just slip in, quick fix, and then I just have to hope that since I don't use my electronic motor break anymore (because I also already destroyed a planetary gearbox) that it wont burn out again. But this thing I build is really heavy, and with driving a lot in the city I just ask a lot of the motor.

so thats a big risk I cant really afford to take if it goes wrong again quickly, I can also start saving up for a 10kw motor, but then I also need a new controller (vec500 instead of my current vec300), and you know, its not really legal for me to ride around with a 10kw on this bike.

last option is to wait a bit, do buy the new 5kw and change my heavy AGM batteries for a LiPo system so I just have less weight. But that will be even more expensive than switching to 10kw I guess.

what ever I do i'm looking at 600 to 1200 euro's, thats money I don't really have for a long time.

any ideas? anywhere that is selling used but still good Golden Motor gear?

[Bikemad]

Hi Jop,

Sorry to hear that your motor is dead, presumably it was the high temperature of the stator windings that also killed the Hall Sensors.

If the Motor overtemperature protection was correctly enabled, I would not have expected the stator windings (or the Hall Sensors) to become hot enough to cause permanent damage, assuming that the temperature protection settings were also set correctly. 

How many seconds did you have set for the Stall Protection Duration (s)?

If the 10kW motor is illegal to use, you will have no option but to replace the damaged motor with another 5kW motor.
However, if it was legally permissible to use a 10kW motor limited to the same 5kW output, the dual stators in the 10kW motor should get less than half as hot as they would both be producing the same overall combined power, but much more efficiently.

Lowering the gearing a bit more would also help to reduce the load on the motor, by simply replacing the 15 tooth front sprocket with the other 13 tooth sprocket you could probably reduce the load on the motor by around 13%.

Alan
 

[Jop Amsterdam]

not sure what the settings where, i'll have a look.

technically the 10kw is illegal, but so was the 5kw yet is was allowed by the road safety agency after inspection.

my vehicle, a 'bakbrommer', is so rare that its even when it still had a petrol engine it was in a total legal greyzone, a normal 'brommer' (max 50cc moped/motorcycle) is allowed to have a max 4kw engine if electric under european law, but my bakbrommer weighs far far more and is meant for transporting even heavier loads. So the argument could be made that it should be more similar to one of those light electric delivery truck and not have a power limit to begin with but a max speed limit.

saw a nice 4kw but geared electric motor in america but that one is totally not tested for the dutch road, at least the goldon motor one is. so I guess running the 10kw would be more(ish) legal than switching to that totally different engineered motor. And if I would get caught with the 10kw I could always decide to reclassify it as a 3 wheeled motorcycle now that I have a proper drivers license. would just cost, again, yet more money.

but its all a bit moot, unless I decide to take my chances with another 5kw I wont have the money either way for a while. so I guess I should just suspend my license plate and put it in storage. Who knows what will be available or affordable by the time I have the time and money to get it back on the road.

it just sucks, I have spend so much time and money already on this conversion and it was so much fun to ride for the few months that it all finally worked.

[Jop Amsterdam]

but yeah, using the 10kw on 5kw limits might be a good idea, just a shame I would need a new controller too, maybe someone wants to trade their vec500 for a vec300 with me?

anyone know whether the plate boltholes of the 10kw are the exact same as the 5kw? there doesnt seem to be a drawing on the golden motor website as there is from the 5kw.

[Bikemad]

Both motors have the same 114mm diameter 3mm deep locating boss and the same 148mm PCD for the mounting bolts, but the bolt hole spacing/pattern is different as the 5kW motor has four mounting bolts at 90° intervals, whereas the 10kW uses six mounting bolts at 60° intervals.

To upgrade to the 10kW motor you'd have to drill another four holes in your existing mounting plate and use another front sprocket and drive key as the spindle is slightly larger diameter on the 10kW motor (25.4mm instead of 22.3mm) and also has a wider drive key slot (stated as 6.4mm on the GM website but shown as 8mm on the drawing instead of 5mm).

A pdf drawing for the 10kW air cooled motor can be found here.

Alan