NeilP
1 GW
Lucky escape for my 12 FET Xlyte sensorless controller last night.
When I saw what I had done last night, I just assumed I must have fried it, but out of a sense of futility I tested it and it is still alive.
I had been up and around the farm since 0600, and done various jobs ; tractor mowing, spraying tidying etc etcd, general farm maintenance, then started a re wire of an 8Fun hub at about midday. No breakfast, lunch snacks and only one coffee at about 0530
The 8FUN was a brand new geared hub, that, although new and never fitted to a bike, must have been dropped and had its wires half chopped through at the axle stub. Owner could not get it to work so came to me for assistance. With interruptions, I finally had it back together by about 1800...so 6 hours work. including replacing hall sensors, as I had snapped the legs off two while moving the wiring about to solder.
So hub was back together and tested fine with the 'Lyen/ebay' generic hub tester
Thought 'I'll just see that it works ion a controller' although tester showed it would. Bad idea after near on a 12 hour day with blood sugar levels probably very low, and feeling tired.
So I connect it up to a working 6 fet Sensored controller. Lots of fiddling with adapter leads and polarity checking to get 50 volts to controller...but no wheel movement....nothing..weird. no current flow..try some more wiring combos..nothing, 5 volt out but no controller output on phase wires Checked LVC, pack voltage, BMS etc..NOTHING ..So next step...try the 12 FET sensorless controller.
so sensorless controller all fitted to the motor. except the power .
So grab the battery and different adapters with the big Andersons, in the middle, so allow for polarity swapping.. One end of the wiring had 4.5mm bullets to the pack, the other end the big spade terminals Ed Lyen supplies
Now, from years of experience, I never plug connectors straight together, I always jstu brush them past each other, with my eyes closed.
Well I am glad I did this this time...and almighty flash and bang as a quarter inch of brass spade connector vapourised in my hands. Ooops, that was more than a capacitor precharge inrush I thought! It was as if I had just shorted a 20 series pack to itself.
Looked at the wiring, to make sure that was not what i had done..nope, definitely connected direct to the controller as it should be.
OK, I thought , must be a short within the controller...but after what was now a 14 hour day with no food or drink..I decided to leave it till the morning.
Well I checked it this morning...and the 'fault' was so obvious.
Remember earlier, I said my power lead had a pair of Andersons in the middle to allow for polarity / gender swapping...yep...the colours were swapped mid wire. So although colours were correct at either end...I had connected the controller reverse polarity to an 84 volt pack capable of many '00's of amps when shorted
Ah that is it I thought..controller is fried. But futile as I thought it was, I corrected the polarity and tried again.....
Well bloody hell...controller is alive and well.
But lesson still won't be learned,.I have said it to myself many many times before...when you are tired and hungry stop doing technical jobs and have a rest..so easy to make simple mistakes when you are tired.
When I saw what I had done last night, I just assumed I must have fried it, but out of a sense of futility I tested it and it is still alive.
I had been up and around the farm since 0600, and done various jobs ; tractor mowing, spraying tidying etc etcd, general farm maintenance, then started a re wire of an 8Fun hub at about midday. No breakfast, lunch snacks and only one coffee at about 0530
The 8FUN was a brand new geared hub, that, although new and never fitted to a bike, must have been dropped and had its wires half chopped through at the axle stub. Owner could not get it to work so came to me for assistance. With interruptions, I finally had it back together by about 1800...so 6 hours work. including replacing hall sensors, as I had snapped the legs off two while moving the wiring about to solder.
So hub was back together and tested fine with the 'Lyen/ebay' generic hub tester
Thought 'I'll just see that it works ion a controller' although tester showed it would. Bad idea after near on a 12 hour day with blood sugar levels probably very low, and feeling tired.
So I connect it up to a working 6 fet Sensored controller. Lots of fiddling with adapter leads and polarity checking to get 50 volts to controller...but no wheel movement....nothing..weird. no current flow..try some more wiring combos..nothing, 5 volt out but no controller output on phase wires Checked LVC, pack voltage, BMS etc..NOTHING ..So next step...try the 12 FET sensorless controller.
so sensorless controller all fitted to the motor. except the power .
So grab the battery and different adapters with the big Andersons, in the middle, so allow for polarity swapping.. One end of the wiring had 4.5mm bullets to the pack, the other end the big spade terminals Ed Lyen supplies
Now, from years of experience, I never plug connectors straight together, I always jstu brush them past each other, with my eyes closed.
Well I am glad I did this this time...and almighty flash and bang as a quarter inch of brass spade connector vapourised in my hands. Ooops, that was more than a capacitor precharge inrush I thought! It was as if I had just shorted a 20 series pack to itself.
Looked at the wiring, to make sure that was not what i had done..nope, definitely connected direct to the controller as it should be.
OK, I thought , must be a short within the controller...but after what was now a 14 hour day with no food or drink..I decided to leave it till the morning.
Well I checked it this morning...and the 'fault' was so obvious.
Remember earlier, I said my power lead had a pair of Andersons in the middle to allow for polarity / gender swapping...yep...the colours were swapped mid wire. So although colours were correct at either end...I had connected the controller reverse polarity to an 84 volt pack capable of many '00's of amps when shorted
Ah that is it I thought..controller is fried. But futile as I thought it was, I corrected the polarity and tried again.....
Well bloody hell...controller is alive and well.
But lesson still won't be learned,.I have said it to myself many many times before...when you are tired and hungry stop doing technical jobs and have a rest..so easy to make simple mistakes when you are tired.
When I did the same thing with 48v, the spark was more normal, and I cooked off the controller before I could unplug it.
I like to "cat nap" but mostly work and play for much more than just 12 hours per day. :lol: (You can find my posts on ES at all hours of the "day" and "night".)
