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VESC 6 hi voltage problem

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mike
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VESC 6 hi voltage problem

Hi,

I have problem with new VESC 6.
My setup is 12S running  in FOC mode. Motor is powering water propeller. Max motor current was set to 90A and it is working fine at lower voltages(<42V). Maybe even at 12S at beginning but I am not sure anymore.

Problem is that when voltage is higher than 42V motor wont start every time. When "pressing throttle" red LED blinks 3 times and than stops. VESC tool shows DRV error briefly and than disappears. If I lower the voltage it runs normal. If I lower the voltage,start the motor and than raise the voltage all way to 50V while it is running(LAB supply) it will continue to run without problem.  Raising voltage above 42V lowers the chance of start.
Max input voltage is set to 57V. 

In console DRV8301 is reporting FETLC_OC | GVDD_OV. If I reset them thay come back.

What could be the problem. Is it possible the driver chip is partially damaged somehow? ​

Is it still advisable to run VESC 6 at 10S like it was case in ver. 4?

 

Thanks, Mike

frank
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Last seen: 6 hours 47 min ago
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Hydrofoil? Long phase wires?

mike
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Joined: 2018-05-04 11:29
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frank you got it. :)

but I believe that is not the problem. 
Problem is that above certain voltage (sometimes 42V sometimes even lower) motor won't even try to start. I think mcu receives nFAULT signal from DRV chip. I will try to measure this directly on nFAULT pin.
Regarding GVDD_OV fault I measured GVDD voltage and it stays at required 11V all the time all way up to 50V.
Regarding FETLC_OC fault I tried to disable OCP but it didn't fix the problem.

I have already ordered new DRV8301 chip for backup. :)

Any other ideas?

 

frank
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what motor do you use? XML export file would also help.

mike
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Last seen: 2 years 3 months ago
Joined: 2018-05-04 11:29
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Looks like I have found the problem.

There was some water ingress to conectors that caused problem. I measured 5-10 k Ohm between phase wires with motor disconected. Funny how such high resistance can make problems considering motor has orders of magnitude  lower resistance...

Does anybody have idea how to make it less sensitive. I have tried both BLDC and FOC.  Same problem in both modes.

BTW motor is  6374