I have an off-road board that uses two parallel setups. Two batteries, two motors, and two VESC's. The batteries are 6S. It's been doing great. Recently I added Hall sensors inside the motors and changed the VESC's to run in hybrid mode (sensored at low ERPM and unsensored at higher ERPM). Not FOC. It ran nicely with the new sensors for a few days; but today one of them fried. My buddy was just cruising around a level parking lot at very low speed. No idea what went wrong. But it looks to me like C51 exploded (if I'm making it out right).
Both VESC units were purchased from diyelectricskateboard.com on 2018-03-20. They are v4.12 Hardware; v2.18 Firmware.
Two questions:
1) Any idea what could have caused this?
2) Can I repair it, or maybe have it repaired? I'm OK at soldering, but we've got a guy at work that's a true expert.
Thanks!
I'm not having any luck uploading images. But here they are...
https://www.dropbox.com/s/fz3u2d8g7kk8uah/VESC1.JPG?dl=0
https://www.dropbox.com/s/6l5ur9k9wpwbifp/VESC2.JPG?dl=0
Just to add a bit more description...
The two VESC controllers run in "parallel" in two ways...
Each has it's own 6S Lipo pack, but I do have the packs paralleled together just to keep them draining equally - particularly if one motor is working harder than the other.
I've simply Y'd the PWM signal from my receiver to both VESC modules (lifting the 5V lead on one of them). I don't use the CANBUS to slave one VESC to the other.
Is it possible that one motor could have been working against the other at low speed such that it fried one of the controllers?
The pcb appears to be damaged...unsolder the cap, clean the pcb up with alcohol and inspect the traces visually (at least). if everything is fine, you could just replace the cap. Check the esc for shorts before you connect the battery after repair and make sure you have a fuse on the positive lead-that could protect your battery in the worst case.
Read this, there might be a clue to what've happened to your setup... https://vesc-project.com/node/80
Great. Thanks for both of those tips. I was in fact doing a Y on the PPM with the power lead lifted on one. But I've had it that way with no problem. I'll change that now.
Regarding replacing the cap... I'm concerned because I don't even see the LED's come on. That seems to me like it would mean something more than the cap is damaged. Am I over-thinking this?
From your pictures it looks like the pcb trace under the capacitor has blown.
I can't tell for sure from the pics, but to me it looks like the pad the cap solders to is blown. Are you saying an additional trace is blown?