Question about inertia switch

[phillipschip]

I am trying to plan out all the wiring for my project (Tesla SDU/openinverter board in Fiat X1/9). I will have two 200v battery packs, one up front and one above/front of motor rear-both with + and - contractors. I have read that it can kill the inverter to cut power while the motor is spinning? If I were to install an inertia switch and it triggered over big bumps etc, could this potentially kill my inverter? Any suggestions on installation for a switch would be great if you have them. Thanks! Chip
Thought after some reading-maybe wire a switch to trigger neutral with a timer delay that would then close contractors or turn off ign?

[jrbe]

I'm not positive the Tesla boards have them but you might be able to use the estop circuit for the inertia switch.

[phillipschip]

There isn’t an emergency stop wire on my harness for the openinverter board unfortunately

[nubster]

I would read through this thread carefully:
viewtopic.php?t=3564

Several solutions are proposed, including having the inertia switch put the car into neutral, adding a capacitor + diode, using software (E.g., Arduino, etc.) to perform an intelligent "emergency shutdown sequence," or even tapping into the HVIL circuit somehow (this is not exposed externally via SDU harness).

Routing the HVIL (CONN2) to an external wire appears to be the recommended/best solution, and maybe you can repurpose the RS232 wires for this, but I might be misunderstanding.

[phillipschip]

Thanks for the response! Yes, I read that and that’s where I got the idea for an inertia switch to neutral+delay for contractors off. I feel this would be pretty simple and safe as a start. What do you think?

[nubster]

Leveraging the HVIL sounds like the ideal approach, but simply switching the car to neutral is much more straightforward and most likely "good enough" from a practical standpoint. I would maybe later add a separate Arduino/controller to detect the inertia switch, wait for the car to stop, then send a STOP command over CAN, and let the inverter turn off the contactors.

I'm not sure how you would test for the proper delay to open the contactors w/o risking the inverter getting fried.

Does anyone know what happens if you STOP the inverter via command or web interface button while it's still spinning? I'm too scared to try it.