Previously, I reported that my
Simovert motor controller was happy in the rear of the car with the motor in the front of the car. It turns out this is not the case. While going up and down the driveway did not uncover any problems, going up and down the road has. The inverter shuts down with a range of errors:
- GateDriveUnit
- LCA Err Latch
- Overcurrent
- VC_Over_Voltage
I am hoping that this is caused by a combination of poor motor phase cable routing and poor motor-inverter grounding. It turns out that the Siemens supplied motor cables have a shield which is grounded in the cable glands, effectively joining and extending the casing of the motor and the inverter to envelope the motor cables. Such a shield will do a lot to control noise radiated by the motor cables. My motor cables had none of this and worse the motor was not well grounded -- I'm told that non-trivial current can flow between the motor and inverter through the ground due to "induction effects". Regardless of how real this is, properly bonding the inverter ground to the motor ground seems reasonable.
I am solving this problem with a 50mm2 3 phase neutral screen cable and appropriate glands. The very stiff underground rated cable I have isn't really appropriate and in hindsight, I should have found a supplier of the right cable, but that story is for my next post.
