Voltage leak from EM57 inverter?

[Tremelune]

When I put 12v across the two high voltage posts of my 2014 Leaf inverter, and test from the inverter case, there is a measurable voltage (it starts with maybe 4-5V and drops to less than 1V). If I use a test light across it, it doesn't light up at all. There is a chance I put ~300V into the inverter without a precharge, and I'm wondering how to figure out if I fried something.

I never tested the behavior before the possible frying, so I'm not sure what's "normal" and what's not. Is there a way to figure this out without opening the case? I'm mainly concerned with, you know, electrocution and all that.

[arber333]

When I put 12v across the two high voltage posts of my 2014 Leaf inverter, and test from the inverter case, there is a measurable voltage (it starts with maybe 4-5V and drops to less than 1V). If I use a test light across it, it doesn't light up at all. There is a chance I put ~300V into the inverter without a precharge, and I'm wondering how to figure out if I fried something.

I never tested the behavior before the possible frying, so I'm not sure what's "normal" and what's not. Is there a way to figure this out without opening the case? I'm mainly concerned with, you know, electrocution and all that.

Probably not. reverse diodes on transistors are leaking back to main capacitor. Also there is a big resistor inside that grabs any residual voltage and drains it. This is why voltage diminishes. Do you have a reason to suspect you have leaking IGBTs? If that happens your Fault pin is your best friend and will stop inverter from operating. If you suspect you have something leaking first try with some 60Vdc before you apply full 300Vdc.

Also there is votage induced capacitively or inductively because of all the winding and magnets inside motor. I see 220Vdc and sparks on my Leaf motor if it is only connected by phase cables. To fight this you absolutely need to connect a 6mm2 cable or wire strap between motor and inverter casing.

[Tremelune]

Interesting, thanks! The inverter is bolted to the motor through a steel adapter (I needed to rotate the inverter 90° to fit in the engine bay), so I suspect that connection is sound.

It sounds like the behavior I'm observing is expected. I'm gonna get the batteries and contactors back in and see how the motor spins.