openinverter forum

Hello all my inverter seems to be getting hot and putting me into a limp mode. If I am accelerating fast or just driving for a period of time. The car will start to shutter then loose all power. Again wait roadside for a few let it cool than continue on. Sometimes I don't make it very fat before it happens again. I can touch the coolant hoses and they aren't overly hot. Touch the inverter side of the LDU and it's hot. Anyone ever experience a cooling issue with the LDU?

Likely got air in there.

johnsongt350 wrote: ↑Tue Jul 16, 2024 2:06 am Hello all my inverter seems to be getting hot and putting me into a limp mode. If I am accelerating fast or just driving for a period of time. The car will start to shutter then loose all power. Again wait roadside for a few let it cool than continue on. Sometimes I don't make it very fat before it happens again. I can touch the coolant hoses and they aren't overly hot. Touch the inverter side of the LDU and it's hot. Anyone ever experience a cooling issue with the LDU?

You may have some air in your plumming. I recommend you inspect for bubbles and cavitation noise from LDU to radiator.
There are some rules when building cooling circuit:
1. Allways put pump at lowest part of the circuit
2. Install a quick valve at the top of your circuit to deair
3. LDU (motor) should be the last thing in your circuit before radiator.

To effectively deair the system i connect a small transparent hose to quick valve at the top of the circuit. Then i run the pump and observe the pressure rise in the hose. I may pull some air (suck manually ) out from the tube and observe liquid settling down. There may be bubbles going out the hose there.
I turn the pump off and let everything settle down.
I repeat several times untill there is no cavitation noise.

Update: I added a larger coolant loop, radiator, and fan. Took the car for a short drive on a cold day. The motor and inverter remained at a normal temperature. The car suddenly lost all power forcing me to pull over. I shut the car off for a minute and then turned it back on. I drove a short distance before the problem started again. I would add throttle input and the car would shutter, no power.

Any suggestions?

johnsongt350 wrote: ↑Tue Jan 07, 2025 10:38 pm ...The motor and inverter remained at a normal temperature. The car suddenly lost all power forcing me to pull over...

You say normal temp but don't mention if that was before, or after the incident and if you were logging.
It really sounds like your setup is airbound like a bunch of others mentioned. The air will insulate the heat from transferring to the coolant. Need to get it out and ideally allow air to escape as part of the design.

The problem should be easily reproducible if it is cooling related. This time make sure to log tmpm and tmphs. Most likely tmphs will go out of check

I will log tmpm and tmphs and get back to you all.

Thank you for the quick response