Help with Tesla LDU v6 First Benchtop Spin  [SOLVED]

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ImportFanatiK
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Help with Tesla LDU v6 First Benchtop Spin

Post by ImportFanatiK »

Hello,

I have soldered the connectors on to the "Large DU Logic Board v6" and confirmed I can log in to it with 12V power.
I have gone through Damien's tests for the LDU and the values seemed to align with his video, so I'm hoping the DU is viable.
I am now preparing to spin it on the bench but want to make sure I am not going to make any sort of catastrophic error.

Parts List:
- Open Inverter “Large DU Logic Board v6”
- Sport LDU
- 100w 50 ohm pre-charge resistor from Amazon
- EV200 contactors from battery hookup (https://batteryhookup.com/products/te-c ... a-0-900vdc )

HV Power Source:
60V 5a benchtop power supply set to 40V and 5a current limit.
This is connected to B+ and B- through the EV200 contactors and the 100W 50ohm pre-charge resistor.

LV Power Source:
12V Car battery w switch and 5a fuse

Setup:
  1. Set benchtop voltage to 40V
  2. Set benchtop current limiting to 5amps
  3. Confirm ENCMODE to “AB”
    (Set encoder mode to AB)
  4. Confirm NUMIMP is 36
    (Because Damiem says to)
  5. Set UDCSW to 39 |
    (using 39V since 40V is full voltage from benchtop power supply?)
  6. Set UDCMIN to 38
    (min voltage of 38 since benchtop power supply will be 40V?)
  7. Set THROTMX to 10
    (max 10% of throttle as a precaution)
  8. Set TRIPMODE to 2
    (In the event of an error, close the precharge contactor and open the main contactor. This helps protect the LDU as 0-"All Off" will kill it for sure if the error happens while its spinning.)
Narrative:
  1. I flip the 12V safety switch which sends 12V to the negative contactor and the inverter board.
    The Inverter activates pre-charge resistor contactor and waits for inverter voltage (UDC) to exceed UDCSW (38V) . Then waits for me to press the start button.
  2. I Press the start button. The Inverter closes main contactor and opens pre-charge contactor.
  3. I send 12V to the forward direction pin.
  4. I turn the potentiometer and the Inverter starts to spin (hopefully)

Questions:
  1. Does the above sound correct? or are there any other major steps & considerations I am leaving out?
  2. Will the benchtop power supply be able to spin the motor with 40V and 5a current limit?
  3. What potentiometer should I use to substitute the throttle for the sake of bench testing?
  4. Do I still need a 10kw heating element in parallel with all HV contactors etc for the sake of testing if I am using a benchtop power supply with current limiting?
  5. How do I safely discharge the inverter capacitors after testing is completed?
  6. Are those UDCMIN and UDCSW values ok? or do I need to set them to zero given the voltage I am using is so low. And if I must set them to zero, then does that mean I have to manage precharging myself (manually trigger the precharge and main contactors)?
ImportFanatiK
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Re: Help with Tesla LDU v6 First Benchtop Spin

Post by ImportFanatiK »

I almost have everything wired. Hoping someone can read my post above and help answer some of the questions at the bottom.

Thanks in advance!
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Re: Help with Tesla LDU v6 First Benchtop Spin

Post by johu »

Sounds mostly correct just don't set tripmode to 2 but 1.
Set throtmin=0 to avoid regen as that would kill your power supply. 40V 5A is quite wimpy, might not spin much
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ImportFanatiK
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Re: Help with Tesla LDU v6 First Benchtop Spin

Post by ImportFanatiK »

Ok, so I tried to spin it today.

24V (2 car batteries in series) w/60A fuse & 4kw hot tub heating element in parallel with the fuse.
(I tested the heating element on the benchtop power supply on its own and it pulled 1.5A@24V)

It technically did spin (extremely slowly and very jiggly) but blew the 60A fuse twice.
(No overcurrent error or anything afterwards)

Is it because the voltage is so low? I would have thought 24V/60A would be enough..

Would anyone have any thoughts or suggestions to share?

Thanks!
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Re: Help with Tesla LDU v6 First Benchtop Spin  [SOLVED]

Post by P.S.Mangelsdorf »

ImportFanatiK wrote: Fri Mar 29, 2024 9:29 pm
It technically did spin (extremely slowly and very jiggly) but blew the 60A fuse twice.
Try swapping the encoder wires.
If at first you don't succeed, buy a bigger hammer.

1940 Chevrolet w/ Tesla LDU - "Shocking Chevy" - Completed 2023 Hot Rod Drag Week
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Re: Help with Tesla LDU v6 First Benchtop Spin

Post by ImportFanatiK »

Yep! swapping the encoder wires (A/B) did it.

I have uploaded a video here:
https://www.youtube.com/watch?v=YUMFOA6nCZY&t=2s


Thanks everyone!!! especially Damien and Johannes!!!

Next step,.. determining if it will actually fit in my rx8 (unlikely)
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