I'm taking a lot longer than expected to wire my DC DC converter and, worse of all, I'm not having any success.
I'm using a TDC-IY-108-12 from a Chinese company named TC Charger (the website www.tccharger.com printed in the manual doesn't exist). I think there are similar converters branded as Elcon. It's a 1kW unit with a nominal DC input of 108V (range can vary from 72V to 162V).
The manual is, like most of these Chinese units, pretty poor and ambiguous. But since the connections are not so many, I really thought it would be much more straightforward than what I've been experiencing.
There is a 12V output which I connected to the 12V battery through a large 100A megaval fuse. The ground pole (which in turn is connect to the converter chassis) is connected to a good ground in the vehicle chassis.
On the HV side of things, used the supplied 4 pins connector to connect to the HV battery negative and, via a minitactor from Gigavac, to the HV battery positive. I say 4 pins but that's on the converter side. Two pins are the so called HV interlock and I think they are short-circuited on the connector and are not available in the back of it. I believe it's for the converter to know if that connector is correctly inserted and disable itself if not.
By the way, for the HV supply, I'm not using the final Nissan Leaf pack with a 32s configuration. I'm keeping the risk lower and using 5 20V battery packs from Parkside/Lidl. The same I used before for the traction test. It outputs around 96V, which should be well between the valid range of this converter (72V to 162V). The under voltage protection is supposed to trigger only at around 70V.
There's an additional 4 pins connector for control. This is where it gets trickier. Again, there are 2 pins named HV interlock, which I assume (unfortunately we need to assume a lot of things due to the poor documentation) work the same way as the HV connector, ie, we need to shunt. I did.
There are two other pins, named Enable and Failure Signal. Firstly, I could understand the pinout -- more specifically, if the drawing is seen from the front or back of the connector. So, I might be switching these two pins but I tried fiddling with both.
Accordingly to the documentation, the Enable input needs a 6V to 30V signal and draws less than 1mA. I don't know if it's an high voltage to enable or otherwise but I tried leaving it open, connecting to 12V high and 12V ground, either at startup and after but nothing.
Since there is no CAN bus (the manual talks about it but I guess it applies only to other variants) or LEDs, all the feedback I can have is through the Failure Signal. Again, there's no clear documentation and the electrical schematic doesn't help (they keep changing the labels/wire names!). In my case, I always read a 0V signal (referenced to 12V ground). I don't know if that's an indication of fault or not.
In practice, the converter output is not the 14V or thereabouts but just the 12.4V the battery is already with when not loaded. So I guess nothing is working. I could use a multimeter to measure the current going from the converter to the car but I'm afraid the 10A rating of the multimeter is not enough. But I will try it nonetheless.
I already tried reversing the HV inputs but still no result. According to the manual, that's safe to do because the reverse voltage protecting on the input will simply disable the converter. No matter what I do, the converter simply seems to not do anything.
It's also worth mentioning that the HV input fuse blew up on the first try in the car (after some tries in the workbench), even though I was using a 600VDC 30A fuse from Littelfuse (fast-acting) while the manual says the max amperage is below 11A (in rush of 4A). I was brave (stupid?) enough to try without it but the results are the same.
I've checked some forums with discussions about similar converters. Some mention that the Enable signal should be connected to the HV battery positive. I haven't tried that because the manual specifies an input range of 6V to 30V. I'm not that desperate, yet...
Do you have any more ideas?