RSP-2000-48 increase current output

Hi everybody,

I'm new here and I'd also like to mention that I'm not an electrical or electronics engineer. Everything I know in this field is self taught.

To get to the point:

I have a RSP-2000-48V that I want to use to power two hobby chargers, the Powerlab 8 Touch and the Powerlab 6. The problem is that the PL6 has an input voltage spec of 32V max and the PL8T of 48V. In this case, I've decided to trim the voltage of the PSU to 30V. Unfortunately, doing this, limits the output power of the PSU to aprox. 1260W (this is my understanding of the manual) when both chargers can suck aprox. 2200W at 30V.

Now, I don't really understand if the PSU limits the current to 42A or can go high to, let's say, 66A, which would reach the power limit of 2000W.

So, my question is, can I safely increase the current limit to 66A? If not, what is the limit on the stock PSU?

Any help is appreciated.

Thanks

PS: I forgot to mention that I read some posts on this matter including this one https://endless-sphere.com/forums/viewtopic.php?f=31&t=64821&p=980948&hilit=rsp+2000+current#p980948 . Unfortunately I still have some difficulties understanding how this PSU operates because the specs state that the limit is 125% of output power not current.

Finally, I tried adjusting the current limit pot (https://endless-sphere.com/forums/viewtopic.php?f=14&t=40692&p=960681&hilit=rsp+2000+current#p959597) and turned it clockwise.

I then tested the current limit with the two chargers I mentioned. It seems that with the pot at max turns clockwise the current limit is aprox 55A. Once it reaches the limit, it lowers the voltage slowly to try and lower the current. In my case, this has the inverse effect because the chargers will increase the current draw to satisfy the charging settings.

In the end I kept the pot at max clockwise and limited the PSU current draw to 53A thus it keeps the voltage stable and at the same time keeping the power limit under 2000W and 30V.

Keep an eye on the supply temperature. It might have a tendency to overheat. More air flow won't hurt.

Thank you for the safety tip.

Actually, one of the reasons I tried increasing the current was that they have the 24V and 12V models with 80A and 100A output respectively. In my thinking, I concluded that the 3 PSUs are similar and the 48V version would support up to 100A if the power output is limited to 2000W (by lowering the output voltage).

Either way, I will ensure proper airflow in the future charging case. The charge cycle for my Lipos is around 20mins from empty, short enough to keep the PSU below a toasty level.

The power totals are similar partly because of the size and form factor. Only so much heat dissipation from a certain area.

Generally, different voltage units have different parts in them, transformers are wound differently for more voltage vs more current, and FETs/etc are different parts for either more voltage or more current handling.

Often enough, FETs good for higher voltages may have higher resistances than those for lower voltages, so running those at higher currents makes more waste heat even if you're running them at lower voltages.

Thank you for the explanation.

I will lower the amp limit on the chargers to 50 amps and will keep a close eye on the temps.

I didn't know the component details.

Thanks again.

Generally they should be designed so that if there is an adjustment on there, it can handle the full range of adjustment, and self-limit as needed to preserve themselves in case of overcurrent, overvoltage, overheating, etc.

It doesn't mean they *are* designed that way, but they *should* be.

Of course but the Amp limit pot is not designed to be tampered with by the end user (or is it, I don't know how some things are considered in this field). Anyway to adjust the the pot you need to remove the cover.

Still, the PSU doesn't seem to mind the increased current, heat wise. After going over 55A, it gradually lowers the voltage.