Nov 02, 2021 - 05:09 PM
The type of behavior you're describing can be caused by the fan speed reduction caused by the PSU being immersed and the fan slows down as its designed to operate in air, not fluid. Because EC-100 is more viscous than air, the fan is slowed down and some high-end PSUs have a low tolerance for the fan speed being different than what it expects. A straightforward way to test this is to remove the cover, remove the fan and then put an extender wire on the fan. Immerse the whole PSU except don't immerse the fan. Now if everything works in this configuration, next drop the fan into the EC-100 and see what happens, if the PSU shuts down then we know it's a fan speed issue. In this case I would put a fan eliminator circuit in place of the fan and see if that works, again some PSUs are way t0o smart and may expect a specific RPM rather than a minimum RPM.
In this case you'll need an adjustable fan speed circuit like we show in our SLIC Primer Presentation and you'll need to dial in the RPM the PSU is looking for. Alternatively, you can get a "less finicky" PSU that doesn't care as much about fan RPM.