Hi axcelenator,
The solid-state relay output shouldn't be connected directly across the power supply, acting itself as a load. Instead, you should connect your load in series with the switch as shown in page 11 of the user manual here. When active, the switch simply acts as a short circuit. Unlike the input terminals, which contain MOSFET-based current-limiting circuits, the USB-6525 itself does not contain any currently limiting circuitry on the output side. Any current limiting you wish to accomplish will need to be done with an external series resistor.
With that said, the device is rated up to +60 VDC between terminals so you should be ok for your application.
