Seventeam ST-380PAS Power Supply Review

Overload Tests

Before overloading power supplies we always test first if the over current protection (OCP) circuit is active and at what level it is configured.

In order to do that we removed the video card power connector from our load tester, so the +12V1 input would be connected to the power supply +12V1 rail and the +12V2 input would be connected to the power supply +12V2 rail. Then we configured a low current at +12V1 (1 A) and increased current on +12V2 until we saw the power supply shutting down. That never happened. So OCP is either disabled (more probable, as the monitoring circuit does not support OCP and Seventeam does not list OCP as a feature) or configured above 33 A, which is the maximum current we can configure on our load tester.

With OCP disable this means that this power supply has, in fact, a single-rail design, despite of what is written on the label.

Then starting from test five we increased currents to the maximum we could with the power supply still running inside ATX specs. The results are below. When we tried to increase one more amp at any output ripple would go to the roof, meaning that the unit stopped working correctly.

The idea behind of overload tests is to see if the power supply will burn/explode and see if the protections from the power supply are working correctly. This power supply didn’t burn and when we tried to pull far more than it could deliver it would shut down, so this unit passed on this test.

When overloaded this power supply presented efficiency below 80% (consider the results marked as "2", as they are the correct ones, measured with our precision power meter).