Seventeam ST-620PAF Power Supply Review

Overload Tests

Before overloading a power supply we always test to see if over current protection (OCP) is active and at what current level it is triggered. To test this we removed the video card auxiliary power connector from our load tester (because it was connected to the +12V2 rail together with the EPS12V/ATX12V cable) and started increasing current on +12V2. We went all the way up to 33 A (the maximum our load tester can deliver) and the power supply didn’t shut down, showing that either OCP is disabled or configured at a value above 33 A.

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. If we tried to increase one amp more on any output the power supply would shut down, showing that one of the protections entered in action.

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.

As you can see Seventeam could have labeled this unit as a 650 W or even 700 W product, but they decided not to do so probably because of efficiency, which drops way below 80% if we pull more than 620 W from it.