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 set +5 V and +3.3 V at 1 A and increased the current at the single +12 V rail from the power supply the maximum we could. We pulled 66 A (the maximum our equipment is able to handle) and the unit didn’t shut down, meaning that either OCP is disabled or configured at a value above 66 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. When we tried to increase one more amp at any output the power supply would shut down, showing that one of its protections was triggered.

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 passed on this test.