Protection Features Evaluation

Every PSU should be equipped with a set of protections which, besides the PSU itself, will also protect the whole system. You can learn more about PSU protections by reading through the corresponding section of our "A Detailed Look Into PSUs" article.

In a snap, the most important protections for PSUs are the following:

• Over Current Protection (OCP)
• Over Power Protection (OPP)
• Over Temperature Protection (OTP)
• Over/Under Voltage Protection (OVP/UVP)
• Short Circuit Protection (SCP)
• No-load Operation (NLO)
• Surge & Inrush Protection (SIP)

We should note that OCP isn't usually offered in single +12V rail PSUs, especially high capacity ones. In these units, OPP takes over a part of the role OCP plays. In addition, we find OTP to be very important and are, for the moment, not messing with OVP/UVP until we find a way to safely evaluate them.


Over current protection on the +12V and 5V rails is reasonably set; however, it is pretty high for 3.3V. The 5VSB rail also has a pretty high OCP triggering point. Over temperature protection shuts down the PSU once the +12V heatsink reaches 85°C, which seems rather low, but didn't create any problems in our high temperature testing.