Protection Features Evaluation

Every PSU should come with a set of protections that not only protect the PSU but 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 protection features 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 and Inrush Protection (SIP)

We should note that OCP isn't usually offered in single +12V rail PSUs, especially high capacity ones. In such units, OPP takes over. OTP is very important, and we won't mess with OVP/UVP until we find a way to safely evaluate them.

There is no OCP at +12V, and the OCP triggering points on the minor rails are where they should be. Only the 5VSB rail has a pretty high OCP triggering point. The unit's OPP level is set to around 745W, which is very high since the minor rails failed to keep their load regulation within the ATX specification's requirements at 745W. Measurements showed 4.728 V and 3.118 V on the minor rails and 11.837 V at 12V with 743.36 W output.

Unfortunately, there is no OTP with the LX600, which we verified by applying a huge thermal load to the PSU's secondary heatsink, under others. To give you an idea, the temperature on the secondary heatsink exceeded 130 °C, and the PSU was still operating. We quickly removed the thermal load after that to avoid destroying the PSU.

The Power Good signal's hold-up time might be less than 16 ms, which is as the ATX specification requires, but it still drops before the rails go out of spec, so we consider it to operate normally since it provides accurate information to the system. There is also its surge and inrush current protection feature, but we would like to see a bypass relay for the NTC thermistor to lower inrush current during start up.