3. POWER OUTPUT: The unit had no trouble at all in the test environment, and ran with great stability at all the lower output levels. Even at 400W output, it ran for a full 5 minutes without any sign of overheating or overload.
After about 3.5 minutes at 470W, however, protection circuitry kicked in and the unit simply shut down. The fans stayed running at least 3 mninutes after the PSU had shut down, as advertised. In this case, this feature seemed like a good thing. After the fans stopped, I reduced the load and turned the power switch off and on. It came right back on without any problems, and no apparent damage.
It is not clear why the unit shut down. There are several protective features that can shut this PSU down:
* Over Voltage Protection - unlikely; none of the output voltages were misbehaving
* Over Load Protection - unlikely; the load was exactly at maximum
* Over Current Protection - maybe: very clear limits are specified, and in setting the load for 470W, I may have exceeded the limit on one of the voltage lines.
* Over Temperature Protection - possible: 40°C is the specified maximum operating temperature, and the case temperature was recorded at 39°C, with exhaust at 44°C. How one defines or where one measures the temperature becomes very difficult. If the Over Temperature Protection function shut the unit down, it is very probable that the operating temperature (as Enermax defines it) was exceeded. As it is so unlikely for any system to reach steady 470W output for any length of time, never mind 3.5 minutes, I have no quibble with the shutdown. It is a very extreme and unrealistic test. In fact, I am pleased that the protection circuitry worked well.
