PSU Fan not spinning?

[Bellboy]

Afternoon,

I just want to check, is the 450w smartpower psu with the antec sonata II case a dual fan, and so I should not be worried if the fan on the back does not turn at the moment? I've just had it on for two hours while installing windows etc (new build) and was a little worried that it didn't come on. However, a mate informs me that it is dual fan so this is normal, just wanted to get this confirmed

 

[Yewen]

Depends on the psu really.

Im not sure on that particular psu though.

 

[RandomTom]

It could quite easily have a thermal sensor, which has a temperature at which it activates both fans to cool the psu more efficiently such as under high load, with the hiper or tagan psus and many others it's quite a good way of keeping it quiet.