My book raid, how hot till the fan kicks on?

I bought a My book Raid [WDBLWE0040JCH-NESN][ that has what apears a built in 50mm fan. At what point does this fan turn on to cool the drives?

I had the unit up to 117F which is much hotter then I ever seen any drive an the fan did not kick on.

WD whitepaper says the RED drives can sustain up to 158F which is absurd and will kill the lifespan.

Nothing in software allows you turn the fan on or off or even adjust it.

Does anybody from WD know at what point the fan should kick on?

I want to rule out I have a defective unit.

Hello pat2000,

 I recommend to have the My book in a well ventilated place to reduce the temperature. The WD Drive Utilities software provides three diagnostic tools to help make sure that  your device is performing well.

You can check page 56  of the manual for more information on how to test your drive.  

http://www.wdc.com/wdproducts/library/UM/ENG/4779-705120.pdf#page=59

Even in a well ventilated area the drives still reached levels I am not accustomed to, namely 119F.

I have contacted WD direct and after a week finally have an answer and not one I was looking for. The unit fan will only kick on at 60C when the drives are already baking thus the fan is useless and will probably never turn on.

This also takes away any advantage of having any active cooling.

I would not trust critical data on drives running 50C+, the magnetic media starts to fail and errors will occur.

I can drop the temperature of the My duo unit to around 82-84F by placing it on top of my case which has a top fan, that is much more ideal for longevity.

I also find it an omission to not have a ON/OFF rocket switch. Once the unit is ejected it is much easier to turn it off then to pull the power plug depending on where it’s setup.

Other then this the unit works well, the RED drives are fairly snappy for 5900 rpm even set to raid1.