Hi, I found that there is a nice thing called surge protection for HDD's even if you PSU fails, the data can be protected.

99% of us have just single PSU so even if you are protected with UPS in epic failure of your PSU there is a possibility to loose all data even in RAID.

 

You can read about the company here http://freemindtronic.com/fmt-fr/fullprotect/safer-evolution-2/?postTabs=1

But the problem is it is quite expensive for a fuse, http://www.pc-look.com/boutik/Prod_Freemindtronic_Electric-Protection-Device--SAFER-Evolution__58941_en.html

 

And this the only shop I found. I think we should buy solid state fuse and just rig it ourselves with polyswitch.

http://freemindtronic.com/fmt-fr/docs/datasheet_fr24082010_v1.1.pdf

 

Here is DIY http://www.secomtel.com/UpFilesPDF/PDF/DataBook/03%20Section/03.C01_drive_(105).pdf

 

For 5V line http://eu.mouser.com/ProductDetail/TE-Connectivity/microSMD075F-2/?qs=F6FIpiMdEVbc5a7rcQhJQg%3d%3d

Hold Current: 0.75 Amp

Trip Current: 1.5 Amps

Maximum Voltage: 6 VoltsDC

Package / Case: 1210 (3225 metric)

0,29 €

 

For 12V line http://eu.mouser.com/ProductDetail/TE-Connectivity-Raychem/MINISMDC075F-2/?qs=sGAEpiMZZMu7EFbsM1w0neRfX3mrvYIvMyAk4mmU%252bDo%3d

Hold Current: 0.75 Amp

Trip Current: 1.5 Amps

Maximum Voltage: 13.2 VoltsDC

Package / Case: 1812 (4532 metric)

0,45 €

Sorry - but I find this all rather suspect.

 

A polyswitch fuse is never going to protect anything against fast voltage spikes.  They are designed to protect against over-current, and like a regular fuse, they take time to do so, during which time damage to data can occur.

 

The company you are posting about may have some other type of surge protection and over current protection in their devices, but in my view that is no substitute for good quality power supplies and external supply protection.  For example - a voltage spike may cause your processor to do something bad which could tell the disk to overwrite some data.  Protecting the disk supply won't help then.  A good power supply fed by a good UPS with protection will do a great deal to protect your server and data against problems that might be caused by external interference.

So the polyswitch fuse is no good then? What could they use then? I was under impression that they simply added microchip to control the LEDS and possibly keep the HDD off if overvoltage, overcurrent is not corrected.

 

Yes there is no substitute for a good power supply, I'm looking for PSU myself for 6HDD NAS.

 

What do you think about http://www.seasonicusa.com/NEW_X-series_Fanless.htm

I selected this 400W because it has high efficiency and is made by seasonic

 

The other PSU's are 650W or more way too much for NAS, the power efficiency will be low loaded at 20% max.

I am not saying they don't use a polyswitch device.  What I am saying is that a polyswitch device will not offer protection against voltage spikes (only against over current where the current lasts long enough to heat the device).  My view is that selling a protective device that connects in the supply line to the disk drive is just a way to make money.  It is not a way to ensure protection for disk drive, or for the data, or for a PC in general.