My WD External Powers Down

Hey I have a WD Live and every time I plugged my WD external into it I can watch a movie anywhere from 15 mins to half and hour and then the external powers down.

Any help would be greatly appreciated.

Is that a passport unit or a My book?

My book

Are you able to see and use the drive on a PC without issues?

If you have the WD smartware installed on your computer, with the drive attached goes to settings and check the sleep mode settings for the drive… It might be activated.