Question Case fan two black ground wires necessary?

[jaymes2015]

I got two Corsair non-pwm AF140 Quiet Edition case fans spec at 7v-12v. Just curious about the two black ground wires on the molex connector. Do I need two ground wires to be connected to run my fans safely? Or can I just use a single black wire? I've seen some molex fan splitter with single ground and double ground.

 

[CountMike]

I got two Corsair non-pwm AF140 Quiet Edition case fans spec at 7v-12v. Just curious about the two black ground wires on the molex connector. Do I need two ground wires to be connected to run my fans safely? Or can I just use a single black wire? I've seen some molex fan splitter with single ground and double ground.

One is enough as fans also have only one ground wire.