I bought a 12v, 30 amp power source, but no power cord was included. I intend to use it to power a battery charger. I want to use a spare computer power cord I have to power it. The cord has a positive, negative and ground wires in the bundle, which matches the terminals on the power source, but also has another bare wire that is the ground for the anti-interference sheathing (which looks like aluminum foil and surrounds the other wires in bundle, all of which is covered by outside plastic tube. What should I do with this extra ground wire for the sheathing? Should I attach it to the ground terminal along with the normal ground wire? Thanks

 

Is the power input to your power supply supposed to be DC?

 

No, my mistake, the input is 110v. Output is 12v, 30 amp. Thanks for responding.

 

Your power supply is about 360W output. Accounting for some losses due to efficiency, you will probably need about 450-500W input under full load.
At 110V, that is about 5A (a bit less). Any standard PC power cord will suffice. Many PC power cords are 18 gauge, which can carry 7A in a 3 wire cable. Any 16 or 14 gauge cord will do as well....
For output, you would need a 10 gauge cable, or larger to carry 30A load. 12G wire may do if it is in clear air and allowed to keep cool, but for any cable, it should be 10G at least.

 

Hi Sagor: Thanks for your input. Do you have any recommendation concerning what to do with the anti-interference sheathing ground wire? (Refer to my original post). Thank you.

 

Hi Sagor: Thanks for your input. Do you have any recommendation concerning what to do with the anti-interference sheathing ground wire? (Refer to my original post). Thank you.

Not sure where that bare wire is connected to. Most power cords for 110V have a hot, neutral and a ground. There usually is no extra wire at all, and usually not needed.
Only in extreme cases, using an outlet with isolated ground (4 pin 110V connector), would there be any 4th wire. This was usually used in extreme computer isolation cases, or perhaps medical situations. For home use, not required, nor feasible...

If the bare wire is on the output side, it is intended for shielding, usually ties to one end at the ground point (usually the power supply), and left NOT connected at the other end.

 

Not sure where that bare wire is connected to. Most power cords for 110V have a hot, neutral and a ground. There usually is no extra wire at all, and usually not needed.
Only in extreme cases, using an outlet with isolated ground (4 pin 110V connector), would there be any 4th wire. This was usually used in extreme computer isolation cases, or perhaps medical situations. For home use, not required, nor feasible...

If the bare wire is on the output side, it is intended for shielding, usually ties to one end at the ground point (usually the power supply), and left NOT connected at the other end.

@siginden
The bare wire is often called a "drain" wire. Its purpose is to make an easy & solderable connection to the aluminum foil shield. Otherwise, as @sagor said.