What I am trying to achieve:

I am trying to use an Arduino nano with a Monster Moto Shield To drive 2 of these 6 Amp fans, As they are 12v fans and I want to drive two of the 6 amp fans I figured I would require at least a 12 amp PSU, After a while searching I could not find a cheap(ish) 12v 12amp PSU but someone recommended that I could use a 12v 30amp PSU.

What I need help with:

First of all I was wondering what gauge wire I need to wire between the PSU and the Motor shield (12 amp), and what gauge wire I would need to wire between the motor shield and each fan (6 amp) I estimate that it would be something like 10-12 AWG but i would appreciate a second opinion. I also wanted to make sure that with the PSU I would get a mains plug with a cable and splice the cable into the relevant live neutral and ground terminals on the PSU. I was also wondering if the power supply is already fused or if I would need to fuse the plug, If there is a fuse in the power supply would it also be a safe decision to put a fuse into the plug to add extra safety. Also what fuses should I use as the PSU is 30 Amps but I am only requiring 12 amps.

Sorry for making the post a very long post, I just want to make sure I am on the right track and keeping myself safe when near electronics.

Any help would be really appreciated, Thank you in advance.

 

Awg 11 is rated at 12amp, Awg 7 is at 30amp.

As for fuses use resetable fuses rated at 10amp or higher.

You could have used an old Atx psu..

 

Awg 11 is rated at 12amp, Awg 7 is at 30amp.

As for fuses use resetable fuses rated at 10amp or higher.

You could have used an old Atx psu..

Do you think this cable would be ok, it says it is rated at 21 amps but it looks a bit thin.

 

Yes, in MM rating is approx 1mm is rated at 18amp, 1.5mm is 25amp, 2mm is 32amp.

Its not a Linear scale as it goes off the Csa of the cable.