Hello. I am helping someone build a house and I have a question about his subpanel. He has wired a subpanel in his garage "attached". He used aluminum #2 sec 2 conuctor with braided ground. I told him he needed 4 conductor because the ground and neutral must be separated at the subpanel. The next time I checked he had just run a bare # 4 copper wire he said he was going to use as ground and he is planning on using the braided aluminum wire as his neutral. This doesn't sound right to me. What say you experts. Thanks, Bud...

Bstrong,
I can not give you an official answer but, I am an electrician and it sound like you are giving good advise to your friend. The braided wire should not be used as a neutral.
It will require that the ground and neutral be separate at the Sub.
If he would have pulled in a white wire of the correct size insyead of the bare copper wire, he just might have been able to get away with the braided wire as the ground.
As for me... if this was my house, I would pull in a neutral(White) and still use the bare copper as a ground.
Hopefully somebody else can give you a good answer to this question.
Thanks

The braided wire of SEC cable is allowed to be used as a neutral.

Per NEC 2005 250.32(B) (2)
The 3 wire is allowed, and must be connected at the subpanel end to the ground, but only if there is no other continuous metallic path between buildings, like water, phone lines, etc.

This will be preferred over running any separate conductors, which is not allowed.

A ground rod must be driven at the subpanel in any case.

Thanks guys for the help...