I live in Nevada and my wife and I separated. The utilities were in her name due to the fact I was at work when we moved into our house. For the past 8 yrs I was the only one bringing home income. We separated not legally, and she moved out and I kept our two children 4 and 5 here with me. One day she got angry at me and without notice she had the utilities disconnected knowing I didn't have the money for a deposit to get them turned back on. Can she legally do that with our children living at the house?

If you were keeping the electric current and depending on the electric company policies and laws I don't think she can, you need to call the electric company and tell them your situation. Landlords are not allowed to have service shut off over disputes, I would think similar would apply here.

Was it 'right?' No. It's legal as far as the electric company goes. There's nothing stopping her as far as small children. They don't know she's married and what's going on. All you have to do is trot down there and show them proof that you are her husband and they have to turn it back on (as long as there are no appreciable past due amounts).
It's foolish to leave anything in a spouse's name when they leave.
You need to get a divorce so you can get child support.

Me thinks maybe she MIGHT be doing this so she can run to court to gain custody or something sneaky??

You asked can "she" legally do it. The answer to that is not black and white. She could be prosecuted for child abuse. But you can definitely use it against her in the custody battle.

The electric company was not wrong since they don't know the facts. However, it might take a court order to force her to reinstate. For you to get the power turned back on might mean you have to put down a deposit. You need to talk to the electric company immediately.

Informal separations somehow never work out -

Go to Court and get some legal opinions.

Maybe the wife has an ulterior motive. Maybe she's being nasty.

Go to Court.