Fencing and Protecting baby chicks

[McGoo]

I've got an electric fence - 4" x 4" openings, so the babies can get through but momma can't.

Question - how soon can I turn the electricity on with little babies. Mine are 3 weeks old....still fuzzy.

I'm thinking that if they get a jolt they'll stay inside. But I don't want to kill them!

Anyone encounter this?

 

[Big C]

Our electric fencing is on the outside to keep predators out...

 

[McGoo]

Yes, I understand, but the chickens stay away from the fence too, cause they feel an uncomfortable mild jolt.
And yes, it's main purpose is to keep predators out... but here's the story...
one of the hens just hatched out 6 little ones and she loves to scratch, etc. So I like to let momma and the chicks out of the smaller/safer pen and give them space... they love it! When I do, I turn off the electric poultry netting because I'm not sure if it could harm the babies.

I'm just wondering when it is safe - the age of a chicken - when it's okay to turn on the electric fence.

Any ideas - PLEASE