The energizer is inside of the coop, then as you can see I ran a strand of elec around the bottom of the pen and the top (in case anything wants to climb) I have 4 African geese that police any weasels that slip through or any hawks/owls.
I had a great rooster that also helped out with...
I've had electric fence around my run for the last 5 years or so now, haven't had a problem with plenty of coyotes and abandoned dogs running in my area from time to time. I think it's nice to not have to worry about most predators, even friends can stop by again with their dogs and in one zap...