Indoor Models: route the transformer cable through the hole on the left side of the controller and connect the wires to the two screws marked 24VAC (pictured)
Outdoor Models: transformer wires are already connected to the AC terminals so all that is required is to connect primary power to the junction box.
NOTE: X-Core outdoor models are water and weather resistant. Connecting the outdoor X-Core to primary AC power should only be done by a licensed electrician following all local codes. Improper installation could result in shock or fire hazard.