Carrier ZC - Manual (Page 16)

Remove the two screws that hold the plastic front (one
at each side).
Unit casing should project ½” (13mm) in to
room to ensure proper fit of decorative grille.
NOTE
16
Tip casing to outside. Tip is necessary for draining
condensate to the rear of the basepan, to allow for
excess condensation run-off. The tip also helps to
prevent leakage into the room by allowing excess water
to drain away from the building.
INSTALL CASING IN WALL
Remove the plastic front.
Remove the safety screw.
Be careful not to be injured by the metal parts.
Disconnect the ground wire and remove the unit
from the wrapper pulling it by the bottom.
The recommended outward tip is 3/16 to 3/8 in. (5 to 10
mm) from inside to outside. This means that back of
casing outside the room must be 3/16 to 3/8 in. (5 to 10
mm) lower than the front edge inside room.