Carrier PREFERRED 577E A Series Installation Instructions Manual page 4

2. Attach shackles, clevis pins, and straps to the base rails of
the unit. Be sure materials are rated to hold the weight of the
unit (See Fig. 7).
3. Attach a clevis of sufficient strength in the middle of the
straps. Adjust the clevis location to ensure unit is lifted level
with the ground.
After the unit is placed on the roof curb or mounting pad, remove
the top skid.
4