Liebert Challenger ITR - Manual (Page 54)

Split System Models
48
7.5 Centrifugal Air-Cooled Condensing Units
7.5.1 Installing the Indoor Condensing Unit
Refer to drawings for unit dimensions and component locations.
The indoor condensing unit is usually mounted above the ceiling and must be securely mounted to the
roof structure. The ceiling and ceiling supports of existing buildings may require reinforcements. Be
sure to follow all applicable codes. Use field-supplied threaded suspension rods and
3/8"-16 factory hardware kit.
Recommended clearance between ceiling grids and building structural members is unit height plus
three inches.
Install the four field-supplied rods by suspending them from suitable building structural members.
Locate the rods so that they will align with the four mounting holes in the flanges that are part of the
unit base.
Using a suitable lifting device, raise the unit up and pass the threaded rods through the four mount-
ing holes in the flanges that are part of the unit base.
Attach the threaded rods to the unit flanges using the supplied nuts and grommets. (See Figure 23 -
Detail of ceiling hanging bracket, Threaded Rod and Hardware Kit Installation). The rubber
grommets provide vibration isolation.
1. Use the plain nuts to hold unit in place. Adjust these nuts so that the weight of the unit is
supported evenly by the four rods, does not rest on the ceiling grid, and is level.
2. Use the Nylock nuts to “jam” the plain nuts.
!
WARNING
Risk of structure collapse. Can cause equipment damage, injury or death.
Before beginning installation, make sure that the supporting roof structure is capable of
supporting the weight of the unit(s) and the accessories during installation and service. (See
Table 28 - Indoor centrifugal condensing unit.)
Be sure to securely anchor the top ends of the suspension rods. Make sure all nuts are tight.
NOTE
The units must be level in order to operate properly.
Table 28 Indoor centrifugal condensing unit
Model
Net Weight
lb (kg) 60 Hz 50 Hz
MC_65A MC_64A 449 (204)
MC_69W MC_68W 282 (128)