Parallel Compressor Systems
absorbing spring mounts (optional equipment) must be placed under the base frame of each unit. See Figure 1 for view of Spring Isolator. The spring mounts are placed under the unit and the unit carefully lowered on to the mounts. Note that no other mounting hardware is required and any unevenness in the floor or uneven weight distribution may be compensated for by turning the spring mount leveling nuts with an open- end wrench. This adjustment should be made after all piping is installed and the system is charged with refrigerant.
Location of Equipment - Outdoor
•The mounting platform or base should be level and located so as to permit free access of supply air.
•Units must not be located in the vicinity of steam, hot air or fume exhausts.
•The unit should be mounted away from noise sensitive spaces such as offices.
•The unit must have adequate support to avoid vibration and noise transmission into the building. Sound and structural consultants should be retained for recommendations.
Ground Mounting
The unit must be set on a flat and level foundation. A single piece concrete slab with footings extending below the frost line and raised approximately six inches above ground level provides a suitable base. Raising the base above ground level provides some protection from ground water and wind blown matter. The concrete slab should be isolated from the building structure. Finally, before tightening mounting bolts, recheck the level of the unit.
Roof Mounting
Rooftop installations require adequate structural beams to support the weight of the unit and service personnel. The design of the beams/supports must minimize deflection and attendant vibration transmission.
Due to the weights involved, a structural analysis by a qualified engineer may be required before mounting. Also, for sound sensitive applications, unit vibration isolators should be used.
Unit Vibration Isolation
Under certain critical conditions, it is recommended that vibration isolators, of a suitable type, be installed under the base. The isolators must be designed for the operating weight of the unit.
Compressor Spring Vibration Isolators
On units with this option, the compressors are secured rigidly to make sure there is no transit damage. Before operating the unit, it is necessary to follow these steps:
1.Remove the upper nuts and washers
2.Discard the shipping spacers
3.Install the neoprene spacers (Spacers located in the electrical panel or tied to compressor)
4.Replace the upper mounting nuts and washers
5.Allow 1/16 inch space between the mounting nut/washer and the neoprene spacer
Figure 3. Spring Mount
Parallel Compressor Systems Installation & Operations Manual, October 2004 | 5 |