Heatcraft Refrigeration Products PARALLEL COMPRESSOR SYSTEMS 25000102 - Manual (Page 5)

Parallel Compressor Systems Installation & Operations Manual, October 2004 5
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
Parallel Compressor Systems
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. Rubber-in-shear or spring type isolators (by others)
are available for this purpose.
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Figure 3. Spring Mount
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.