Step 2 - Rig And Place Unit; Placing The Unit; Step 3 - Install Additional Vibration Isolation; (If Required) - Carrier Omnizone 50XCA06 Installation, Start-Up And Service Instructions Manual

Step 2 — Rig and Place Unit
Units are mounted on pallets. Leave the unit on the pallet until it is
in the final position. While on the pallet, the unit can be rolled,
dragged or forklifted; do not apply force to the unit. Use a mini-
mum of 3 rollers when rolling, and raise from above to remove the
pallet when unit is in the final position. See Fig. 10 for rigging de-
tails.
SUPPORTS
UNDER PALLET
Fig. 10 — 50XCA Unit Rigging

PLACING THE UNIT

The selected unit location should not be adjacent to an acoustically
sensitive space. The best locations for these units are mechanical
rooms, near elevator shafts, near restrooms, near stairwells or oth-
er similar locations. Position the unit where large supply of out-
door air is available for the unit inlet. Be sure to leave enough
space for the return air inlet access to the evaporator and condens-
er coils for cleaning and maintenance. Units located on the same
floor should have a minimum of 6 ft of clearance between con-
denser air openings. Units located floor-to-floor should have a
minimum of 10 ft between units to prevent recirculation of condi-
tioned air. DO NOT locate units where they will recirculate con-
denser air. This will cause increased head pressure which can
cause units to trip on high pressure. See Fig. 11 for recommended
unit clearances.
Either provide inlet filters to protect the coils, or locate the unit in
an area free from airborne dirt or other foreign material which
could clog the coils.
The units are designed to pass through most door openings. The
filter rack may also be removed for additional clearance.
24 (TYP)
NOTE: Dimensions are in inches.
Fig. 11 — Unit Clearances
Step 3 — Install Additional Vibration Isolation

(if required)

Unit compressors are internally isolated and the compressor com-
partment is lined with acoustical insulation. If additional vibration
isolation is desired, rubber pads may be located under each unit
corner or unit may be mounted on rubber shear isolators. Contact
Carrier for application assistance. Spring isolators are not normal-
ly required. Ductwork attached to the unit should be isolated from
the unit with a flexible collar on the inlet and outlet ducts.
SPREADER BAR
36
36
Step 4 — Install Ductwork
The 50XCA unit is designed for use either with or without
ductwork. If no ductwork is used, ensure that customer supplied
wire fan guards are installed on condenser outlet to prevent injury.
If either ductwork or no ductwork is used, care must be taken to
eliminate air recirculation. Recirculation can be minimized by dis-
charging through an extension elbow. When properly designed,
single or double deflection discharge louvers can be applied to
ductwork and to the unit air discharge. Fixed rain louvers over dis-
charge outlets can cause excessive recirculation and nuisance
high-pressure switch cutouts. Obstructions closer than 10 ft to the
discharge air pattern can also cause significant recirculation.
See Fig. 12 for recommended duct sizing

CONDENSER AIR DUCT

The condenser supply and discharge air duct should be as short
and straight as possible. The cross section area of the duct should
be equal to the face area of the unit openings. Ductwork should be
insulated to prevent moisture condensation on the unit panels
during cold weather. (See Fig. 13.) Condenser discharge ducts for
units with multiple blowers should consist of a "pair of pants" and
be constructed in accordance with the System Design Manual and
ASHRAE guidelines. (See Fig. 14.) Settling media may be re-
quired for uniform flow.

CONDENSER AIRFLOW LOUVERS

Separate inlet and discharge louvers are recommended (see
Fig. 12) to avoid air recirculation. A baffle may also be used on
the outside of the building to direct discharge away from the air in-
let. See Fig. 12 for recommended dimensions.

EVAPORATOR DUCTWORK

The units should use a "pair of pants" configuration as shown in
Fig. 14. Refer to the Carrier System Design Manual or ASHRAE
standards for the recommended duct connection to unit with 2 or
more fans.
A flexible canvas duct connector is recommended on both supply
and return air sides of the units to be connected to the system
ductwork.
All metal ductwork should be adequately insulated to avoid heat
loss or gain and to prevent condensation from forming on the duct
walls. Uninsulated ductwork is not recommended, as the unit's
performance will be adversely affected.
Do not connect discharge ducts directly to the blower(s). The fac-
tory filter should be left in place on a free return system.
If the unit will be installed in a new installation, the duct system
should be designed in accordance with the System Design Manual,
Part 2 and with ASHRAE procedures for duct sizing. If the unit will
be connected to an existing duct system, check that the existing duct
system has the capacity to handle the required airflow for the unit
application at an acceptable system static pressure. If the existing
duct system is too small, larger ductwork must be installed.
Units with two fans or more should have a properly designed "pair
of pants" duct connection. (See Fig. 14.) Settling media may be re-
quired for uniform flow.
Units with two or more fans should not be ducted separately.
An adequate straight length of ducting from the unit should be al-
lowed before elbows are installed. See table below for recom-
mended straight length.
50XCA UNIT LENGTH (in.)
06 36.5
08 36.5
12 36.7
Elbows should turn in the direction of fan rotation, if possible.
Abrupt turns will generate air turbulence, and excessive noise.
Turning vanes should be used in all short radius bends. Ensure that
ducting does not obstruct access to the unit for routine servicing.
13
50XCA UNIT LENGTH (in.)
14 36.7
16 36.7
24 40.0