Carrier 38AUD 16 Series - Step 3 - Prepare Unit Mounting Support; Step 4 - Rig and Mount the Unit; Step 5 - Complete Refrigerant Piping Connections

12
Note: If vibration isolators are required for a particular
installation, use the data in Fig. 3 and Fig. 4 to make the
proper selection.
Step 3 — Prepare Unit Mounting Support
Slab Mount —
Provide a level concrete slab that extends a minimum of 6
in. (150 mm) beyond unit cabinet. Install a gravel apron in
front of condenser coil air inlet to prevent grass and
foliage from obstructing airflow.
Step 4 — Rig and Mount the Unit
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
dama ge.
All panels must be in place when riggi ng. Unit is not
designed for handling by fork truck.
CAUTION
!
Rigging: These units are designed for overhead rigging.
Refer to the rigging label for preferred rigging method.
Spreader bars are not required if top crating is left on the
unit. All panels must be in place when rigging. As further
protection for coil faces, plywood sheets may be placed
agai nst the sides of the unit, behind cables. Run c ables to
a central suspension point so that the angle from the
horizontal is not less than 45 degrees. Raise and set the
unit down carefully.
If it is necessary to roll the unit into position, mount the
unit on longitudinal rails, using a minimum of 3 rollers.
Apply force to the rails, not the unit. If the unit is to be
skidded into position, place it on a large pad and drag it
by the pad. Do not apply any force to the unit.
Raise from above to lift the unit from the rails or pad
when unit is in its final position.
After the unit is in position, remove all shipping materials
and top crating.
Step 5 — Determine Refrigerant Pipe Sizes —
Select the recommended line sizes for 38AUZ and
38AUD unit from the appropriate tables.
Determine the linear length of interconnecting piping
require d between the outdoor unit and indoor unit
(evapora tor). Consider and identify also the a rrangement
of the tubing path (quantity and type of elbows in both
lines), liquid line solenoid size, filter drier and any other
refrigeration specialties located in the liquid line. Refer to
the indoor unit installation instructions for additional
details on refrigeration specialties devices.
Determine equivalent line length adjustments for path and
components and add to linear line lengths. See Table 4,
Equivalen t Length s for Common Fittings , for usual fitting
types . Also identify adjustments for refriger ation specialties .
Refer to Part 3 of the Carrier System Design Manual for
additional data and information on equivalent lengths.
Table 4 – Equivalent Lengths for Common Fittings (ft)
Nominal
Tube OD
Elbows
90 Std 90 Lrad 90 Street 45 Std 45 Street
3
/
8
1.3 0.8 2.2 0.6 1
1
/
2
1.4 0.9 2.3 0.7 1.1
5
/
8
1.6 1 2.5 0.8 1.3
3
/
4
1.8 1.2 2.9 0.9 1.5
7/
8
2 1.4 3.2 0.9 1.6
1
1
/
8
2.6 1.7 4.1 1.3 2.1
1
3
/
8
3.3 2.3 5.6 1.7 3
1
5
/
8
4 2.6 6.3 2.1 3.4
2
1
/
8
5 3.3 8.2 2.6 4.5
Nominal
Tube OD
Tees
Branch
Flow
Straight-Thru
No Reduct Reduce 25% Reduce 50%
3
/
8
2.6 0.8 1.1 1.3
1
/
2
2.7 0.9 1.2 1.4
5
/
8
3 1 1.4 1.6
3
/
4
3.5 1.2 1.7 1.8
7/
8
4 1.4 1.9 2
1
1
/
8
5 1.7 2.3 2.6
1
3
/
8
7 2.3 3.1 3.3
1
5
/
8
8 2.6 3.7 4
2
1
/
8
10 3.3 4.7 5
Note: Equivalent line lengths will vary based on tube
diameter. Calculate equivalent line length for each pipe by
adding equivalent length adjustme nts to linear lengths for
each pipe.
Enter the appropriate table to select the recommended line
sizes.
Model/
Position #6:
Ta bl e Quantity of Line Sets
38AUZ / all 5 1
38AUD / A,B 6 2
38AUD / C 7 2
Liquid Lift —
A liquid lift condition exists when the outdoor unit is
loca ted below the indoor (evaporator) unit and liquid
flows vertically up in a portion of the liquid line. The
vertical column of liquid reduces the available state point
subcooling at the evaporator coil’s thermal expansion
valve. This effect reduces the length of liquid lift (feet of
elevation) that a liquid line size can accommodate.
Longer linear tube lengths will also reduce the amount of
liquid lift possible.
Check Tables 5 (38AUZ), 6 (38AUDA/B) and 7
(38AUDC) for maximum liquid lift capabilities for line
sizes. Note for size 16 that condenser coil type also effects
maximum liquid lift; ensure the lines for this unit’s
specific coil type are being used.
38AU