Carrier 38AU - Manual (Page 9)

9
Matching 38AU Model To Evaporator Coil –
The Model 38AUZ is a single-circuit unit design, requiring one
set of refrigeration piping. This model can be connected to an
evaporator coil with one circuit or with two circuits (by mani-
folding the evaporator connections into a single piping system).
The Model 38AUD is a dual-circuit unit design that requires
two sets of refrigeration piping between the outdoor unit and
the evaporator coil (or coils). This model can only be connect-
ed to an evaporator coil that has two refrigeration circuits (or to
two separate evaporator coils). The Model 38AUD CANNOT
be connected to a single-circuit evaporator coil. The Model
38AUD CANNOT be field-converted to a single-circuit de-
sign.
Before unpacking this new 38AU model, compare the evapora-
tor coil design to the 38AU model.
Table 3 — Evaporator Coil Connections
INSTALLATION
Jobsite Survey
Complete the following checks before installation.
1. Consult local building codes or the U.S. A. National Elec-
trical Code (Ref: ANSI/NFPA 70 [American National
Standards Institute/National Fire Protection Association],
latest version) for special installation requirements.
2. Determine unit location (from project plans) or select unit
location.
3. Check for possible overhead obstructions which may in-
terfere with unit lifting or rigging.
Step 1 — Plan for Unit Location
Select a location for the unit and its support system (pad, rails
or other) that provides for the minimum clearances required for
safety. This includes minimum working space, clearances be-
tween live electrical components and nearest barriers (ground-
ed or ungrounded), clearances for unit performance and service
access below, around and above unit as specified in unit draw-
ings. See Fig. 4.
NOTE: Local codes may require different clearances than
specified in Fig. 4. It is the responsibility of installers to be
knowledgeable in local codes and to modify the recom-
mended clearances to satisfy local codes.
NOTE: Consider also the effect of adjacent units on airflow
performance and control box safety clearance.
Do not install the outdoor unit in an area where fresh air supply
to the outdoor coil may be restricted or when recirculation from
the condenser fan discharge is possible. Do not locate the unit
in a well or next to high walls.
Evaluate the path and required line length for interconnecting
refrigeration piping, including suction riser requirements (out-
door unit above indoor unit), liquid line lift (outdoor unit below
indoor unit) and hot gas bypass line. Relocate sections to mini-
mize the length of interconnecting tubing.
Although unit is weatherproof, avoid locations that permit
water from higher level runoff and overhangs to fall onto the
unit.
Fig. 4 — Service Clearance Dimensional Drawing
Step 2 — Complete Pre-Installation Checks
CHECK UNIT ELECTRICAL CHARACTERISTIC —
Confirm before installation of unit that voltage, amperage and
circuit protection requirements listed on unit data plate agree
with power supply provided.
— UNCRATE UNIT — Remove unit packaging except for
the top skid assembly, which should be left in place until after
the unit is rigged into its final location.
INSPECT SHIPMENT — File a claim with shipping compa-
ny if the shipment is damaged or incomplete.
CONSIDER SYSTEM REQUIREMENTS
• Consult local building codes and National Electrical
Code (NEC, U.S.A.) for special installation requirements.
• Allow sufficient space for airflow clearance, wiring,
refrigerant piping, and servicing unit. See Fig.1 for unit
dimensions and weight distribution data.
• Locate the unit so that the outdoor coil (condenser) air-
flow is unrestricted on all sides and above.
• The unit may be mounted on a level pad directly on the
base channels or mounted on raised pads at support
points. See Tables 1A through 2B for unit operating
weights. See Fig. 1 for weight distribution based on rec-
ommended support points.
NOTE: If vibration isolators are required for a particular
installation, use the data in Fig. 1 to make the proper
selection.
Step 3 — Prepare Unit Mounting Support
Slab Mount —
Provide a level concrete slab that extends a minimum of 150
mm (6 in.) 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
RIGGING — These units are designed for overhead rigging.
Refer to the rigging label for preferred rigging method. Spread-
er bars are not required if top crating is left on the unit. All pan-
els must be in place when rigging. As further protection for coil
Evaporator Coil has Connect to Model Notes
Single Circuit 38AUZ ONLY
Two Circuits
38AUZ
Manifold evaporator
circuits into single
piping system
Or
38AUD
Use two separate
piping systems
DO NOT BURY REFRIGERATION LINES.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage.
All panels must be in place when rigging. Unit is not
designed for handling by fork truck.
REAR:
Min 457 mm (18”)
requried for service
Note: Observe requirements for 914 mm (39”) operating clearance
on either Left or Rear coil opening.
RIGHT:
Min 457 mm (18”)
requried for service
LEFT:
Min 457 mm (18”)
requried for service
FRONT:
1067 mm (42”)