Carrier 38AUM Series Installation, Operation & Maintenance Manual page 8

Matching 38AUM Model to Evaporator Coil
The Model 38AUMZ 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 manifolding the evaporator connections into a
single piping system). The Model 38AUMD 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 connected to an evaporator coil
that has two refrigeration circuits (or to two separate evaporator coils). The Model 38AUMD CANNOT be connected to
a single-circuit evaporator coil. The Model 38AUMD CANNOT be field-converted to a single-circuit design. Before
unpacking this new 38AUM model, compare the evaporator coil design to the 38AUM model.
Evaporator Coil has
Single Circuit
Two Circuits
NEW INSTALLATION
Jobsite Survey
Complete the following checks before installation.
1. Consult local building codes or the U.S.A. National Electrical Code (Ref: ANSI/NFPA 70, [American National
Standards Institute/National Fire Protection Association], latest revision) for special installation requirements
2. Determine unit location (from project plans) or select unit location.
3. Check for possible overhead obstructions which may interfere 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 the clearance to combustible surfaces, unit performance and service access below,
around and above unit as specified in unit drawings. See Service Clearance Dimensional Drawing.
NOTE: Local codes may require different clearances than specified in Service Clearance Dimensional Drawing. It is
the responsibility of installers to be knowledgeable in local codes and to modify the recommended 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
(outdoor unit above indoor unit), liquid line lift (outdoor unit below indoor unit) and hot gas bypass line. Relocate
sections to minimize 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.
DO NOT BURY REFRIGERATION LINES.
Evaporator Coil Connections
Connect to Model
38AUMZ
38AUMD
Fig: - Service Clearance Dimensional Drawing
Page 8
Notes
Use two separate piping systems