Carrier 38AUZ User Manual
38AUZ
Air-Cooled Condensing Units
60 Hz
®
with Puron
(R-410A) Refrigerant
Sizes 07, 08, 12, 14
Installation, Start-Up and
Service Instructions
CONTENTS
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . 1
INSTALLATION GUIDELINES. . . . . . . . . . . . . . . . . . . . . . . 2
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13
Step 1 — Plan for Unit Location . . . . . . . . . . . . . . . . . . 7
Step 2 — Complete Pre-Installation Checks. . . . . . . . . 7
Step 3 — Prepare Unit Mounting Support . . . . . . . . . 7
Step 4 — Rig and Mount the Unit . . . . . . . . . . . . . . . . . 7
Step 5 — Complete Refrigerant Piping Connections . 7
Step 6 — Install Accessories . . . . . . . . . . . . . . . . . . . . . 9
Step 7 – Complete Electrical Connections . . . . . . . . . . 9
PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Turn On Crankcase Heater . . . . . . . . . . . . . . . . . . . . . . 14
Preliminary Charge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
START-UP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 -18
38AUZ Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
OPERATING SEQUENCE. . . . . . . . . . . . . . . . . . . . . . . . . . 18
Cooling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
ROUTINE SYSTEM MAINTENANCE. . . . . . . . . . . . . . . 18
Quarterly Inspection (and 30 days after initial start) . 18
Seasonal Maintenance . . . . . . . . . . . . . . . . . . . . . . . . 18
SERVICE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 - 23
Comfort Alert Diagnostic Module. . . . . . . . . . . 19 - 21
Crankcase Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Compressor Protection. . . . . . . . . . . . . . . . . . . . . . . . . . 21
Low-Pressure Switches . . . . . . . . . . . . . . . . . . . . . . . . . 21
High-Pressure Switches . . . . . . . . . . . . . . . . . . . . . . . . . 21
Outdoor Fans. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
NOVATION™ Coil Cleaning and Maintenance . . . . 22
Repairing NOVATION Condenser Tube Leaks. . . . . 22
Replacing NOVATION Condenser Coil . . . . . . . . . . 22
Field Refrigerant Access Ports . . . . . . . . . . . . . . . . . 22
Factory High-Flow Access Ports. . . . . . . . . . . . . . . . 22
Fastener Torque Values . . . . . . . . . . . . . . . . . . . . . . . 23
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . 23, 24
APPENDIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Air Conditioner and Heat Pump with Puron® —
Quick Reference Guide . . . . . . . . . . . . . . . . . . . . . . . 25
START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . CL-1, CL-2
SAFETY CONSIDERATIONS
Improper installation, adjustment, alteration, service,
maintenance, or use can cause explosion, fire, electrical shock
or other conditions which may cause personal injury or
property damage. Consult a qualified installer, service agency,
or your distributor or branch for information or assistance. The
qualified installer or agency must use factory-authorized kits or
accessories when modifying this product. Refer to the
individual instructions package
Follow all safety codes. Wear safety glasses and work gloves.
Use quenching cloths for brazing operations and have a fire
extinguisher available. Read these instructions thoroughly and
follow all warnings or cautions attached to the unit. Consult
local building codes and appropriate national electrical codes
(in USA, ANSI/NFPA70, National Electrical Code (NEC); in
Canada, CSA C22.1) for special requirements.
It is important to recognize safety information. This is the
safety-alert symbol . When you see this symbol on the unit
and in instructions or manuals, be alert to the potential for
personal injury.
Understand the signal words DANGER, WARNING,
CAUTION, and NOTE. These words are used with the safetyalert symbol. DANGER identifies the most serious hazards
which will result in severe personal injury or death.
WARNING signifies hazards which could result in personal
injury or death. CAUTION is used to identify unsafe practices,
which may result in minor personal injury or product and
property damage. NOTE is used to highlight suggestions
which will result in enhanced installation, reliability, or
operation.
INSTALLATION GUIDELINE
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could cause personal injury
or death.
Before performing service or maintenance operations on
unit, always turn off main power switch to unit and install
lockout tag. Unit may have more than one power switch.
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal injury,
death and/or equipment damage.
Puron® (R-410A) refrigerant systems operate at higher
pressures than standard R-22 systems. Do not use R-22
service equipment or components on Puron refrigerant
equipment.
PERSONAL INJURY AND ENVIRONMENTAL
HAZARD
Failure to follow this warning could cause personal injury
or death.
Relieve pressure and recover all refrigerant before system
repair or final unit disposal.
Wear safety glasses and gloves when handling refrigerants.
Keep torches and other ignition sources away from
refrigerants and oils.
CUT HAZARD
Failure to follow this caution may result in personal injury.
Sheet metal parts may have sharp edges or burrs. Use care
and wear appropriate protective clothing, safety glasses and
gloves when handling parts and servicing 38AU units.
Replacement /Retrofit – R22 to Puron
Replacement/retrofit installations require change-out of
outdoor unit, metering device, and filter driers. Change-out of
indoor coil (evaporator) and interconnecting tubing is
recommended.
Existing evaporator coil – If the existing evaporator coil may
be re-used, check with the coil manufacturer to verify the coil
construction is suitable for operation with the higher pressures
of Puron
is compatible with R-410A, replace if necessary. The minimum
factory test pressure rating must be 250 psig (1725 kPa).
Existing coil will need to be purged with Nitrogen to remove as
much mineral oil as possible to eliminate cross contamination
of oils.
Acid test – If the existing system is being replaced because of a
compressor electrical failure, assume acid is in system. If
system is being replaced for any other reason, use an approved
acid test kit to determine acid level. If even low levels of acid
are detected, install a 100 percent activated alumina suctionline filter drier in addition to the replacement liquid-line filter
drier. Remove the suction line filter drier as soon as possible,
with a maximum of 72 hr of operation. Recommendation:
Install a ball valve in the liquid line at the filter drier location
when installing a suction filter in the suction line.
®
(R-410A). Also determine if the existing TXV valve
®
Installation –
1. Remove the existing evaporator coil or fan coil and install
the replacement coil when appropriate.
2. Drain oil from low points and traps in suction line tubing
(and hot gas bypass tubing if appropriate) and evaporator
if they were not replaced. Removing oil from evaporator
coil may require purging of the tubing with dry nitrogen.
3. Unless indoor unit is equipped with a Puron® approved
metering device, change the metering device to a thermal
expansion valve (TXV) designed for Puron® (R-410A).
4. Remove the existing outdoor unit. Install the new outdoor
unit according to these installation instructions.
5. Install a new field-supplied liquid-line filter drier at the
indoor coil just upstream of the TXV or fix orifice
metering device.
6. If a suction line filter drier is also to be installed, install
suction line drier downstream of suction line service
valve at condensing unit.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
Never install suction-line filter drier in the liquid-line of a
®
Puron
system.
7. If required, install a 100% activated alumina suction line
filter drier at the outdoor unit.
8. Evacuate and charge the system according to the
instructions in this installation manual.
9. Operate the system for 10 hr. Monitor the pressure drop
across the suction line filter drier. If pressure drop
exceeds 3 psig (21kPa), replace suction-line and
liquid-line filter driers. Be sure to purge system with dry
nitrogen and evacuate when replacing filter driers.
Continue to monitor the pressure drop across suction-line
filter drier. Repeat filter changes is necessary. Never leave
suction-line filter drier in system longer than 72 hr (actual
time).
2
Fig. 1 — 38AUZ*07-14 Unit Dimensions
UNIT
Standard
Weight
Corner
A
Corner
B
Corner
C
Corner
D
Center of Gravity Unit Height
lbs. kg. lbs. kg. lbs. kg. lbs. kg. lbs. kg. X Y Z H
38AUZ*07
328 149 128 58 68 31 62 28 70 32
21.00
[533.4]
19.00
[482.6]
13.00
[330.2]
42.36
[1076.0]
38AUZ*08
353 160 138 63 72 33 65 29 78 35
19.00
[482.6]
23.00
[584.2]
13.00
[330.2]
42.36
[1076.0]
38AUZ*12
418 190 165 75 85 39 78 35 90 41
23.00
[584.2]
20.00
[508.0]
15.00
[381.0]
50.36
[1279.2]
38AUZ*14
431 196 162 73 82 37 92 42 95 43
19.00
[482.6]
23.00
[584.2]
15.00
[381.0]
50.36
[1279.2]
3
Table 1A — Physical Data — 38AUZ*07-14 Units — 60 Hz English
UNIT SIZE 38AU Z*07Z*08Z*12Z*14
NOMINAL CAPACITY (tons)
6 7.5 10 12.5
OPERATING WEIGHT (lb)
Aluminum-Fin Coils (Standard) 328 353 418 431
REFRIGERANT TYPE*
R-410A
Operating Charge, Typical (lb)† 8.4 10.2 13.8 18.0
Shipping Charge (lb) 4.4 4.9 6.3 7.3
COMPRESSOR
Scroll
Qty...Model 1...ZP61 1...ZP83 1...ZP103 1...ZP137
Oil Charge (oz) 56 60 110 110
No. Cylinders N/A
Speed (rpm) 3500
CONDENSER FANS
Qty...Rpm 2...1100
Motor Hp
1
/
4
Diameter 22
Nominal Airflow (Cfm Total) 6000
Watts (Total) 610
CONDENSER COIL (Qty)
1...NOVATION
Face Area (sq ft total) 17.5 20.5 25.0 31.8
Rows/Fins per inch (FPI) 1/17 1/17 1/17 1/17
Storage Capacity (lb)** 5.5 6.0 7.4 8.7
CONTROLS
Pressurestat Settings (psig)
High Cutout 630 ± 10
Cut-in 505 ± 20
Low Cutout 54 ± 3
Cut-in 117 ± 5
PIPING CONNECTIONS (in. ODS)
Qty...Suction 1...1
Qty...Liquid
LEGEND
ODS — Outside Diameter Sweat (socket)
* Unit is factory-supplied with partial charge only.
† Typical operating charge with 25 ft of interconnecting piping.
** Storage capacity of condenser coil with coil 80% full of liquid R-410A at 95°F.
1...
1
/
/
8
1...1/
1...11/
8
3
1...13/
8
2
1...1/
1...13/
8
2
1...5/
8
8
4
Table 1B — Physical Data — 38AUZ*07-14 Units — 60 Hz SI
UNIT SIZE 38AU Z*07 Z*08 Z*12 Z*14
NOMINAL CAPACITY (kW)
21.1 26.4 35.1 44
OPERATING WEIGHT (kg)
Aluminum-Fin Coils (Standard) 149 160 190 196
REFRIGERANT TYPE*
R-410A
Operating Charge, Typical (kg)† 3.8 4.6 6.3 8.2
Shipping Charge (kg) 2.0 2.2 2.9 3.3
COMPRESSOR
Scroll
Qty...Model 1...ZP61 1...ZP83 1...ZP103 1...ZP137
Oil Charge (L) 1.7 1.8 3.3 3.3
No. Cylinders N/A
Speed (r/s) 58
CONDENSER FANS
Qty...r/s 2...18
Motor Hp NEMA
1
/
4
Diameter (mm) 560
Nominal Airflow (L/s) 2832
Watts (Total) 610
CONDENSER COIL (Qty)
1...NOVATION
Face Area (sq m total) 1.6 1.9 2.3 3.0
Rows/Fins per Meter (Fins/m) 1...670 1...670 1...670 1...670
Storage Capacity (kg)** 2.5 2.7 3.4 3.9
CONTROLS
Pressurestat Settings (kPa)
High Cutout 4347 ± 70
Cut-in 3482 ±138
Low Cutout 372 ± 21
Cut-in 807 ± 34
PIPING CONNECTIONS (in. ODS)
Qty...Suction 1...1
Qty...Liquid
1...
1
/
1...11/
8
3
/
8
1...1/
1...13/
8
2
1...1/
1...13/
8
2
1...5/
LEGEND
NEMA — National Electrical Manufacturers Association
ODS — Outside Diameter Sweat (socket)
* Unit is factory-supplied with partial charge only.
† Typical operating charge with 7.62 m of interconnecting piping.
** Storage capacity of condenser coil with coil 80% full of liquid R-410A at 35°C.
8
8
5
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
3 8 A U Z A 0 4 A 0
G
6 – 0 A 0 A 0
_____________ ____
Model Type Packaging
38AU= Carrier Condensing Unit
Puronr R ---410A Refrigerant
0=Standard
Type o f Co il
Electrical Options
Z = Single Circuit, A/C Scroll Compressor
A=None
C = Non-Fused Disconnect
1=LTL
Service Options
0=None
1 = Un-powered Convenience Outlet
Nominal Tonnage
1=
07 = 6 Tons
08 = 7.5 Tons
Not Used
12 = 10 Tons
A=PlaceHolder
14 = 12.5 Tons
Base Unit Controls
0 = Electro-Mechanical Controls
Not Used
A=Not Used
Design Rev
--- = Catalog Model Number
Voltage
1 = 575/3/60
5 = 208/ 230/3/60
6 = 460/3/60
Refrigerant Options
A = None
B = Low Ambient
Not Used
0=Not Used
Coil Options
G=Al/Al
2 = Powered Convenience Outlet
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POSITION NUMBER
TYPICAL
Year of manufacture (”08” = 2008)3−4
Fig. 2 — Model Number Nomenclature
Fig. 3 — Serial Number Nomenclature
6
.INSTALLATION
REAR:
Min 18” (457 mm)
requried for service
Note: Observe requirements for 39” (914 mm) operating clearance
on either Left or Rear coil opening.
RIGHT:
Min 18” (457 mm)
requried for service
LEFT:
Min 18” (457 mm)
requried for service
FRONT:
42” (1067 mm)
Jobsite Survey
Complete the following checks before installation.
1. Consult local building codes and the NEC (National
Electrical Code) ANSI/NFPA 70 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 Fig. 4.
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.
DO NOT BURY REFRIGERATION LINES.
Although unit is weatherproof, avoid locations that permit
water from higher level runoff and overhangs to fall onto the
unit.
• Locate the unit so that the outdoor coil (condenser) airflow 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 and 1B for unit operating weights.
See Fig. 1 for weight distribution based on recommended
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 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
damage.
All panels must be in place when rigging. Unit is not
designed for handling by fork truck.
.
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 against the sides of the
unit, behind cables. Run cables 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 — Complete Refrigerant Piping
Connections
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 company 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.
IMPORTANT: Do not bury refrigerant piping underground.
IMPORTANT: A refrigerant receiver is not provided with
the unit. Do not install a receiver.
PROVIDE SAFETY RELIEF — The 38AUZ unit is provided
with a fusible joint in the suction line in accordance with
applicable UL standards for pressure relief. If local codes
dictate an additional safety relief device, purchase locally and
install locally. Installation will require the recovery of the
factory shipping charge before the factory tubing can be cut
and the supplemental relief device is installed.
SIZE REFRIGERANT LINES — Consider the linear length
of piping required between the outdoor unit and indoor unit
(evaporator), the amount of liquid lift (indoor section installed
above the outdoor section), and compressor oil return.
Consider and identify also the arrangement of the tubing path
(quantity and type of elbows in both lines), liquid line solenoid
size, filter drier and any other refrigeration specialties located
7
in the liquid line. Refer to the indoor unit installation
instructions for additional details.
Determine equivalent line length adjustments for path and
components and add to linear line lengths. See Tables 2 and 3;
also refer to Part 3 of the Carrier System Design Manual and
E20-II® software for design details and line sizing.
Suction line sizing – Select a tube size that produces a suction
pressure drop in range of 1.5 to 3.0°F (0.8 to 1.7°C). (Higher
pressure drops are permissible but there will be a loss in
cooling capacity due to the higher pressure drop.) Insulate the
suction line.
Liquid line sizing – For linear line lengths up to 50-ft (15 m),
select a tube size that produces a liquid pressure drop of
approximately 2°F (1.1°C). For linear line lengths greater than
50-ft (15 m), select a line size that will permit the liquid
state-point subcooling entering the indoor coil’s TXV to be a
minimum of 2°F (1.1°C).
Hot Gas Bypass – Hot gas bypass, if used, should be
introduced before the evaporator. (A bypass route that also
bypasses the evaporator circuit may lead to oil trapping in the
evaporator circuit during low load conditions and then to oil
slugging as evaporator load increases.) Model 38AUZA units
do not include a hot gas stub connection; a tee must be fieldsupplied and installed in the compressor discharge line. Run a
½-in OD line between outdoor unit and evaporator coil inlet.
Install an Auxiliary Side Connector at the evaporator between
TXV and distributor (follow instructions for the side connector
part). Insulate the hot gas line.
Note that refrigerant suction piping should be insulated.
IMPORTANT: For 38AUZ*07-14 applications with liquid
lift greater than 20 ft (6 m), use
5
/8-in. liquid line.
Maximum lift is 60 ft (18 m).
Table 2 — Liquid Line Data —
38AUZ*07-14 60 Hz Units,
Table 3 — Refrigerant Piping Sizes —
38AUZ*07-14 60 Hz Units
LINEAR LENGTH OF INTERCONNECTING PIPING —
UNIT
38AU
Z*07
Z*08
Z*12
Z*14
LEGEND
L — Liquid Line S — Suction Line
*Field-supplied suction accumulator required for pipe length 75-100 ft
(23-30 m).
NOTES:
1. Pipe sizes are based on a 2°F (1°C) saturated temperature
2. Pipe sizes are based on the maximum linear length, shown for
3. Charge unit with R-410A and verify that subcooled liquid exists
0-25
(0-7.5)
LSLSLSLS
3
/811/
3
/811/
1
/213/
1
/213/
loss for liquid and suction lines.
each column, plus a 50% allowance for fittings.
at TXV by checking for a full liquid line sight glass or by calculating subcooling at TXV.
8
8
8
8
3
/811/
1
/211/
1
/213/
1
/213/
FT (m)
25-50
(7.5-15)
Line Size (in. OD)
8
8
8
8
50-75
(15-23)
3
/811/
1
/211/
1
/213/
1
/213/
8
8
8
8
75-100
(23-30)*
3
/811/
1
/213/
1
/213/
1
/213/
8
8
8
8
INSTALL FILTER DRIER(S) AND MOISTURE
INDICATOR(S) — Every unit should have a filter drier and a
liquid-moisture indicator (sight glass). Refer to Table 4. In
some applications, depending on space and convenience requirements, it may be desirable to install 2 filter driers and sight
glasses. One filter drier and sight glass may be installed at A
locations in Fig. 5; or, 2 filter driers and sight glasses may be
installed at B
locations.
Select the filter drier for maximum unit capacity and minimum
pressure drop. Complete the refrigerant piping from the indoor
unit to the outdoor unit before opening the liquid and suction
lines at the outdoor unit.
MAXIMUM
ALLOWABLE
LIQUID LIFT
ft (m)
60 (18) 7 (48) 2 (1)
*Inlet and outlet.
NOTE: Data shown is for units operating at 45°F (7.2°C) saturated
suction temperature and 95°F (35°C) entering air temperature. For
38AUZ*07-14 applications with liquid lift greater than 20 ft (6 m),
5
use
/8-in. liquid line. Maximum lift is 60 ft (18 m).
LIQUID LINE
Maximum
Allowable
Pressure
Drop
psig (kPa)
Maximum
Allowable
Tem p.
Loss
°F (°C)
INSTALL LIQUID LINE SOLENOID VALVE —
SOLENOID DROP — It is recommended that a solenoid
valve be placed in the main liquid line (see Fig. 5) between the
condensing unit and the evaporator coil. Refer to Table 4. (A
liquid line solenoid valve is required when the liquid line
length exceeds 75 ft [23 m] or when the condensing unit is connected to a chiller barrel in a built-up chiller system.) This
valve prevents refrigerant migration (which causes oil dilution)
to the compressor during the off cycle, at low outdoor ambient
temperatures. Wire the solenoid in parallel with the compressor
contactor coil (see Fig. 5). This means of electrical control is
referred to as solenoid drop control.
INSTALL LIQUID LINE SOLENOID VALVE (Optional)
— CAPACITY CONTROL — If 2-step cooling is desired,
place a solenoid valve in the location shown in Fig. 5.
MAKE PIPING CONNECTIONS — Piping connections at
the 38AU unit are ball valves with stub tube extensions. Do not
open the unit service valves until all interconnecting tube brazing as been completed.
The stub tube connections include ¼-in SAE service fittings
with Schrader valve cores (see Fig. 6). Before making any
brazed connections to the unit service valves, remove both
Schrader valve caps and cores and save for re-installation. Connect a source for nitrogen to one of these service fittings during
tube brazing to prevent the formation of copper oxides inside
the tubes at brazed joints.
When connecting the field tubing to the 38AU service valves,
wrap the valves in wet rags to prevent overheating.
8
Table 4 — Refrigerant Specialities Part Numbers.
LEGEND
TXV — Thermostatic Expansion Valve
Factory
High-Flow
Access Port
Service Valve
with Stem Cap
Field Service
Access Port
(Schrader core)
Sweat
Connection
UNIT
38AUZ*07
38AUZ*08
38AUZ*12
38AUZ*14
*Bushings required.
LIQUID LINE
SIZE (in.)
Fig. 5 — Location of Sight Glass(es)
3
/
8
3
/
8
1
/
2
1
/
2
5
/
8
SOLENOID VALVE (LLSV)
and Filter Driers
LIQUID LINE
200RB5T3M AMG/24V AMI-1TT3 P502-8304S* S-7063S*
200RB5T3M AMG/24V AMI-1TT3 P502-8304S* S-7063S*
200RB5T4M AMG/24V AMI-1TT4 P502-8304S S-7063S*
200RB6T4M AMG/24V AMI-1TT4 P502-8307S* S-7063
200RB6T5M AMG/24V AMI-1TT5 P502-8307S* S-7063
LLSV
COIL
SIGHT
GLASS
FILTER
DRIER
SUCTION LINE
ACCUMULATOR
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal injury,
death and/or equipment damage.
Puron® (R-410A) refrigerant systems operate at higher
pressures than standard R-22 systems. Do not use R-22
service equipment or components on Puron refrigerant
equipment.
PRELIMINARY CHARGE — Before starting the unit, charge
R-410A liquid refrigerant into the high side of the system
through the liquid service valve. The amount of refrigerant
added must be at least 80% of the operating charge listed in the
Physical Data table (Tables 1A and 1B, pages 4 and 5) LESS
the factory charge quantity (if factory shipping charge has not
been removed). Allow high and low side pressures to equalize.
If pressures do not equalize readily, charge R-410A vapor
(using special service manifold with expansion device) into the
suction line service port for the low side of system to assure
charge in the evaporator. Refer to GTAC II, Module 5,
Charging, Recover, Recycling, and Reclamation for liquid
charging procedures.
Step 6 — Install Accessories
Accessories requiring modifications to unit wiring should be
completed now. These accessories may include Winter Start
controls, Low Ambient controls, phase monitor, Compressor
LOCout. Refer to the instructions shipped with the accessory.
Fig. 6 — Typical Piping Connection Assembly
Pressure-test all joints from outdoor unit connections over to
the evaporator coil, using nitrogen as pressure and with soapand-bubbles.
When pressure-testing is completed, remove the nitrogen
source at the outdoor unit service valves and re-install the two
Schrader valve cores. Torque the cores to 2-3 in-lbs (23-34
N-cm).
EVACUATION/DEHYDRATION — Evacuate and dehydrate
the connected refrigeration system (excluding the 38AU unit)
to 500 microns using a two-stage vacuum pump attached to the
service ports outside the 38AU service valves, following description in GTAC II, Module 4, System Dehydration.
Step 7 — Complete Electrical Connections
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Do not use gas piping as an electrical ground. Unit cabinet
must have an uninterrupted, unbroken electrical ground to
minimize the possibility of personal injury if an electrical
fault should occur. This ground may consist of electrical
wire connected to unit ground lug in control compartment,
or conduit approved for electrical ground when installed in
accordance with NEC (National Electrical Code); ANSI/
NFPA 70, latest edition (in Canada, Canadian Electrical
Code CSA [Canadian Standards Association] C22.1), and
local electrical codes.
NOTE: Check all factory and field electrical connections
for tightness. Field-supplied wiring shall conform with the
limitations of 63°F (33°C) rise.
Field Power Supply —
If equipped with optional Powered Convenience Outlet: The
power source leads to the convenience outlet's transformer
primary are not factory connected. Installer must connect these
9
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