38AU
Air Cooled Condensing Units
60 Hz
With PuronR(R---410A) Refrigerant
S i z e s 1 6 --- 2 5
Installation, Start---Up and
Service Instructions
CONTENTS
SAFETY CONSIDERATIONS 2....................
INSTALLATION GUIDELINES 2..................
Replacement/Retrofit — R--22 to Puron 2...........
INSTALLATION 11 - 22.........................
Jobsite Survey 11...............................
Step 1 -- Plan for Unit Location 11.................
Step 2 -- Complete Pre--Installation Checks 11........
Step3–PrepareUnitMounting Support 12..........
Step4–RigandMount the Unit 12................
Step5–CompleteRefrigerantPipingConnections 12...
Step6–InstallAccessories 17....................
Step7–CompleteElectricalConnections 18.........
PRE-START-UP 23...............................
System Check 23...............................
Turn On Crankcase Heater 23.....................
Preliminary Charge 23...........................
START--UP 23 - 31..............................
Preliminary Checks 23...........................
Start Unit 24...................................
OPERATING SEQUENCE 32......................
Indoor (Supply) Fan 32..........................
Cooling, Unit Without Economizer 32..............
Cooling, Unit With Economizer 32.................
Heating 32....................................
ROUTINE SYSTEM MAINTENANCE 33............
Quarterly Inspection (and 30 days after initial start) 33...
Seasonal Maintenance 33........................
SERVICE 33 - 44................................
Compressor Oil 33..............................
Servicing Systems on Roofs with
Synthetic Materials 33...........................
Liquid Line Filter Drier 34.......................
Field Refrigerant Access Ports 34..................
Factory High--Flow Access Ports 34................
Comfort Alert Diagnostic Module 35...............
Compressor Protection 37........................
Crankcase Heater 37............................
Low--Pressure Switch 37.........................
High--Pressure Switch 37.........................
Outdoor Fans 37................................
Lubrication 37.................................
Coil Type Identification 42.......................
N O VAT I O N tCoil Cleaning and Maintenance 42.....
Repairing NOVATION Condenser Tube Leaks 42.....
Replacing NOVATION Condenser Coil 43...........
Routine Cleaning of Round-Tube Plate Fin
(RTPF) Coils 43................................
Fastener Torque Values 44........................
TROUBLESHOOTING 44 -- 45.....................
APPENDIX A
Air Conditioner & Heat Pump with Puron
Quick Reference Guide 46.........................
APPENDIX B
Wiring Diagram List 46...........................
APPENDIX C
Low Ambient Option — Factory Installed 47..........
START--UP CHECKLIST 55 -- 56...................
R
—
Refrigeration System 33.........................
1
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.
38AU
It is important to recognize safety information. This is the
safety--alert symbol
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
safety-alert 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.
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could cause in 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 in personal
injury,death and/or equipment damage.
R
Puron
higher pressures than standard R--22 systems. Do not
use R--22 service equipment or components on Puron
refrigerant equipment.
(R--410A) refrigerant systems operate at
. When you see this symbol on the
WARNING
WARNING
!
WARNING
PERSONAL INJURY AND ENVIRONMENTAL
HAZARD
Failure to follow this warning could cause in 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.
!
CAUTION
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.
INSTALLATION GUIDELINE
Replacement/Retrofit — R--22 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
the existing TXV valve 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 suction-line 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.
Existing refrigeration piping – Reuse of existing refrigerant
piping involves three issues: quality (strength) of existing
tubing, cleanliness and tube size. Inspect all tube segments
and joints for signs of damage, corrosion or poor brazing.
Flush the interconnecting piping system with dry Nitrogen to
eliminate as much trace of mineral oil as possible.
R
(R-410A). Also determine if
R
2
Same tube sizes are capable of handling higher flowrates
(expressed as tons of cooling capacity) with Puron
refrigerant compared to R--22 at constant pressure drops.
For example, a
higher tons with Puron
drop). A 1
tons with Puron than with R--22 (at 2_F pressure drop).
Refrigeration lines selected for R--22 use are typically
oversized for Puron applications. Carefully check the
existing suction line size against the table for maximum size
(see Table 7); replace vertical riser segments if necessary.
Check existing liquid line size against sizing data in Table 5
or 6; replace with smaller lines when feasible.
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
4. Remove the existing outdoor unit. Install the new outdoor unit according to these installation instructions.
1
/2--inch OD liquid line is rated at 33%
R
1
/8--inch OD suction line is rated at 53% higher
R
(R-410A).
than with R--22 (at 5_F pressure
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.
!
CAUTION
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
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).
R
system.
38AU
3
38AU
C10942
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*16
(MCHX)
38AUD*16
(MCHX)
38AUZ*16
(RTPF)
38AUD*16
(RTPF)
LEGEND: MCXH = Novation™ coil
633 288 220 100 134 61 135 61 144 65.5
633 288 220 100 134 61 135 61 144 65.5
731 332 237 107 172 78 135 61 186 84
731 332 237 107 172 78 135 61 186 84
RTPF = Round Tube/Plate Fin coil
38
[965.2]
38
[965.2]
38
[965.2]
38
[965.2]
19
[482.6]
19
[482.6]
19
[482.6]
19
[482.6]
15
[381]
15
[381]
17
[431.8]
17
[431.8]
503/
8
[1279.2]
503/
8
[1279.2]
503/
8
[1279.2]
503/
8
[1279.2]
Fig. 1 -- 38AU**16 Unit Dimensions
4
UNIT
Standard
Weight
Corner
A
lbs. kg. lbs. kg. lbs. kg. lbs. kg. lbs. kg. X Y Z H
38AUZ*25
(RTPF)
38AUD*25
(RTPF)
LEGEND: RTPF = Round Tube/Plate Fin coil
978 444 360 163 188 85 147 67 283 128
978 444 360 163 188 85 147 67 283 128
Corner
B
Corner
C
Corner
D
Fig. 2 -- 38AU**25 Unit Dimensions
Center of Gravity
38
[965.2]
38
[965.2]
23
[584.2]
23
[584.2]
17
[431.8]
17
[431.8]
Unit
Height
503/
[1279.2]
503/
[1279.2]
38AU
C10943
8
8
5
Table 1A — Physical Data — 38AUZ*16-25 Units — 60 Hz English
UNIT SIZE 38AU Z*16 Z*25
NOMINAL CAPACITY (tons) 15 20
OPERATING WEIGHTS (lb)
NOVATION™ Coil (Al Tube) 633 ---
Round Tube/Plate Fin Coil (Cu/Al) 731 900
REFRIGERANT TYPE
NOVATION Operating Charge, Typical (lb)
NOVATION Shipping Charge (lb) 12.2 ---
RTPF Operating Charge, Typical (lb)
RTPF Shipping Charge (lb) 32.0 28.0
COMPRESSOR
Qty...Type 2...Scroll 2...Scroll
38AU
Oil Charge (oz) 60 110
CONDENSER FANS
Qty...Rpm 3...1100 4...1100
Motor Hp
Diameter 22 22
Nominal Airflow (Cfm Total) 9,000 12,000
Watts (Total) 970 1150
RTPF CONDENSER COIL
Material (Tube/Fin) Cu / Al Cu / Al
Coil Type
Rows/Fins per inch (FPI) 2/17 2/17
Face Area (sq ft total) 47.0 50.0
NOVATION CONDENSER COIL
Material (Tube/Fin) Al / Al ---
Coil Type Novation ---
Rows/Fins per inch (FPI) 1/17 ---
Face Area (sq ft total) 50.0 ---
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...13/
Qty...Liquid 1...5/
LEGEND
RTPF — Round Tube/Plate Fin
ODS — Outside Diameter Sweat (socket)
‡
Unit is factory-suppl ied with partial charge on ly.
†
Typical operating ch arge with 25 ft of interconnecting piping.
‡
†
†
24.6 ---
43.0 38.0
3
/8--- i n R T P F
R-410A
1
/
4
8
8
1
/
4
3
/8--- i n R T P F
1...15/
1...5/
8
8
6
Table 1B — Physical Data — 38AUZ*16-25 Units — 60 Hz SI
UNIT SIZE 38AU Z*16 Z*25
NOMINAL CAPACITY (kW) 52.7 70.3
OPERATING WEIGHT (kg)
NOVATION™ Coil (Al Tube) 288 ---
Round Tube/Plate Fin Coil (Cu/Al) 332 409
REFRIGERANT TYPE
NOVATION Operating Charge, Typical (kg)
NOVATION Shipping Charge (kg) 5.4 ---
RTPF Operating Charge, Typical (kg)
RTPF Shipping Charge (kg) 14.5 12.7
COMPRESSOR Scroll
Qty...Type 2...Scroll 2...Scroll
Oil Charge (L) 1.7 3.2
CONDENSER FANS
Qty...r/s 3...18 4...18
Motor Hp NEMA
Diameter (mm) 560 560
Nominal Airflow (L/s) 4248 5663
Watts (Total) 970 1150
RTPF CONDENSER COIL (Qty)
Material (Tube/Fin) Cu / Al Cu / Al
Coil Type
Rows/Fins per Meter (Fins/m) 1...670 2...670
Face Area (sq m total) 4.4 4.6
NOVATION CONDENSER COIL
Material (Tube/Fin) Al / Al ---
Coil Type Novation ---
Rows/Fins per Meter (Fins/m) 1...670 ---
Face Area (sq m total) 4.6 ---
CONTROLS
Pressurestat Settings (kPa)
High Cutout 4347 ± 70
Cut-in 3482 ±138
Low Cutout 372 ± 21
Cut-in 807 ± 34
PIPING CONNECTIONS (mm ODS)
Qty...Suction 1...34.9 1...38.7
Qty...Liquid 1...13.3 1...13.3
LEGEND
RTPF — Round Tube/Plate Fin
NEMA — National Electrical Manufacturers Association
ODS — Outside Diameter Sweat (socket)
‡
Unit is factory-suppl ied with partial charge on ly.
†
Typical operating charge with 7.62 m of interconnecting piping.
‡
†
†
11.1 ---
19.5 17.2
3
/8--- i n R T P F
R-410A
1
/
4
1
/
3
/8--- i n R T P F
38AU
4
7
Table 2A — Physical Data — 38AUD*16-25 Units — 60 Hz English
UNIT SIZE 38AU D*16 D*25
NOMINAL CAPACITY (tons) 15 20
OPERATING WEIGHTS (lb)
NOVATION™ Coil (Al Tube) 633 ---
Round Tube/Plate Fin Coil (Cu/Al) 731 900
REFRIGERANT TYPE
NOVATION Operating Charge A/B, Typical (lb)
NOVATION Shipping Charge A/B (lb) 6.0 / 6.0 ---
RTPF Opera ting Charge A/B, Typical (lb)
RTPF Shipping Charge A/B (lb) 16.0 / 16.0 14.0 / 14.0
COMPRESSOR
Qty...Type 2...Scroll 2...Scroll
38AU
Oil Charge A/B (oz) 60 / 60 110 / 110
CONDENSER FANS
Qty...Rpm 3...1100 4...1100
Motor Hp
Diameter 22 22
Nominal Airflow (Cfm Total) 9,000 12,000
Watts (Total) 970 1150
RTPF CONDENSER COIL
Material (Tube/Fin) Cu / Al Cu / Al
Coil Type
Face Area (sq ft total) 47 50
Rows/Fins per inch (FPI) 2/17 2/17
NOVATION CONDENSER COIL
Material (Tube/Fin) Al / Al ---
Coil Type Novation ---
Face Area (sq ft total) 50 ---
Rows/Fins per inch (FPI) 1/17 ---
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 2...13/
Qty...Liquid 2...1/
LEGEND
RTPF — Round Tube/Plate Fin
ODS — Outside Diameter Sweat (socket)
‡
Unit is factory-suppl ied with partial charge on ly.
†
Typical operating ch arge with 25 ft of interconnecting piping.
‡
†
12.0 / 12.0 ---
†
22.0 / 22.0 19.0 / 19.0
3
/8--- i n R T P F
R-410A
1
/4
8
2
1
/
4
3
/8--- i n R T P F
2...13/
2...1/
8
2
8
Table 2B — Physical Data — 38AUD*16-25 Units — 60 Hz SI
UNIT SIZE 38AU D*16 D*25
NOMINAL CAPACITY (kW) 52.7 70.3
OPERATING WEIGHT (kg)
NOVATION™ Coil (Al Tube) 288 ---
Round Tube/Plate Fin Coil (Cu/Al) 332 409
REFRIGERANT TYPE
NOVATION Operating Charge A/B, Typical (kg)
NOVATION Shipping Charge A/B (kg) 2.7 / 2.7 ---
RTPF Operating Charge A/B, Typical (kg)
RTPF Shipping Charge A/B (kg) 7.3 / 7.3 6.8 / 6.8
COMPRESSOR
Qty...Type 2...Scroll 2...Scroll
Oil Charge A/B (L) 1.7 / 1.7 3.2 / 3.2
CONDENSER FANS
Qty...r/s 3...18 4...18
Motor Hp NEMA
Diameter (mm) 560 560
Nominal Airflow (L/s) 4248 5663
Watts (Total) 970 1150
RTPF CONDENSER COIL (Qty)
Material (Tube/Fin) Cu / Al Cu / Al
Coil Type
Rows/Fins per Meter (Fins/m) 1...670 2...670
Face Area (sq m total) 4.4 4.6
NOVATION CONDENSER COIL
Material (Tube/Fin) Al / Al ---
Coil Type Novation ---
Rows/Fins per Meter (Fins/m) 1...670 ---
Face Area (sq m total) 4.6 ---
CONTROLS
Pressurestat Settings (kPa)
High Cutout 4347 ± 70 4347 ± 70
Cut-in 3482 ±138 3482 ±138
Low Cutout 372 ± 21 372 ± 21
Cut-in 807 ± 34 807 ± 34
PIPING CONNECTIONS (mm ODS)
Qty...Suction 2...34.9 2...34.9
Qty...Liquid 2...12.7 2...12.7
LEGEND
RTPF — Round Tube/Plate Fin
NEMA — National Electrical Manufacturers Association
ODS — Outside Diameter Sweat (socket)
‡
Unit is factory-suppl ied with partial charge on ly.
†
Typical operating charge with 7.62 m of interconnecting piping.
‡
†
†
R-410A R-410A
5.4 / 5.4 ---
10.0 / 10.0 8.6 / 8.6
1
/
4
3
/8--- i n R T P F
1
3
/8--- i n R T P F
/
4
38AU
9
1 2 3 4 5 6 7 8 9 101112131415161718
38AUZA25A0G6A0A0A0
Model Type
38AU= Carrier Condensing Unit
®
Puron
R--- 410A Refrigerant
Typ e o f C oi l
Z = Single Circuit, A/C Scroll Compressor
D = Dual Circuit, A/C Scroll Compressor
Refrigerant Options
A = None
B = Low Ambient
Nominal Tonnage
16 = 15 Tons
25 = 20 Tons
Not Used
A = Not Used
38AU
Not Used
0 = Not Used
Packaging
0=Standard
1=LTL
Electrical Options
A=None
C = Non-Fused Disconnect
Service Options
0=None
1 = Un-powered Convenience Outlet1=
2 = Powered Convenience Outlet
Not Used
A=PlaceHolder
Base Unit Controls
0 = Electro-Mechanical Controls
Design Rev
A = Initial Release
Voltage
1 = 575/3/60
5 = 208 / 230/3/60
6 = 460/3/60
POSITION NUMBER
TYPICAL
Coil Options
NOVATION™ (Size 16 only)
G= Al/Al
K = E-Coat Al/Al
T = Al/Al with Hail Guard
W= E-Coat Al/Al with Hail Guard
RTPF (Sizes 16 & 25)
A= Cu/Al
B = Precoat (Cu/Al)
C = E-Coat (Cu/Al)
M= Cu/Al with Hail Guard
N = Precoat (Cu/Al) with Hail Guard
P = E-Coat (Cu/Al) with Hail Guard
Fig. 3 -- Model Number Nomenclature
12345678910
0510U12345
POSITION
1 – 2
3 – 4
5
6 – 10
Week of manufacture (fiscal calendar)
Year of manufacture ("10" = 2010)
Manufacturing location (U = Monterrey, Mexico)
DESIGNATES
Sequence number
Fig. 4 -- Serial Number Nomenclature
C10944
C101041
10
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 manifolding 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 connected 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 design.
Table 3 – Evaporator Coil Connections
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.
REAR:
Min 18” (457 mm)
requried for service
RIGHT:
Min 18” (457 mm)
requried for service
Evaporator Coil has Connect to Model Notes
Single Circuit 38AUZ ONLY
Two Circuits
38AUZ
Or
38AUD Use two separate
Manifold evaporator
circuits into single
piping system
piping systems
Before unpacking this new 38AU model, compare the
evaporator coil design to the 38AU model.
.INSTALLATION
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. 5.
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.
LEFT:
Min 18” (457 mm)
requried for service
Note: Observe requirements for 39” (914 mm) operating clearance
on either Left or Rear coil opening.
FRONT:
42” (1067 mm)
C10201
Fig. 5 -- Service Clearance Dimensional Drawing
Step 2 — Complete Pre-Installation Checks
Check Unit Electrical Characteristics: Confirm before
installation of unit that voltage, amperage and circuit
protection requirements listed on unit data plate agree with
power supply provided.
Un--crate 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:
S Consult local building codes and National Electrical
Code (NEC, U.S.A.) for special installation
requirements.
S Allow sufficient space for airflow clearance, wiring,
refrigerant piping, and servicing unit. See Fig.1 and
Fig. 2 for unit dimensions and weight distribution data.
S Locate the unit so that the outdoor coil (condenser)
airflow is unrestricted on all sides and above.
S 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 and Fig. 2 for weight distribution
based on recommended support points.
NOTE: If vibration isolators are required for a particular
installation, use the data in Fig. 1 and Fig. 2 to make the
proper selection.
38AU
11
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.
38AU
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.
CAUTION
Step 5 — Complete Refrigerant Piping
Connections
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 —
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.
Model 38AUD has two separate refrigeration systems. If
required, each circuit will require a field-supplied/installed
supplemental relief device.
Table 4 – Equivalent Lengths for Common Fittings (ft)
Nominal
Tube OD
3
/
8
1
/
2
5
/
8
3
/
4
7/
8
11/
8
13/
8
15/
8
21/
8
Nominal
Tube OD
3
/
8
1
/
2
5
/
8
3
/
4
7/
8
11/
8
13/
8
15/
8
21/
8
90° Std 90° Lrad 90° Street 45° Std 45° Street
1.3 0.8 2.2 0.6 1
1.4 0.9 2.3 0.7 1.1
1.6 1 2.5 0.8 1.3
1.8 1.2 2.9 0.9 1.5
2 1.4 3.2 0.9 1.6
2.6 1.7 4.1 1.3 2.1
3.3 2.3 5.6 1.7 3
4 2.6 6.3 2.1 3.4
5 3.3 8.2 2.6 4.5
Branch
Flow
2.6 0.8 1.1 1.3
2.7 0.9 1.2 1.4
3.5 1.2 1.7 1.8
10 3.3 4.7 5
No Reduct Reduce 25% Reduce 50%
3 1 1.4 1.6
4 1.4 1.9 2
5 1.7 2.3 2.6
7 2.3 3.1 3.3
8 2.6 3.7 4
Elbows
Tees
Straight-Thru
Check 38AU Model with Evaporator Coil Connections —
Confirm before installation of unit that the evaporator coil
connections are consistent with this 38AU model. See
Table 3 on page 11.
Determine Refrigerant Line Sizes —
Select the recommended line sizes for 38AUZ and
38AUD unit from the appropriate tables.
Determine the linear length of interconnecting piping
required between the outdoor unit and indoor unit
(evaporator). 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 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,
Equivalent Lengths for Common Fittings, for usual fitting
types. Also identify adjustments for refrigeration
specialties. Refer to Part 3 of the Carrier System Design
Manual for additional data and information on equivalent
lengths.
NOTE: Equivalent line lengths will vary based on tube
diameter. Calculate equivalent line length for each pipe by
adding equivalent length adjustments to linear lengths for
each pipe.
12
Enter the appropriate table to select the recommended line
sizes.
Model: Line Sizes Table Quantity of Line Sets
38AUZ 5 1
38AUD 6 2
Liquid Lift —
A liquid lift condition exists when the outdoor unit is
located 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) and 6 (38AUD) for maximum
liquid lift capabilities for line sizes. Reselect the liquid
Table 5 – 38AUZ 16-25 Piping Recommendations (Single-Circuit Unit)
R-410A Equivalent Length
Ft 0-38 38-75 75-113 113-150 150-188
m 0-12 12-23 23-34 34-46 46-57
Linear Length
Ft 0-25 25-50 50-75 75-100 100-125
Model
38AUZ*16 Liquid Line
38AUZ*25 Liquid Line
Legend:
Equivalent
Length
Linear Length Typical linear tubing length, (50% added to l inear to define E quivalent Length for this table)
Liquid Line Tubing size, inches OD.
Max Lift Maximum liquid lift (indoor unit ABOVE outdoor unit only), at maximum permitted liquid line pressure drop —
Suction Line Tube size, inches OD
Charge Charge Quantity, lbs. Calculated for both liquid line sizes (where applicable), but only with larger suction line size
NOTE: For applications with equivalent length greater than 188 ft (57 m) and/0r linear length greater than 125 ft (38 m),
m 0-8 8-15 15-23 23-30 30-38
5
/
8
Max Lift 25 50 75 100 125
Suction Line 1-1/
Charge (lbs)
Novation 24.3 27.5 30.6 33.7 37.8
RTPF 42.7 45.9 49.0 52.1 56.2
Max Lift 25 50 71 77 63
Suction Line 1-1/81-3/81-3/
Charge (lbs) 37.8 40.8 44.6 47.8 51.1
Equivalent tubing length, including effects of refrigeration specialties devices
S Linear Length Less than 75 ft (23 m): Minimum 2.0° F subcooling entering TXV
S Linear Length Greater than 75 ft (23m): Minimum 0.5° F subcooling entering TXV
(where applicable)
contact your local Carrier representative.
8
5
/
8
5
/
1-3/
5
/
8
8
8
8
line tube size if necessary. If maximum available tube size
cannot provide the required lift distance on this
installation, relocate the outdoor unit to reduce the
equivalent line length or the lift requirement.
Suction Riser —
A suction riser condition exists when the outdoor unit is
located above the indoor (evaporator) unit and suction
vapor must flow vertically up to return to the compressor.
Oil return is a concern when the suction tube size is too
large to produce the minimum refrigerant velocity to
ensure oil return at minimum load conditions.
Check Table 7 for maximum suction tube size for 38AU
units at minimum load conditions. Consider suction speed
riser (reduced tube size for vertical segment only) or
double suction riser arrangement if the recommended
suction tube size does not provide necessary minimum
flowrates for this riser.
5
/
8
1-3/
8
5
/
8
1-3/81-5/81-5/
5
/
1-3/
5
/
5
8
8
8
8
/
8
1-3/81-5/
5
/
8
1-5/
8
8
38AU
13
Table 6 – 38AUD 16-25 Piping Recommendations (Two-Circuit Unit)
NOTE: 38AUD requires TWO sets of refrigeration piping
R-410A Equivalent Length
Ft 0-38 38-75 75-113 113-150 150-188
m 0-12 12-23 23-34 34-46 46-57
Linear Length
Ft 0-25 25-50 50-75 75-100 100-125
Model
38AUD*16 Liquid Line
38AUD*25 Liquid Line
38AU
Legend:
Equivalent
Length
Linear Length Typical linear tubing length (50% added to linear to define Equivalent L ength for this table)
Liquid Line Tubing size, inches OD.
Max Lift Maximum liquid lift (indoor unit ABOVE outdoor unit only), at maximum permitted liquid line pressure drop —
Suction Line Tube size, inches OD
Charge Charge Quantity, lbs. Calculated for both liquid line sizes (where applicable), but only with larger suction line size
NOTE: For applications with equivalent length greater than 188 ft (57 m) and/0r linear length greater than 125 ft (38 m),
m 0-8 8-15 15-23 23-30 30-38
1
/
2
Max Lift 25 50 75 100 125
Suction Line
Charge ea. (lbs)
Novation 11.7 13.8 15.7 17.6 19.6
RTPF 21.7 23.8 25.7 27.6 29.6
Max Lift 25 50 54 75 60 99 46 95
Suction Line 11/
Charge (lbs) 1219.3
Equivalent tubing length, including effects of refrigeration specialties devices
S Linear Length Less than 75 ft (23 m): Minimum 2.0° F subcooling entering TXV
S Linear Length Greater than 75 ft (23m): Minimum 0.5° F subcooling entering TXV
(where applicable)
contact your local Bryant representative.
7
/
8
1
/
2
18.3
8
1
/
2
11/
1
/
2
11/
21.0
20.3
1
/
2
8
8
11/
1
/
2
11/
23.0
22.0
8
5
8
26.0
25.0
1
/
2
11/
8
1
/
8
11/
25.9
24.9
/
2
8
5
13/813/
29.7
28.7
1
/
2
11/
8
1
/
8
28.0
27.0
5
/
2
8
32.7
31.7
/
8
Ta bl e 7 – 38AU Maximum Suction Pipe Size
Model: Unit Size Maximum Tube Size
38AUZ
38AUD
16 15/
25 15/
16 15/
25 15/
8
8
8
8
Vertical Separation (outdoor unit above indoor unit) –
Vertical elevation difference of 200 ft (60 m) is permitted
when the outdoor unit (38AUZ or 38AUD) is located
above the indoor unit.
Insulate Suction Lines —
Apply closed-cell tubular insulation to all suction lines
between evaporator coil connection and 38AU unit’s
suction service valve.
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 38AU units do not include
a hot gas stub connection; a tee must be field-supplied and
1
installed in the compressor discharge line. Run a
/2-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.
38AUD: Generally only one hot gas bypass system will be
applied on a two-circuit unit. Connect the hot gas bypass
system to Circuit 1 (first-on/last-off, connected to the
evaporator coil’s bottom circuit).
38AUD Piping Connections —
The 38AUD’s two circuits are designated Circuit 1 and
Circuit 2. Circuit 1 is controlled by the thermostat’s Y1 (or
TC1) contact and will be the first circuit on and last circuit
off. Circuit 2 is controlled by the thermostat’s Y2 (or TC2)
contact and this circuit is always the “lag” circuit.
See Fig. 6 for location of Circuit 1 and Circuit 2 service
valves and field piping connections. Circuit 1 is on the
left-hand side of the service valve compartment; Circuit 2
is on the right.
When a single piece evaporator coil with two separate
circuits is connected to a 38AUD, the lower coil circuit
should be connected to the 38AUD’s Circuit 1 so that the
evaporator’s lower coil segment is first-on/last-off (to avoid
re-evaporation of condensate on dry lower coil segments).
14
CKT
1
CKT
1
CKT
2
CKT
2
Circuit 1
Connections
38AU units include one (38AUZ) or two (38AUD)
Puron-duty filter drier(s), shipped in cartons attached to
the unit basepan. Remove the filter drier(s) and prepare to
install in the liquid line(s) at the evaporator coil. Do not
remove connection fitting plugs until ready to connect and
braze the filter drier into the liquid line position.
Circuit 2
Connections
1
C10355
Fig. 6 -- 38AUD Service Valve Locations
Plan the Circuit 1 and Circuit 2 tubing segments carefully,
mark each segment and check constantly as piping
systems are assembled to avoid piping errors.
38AUD unit cannot be field-piped as a
single-circuit/tandem system.
Connecting 40RU to 38AUD: The 40RU fan coil in sizes
16, 25 and 28 is a face-split coil design that also has its
circuits designated as 1 and 2. See Fig. 7. Note that the
lower coil segment changes as the arrangement of the
40RU changes. In a vertical arrangement, the 40RU’s
lower coil segment is segment 2; this segment should be
connected to the 38AUD’s Circuit 1. In a horizontal
arrangement, the 40RU’s lower segment is now segment
1; this segment should be connected to the 38AUD’s
Circuit 1.
Note that refrigerant suction piping should be insulated.
40RU
Arrangement
Vertical
Horizontal
Cooling
Stage
Y1
Y2
Y1
Y2
40RU Coil
Segment
2
1
1
2
Connect to
38AUD
Circuit 1
Circuit 2
Circuit 1
Circuit 2
Install Filter Drier(s) and Moisture Indicator(s) —
2
FIRS T ON/LA ST OFF = 2
VERTICAL INSTALLATION
2
1
FIRS T O N/LAS T OF F = 1
HORIZONTAL INSTALLATION
C10071
Fig. 7 -- Typical Evaporator Coil Connections (40RU)
Table 8 – Puron-duty Filter Drier(s)
Model-Size Qty
38AUZ*16 1
38AUZ*25 1
38AUD*16 2
38AUD*25 2
Liquid
Line OD
5
/8-in 30 cu. in. KH43LG087
5
/8-in 30 cu. in. KH43LG087
1
/2-in 16 cu. in. KH43LG085
1
/2-in 16 cu. in. KH43LG085
Desiccant
Volume
Part
Number Ref
38AU
Every unit MUST have a filter drier in the liquid line.
38AUD models require two filter driers (one in each
liquid line). Locate the filter drier(s) at the indoor unit,
close to the evaporator coil’s thermal expansion valve
(TXV) inlets.
Table 9 – Refrigerant Specialties Part Numbers.
LIQUID LINE
SIZE (in.)
1
/
2
5
/
8
38AUD units require TWO sets of parts.
LIQUID LINE
SOLENOID VALVE (LLSV)
EF680035 EF680037 KM680004
EF680036 EF680037 KM680005
Installation of liquid line moisture indicating sightglass in
each circuit is recommended. Locate the sightglass(es)
between the outlet of the filter drier and the TXV inlet.
Refer to Table 9 for recommendations on refrigeration
specialties.
LLSV
COIL
15
SIGHT
GLASS
FILTER
DRIER
provided with unit
see Table 8
8 DIAMS
MIN
8 DIAMS
MIN
8 DIAMS
EQUALIZER LINE
TXV
EQUALIZER LINE
TXV
CKT 2
SIGHT
GLASSES
B LOCATION
TXV
CKT 1
MIN
SIGHT GLASS
A LOCATION
FILTER
DRIERS
B LOCATION
FILTER DRIER
A LOCATION
LIQUID LINE
SOLENOID
VALVE
SIGHT GLASS
A LOCATION
INDOOR
COIL CKT
AIRFLOW
INDOOR
COIL CKT 2
AIRFLOW
INDOOR
COIL CKT 1
38AU
AIRFLOW
TXV
SENSING
BULB
15 DIAMS
10
MIN
DIAMS
Single Circuit Coil Piping Configuration
For single compressor condensing units
TXV
SENSING
BULB
15 DIAMS
10
MIN
DIAMS
TXV
SENSING
BULB
15 DIAMS
10
MIN
DIAMS
Dual Circuit Coil Piping Configuration
For single compressor condensing units
Fig. 8 -- Location of Sight Glass(es) and Filter Driers
Typical 38AUZ Systems
8 DIAMS
MIN
8 DIAMS
EQUALIZER LINE
TXV
CKT 2
TXV
CKT 1
MIN
SIGHT
GLASSES
FILTER
DRIERS
AIRFLOW
AIRFLOW
SUCTION
CIRCUIT 2
TXV
SENSING
BULB
15 DIAMS
15 DIAMS
SUCTION
CIRCUIT 1
10
MIN
DIAMS
TXV
SENSING
BULB
10
MIN
DIAMS
Dual Circuit Coil Piping Configuration
For two circuit condensing units
Fig. 9 -- Location of Sight Glasses and Filter Driers
Typical 38AUD Systems
In some applications, depending on space and convenience
requirements, it may be desirable to install 2 filter driers and
sight glasses in a single circuit application. One filter drier
and sight glass may be installed at A locations (see Fig. 8) or
2 filter driers and sight glasses may be installed at B
locations (see Figs. 8 and 9).
Select the filter drier for maximum unit capacity and
minimum pressure drop. Complete the refrigerant piping
FLOW
FILTER DRIER
A LOCATION
LIQUID LINE
SOLENOID
VALVE
LIQUID LINE
SOLENOID VALVE
CIRCUIT 2
LIQUID LINE
SOLENOID VALVE
CIRCUIT 1
FLOW
C10202
FLOW
FLOW
C10072
from the indoor unit to the outdoor unit before opening
the liquid and suction lines at the outdoor unit.
Install Liquid Line Solenoid Valve —
It is recommended that a solenoid valve be placed in the
main liquid line (see Figs. 8 & 9) between the condensing
unit and the evaporator coil. Locate the solenoid valve at the
outlet end of the liquid line, near the evaporator coil
connections, with flow direction arrow pointed at the
evaporator coil. Refer to Table 9. (A liquid line solenoid
valve is required when the liquid line length exceeds 75 ft
[23 m].) 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 Figs. 8 & 9).
This means of electrical control is referred to as solenoid
drop control.
Solenoid drop control wiring: Control the power to the
liquid line solenoid through a Solenoid Valve Relay (SVR)
in all units. Use part number HN61PC005 (field--supplied,
installed). 38AUZ unit requires one SVR; 38AUD unit
requires two relays.
38AUD unit also requires a separate control power
transformer for the liquid solenoid valve loads. Select
transformer part number according to unit power supply.
Unit Power Transformer Part #
208/230 HT01BD202
460 HT01BD702
575 HT01BD902
Mount the SVR (and transformer TRAN3 when used) in
unit control box. Connect per wiring schematic label on
unit or per Fig. 29 (38AUZ) or Fig. 30 (38AUD).
Capacity Control Liquid Line Solenoid Valve:
Evaporator capacity staging control via direct thermostat
control of a liquid solenoid valve on the evaporator’s
second stage circuit is not possible with 38AU models. If
this installation is a retrofit for a unit that included
automatic pressure--operated unloading, check the existing
thermostat and liquid solenoid valve wiring for possible
direct thermostat control of a solenoid valve; re--wire per
Figs. 17 or 18 and 29 or 30.
Selecting an Accumulator –
Because all 38AU models use scroll compressors, an
accumulator is not required. If an accumulator is to be
added, check the accumulator manufacturer’s literature
carefully for indication of its suitability for use with
R--410A; look for minimum working pressure of 200 psig
(1380 kPa). Select the accumulator first on the basis of its
cataloged minimum capacity (tons) to ensure oil return from
the accumulator, then on tube size or holding capacity.
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 has been completed.
16
The stub tube connections include1/4-in SAE service
A
fittings with Schrader valve cores (see Fig. 10). 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.
charging. For a cylinder without a dip tube, invert the
cylinder (access valve on the bottom) when removing
liquid refrigerant.
Because Puron (R--410A) refrigerant is a blend, it is
strongly recommended that refrigerant always be removed
from the cylinder as a liquid. Admit liquid refrigerant into
the system in the discharge line. If adding refrigerant into
the suction line, use a commercial metering/expansion
device at the gauge manifold; remove liquid from the
cylinder, pass it through the metering device at the gauge
set and then pass it into the suction line as a vapor. Do not
remove Puron (R–410A) refrigerant from the cylinder as a
vapor.
Preliminary Charge —
Factory
High-Flow
ccess Port
Field Service
Access Port
(Schrader core)
Before starting the unit, charge R-410A liquid refrigerant
Service Valve
with Stem Cap
Sweat
Connection
Fig. 10 -- Typical Piping Connection Assembly
C10203
into the high side of each 38AU circuit through the liquid
service valve(s). The amount of refrigerant added must be
at least 80% of the operating charge listed in Tables 5 or 6
for LINEAR line length LESS the factory charge quantity
(if factory shipping charge has not been removed). See
38AU
example below.
When connecting the field tubing to the 38AU service
valves, wrap the valves in wet rags to prevent overheating
Pressure-test all joints from outdoor unit connections over
to the evaporator coil, using nitrogen as pressure and with
soap-and-bubbles.
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
When pressure-testing is completed, remove the nitrogen
charging procedures.
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(s) (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.
!
WARNING
Example:
38AUD*25 (RTPF)
60-ft (18.3 m) linear line length
Equivalent line length 90-ft (27.4 m)
Liquid Lift: 20-ft (6.1 m)
Select line sizes from Table 6 (38AUD):
1
Liquid
Suction 1-
/2in
1
/8in.
Charge
Circuit 1: 23.0 lbs (at 75-ft linear length)
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal
injury, death and/or equipment damage.
R
Puron
(R--410A) refrigerant systems operate at
higher pressure than standard R--22 systems. Do not
use R--22 service equipment or components on Puron
refrigerant equipment.
Circuit 2: 22.0 lbs
80% of Operating Charge:
Circuit 1: 0.80 x 23.0 = 18.4 lbs
Circuit 2: 0.80 x 22.0 = 17.6 lbs
Factory Shipping Charge: 15 lbs
Field-Charge
Circuit 1: 18.4 -- 15 = 3.4 lbs
This unit is designed for use with Puron (R--410A)
refrigerant. Do not use any other refrigerant in this
system.
Puron (R--410A) refrigerant is provided in pink (rose)
colored cylinders. These cylinders are available with and
without dip tubes; cylinders with dip tubes will have a
label indicating this feature. For a cylinder with a dip
tube, place the cylinder in the upright position (access
valve at the top) when removing liquid refrigerant for
Circuit 2: 17.6 -- 15 = 2.6 lbs
For linear line lengths longer than 125 ft (38 m), contact
your local Carrier representative for system charge value.
Step 6 — Install Accessories
Accessories requiring modifications to unit wiring should
be completed now. These accessories may include Winter
Start controls and Low Ambient controls. Refer to the
instructions shipped with the accessory.
17
Step 7 — Complete Electrical Connections
!
WARNING
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.
!
WARNING
FIRE HAZARD
Failure to follow this warning could cause in personal
injury, death and/or equipment damage.
Do not connect aluminum wire between disconnect
switch and condensing unit. Use only copper wire.
(See Fig. 11.)
ELECTRIC
DISCONNECT
SWITCH
COPPER
WIRE ONLY
38AU
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 leads according to required operation
of the convenience outlet. If an always-energized
convenience outlet operation is desired, connect the
source leads to the line side of the unit-mounted
disconnect. (Check with local codes to ensure this method
is acceptable in your area.) If a de-energize via unit
disconnect switch operation of the convenience outlet is
desired, connect the source leads to the load side of the
unit disconnect. On a unit without a unit-mounted
disconnect, connect the source leads to compressor
contactor C and indoor fan contactor IFC pressure lugs
with unit field power leads..
Field power wires are connected to the unit at line-side
pressure lugs on compressor contactor C and TB1 (see
wiring diagram label for control box component
arrangement) or at factory-installed option non-fused
disconnect switch. Max wire size is #4 AWG (copper
only).
NOTE: TEST LEADS - Unit may be equipped with short
leads (pigtails) on the field line connection points on
contactor C or optional disconnect switch. These leads are
for factory run-test purposes only; remove and discard
before connecting field power wires to unit connection
points. Make field power connections directly to line
connection pressure lugs only.
ALUMINUM
WIRE
A93033
Fig. 11 -- Disconnect Switch and Unit
Units Without Factory-Installed Disconnect —
When installing units, provide a disconnect switch per
NEC (National Electrical Code) of adequate size.
Disconnect sizing data is provided on the unit informative
plate. Locate on unit cabinet or within sight of the unit per
national or local codes. Do not cover unit informative
plate if mounting the disconnect on the unit cabinet.
Units with Factory-Installed Disconnect —
The factory-installed option disconnect switch is located
in a weatherproof enclosure located under the main
control box. The manual switch handle is accessible
through an opening in the access panel.
All Units —
All field wiring must comply with NEC and all local
codes. Size wire based on MCA (Minimum Circuit Amps)
on the unit informative plate. See Fig. 12 for power wiring
connections to the unit contactor and terminal block and
equipment ground.
Provide a ground-fault and short-circuit over-current
protection device (fuse or breaker) per NEC Article 440
(or local codes). Refer to unit informative data plate for
MOCP (Maximum Over-current Protection) device size.
All units except 208/230-v units are factory wired for the
voltage shown on the nameplate. If the 208/230-v unit is
to be connected to a 208-v power supply, the control
transformer must be rewired by moving the black wire
with the
connection and moving it to the 208-v
1
/
-in. female spade connector from the 230-v
4
1
/
-in. male
4
terminal on the primary side of the transformer. Refer to
unit label diagram for line-side information.
18
Units Without Disconnect Option
CTB1
11 1 3
Disconnect
per
NEC
L1
L2 L3
208/230-3-60
460-3-60
575-3-60
Units With Disconnect Option
and mounted on a bracket behind the convenience outlet;
access is through the unit’s control box access panel. See
Fig. 13.
Convenience
Outlet
GFCI
Pwd-CO
Fuse
Switch
Pwd-CO
Transformer
L1
L2
L3
2
4
6
Optional
Disconnect
Switch
1
3
5
Factory
Wiring
Disconnect factory test leads; discard.
C10204
Fig. 12 -- Power Wiring Connections
Affix the crankcase heater warning sticker to the unit
disconnect switch.
Convenience Outlets —
!
WARNING
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal
injury or death.
Units with convenience outlet circuits may use
multiple disconnects. Check convenience outlet for
power status before opening unit for service. Locate
its disconnect switch, if appropriate, and open it.
Tag-out this switch, if necessary.
Control Box
Access Panel
C10205
Fig. 13 -- Convenience Outlet Location
The primary leads to the convenience outlet transformer are
not factory-connected. Selection of primary power source is
a customer-option. If local codes permit, the transformer
primary leads can be connected at the line-side terminals on
the unit-mounted non-fused disconnect switch; this will
provide service power to the unit when the unit disconnect
switch is open. Other connection methods will result in the
convenience outlet circuit being de-energized when the unit
disconnect is open. See Fig. 14.
38AU
Two types of convenience outlets are offered on 38AU
models: Non-powered and unit-powered. Both types
provide a 125-volt GFCI (ground-fault circuit-interrupter)
duplex receptacle rated at 15-A behind a hinged
waterproof access cover, located on the end panel of the
unit. See Fig. 13.
Non-powered type: This type requires the field
installation of a general-purpose 125-volt 15-A circuit
powered from a source elsewhere in the building. Observe
national and local codes when selecting wire size, fuse or
breaker requirements and disconnect switch size and
location. Route 125-v power supply conductors into the
bottom of the utility box containing the duplex receptacle.
Unit-powered type: A unit-mounted transformer is
factory-installed to stepdown the main power supply voltage
to the unit to 115-v at the duplex receptacle. This option also
includes a manual switch with fuse, located in a utility box
C10206
UNIT
VOLTAGE
CONNECT
AS
208,
230
460 480
575 600
240
PRIMARY
CONNECTIONS
L1: RED + YEL
L2: BLU + GRA
L1: RED
Splice BLU +
YEL
L2: GRA
L1: RED
L2: GRA
TRANSFORMER
TERMINALS
H1 + H3
H2 + H4
H1
H2 + H3
H4
H1
H2
Fig. 14 -- Powered Convenience Outlet Wiring
The unit-powered convenience outlet has a 1000 VA rated
transformer. Maximum continuous current must not
exceed 8 Amps.
19
NOTICE
Convenience Outlet Utilization
Maximum Continuous use : 8 Amps 24/7
Fig. 15 -- Convenience Outlet Utilization Notice Label
Test the GFCI receptacle by pressing the TEST button on
the face of the receptacle to trip and open the receptacle.
Check for proper grounding wires and power line phasing
if the GFCI receptacle does not trip as required. Press the
RESET button to clear the tripped condition.
Fuse on power type: The factory fuse is a Bussman
“Fusetron” T-15, non-renewable screw-in (Edison base)
type plug fuse.
38AU
!
WARNING
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal
injury or death.
Using unit-mounted convenience outlets: Units with
unit-mounded convenience outlet circuits will often
require that two disconnects be opened to de-energize
all power to the unit. Treat all units as electrically
energized until the convenience outlet power is also
checked and de-energization is confirmed. Observe
National Electrical Code Article 210, Branch Circuits,
for use of convenience outlets.
Installing Weatherproof Cover: A weatherproof while in
use cover for the factory installed convenience outlets is
now required by UL standards. This cover cannot be
factory mounted due its depth; it must be installed at unit
installation. For shipment, the convenience outlet is
covered with a blank cover plate.
The weatherproof cover kit is shipped in the unit’s control
box. The kit includes the hinged cover, a backing plate
and gasket.
DISCONNECT ALL POWER TO UNIT AND
CONVENIENCE OUTLET.
Remove the blank cover plate at the convenience outlet;
discard the blank cover.
Loosen the two screws at the GFCI duplex outlet, until
approximately
exposed. Press the gasket over the screw heads. Slip the
backing plate over the screw heads at the keyhole slots
and align with the gasket; tighten the two screws until
snug (do not overtighten).
1
/
in (13 mm) under screw heads are
2--
B50HJ542739
C10207
C09022
Fig. 16 -- Weatherproof Cover Installation
All Units —
Voltage to compressor terminals during operation must be
within voltage range indicated on unit nameplate. See
Tables 10 and 11. On 3-phase units, voltages between
phases must be balanced within 2% and the current within
10%. Use the formula shown in the legend for Tables 10
and 11, Note 5 (see page 22) to determine the percent of
voltage imbalance. Operation on improper line voltage or
excessive phase imbalance constitutes abuse and may
cause damage to electrical components. Such operation
would invalidate any applicable Carrier warranty.
Field Control Wiring —
38AU unit control voltage is 24 v. See Fig. 29 (38AUZ)
and Fig. 30 (38AUD) for typical field control connections
and the unit’s label diagram for field-supplied wiring
details. Route control wires to the 38AU unit through the
opening in unit’s end panel to the connections terminal
board in the unit’s control box.
Remainder of the system controls connection will vary
according to the specific construction details of the indoor
section (air handler or packaged fan coil). Fig. 17
(38AUZ) and Fig. 18 (38AUD) depict typical connections
to a Carrier 40RU fan coil unit. Plan for field connections
carefully and install control wiring correctly per the
project plan. Additional components and supplemental
transformer accessory may be required.
The 38AU unit requires an external temperature control
device. This device can be a thermostat (field-supplied) or
a PremierLink controller (available as a field-installed
accessory, for use on a Carrier Comfort Network or as a
stand alone control).
Mount the weatherproof cover to the backing plate as
shown in Fig. 16. Remove two slot fillers in the bottom of
the cover to permit service tool cords to exit the cover.
Check for full closing and latching.
20
Thermostat —
Install a Carrier-approved accessory thermostat according
to installation instructions included with the accessory.
Locate the thermostat accessory on a solid wall in the
conditioned space to sense average temperature in
accordance with the thermostat installation instructions.
The 38AUZ is a single-circuit, two--stage cooling unit.
Select a two—stage cooling thermostat, with or without
supplemental heating as needed.
The 38AUD is a dual--circuit, two-stage cooling unit.
Select a two—stage cooling thermostat, with or without
supplemental heating as needed.
Select a thermostat cable or equivalent single leads of
different colors with minimum of five leads for 38AUZ or
six leads for 38AUD unit. Check the thermostat
installation instructions for additional features which
might require additional conductors in the cable.
For wire runs up to 50 ft. (15 m), use no. 18 AWG
(American Wire Gage) insulated wire (35C minimum).
For50to75ft.(15to23m),useno.16AWGinsulated
wire (35C minimum). For over 75 ft. (23 m), use no. 14
AWG insulated wire (35C minimum). All wire sizes
larger than no. 18 AWG cannot be directly connected to
the thermostat and will require a junction box and splice
at the thermostat.
PremierLink (accessory installation) – Refer to Form
33CS-58SI for details on connecting the PremierLink
controller and its various sensors.
(Note 1)
(Note 3)
(Note 3)
(Note 2)
Note 1: Typical multi-function marking. Follow manufacturer’s configuration
instructions to select Y2.
Note 2: Connect only if thermostat requires 24-vac power source.
Note 3: Connect W1 and W2 if supplemental heaters are installed
Field Wiring
C10078
Fig. 18 -- Typical Remote Thermostat Connections
— 38AUD
Control Circuit Wiring —
Control voltage is 24 v. See Fig. 12 and the unit’s label
diagram for field--supplied wiring details. Route control
wires through the opening in unit’s end panel to the
connection in the unit’s control box.
38AU
(Note 1)
(Note 3)
(Note 3)
(Note 2)
Note 1: Typical multi-function marking. Follow manufacturer’s configuration
instructions to select Y2.
Note 2: Connect only if thermostat requires 24-vac power source.
Note 3: Connect W1 and W2 if supplemental heaters are installed
Field Wiring
C10208
Fig. 17 -- Typical Remote Thermostat Connections
— 38AUZ
Control Transformer Wiring —
On multi voltage units, check the transformer primary
wiring connections. See Fig. 19 or refer to the unit’s label
diagram.
If the unit will be operating at 208-3-60 power, remove
the black wire (BLK) from the transformer primary
connection labelled “230” and move it to the connection
labelled “208”. See Fig. 19.
C10079
Fig. 19 -- Control Transformer Wiring
21
Table 10 – Unit Wire/Fuse or HACR Breaker Sizing Data
NOMINAL
UNIT
SIZE
38AU
D*16
Z*16
D*25
Z*25
UNIT
SIZE
38AU
38AU
D*16
Z*16
D*25
Z*25
POWER
SUPPLY
V --- P h --- H z Min Max RLA LRA RLA LRA Qty
208/230---3- --60 187 253 25.0 164 25.0 164 3 1.5 60.8/60.8 80/80 63/63 337/337
4 6 0 --- 3 --- 6 0 414 506 12.2 100 12.2 100 3 0.8 29.9 40 31 206
5 7 5 --- 3 --- 6 0 518 633 9.0 78 9.0 78 3 0.7 22.4 30 23 162
208/230---3- --60 187 253 30.1 225 30.1 225 4 1.5 73.7/73.7 100/100 76/76 462/462
4 6 0 --- 3 --- 6 0 414 506 16.7 114 16.7 114 4 0.8 40.8 50 42 236
5 7 5 --- 3 --- 6 0 518 633 12.2 80 12.2 80 4 0.7 30.3 40 31 168
NOMINAL
POWER
SUPPLY
V --- P h --- H z Min Max RLA LRA RLA LRA Qty
208/230---3- --60 187 253 25.0 164 25.0 164 3 1.5 65.6/65.6 90/90 68/68 342/342
4 6 0 --- 3 --- 6 0 414 506 12.2 100 12.2 100 3 0.8 32.1 40 33 208
5 7 5 --- 3 --- 6 0 518 633 9.0 78 9.0 78 3 0.7 24.1 30 25 164
208/230---3- --60 187 253 30.1 225 30.1 225 4 1.5 78.5/78.5 100/100 82/82 467/467
4 6 0 --- 3 --- 6 0 414 506 16.7 114 16.7 114 4 0.8 43 50 45 238
5 7 5 --- 3 --- 6 0 518 633 12.2 80 12.2 80 4 0.7 32 40 33 170
VOLTAGE
RANGE
VOLTAGE
RANGE
COMPRESSOR NO C.O. or UNPWRD C.O.
No. 1 No. 2 OFM POWER SUPPLY DISCONNECT SIZE
MCA
MCA
FUSE or
HACR
BRKR
FUSE or
HACR
BRKR
FLA LRA
FLA LRA
FLA
(ea)
COMPRESSOR w/ PWRD C.O.
No. 1 No. 2 OFM POWER SUPPLY DISCONNECT SIZE
FLA
(ea)
Legend and Notes for Table 10
LEGEND:
BRKR --- Circuit breaker
CO --- Convenient outlet
F L A --- F u l l L oa d A m p s
LRA --- Locked Rotor Amps
MCA --- Minimum Circuit Amps
Protection
NEC --- National Electrical Code
PWRD CO --- Powered convenient outlet
RLA --- Rated Load Amps
UNPWR CO --- Unpowered convenient outlet
NOTES:
1. In compliance with NEC requirements for multimotor and
combination load equipment (refer to NEC Articles 430 and
440), the overcurrent protective device for the unit shall be
fuse or HACR breaker. Canadian units may be fuse or circuit
breaker.
2. The MCA values are calculated in accordance with The NEC.
Article 440.
3. Motor RLA and LRA values are established in accordance
with Underwriters’ Laboratories (UL). Standard 1995.
4 . T h e 5 75 --- v u n i t s a re U L , C an a d a --- l is t e d o n l y.
5. Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply
voltage is greater than 2%. Use the following formula to determine the percentage of voltage imbalance.
Example: Supply voltage is 230-3-60
% Voltage Imbalance = 100 x
max voltage deviation from average voltage
average voltage
AB = 224 v
BC = 231 v
AC = 226 v
Average Voltage =
(224 + 231 + 226)
= 227
3
=
681
3
Determine maximum deviation from average voltage.
(AB) 227 – 224 = 3 v
(BC) 231 – 227 = 4 v
(AC) 227 – 226 = 1 v
Maximum deviation is 4 v.
Determine percent of voltage imbalance.
% Voltage Imbalance = 100 x
= 1.76%
4
227
This amount of phase imbalance is satisfactory as it is below the
maximum allowable 2%.
IMPORTANT: If the supply voltage p h ase imbalance is more than
2%, contact your local electric utility company immediately.
22
PRE-START-UP
!
CAUTION
IMPORTANT: Before beginning Pre-Start-Up or
Start-Up, review Start-Up Checklist at the back of this
book. The Checklist assures proper start-up of a unit
and provides a record of unit condition, application
requirements, system information, and operation at
initial start-up.
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage.
Do not attempt to start the condensing unit, even
momentarily, until the following steps have been
completed. Compressor damage may result.
CAUTION
System Check
1. The electrical power source must agree with the unit’s
nameplate rating.
2. Check all air handler(s) and other equipment auxiliary
components. Consult the manufacturer’s instructions regarding any other equipment connected to the condensing unit. If the unit has field-installed accessories, be
sure all are properly installed and correctly wired. If
used, the airflow switch must be properly installed.
3. Check tightness of all electrical connections.
4. Be sure liquid line and low side of the system are
properly leak checked and dehydrated.
5. Be sure the unit is properly charged. See “Preliminary
Charge”, below.
6. Open the liquid line and suction line service valves.
7. The crankcase heater must be firmly attached to the
compressor crankcase. Be sure the crankcase is warm
(heater must be on for 24 hours before starting compressor).
Turn On Crankcase Heater —
Turn on the crankcase heater for 24 hours before starting
the unit to be sure all the refrigerant is out of the oil.To
energize the crankcase heater, proceed as follows:
1. Set the space thermostat set point above the space
temperature so there is no demand for cooling.
2. Close the field disconnect.
Preliminary Charge —
Before starting the unit, charge 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
through 2B, pages 6 through 9). Allow high and low side
pressures to equalize before starting compressor. If pressures
do not equalize readily, charge vapor on 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.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage.
Prior to starting compressor, a preliminary charge of
refrigerant must be added to avoid possible
compressor damage.
START-UP
38AU Units: The compressor crankcase heater must be on
for 24 hours before start-up. After the heater has been on
for 24 hours, the unit can be started. If no time elapsed
since the preliminary charge step was completed, it is
unnecessary to wait the 24-hour period.
Preliminary Checks
1. Check that electric power supply agrees with unit
nameplate data.
2. Verify that the compressor crankcase heater is securely in place.
3. Check that the compressor crankcase heater has been
on at least 24 hours.
4. Recheck for leaks using the procedure outlined in the
Pre-Start-Up section, Leak Test and Dehydration. If
any leaks are detected, repair as required. Evacuate
and dehydrate as described in the Leak Test and Dehydration section.
5. Ensure that the preliminary charge has been added as
described in the Pre-Start-Up section, Preliminary
Charge.
6. All internal wiring connections must be tight, and all
barriers and covers must be in place.
NOTE: The 38AU units are factory charged with the
required amount of oil. If recharging in required, use
Emkarate RL 32-3MAF for the 38AU units.
Compressor Rotation —
On 3--phase units with scroll compressors, it is important to
be certain that the compressor is rotating in the proper
direction. 38AU units are equipped with a Comfort Alert
Diagnostic Module (CADM). Alert Code 7 indicates reverse
power phasing.
To correct phase order:
1. Turn off power to the unit, tag disconnect.
2. Reverse any two of the unit power leads.
3. Reapply power to the compressor, verify correct pressures.
To verify the compressor is rotating in the proper
direction:
1. Connect service gages to the suction and liquid pressure fittings.
2. Energize the compressor.
3. The suction pressure should drop and the liquid pressure should rise, as is normal on any start--up.
38AU
23
Compressor Overload —
Start Unit
This overload interrupts power to the compressor when
either the current or internal motor winding temperature
becomes excessive, and automatically resets when the
internal temperature drops to a safe level. This overload
may require up to 60 minutes (or longer) to reset. If the
internal overload is suspected of being open, disconnect
the electrical power to the unit and check the circuit
through the overload with an ohmmeter or continuity
tester.
Advanced Scroll Temperature Protection (ASTP) —
A label located above the terminal box identifies Copeland
Scroll compressor models that contain this technology. See
Fig. 20. Advanced Scroll Temperature Protection (ASTP) is
a form of internal discharge temperature protection, that
unloads the scroll compressor when the internal temperature
reaches approximately 149_C (300_F). At this temperature,
an internal bi--metal disk valve opens and causes the scroll
38AU
elements to separate, which stops compression. Suction and
discharge pressures balance while the motor continues to
run. The longer the compressor runs unloaded, the longer it
must cool before the bi--metal disk resets. See Fig. 21.
Fig. 20 -- Advanced Scroll Temperature Protection Label
120
110
100
90
80
70
60
50
(Minutes)
40
30
20
Recommended Cooling Time*
10
0
0 10203040 6070809050
*Times are approximate.
NOTE: Various factors, including high humidity, high ambient
temperature, and the presence of a sound blanket will
increase cool-down times.
Compressor Unloaded Run Time (Minutes)*
Fig. 21 -- Recommended Minimum Cool-Down Time
After Compressor is Stopped
C10080
C10081
Set the space thermostat to a set point above space
temperature so that there is no demand for cooling. Close
the 38AU disconnect switch. Only the crankcase heater
will be energized.
Reset the space thermostat below ambient so that a call
for cooling is ensured.
!
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage.
Never charge liquid into the low-pressure side of
system. Do not overcharge. During charging or
removal of refrigerant, be sure indoor-fan system is
operating. Ensure both outdoor fan motors are
running; bypass any Motormaster function.
Adjust Refrigerant Charge —
Refer to Cooling Charging Charts, Fig. 23 through Fig. 28.
For applications with line lengths greater than 125 ft (38 m),
contact Carrier representative. Vary refrigerant until the
conditions of the chart are met. Note that the charging charts
are different from the type normally used. The charts are
based on charging the units to the correct subcooling for the
various operating conditions. Accurate pressure gage and
temperature sensing device are required. Connect the
pressure gage to the service port on the liquid line service
valve. Mount the temperature sensing device on the liquid
line close to the liquid line service valve, and insulate it so
that outdoor ambient temperature does not affect the reading.
Indoor airflow must be within the unit’s normal operating
range. Operate the unit for a minimum of 15 minutes.
Ensure that pressure and temperature readings have
stabilized. Plot the liquid pressure and temperature on chart
and add or reduce the charge to meet the curve. Adjust the
charge to conform with the charging chart, using the liquid
pressure and temperature to read the chart.
Using plotted operating point:
If plotted operating condition is --
Adjust charge by --
BELOW the curve REDUCE charge
ABOVE the curve ADD charge
To manually reset ASTP, the compressor should be
stopped and allowed to cool. If the compressor is not
stopped, the motor will run until the motor protector trips,
which occurs up to 90 minutes later. Advanced Scroll
Temperature Protection will reset automatically before the
motor protector resets, which may take up to 2 hours.
24
38AUZ*25 Check Compressor Oil Level —
After adjusting the refrigerant charge, allow the unit to
run fully loaded for 20 minutes. Stop the compressors and
1
check the oil level. Oil level should be
/3to1/2up on the
sight glass (see Fig. 22).
1
/2 (MAX)
1
/3 (MIN)
C01377
Fig. 22 -- Recommended Oil Level — 38AUZ*25
IMPORTANT: Oil level should only be checked
when the compressors are off.
Add oil only if necessary to bring the oil into view in the
sight glass. If oil is added, run the circuit for an additional
10 minutes, then stop and check oil level. If the level
remains low, check the piping system for proper design
for oil return; also, check the system for leaks. If checking
the oil level with unit running in part load, let unit run one
hour, then run at full load for 10 minutes. If oil does not
return to acceptable sight glass levels, check for correct
suction piping and line sizing.
Final Checks —
Ensure that all safety controls are operating, control panel
covers are on, and the service panels are in place.
38AU
Fig. 23 -- 38AUZ*16 Charging Chart (Novation)
25
C10945
(CIRCUIT 1)
38AU
(CIRCUIT 2)
Fig. 24 -- 38AUD*16 Charging Chart (Novation)
C10946
26
Fig. 25 -- 38AUZ*16 Charging Chart (RTPF)
38AU
C10947
Fig. 26 -- 38AUZ*25 Charging Chart (RTPF)
27
C10948
38AU
Fig. 27 -- 38AUD*16 Charging Chart (RTPF)
28
C10949
(CIRCUIT 1)
38AU
(CIRCUIT 2)
Fig. 28 -- 38AUD*25 Charging Chart (RTPF)
C10950
29
38AU
Fig. 29 -- Typical 38AUZ Wiring Diagram - (15 Ton 230V Tandem Unit Shown)
30
C10212A
38AU
Fig. 30 -- Typical 38AUD Wiring Diagram - (15 Ton 230V Dual Unit Shown)
31
C10213A
OPERATING SEQUENCE
Base Unit Controls
Indoor (Supply) Fan —
The indoor fan contactor (IFC) is remotely located at the fan
coil or fan section. If the thermostat fan operation is selected
as Continuous, the IFC is energized and the indoor (supply)
fan motor runs continuously. If the thermostat fan operation
is selected as Automatic, the IFC will be energized on a call
for Cooling; indoor (supply) fan motor runs. When
thermostat call for Cooling is satisfied, the IFC is
de-energized and indoor (supply) fan motor stops.
Cooling, Unit Without Economizer —
38AUZ (Single Circuit)
On a thermostat call for Cooling, IFC will be energized
and indoor (supply) fan motor runs. Thermostat output Y1
38AU
is energized; terminal Y1 at 38AUZ unit receives 24-v.
24-v received at CADM1 terminal Y. If anti-recycle time
delay period has not expired, CADM1 relay will remain
open, de-energizing Solenoid Valve Relay (SVR) and
preventing compressor start. When safety pressure
switches are closed and CADM1 time delay expires,
CADM1 relay closes, SVR and compressor contactor C1
are energized; liquid line solenoid valve LLSV opens, all
outdoor fan motors start and Compressor 1 starts.
On a thermostat calling for Stage 2 Cooling, thermostat
output Y2 is energized; terminal Y2 at 38AUZ unit
receives 24-v. 24-v received at CADM2 terminal Y. If
anti-recycle time delay period has not expired, CADM2
relay will remain open, preventing Compressor 2 start.
When safety pressure switches are closed and CADM2
time delay expires, CADM2 relay closes, compressor
contactor C2 is energized; Compressor 2 starts.
As space cooling load is satisfied, thermostat outputs Y2
and Y1 are de--energized, removing 24-v at 38AUZ
terminals Y2 and Y1. Compressor 2 stops on Y2 opening.
CADM2 begins its three-minute anti-recycle time delay.
On Y1 opening, Compressor 1 stops, all outdoor fan
motors stop and SVR relay is de-energized. Liquid line
solenoid valve is de-energized and valve closes. CADM1
begins its three-minute anti-recycle time delay.
38AUD (Two Circuit)
On a thermostat call for Cooling, IFC will be energized
and indoor (supply) fan motor runs. Thermostat output Y1
is energized; terminal Y1 at 38AUD unit receives 24-v.
24-v received at CADM1 terminal Y. If anti-recycle time
delay period has not expired, CADM1 relay will remain
open, de-energizing Solenoid Valve Relay 1 (SVR1) and
preventing compressor start. When safety pressure
switches are closed and CADM1 time delay expires,
CADM1 relay closes, SVR1 and compressor contactor C1
are energized; liquid line solenoid valve LLSV1 opens, all
outdoor fan motors start and Circuit 1 compressor starts.
On a thermostat calling for Stage 2 Cooling, thermostat
output Y2 is energized; terminal Y2 at 38AUD unit
receives 24-v. 24-v received at CADM2 terminal Y. If
anti-recycle time delay period has not expired, CADM2
relay will remain open, de-energizing Solenoid Valve
Relay 2 (SVR2) and preventing compressor start. When
safety pressure switches are closed and CADM2 time
delay expires, CADM2 relay closes, SVR2 and
compressor contactor C2 are energized; liquid line
solenoid valve LLSV2 opens and Circuit 2 compressor
starts.
As space cooling load is satisfied, thermostat outputs Y2
and Y1 are de--energized, removing 24-v at 38AUD
terminals Y2 and Y1. Circuit 2 compressor stops on Y2
opening; SVR2 is de-energized and LLSV2 closes.
CADM2 begins its three-minute anti-recycle time delay.
On Y1 opening, Circuit 1 compressor stops, all outdoor
fan motors stop and SVR1 relay is de-energized. Liquid
line solenoid valve LLSV1 is de-energized and valve
closes. CADM1 begins its three-minute anti-recycle time
delay.
All Units
If either the Low Pressure Switch or High Pressure Switch
opens while thermostat output Y1 or Y2 remain energized,
the compressor contactor is de-energized, the compressor
stops and liquid line solenoid is de-energized (valve
closes). CADM initiates a TRIP event (cooling demand
sensed at CADM terminal Y but no current is measured at
T1, T2, T3 motor sensors); CADM relay opens and RED
LED is illuminated. TRIP condition maintains lockout of
compressor operation until CADM is manually reset.
Reset CADM by cycling unit main power.
Complete system shutdown may be caused by loss of
main power, open compressor internal overload, open
low-pressure or high-pressure switch, or a fault detected
by the CADM logic. Compressor operation without
cooling may indicate the compressor’s ASTP feature is
active; disconnect unit power and allow compressor to
cool. See Service section for further details.
Cooling, Unit With Economizer —
Refer to fan coil unit installation instructions and
economizer accessory installation instructions for
operating sequences when system is equipped with
accessory economizer.
Heating —
Refer to fan coil unit installation instructions and accessory
heating device installation instructions for operating
sequences in heating mode.
32
ROUTINE SYSTEM MAINTENANCE
SERVICE
These items should be part of a routine maintenance
program, to be checked every month or two, until a specific
schedule for each can be identified for this installation:
Quarterly Inspection (and 30 days after initial start) —
Indoor section
S Condenser coil cleanliness checked.
S Return air filter replacement
S Outdoor hood inlet filters cleaned
S Belt tension checked
S Belt condition checked
S Pulley alignment checked
S Fan shaft bearing locking collar tightness checked
S Condensate drain checked
Seasonal Maintenance —
These items should be checked at the beginning of each
season (or more often if local conditions and usage patterns
dictate):
Air Conditioning
S Condenser fan motor mounting bolts tightness
S Compressor mounting bolts
S Condenser fan blade positioning
S Control box cleanliness and wiring condition
S Wire terminal tightness
S Refrigerant charge level
S Evaporator coil cleaning
S Evaporator blower motor amperage
Heating
S Power wire connections
S Fuses ready
S Manual-reset limit switch is closed
Economizer or Outside Air Damper
S Inlet filters condition
S Check damper travel (economizer)
S Check gear and dampers for debris and dirt
Refrigeration System
!
CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in damage to
equipment.
This system uses Puron
pressures than R-22 and other refrigerants. No other
refrigerant may be used in this system. Gage set,
hoses, and recovery system must be designed to
handle Puron. If you are unsure consult the equipment
manufacturer.
Compressor Oil —
!
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in damage to
equipment.
The compressor in a Puron system uses a polyolester
(POE) oil. This oil is extremely hygroscopic, meaning
it absorbs water readily. POE oils can absorb 15 times
as much water as other oils designed for HCFC and
CFC refrigerants. Take all necessary precautions to
avoid exposure of the oil to the atmosphere.
Servicing Systems on Roofs With Synthetic Materials —
POE (polyolester) compressor lubricants are known to cause
long term damage to some synthetic roofing materials.
Exposure, even if immediately cleaned up, may cause
embrittlement (leading to cracking) to occur in one year or
more. When performing any service which may risk
exposure of compressor oil to the roof, take appropriate
precautions to protect roofing. Procedures which risk oil
leakage include but are not limited to compressor
replacement, repairing refrigerants leaks, replacing
refrigerant components such as filter drier, pressure switch,
metering device, coil, accumulator, or reversing valve.
Synthetic Roof Precautionary Procedure:
1. Cover extended roof working area with an impermeable polyethylene (plastic) drop cloth or tarp.
Cover an approximate 10 x 10 ft (3.3 x 3.3 m) area.
2. Cover area in front of the unit service panel with a
terry cloth shop towel to absorb lubricant spills and
prevent run-offs, and protect drop cloth from tears
caused by tools or components.
3. Place terry cloth shop towel inside unit immediately under component(s) to be serviced and prevent lubricant
run-offs through the louvered openings in the base pan.
4. Perform required service.
5. Remove and dispose of any oil contaminated material
per local codes.
R
refrigerant which has higher
CAUTION
38AU
33
Liquid Line Filter Drier —
Factory High-Flow Access Ports —
The factory-provided filter drier is specifically designed to
operate with Puron
®
. Replace the filter drier with
factory-authorized components only with a filter drier
with desiccant made from 100% molecular sieve grade
XH-11. Filter drier must be replaced whenever the
refrigerant system is opened.
When removing a filter drier, use a tubing cutter to cut the
drier from the system. Do not unsweat a filter drier from
the system. Heat from unsweating will release moisture
and contaminants from drier into system.
Field Refrigerant Access Ports —
Field service access to refrigerant pressures is through the
access ports located at the service valves (see Figs 34 and
38). These ports are
1
/4-in SAE Flare couplings with
Schrader check valves and service caps. Use these ports to
admit nitrogen to the field tubing during brazing, to
38AU
evacuate the tubing and evaporator coil, to admit initial
refrigerant charge into the low-side of the system and
when checking and adjusting the system refrigerant
charge. When service activities are completed, ensure the
service caps are in place and secure; check for leaks. If
the Schrader check valve must be removed and
re-installed, tighten to 2-3 in-lbs (23-34 N-cm).
There are two additional access ports in the system - on
the suction tube between the compressor and the suction
service valve and on the liquid tube near the liquid service
valve (see Figs 35 and 39). These are brass fittings with
black plastic caps. The hose connection fittings are
standard
1
/4-in SAE Male Flare couplings.
The brass fittings are two-piece High Flow valves, with a
receptacle base brazed to the tubing and an integral
spring-closed check valve core screwed into the base. (See
Fig. 31) This check valve is permanently assembled into
this core body and cannot be serviced separately; replace
the entire core body if necessary. Service tools are
available from RCD that allow the replacement of the
check valve core without having to recover the entire
system refrigerant charge. Apply compressor refrigerant
oil to the check valve core’s bottom o-ring. Install the
fitting body with 96 ±-10 in-lbs (1085 ±23 N-cm) of
torque; do not overtighten.
5/8” HEX
SEAT
.47
CORE
(Part No. EC39EZ067)
1/2-20 UNF RH
0.596
30°
WASHER
O-RING
This surface provides a metal to metal seal when
torqued into the seat. Appropriate handling is
required to not scratch or dent the surface.
1/2" HEX
Fig. 31 -- CoreMax Access Port Assembly
45°
DEPRESSOR PER ARI 720
+.01/-.035
FROM FACE OF BODY
7/16-20 UNF RH
C08453
34
Comfort Alert Diagnostic Module
The Comfort Alert Diagnostic Module (CADM) monitors
and analyzes data from the Copeland Scroll® three-phase
compressor and the thermostat demand. The CADM also
provides a 3-minute anti-recycle time delay to compressor
cycling. Each compressor has a separate CADM module.
The CADM detects causes for electrical and system
related failures without any sensors. Flashing LEDs
communicate the Alert codes to guide service technicians
in accurately and quickly troubleshooting the system and
determining root cause for the failure.
POWER
(GRN)
ALERT
(YEL)
Inputs to the CADM include 24-vac power, thermostat Y1
or Y2, compressor contactor coil (common side) and
compressor power leads (from the compressor contactor).
Input Te r mi n al Voltage
Control
Power
Control
Common
Cooling Y 24-V
Contactor
Coil
Line A T1 Line
Line B T2 Line
Line C T3 Line
R 24-V
C 24-V
P 24-V
Control of the compressor contactor coil is through a
normally-closed (power on the module) contact between
terminals P and C.
Communications of status and alert conditions is through
three LEDs located on the top edge of the module housing
(see Fig. 32): POWER (green), ALERT (yellow), and
TRIP (red).
The POWER LED indicates the presence of control power
to the CADM.
TRIP
(RED)
C10086
Fig. 32 -- CADM Housing/LED Locations
The TRIP LED indicates either a time-delay period is
currently active (RED LED is blinking) or the module has
locked out the compressor (RED LED is on steady). A
lockout condition will occur when the CADM detects a
thermostat demand at input Y but there is no power at the
compressor line terminals T1 or T2 or T3. This lockout
can occur due to a safety switch (LPS or HPS) opening
and de-energizing the compressor contactor, the
compressor-motor internal overload opens, or other
internal power interruption has occurred. Reset of the
TRIP LED requires that unit main power be recycled after
the loss of power to the compressor condition has been
detected and corrected.
Simultaneous Blinking of YELLOW and RED LEDs
indicates control power input to the CADM is low. Check
control circuit transformer and wiring.
Troubleshooting the CADM Wiring – Flashing LEDs also
indicate wiring problems to the CADM. See Table 12 for
discussion of additional LED flash codes and
troubleshooting instructions.
38AU
The ALERT LED indicates an abnormal condition exists
in the system through a flash code. The ALERT LED will
blink a number of times consecutively, pause and the
repeat the process. The number of blinks, defined in Table
11, correlates to a particular abnormal condition;
troubleshooting tips are provided for each Alert code.
Reset of the ALERT may be automatic or manual. If the
fault condition causing the Alert is self-corrected, the
Alert code will be removed and the CADM will
automatically reset and allow the system to restart
normally. Manual reset requires that main power to the
38AU unit be recycled after the cause for the Alert
condition has been detected and corrected.
35
Table 11 – LED Status Codes
Status LED Status LED Description Status LED Troubleshooting Information
Green “POWER” Module has power Supply voltage is present at module terminals
Red “TRIP”
LED On Solid
Red “TRIP” LED
Flashing
Module locks out compressor when compressor damaging ALERT code appears.
Lockout ALERT codes are noted in the Status LED Description.
During a compressor lock out, 24VAC power must be removed from module to manually reset.
Yellow “ALERT”
LED On Solid
Thermostat demand signal
Y is present, but the compressor is not running.
The anti-short cycle timer (3 minutes) in module is preventing compressor restart.
A short circuit or over current condition exists on
PROT terminal.
38AU
Yellow “ALERT”
Flash Code 2
Yellow “ALERT”
Flash Code 3
Yellow “ALERT”
Flash Code 4
Yellow “ALERT”
Flash Code 5
Yellow “ALERT”
Flash Code 6
Yellow “ALERT”
Flash Code 7
Yellow “ALERT”
Flash Code 8
Yellow “ALERT”
Flash Code 9
System Pressure Trip
Discharge pressure out of
limits or compressor overload (if no high pressure
switch in system)
LOCKOUT
Short Cycling
Compressor is running only
briefly (four consecutive
cycles of less than three
minutes each)
LOCKOUT
Locked Rotor
LOCKOUT
Open Circuit
Missing Phase
LOCKOUT
Reverse Phase
LOCKOUT
Welded C ontactor
Compressor always runs
Low Voltage
Control circuit < 18VAC
1. Compressor protector is open
2. Condensing unit power disconnect is open
3. Compressorcircuitbreakerorfuse(s)isopen
4. Broken supply wires or connector is not making contact
5. Compressor power wires not routed through Comfort Alert
6. Compressor contactor has failed open
1. Compressor contactor coil shorted
2. Electrical load too high for PROT circuit (maximum 1 Amp)
3. 24 V AC wired directly to PROT terminal
1. High head pressure
2. Condenser coil poor air circulation (dirty, blocked, damaged)
3. Condenser fan is not running
4. If low pressure switch is open: Refer to Code 3 for troubleshooting
1. If low pressure switch is open:
a. Low refrigerant charge
b. Evaporator blower is not running
c. Evaporator coil is frozen
d. Faulty metering device
e. Condenser coil is dirty
f. Liquid line restriction (filter drier blocked if present)
2. If high pressure switch is open, go to Flash Code 2 information
3. Intermittent thermostat demand signal
4. System or control board defective
1. Low line voltage to compressor
2. Excessive liquid refrigerant in compressor
3. Compressor bearings are seized
1. Condensing unit power disconnect is open
2. Compressorcircuitbreakerorfusesareopen
3. Compressor contactor has failed open
4. High pressure switch is open and requires manual reset
5. Broken supply wires or connector is not making contact
6. Unusually long compressor protector reset time due to extreme
ambient temperature
7. Compressor windings are damaged
1. Compressorfuseisopenononephase
2. Broken wire or connector on one phase
3. Compressor motor winding is damaged
4. Utility supply has dropped one phase
1. Compressor running backward due to supply phase reversal
1. Compressor contactor has failed closed
2. Thermostat demand signal not connected to module
1. Control circuit transformer is overloaded
2. Low line voltage to compressor
36
Table 12 – CADM Troubleshooting
Miswired Module Indication Recommended Troubleshooting Action
Green LED is not on,
module does not power up
Green LED Intermittent,
module powers up only
when compressor runs
TRIP LED is on but system
and compressor check OK
TRIP LED and ALERT LED
flashing together
ALERT Flash Code 3
(Compressor Short Cycling)
displayed incorrectly
ALERT Flash Code 5 or 6
(Open Circuit, Missing Phase)
displayed incorrectly
Alert Flash Code *
(Welded Contactor)
displayed incorrectly
Determine if both R and C module terminals are connected. Verify voltage in present at module’s R
and C terminals.
NOTE: The CADM requires a constant nominal 24VAC power supply. The wiring to the module’s R
and C terminals must be directly from the control transformer. The module cannot receive its power
from another device that will interrupt the 24VAC power supply. See the 38AU Wiring Diagram(s)
(Fig. 29 and Fig. 30).
Determine if R and Y terminals are wired in reverse. Verify module’s R and C terminals have a constant source. See “NOTE” above for details on R and C wiring.
Verify Y terminal is wired properly per the 38AU wiring diagram (see Fig. 29 and Fig. 30). Verify
voltage at contactor coil falls below 0.5VAC when off. Verify 24VAQC is present across Y and C
when thermostat demand signal is present. If not, R and C are reverse wired.
Verify R and C terminals are supplied with 19-28VAC.
Verify Y terminal is connected to 24VAC at contactor coil. Verify voltage at contactor coil falls below
0.5VAC when off.
Check that compressor T1 and T3 wires are through module’s current sensing holes. Verify Y terminal is connected to 24VAC at contactor coil. Verify voltage at contactor coil falls below 0.5VAC
when off.
Determine if module’s Y terminal is connected. Verify Y terminal is connected to 24VAC at contactor
coil. Verify 24VAC is present across Y and C when thermostat demand signal is present. If not, R
and C are reverse wired. Verify voltage at contactor coil falls below 0.5VAC when off.
38AU
Compressor Protection
Compressor Overtemperature Protection (IP) —
A thermostat installed on the compressor motor winding
reacts to excessively high winding temperatures and shuts
off the compressor.
CrankcaseHeater—
The heater minimizes absorption of liquid refrigerant by
oil in the crankcase during brief or extended shutdown
periods. The heater is wired to cycle with the compressor;
the heater is off when compressor is running, and on when
compressor is off.
The crankcase heater will operate as long as the power
circuit is energized. The main disconnect must be on to
energize the crankcase heater.
IMPORTANT: Never open any switch or disconnect
that energizes the crankcase heater unless unit is
being serviced or is to be shut down for a prolonged
period. After a prolonged shutdown on a service job,
energize the crankcase heater for 24 hours before
starting the compressor.
Advanced Scroll Temperature Protection (ASTP) —
See “Advanced Scroll Temperature Protection (ASTP)” on
page 24.
Low-Pressure Switch —
The 38AU low-pressure switch is stem-mounted on the
suction line. Switches are all fixed, non-adjustable type.
High--Pressure Switch —
The high--pressure switch is stem mounted on the
discharge line. The switch is a fixed, non-adjustable type.
Outdoor Fans —
Each fan is supported by a formed-wire mount bolted to
the fan deck and covered with a wire guard. Fan motors
have permanently lubricated bearings.
1. Shut off unit power supply. Install lockout tag.
2. Remove outdoor fan assembly (grille, motor, and fan).
3. Loosen fan hub setscrews.
4. Adjust fan height as shown in Fig. 33.
5. Tighten setscrews to 84 in--lbs (949 N--cm).
6. Replace outdoor fan assembly.
3.6 mm +0/0/-0.8
C10103
Fig. 33 -- Outdoor Fan Blade Position
Lubrication —
Fan Motors: The fan motors have sealed bearings. No
provisions are made for lubrication.
Compressor: The compressor has its own oil supply. Loss
of oil due to a leak in the system should be the only
reason for adding oil after the system has been in
operation.
37
Condenser Fans/Motors
38AU
Access Panel Control Box &
Compressors
Service
Valves
C10087
Fig. 34 -- 38AUD Size 16 Cabinet
Fig. 35 -- 38AUD*16 Piping
38
C10095
Oil Equalizer Line
Equalization
LPS
38AU
Fig. 36 -- 38AUZ*16 Compressor Assembly (Rear View)
C10079
Fig. 37 -- 38AUD*16 Compressor Assembly (Rear View)
39
C10214
Condenser Fans/Motors
38AU
Access Panel Control Box &
Compressors
Service
Valves
C10089
Fig. 38 -- 38AUZ,D Size 25 Cabinet
CKT
CKT
1
CKT
HPS
1
LPS
C10090
2
HPS
LPS
CKT
2
Fig. 39 -- 38AUD*25 Piping
40
Fig. 40 -- 38AUZ*25 Compressor Assembly (Rear View)
38AU
C10215
Fig. 41 -- 38AUD*25 Compressor Assembly (Rear View)
41
C10091
Coil Type Identification
38AU units are available with different coil types. Cleaning
methods differ for each type so identifying the coil type is
important. Unit model number and appearance can identify
the coil type.
NOVATIONt Type —
The new NOVATION Heat Exchanger Technology is an
all--aluminum construction with louvered serpentine fins
over single--depth crosstubes. The horizontal crosstubes have
large diameter aluminum headers on each end. Various
optional coatings are also available.
38AU units use two--row segmented coils.
TUBES
FINS
38AU
MICROCHANNELS
Fig. 42 -- NOVATION Heat Exchanger Coil
Model number designation: See Fig. 3 for general unit
model number format. Position 11 indicates the coil type
and coating. Position 11 values of G, K, T and W indicate
NOVATION coil type is on this unit.
Round--Tube Plate--Fin (RTPF) Type —
This construction uses a series of small diameter copper
hairpin tubes running horizontally with vertical plate fins.
The plate fins may be aluminum (standard) or copper
(optional). Various optional coatings are also available.
These coils may be one--row or two--row.
Model number designation: See Fig. 3 for general unit
model number format. Position 11 indicates the coil type
and coating. Position 11 values of A, B, C, M, N and P
indicate RTPF coil type is on this unit.
NOVATION Coil Cleaning and Maintenance —
MANIFOLD
C07273
C10216
Fig. 43 -- Pivot and Support Top Cover
3. Carefully remove any foreign objects or debris attached to the coil face or trapped within the mounting
frame and brackets.
4. Using a high pressure water sprayer, purge any soap
or industrial cleaners from hose and/or dilution tank
prior to wetting the coil. Clean condenser face by
spraying the coil core steadily and uniformly from top
to bottom, directing the spray straight into or toward
the coil face. Do not exceed 900 psig or a 45 degree
angle; nozzle must be at least 12 in. (30 cm) from the
coil face. Reduce pressure and use caution to prevent
damage to air centers (fins). Do not fracture the braze
between air centers and refrigerant tubes. Allow water
to drain from the coil core and check for refrigerant
leaks prior to start?up.
5. Replace top cover and rear corner posts.
!
CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage.
Chemical cleaning should NOT be used on the
aluminum microchannel (NOVATION) condenser.
Damage to the coil may occur. Only approved
cleaning is recommended.
To clean the NOVATION condenser coil, chemicals are
NOT to be used; only water is approved as the cleaning
solution. Only clean potable water is authorized for cleaning
NOVATION condensers.
Clean the coil as follows:
1. Turn off unit power.
2. Remove screws holding rear corner posts and top cover
in place. Pivot top cover up 12 to 18 in. (305 to 457
mm) and support with a rigid support. See Fig. 43.
Repairing NOVATION Condenser Tube Leaks —
RCD offers service repair kit Part Number 50TJ660007 for
repairing tube leaks in the NOVATION coil crosstubes. This
kit includes approved braze materials (aluminum fluxcore
braze rods), a heat shield, a stainless steel brush, replacement
fin segments, adhesive for replacing fin segments, and
instructions specific to the NOVATION aluminum coil. See
EPIC for instruction sheet 99TA526379.
The repair procedure requires the use of MAPP gas and
torch (must be supplied by servicer) instead of conventional
42
oxyacetylene fuel and torch. While the flame temperature
for MAPP is lower than that of oxyacetylene (and thus
provides more flexibility when working on aluminum), the
flame temperature is still higher than the melting
temperature of aluminum, so user caution is required. Follow
instructions carefully. Use the heat shield.
Replacing NOVATIONt Condenser Coil —
The service replacement coil is preformed and is equipped
with transition joints with copper stub tubes. When
brazing the connection joints to the unit tubing, use a wet
cloth around the aluminum tube at the transition joint.
Avoid applying torch flame directly onto the aluminum
tubing.
Routine Cleaning of Round-Tube Plate Fin (RTPF)
Coils —
®
Periodic cleaning with Totaline
cleaner is essential to extend the life of RTPF coils. This
cleaner is available from Carrier Replacement parts division
as part number P902-0301 for a one gallon container, and
part number P902-0305 for a 5 gallon container. It is
recommended that all RTPF coils be cleaned with the
Totaline environmentally sound coil cleaner as described
below.
NOTE: Do NOT use Totaline
cleaner, or any other coil cleaner on NOVATION coils. See
“NOVATION Coil Cleaning and Maintenance” for
instructions on cleaning NOVATION coils.
Coil cleaning should be part of the unit’s regularly
scheduled maintenance procedures to ensure long life of
the coil. Failure to clean the coils may result in reduced
durability in the environment.
Avoid the use of:
S coil brighteners
S acid cleaning prior to painting
S high pressure washers
S poor quality water for cleaning
Totaline environmentally sound coil cleaner is
non-flammable, hypoallergenic, non-bacterial, and a
USDA accepted biodegradable agent that will not harm
the coil or surrounding components such as electrical
wiring, painted metal surfaces, or insulation. Use of
non-recommended coil cleaners is strongly discouraged
since coil and unit durability could be affected.
Totaline Environmentally Sound Coil Cleaner
Application Equipment —
1
/2gallon garden sprayer
S 2
S water rinse with low velocity spray nozzle
environmentally sound coil
®
environmentally sound coil
!
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in corrosion
and damage to the unit.
Harsh chemicals, household bleach or acid or basic
cleaners should not be used to clean outdoor or indoor
coils or any kind. These cleaners can be very difficult
to rinse out of the coil and can accelerate corrosion at
the fin/tube interface where dissimilar materials are in
contact. If there is dirt below the surface of the coil
use the Totaline environmentally sound coil cleaner as
described above.
!
CAUTION
UNIT RELIABILITY HAZARD
Failure to follow this caution may result in reduced
unit performance.
High velocity water from a pressure washer, garden
hose, or compressed air should never be used to clean
a coil. The force of the water or air jet will bend the
fin edges and increase airside pressure drop.
Totaline Environmentally Sound Coil Cleaner
Application Instructions:
NOTE: Proper eye protection such as safety glasses is
recommended during mixing and application.
1. Turn off unit power.
2. Remove screws holding rear corner post and top cover
in place. Pivot top cover up 12 to 18 inches (305 to 457
mm) and support with a rigid support. See Fig. 43.
3. Remove all surface loaded fibers and dirt with a vacuum cleaner. If a vacuum cleaner is not available, a
soft non-metallic bristle brush may be used. In either
case, the tool should be applied in the direction of the
fins. Coil surfaces can be easily damaged (fin edges
can be easily bent over and damage to the coating of
a protected coil) if the tool is applied across the fins.
NOTE: Use of a water stream, such as a garden hose,
against surface loaded coil will drive the fibers and dirt
into the coil, making cleaning efforts more difficult.
Surface loaded fibers must be completely removed prior
to using low velocity clean water rinse.
4. Using a low velocity garden hose thoroughly wet
finned surfaces with clean water. Be careful not to
bend the fins.
5. Mix Totaline environmentally sound coil cleaner in a
1
/2gallon garden sprayer according to the instruc-
2
tions included with the cleaner. The optimum solution
temperature is 100°F(38°C).
NOTE: Do NOT USE water in excess of 130°F(54°C),
as the enzymatic activity will be destroyed.
®
6. Thoroughly apply Totaline
coil cleaner solution to all coil surfaces including the
finned area, tube sheets and coil headers.
environmentally sound
38AU
43
7. Hold garden sprayer nozzle close to finned areas and
apply cleaner with a vertical, up-and-down motion.
Avoid spraying in horizontal pattern to minimize potential for fin damage.
8. Ensure cleaner thoroughly penetrates deep into finned
areas.
9. Interior and exterior finned areas must be thoroughly
cleaned.
10. Finned surfaces should remain wet with cleaning
solution for 10 minutes.
11. Ensure surfaces are not allowed to dry before rinsing.
Reapply cleaner as needed to ensure 10-minute saturation is achieved.
12. Thoroughly rinse all surfaces with low velocity clean
water using downward rinsing motion of water spray
nozzle. Protect fins from damage from the spray
nozzle.
13. Replace top cover and rear corner posts.
38AU
TROUBLESHOOTING
PROBLEM SOLUTION
COMPRESSOR DOES NOT RUN
Contactor Open
1. Power off. 1. Restore power.
2. Fuses blown in field power circuit. 2. After finding cause and correcting, replace with correct size fuse.
3. No control power. 3. Check control transformer primary connections and circuit breaker.
4. Thermostat circuit open. 4. Check thermostat setting.
5. Safety device lockout circuit active. 5. Reset lockout circuit.
6. Low-pressure switch open. 6. Check for refrigerant undercharge, obstruction of indoor airflow. Make
7. High-pressure switch open. 7. Check for refrigerant overcharge, obstruction of outdoor airflow, air in system.
8. Compressor overtemperature switch open. 8. Check for open condition. Allow for reset. Replace compressor if necessary
9. Loose electrical connections. 9. Tighten all connections.
10. Compressor stuck. 10. See compressor service literature.
Contactor Closed
1. Compressor leads loose. 1. Check connections.
2. Motor windings open. 2. See compressor service literature.
3. Single phasing. 3. Check for blown fuse. Check for loose connection at compressor terminal.
COMPRESSOR STOPS ON HIGH-PRESSURE SWITCH
Outdoor Fan On
1. High-pressure switch faulty. 1. Replace switch.
2. Reversed fan rotation. 2. Confirm rotation, correct if necessary.
3. Airflow restricted. 3. Remove obstruction.
4. Air recirculating. 4. Clear airflow area.
5. Noncondensables in system. 5. Recover refrigerant and recharge as required.
6. Refrigerant overcharge. 6. Recover refrigerant as required.
7. Line voltage incorrect. 7. Consult power company.
8. Refrigerant system restrictions. 8. Check or replace filter drier, expansion valve, etc.
Outdoor Fan Off
1. Fan slips on shaft. 1. Tighten fan hub setscrews.
2. Motor not running. 2. Check power and capacitor.
3. Motor bearings stuck. 3. Replace bearings.
4. Motor overload open. 4. Check overload rating. Check for fan blade obstruction.
5. Motor burned out. 5. Replace motor .
FASTENER TORQUE VALUES
Table 13 – Torque Values
Compressor mounting bolts 65--- 75 in–lbs
(734–847 N–cm)
Condenser fan motor mounting bolts 20 ±2in–lbs
(226 ±23 N–cm)
Condenser fan hub setscrew 84 ±2in–lbs
(949 ±136 N–cm)
High-flow service port 96 ±10 in–lbs
(1085 ±23 N–cm)
Schrader-type service check valve 2–3 in–lbs
(23–34 N–cm)
Compressor oil sightglass thread 330 ±31 in–lbs
(23–34 N–cm)
Compressor to Compressor rail torque 120–168 in–lbs
(1356–1898 N–cm)
Compressor rail to base pan torque 70 ±5in–lbs
(791 ±57 N–cm)
sure liquid line solenoid valve(s) is open.
Be sure outdoor fans are operating correctly.
44
TROUBLESHOOTING (cont)
PROBLEM SOLUTION
COMPRESSOR CYCLES ON LOW-PRESSURE SWITCH
Indoor-Air Fan Running
1. Liquid line solenoid valve(s) fails to open. 1. Check liquid line solenoid valve(s) for proper operation. Replace if necessary.
2. Filter drier plugged. 2. Replace filter drier.
3. Expansion valve power head defective. 3. Replace power head.
4. Low refrigerant charge. 4. Add charge. Check low-pressure switch setting.
Airflow Restricted
1. Coil iced up. 1. Check refrigerant charge.
2. Coil dirty. 2. Clean coil fins.
3. Air filters dirty. 3. Clean or replace filters.
4. Dampers closed. 4. Check damper operation and position.
Indoor-Air Fan Stopped
1. Electrical connections loose. 1. Tighten all connections.
2. Fan relay defective. 2. Replace relay.
3. Motor overload open. 3. Power supply.
4. Motor defective. 4. Replace motor.
5. Fanbeltbrokenorslipping. 5. Replaceortightenbelt.
COMPRESSOR RUNNING BUT COOLING INSUFFICI ENT
Suction Pressure Low
1. Refrigerant charge low. 1. Add refrigerant.
2. Head pressure low. 2. Check refrigerant charge. Check outdoor-air fan thermostat settings.
3. Air filters dirty. 3. Clean or replace filters.
4. Expansion valve power head defective. 4. Replace power head.
5. Indoor coil partially iced. 5. Check low-pressure setting.
6. Indoor airflow restricted. 6. Remove obstruction.
Suction Pressure High
1. Heat load excessive. 1. Check for open doors or windows in vicinity of fan coil.
UNIT OPERATES TOO LONG OR CONTINUOUSLY
1. Low ref rigerant charge. 1. Add refrigerant.
2. Control contacts fused. 2. Replace control.
3. Air in system. 3. Purge and evacuate system.
4. Partially plugged expansion valve or filter drier. 4. Clean or replace.
SYSTEM IS NOISY
1. Piping vibration. 1. Support piping as required.
2. Compressor noisy. 2. Replace compressor if bearings a re worn.
COMPRESSOR LOSES OIL
1. Leak in system. 1. Repair leak.
2. Crankcase heaters not energized during shutdown. 2. Check wiring and relays. Check heater and replace if defective.
3. Improper interconnecting piping design. 3. Check piping for oil return. Replace if necessary.
FROSTED SUCTION LINE
Expansion valve admitting excess refrigerant. Adjust expansion valve.
HOT LIQUID LINE
1. Shortage of ref rigerant due to leak. 1. Repair leak and recharge.
2. Expansion valve opens too wide. 2. Adjust expansion valve.
FROSTEDLIQUIDLINE
1. Restricted filter drier. 1. Remove restriction or replace.
2. Liquid line solenoid valve partially closed. 2. Replace valve.
38AU
45
APPENDIX A
Air Conditioner & Heat Pump with PURON
— Quick Reference Guide
S Puron®(R-410A) refrigerant operates at 50 percent to
70 percent higher pressures than R-22. Be sure that
servicing equipment and replacement components are
designed to operate with Puron®.
S Puron® refrigerant cylinders are rose colored.
S Recovery cylinder service pressure rating must be 400
psig, DOT 4BA400 or DOT BW400.
S Puron® systems should be charged with liquid
refrigerant. Use a commercial type metering device in
the manifold hose when charging into suction line with
compressor operating.
S Manifold sets should be 700 psig high side and 180 psig
38AU
low side with 550 psig low-side retard.
S Use hoses with 700 psig service pressure rating.
S Leak detectors should be designed to detect HFC
refrigerant.
S Puron®, as with other HFCs, is only compatible with
POE oils.
S Vacuum pumps will not remove moisture from oil.
S Use only factory specified liquid-line filter driers with
rated working pressures greater than 600 psig.
S Do not install a suction-line filter drier in liquid-line.
®
S POE oils absorb moisture rapidly. Do not expose oil to
atmosphere.
S POE oils may cause damage to certain plastics and
roofing materials.
S Wrap all filter driers and service valves with wet cloth
when brazing.
S A factory approved, liquid-line filter drier is required on
every unit.
S Do not use an R-22 TXV.
S If indoor unit is equipped with a TXV, it must be
®
changedtoaPuron
TXV.
S Never open system to atmosphere while it is under a
vacuum.
S When system must be opened for service, recover
refrigerant, break vacuum with dry nitrogen before
opening system.
S Always replace filter drier after opening system for
service.
®
S Do not vent Puron
into the atmosphere.
S Do not use capillary tube coils.
S Observe all warnings, cautions,andbold text.
®
S All Puron
S Do not leave Puron
heat pumps must have indoor TXV.
®
suction line driers in place for
more than 72 hours.
APPENDIX B
Wiring Diagram List
Unit Electrical Characteristics Diagram Number
38AUD*16
38AUD*25
38AUZ*16
38AUZ*25
208/230-3-60 38AU500540
460-3-60 38AU500541
575-3-60 38AU500542
208/230-3-60 38AU500565
460-3-60 38AU500566
575-3-60 38AU500567
208/230-3-60 38AU500537
460-3-60 38AU500538
575-3-60 38AU500539
208/230-3-60 38AU500568
460-3-60 38AU500569
575-3-60 38AU500570
46
APPENDIX C
Low Ambient Option — Factory Installed
Units with the factory installed low ambient option are
equipped with a Motormaster
control which regulates fan speed. A temperature sensor,
mounted on circuit 1 of the outdoor coil (see Figs. 44 and
45) controls the speed of approved outdoor fan motors in
order to maintain a constant head pressure in the outdoor
coil. The control maintains the appropriate head pressure
at low ambient temperatures down to --20_F(--28_C).
Wind baffles are required to prevent wind cross currents
from causing abnormally low condensing temperatures.
S Use 20--gauge sheet metal to fabricate wind baffles (see
Fig. 46 and Table 14) and mounting brackets (see Fig.
47).
NOTE: Mounting brackets are for use on 15 ton model
units only.
S Install the wind baffles as show in Fig. 48, for 15 ton
units and Fig. 49, for 20 ton units .
Operation —
Fan on/off control in cooling--only units (38AUZ,
38AUD) is provided by an outdoor fan relay (OFR).
In cooling mode, fan motor speed of outdoor motors
OFM1 and OFM3 is regulated by the speed control
temperature sensor on outdoor coil 1 for a minimum coil
condensing temperature of approximately 100_F(38_C)
at higher outdoor ambient temperature and 80_F(27_C) at
lower ambient. Additionally, outdoor fan motor OFM2
and OFM4 are turned on/off by the low ambient
temperature switch, LAS, operating the low ambient relay
(LAR). The LAS control temperatures are open 42_F+/-5_F, close 57_F+/--5_F (open 5.5_C+/--2.8_C, close
13.9_C+/--2.8_C).
To override the speed control for full fan speed operation
during service or maintenance, either:
a. remove sensor and place in hot water >120_F
(>49_C), or
b. rewire to bypass control by connecting speed
control input and output power wires.
R
solid--state head pressure
Troubleshooting —
OBSERVATION POSSIBLE REMEDY
Fans won’t start All fans:
Cooling --- Center outdoor
fans (OFM2, OFM4) off
below approximately 60_F
(16_C) outdoor ambient.
Cooling --- Center outdoor
fans (OFM2, OFM4) not on
above approximately 60_F
(16_C) outdoor ambient
Cooling --- Slow fan speed
for outer fans (OFM1,
OFM3) at start or during
low outdoor ambient
Cooling --- Slow fan speed
for outer fans (OFM1,
OFM3) above 85_F(29_F)
outdoor ambient (should
be full speed)
Cooling --- motor current
into speed control is
greater than motor nameplate FLA
Check power & wiring
Check outdoor fan relay (OFR)
OFM1, OFM3 only:
Check speed control sensor location
Check speed sensor resistance
OFM2, OFM4 only:
Check low ambient switch (LAS)
Check low ambient relay (LAR)
Normal operation
Check low ambient switch (LAS)
Check low ambient relay (LAR)
Normal operation
Check speed control sensor location
Check speed control sensor
resistance
Check fan motor capacitor
Normal operation
Up to 30% higher A at partial speed
at low ambient
Speed Control Sensor Resistance —
TEMPERATURE RESISTANCE
_F + / --- 2 _F _C + / --- 1 _C Ohms, nomin al
--- 2 2 --- 3 0 88350
--- 4 --- 2 0 48485
14 --- 1 0 27650
32 0 16325
50 10 9950
68 20 6245
77 25 5000
86 30 4028
104 40 2663
122 50 1801
140 60 1244
158 70 876
38AU
47
38AU
Motormaster Sensor Must be positioned
on Vapor Stub of
Circuit 1 coil only.
Motormaster
Sensor Attach to
Circuit 1 coil only.
508 mm (20 in)
for Single Circuit
254 mm (10 in)
for Dual Circuit
Fig. 44 -- Motormaster Sensor Location:
38AUZ*16 & 38AUD*16 (Novation)
C10093
C10094
Fig. 45 -- Motormaster Sensor Location:
38AUZ*16/25 & 38AUD*16/25 (RTPF)
48
Table14–WindBaffleDimension
DIMENSIONS - -- INCHES
UNIT BAFFLE A B C D E F G H J
38AUZ*16
38AUD*16
(MCHX)
BACK 801/
81 813/4431/
4
RIGHT SIDE 383/4391/2401/4431/
FRONT 341/8347/8355/8431/
LEFT SIDE 103/4111/2121/4431/
LEFT SIDE 193/4201/2211/4431/
38AUZ*16
38AUD*16
(RTPF)
BACK 801/
81 813/4431/
4
RIGHT SIDE 383/4391/2401/4431/
FRONT 27 273/4281/2 431/
LEFT SIDE 327/8335/8343/8431/
38AUZ*25
38AUD*25
(RTPF)
BACK 473/4481/2491/4431/
RIGHT SIDE 611/8617/8625/8431/
FRONT 201/8207/8215/8431/
DIMENSIONS - -- MM
UNIT BAFFLE A B C D E F G H J
LEFT SIDE 501 520 539 1095 212 457 694 1015 --38AUZ*16
38AUD*16
(MCHX)
BACK 2037 2056 2075 1095 212 457 694 1015 ---
RIGHT SIDE 983 1002 1021 1095 212 457 694 1015 ---
FRONT 866 885 904 1095 174 419 656 977 ---
LEFT SIDE 272 291 310 1095 108 337 565 794 1022
38AUZ*16
38AUD*16
(RTPF)
BACK 2037 2056 2075 1095 212 457 694 1015 ---
RIGHT SIDE 983 1002 1021 1095 212 457 694 1015 ---
FRONT 684 704 723 1095 95 324 552 781 1010
LEFT SIDE 834 853 872 1095 108 337 565 794 1022
38AUZ*25
38AUD*25
(RTPF)
BACK 1214 1233 1252 1095 108 337 565 794 1022
RIGHT SIDE 1551 1570 1589 1095 95 324 552 781 1010
FRONT 510 530 549 1095 95 324 552 781 1010
83/
8
83/
8
83/
8
67/
8
41/4 131/4 221/4311/
8
83/
8
83/
8
33/
8
41/
8
41/
8
33/
8
33/
8
18 271/
8
18 271/
8
18 271/
8
161/2253/4381/
8
18 271/
8
18 271/
8
123/4213/4303/
4
131/4221/4311/4401/
4
131/4221/4311/4401/
4
123/4213/4303/4393/
4
123/4213/4303/4393/
4
4
4
4
4
4
40 ---
40 ---
40 ---
2
4
40 ---
40 ---
4
---
401/
393/
4
4
4
4
4
4
38AU
MCHX: NOVATION coil model
49
C10363A
38AU
Fig. 46 -- Wind Baffles -- Fabrication
50
C10366
38AU
51
Fig. 47 -- 15 Ton Wind Baffle Brackets -- Fabrication
C10367
BOTTOM
BRACKET
BACK
38AU
TOP BRACKETS
RIGHT
FRONT
Fig. 48 -- Wind Baffle Installation — 15 Ton Units
52
LEFT
BACK
C10368
38AU
FRONT
RIGHT
Fig. 49 -- Wind Baffle Installation — 20 Ton Units
53
LEFT
38AU
Copyright 2010 Carrier Corp. D 7310 W. Morris St. D Indianapolis, IN 46231 Printed in U.S.A. Edition Date: 11/10
Manufacturer reserves the right to change, at any ti me, specifications and designs without notic e and without obligations.
54
Catalog No: 38AU--- 09SI
Replaces: 38AU ---07SI
START-UP CHECKLIST
I. PRELIMINARY INFORMATION
OUTDOOR: MODEL NO. SERIAL NO.
INDOOR: AIRHANDLER MANUFACTURER
MODEL NO. SERIAL NO.
ADDITIONAL ACCESSORIES
II. PRE-START-UP
OUTDOOR UNIT
IS THERE ANY SHIPPING DAMAGE? (Y/N)
IF SO, WHERE:
WILL THIS DAMAGE PREVENT UNIT START-UP? (Y/N)
CHECK POWER SUPPLY. DOES IT AGREE WITH UNIT? (Y/N)
HAS THE GROUND WIRE BEEN CONNECTED? (Y/N)
HAS THE CIRCUIT PROTECTION BEEN SIZED AND INSTALLED PROPERLY? (Y/N)
ARE THE POWER WIRES TO THE UNIT SIZED AND INSTALLED PROPERLY? (Y/N)
CONTROLS
ARE THERMOSTAT AND INDOOR FAN CONTROL WIRING CONNECTIONS MADE AND CHECKED?
(Y/N)
ARE ALL WIRING TERMINALS (including main power supply) TIGHT? (Y/N)
HAS CRANKCASE HEATER BEEN ENERGIZED FOR 24 HOURS? (Y/N)
INDOOR UNIT
HAS WATER BEEN PLACED IN DRAIN PAN TO CONFIRM PROPER DRAINAGE? (Y/N)
ARE PROPER AIR FILTERS IN PLACE? (Y/N)
HAVE FAN AND MOTOR PULLEYS BEEN CHECKED FOR PROPER ALIGNMENT? (Y/N)
DO THE FAN BELTS HAVE PROPER TENSION? (Y/N)
HAS CORRECT FAN ROTATION BEEN CONFIRMED? (Y/N)
PIPING
ARE LIQUID LINE SOLENOID VALVES LOCATED AT THE INDOOR COILS AS REQUIRED? (Y/N)
38AU
HAVE LEAK CHECKS BEEN MADE AT COMPRESSOR, OUTDOOR AND INDOOR COILS,
TXVs (Thermostatic Expansion Valves), SOLENOID VALVES, FILTER DRIERS, AND FUSIBLE PLUGS
WITH A LEAK DETECTOR? (Y/N)
LOCATE, REPAIR, AND REPORT ANY LEAKS.
HAVE LIQUID LINE SERVICE VALVES BEEN OPENED? (Y/N)
HAVE SUCTION LINE SERVICE VALVES BEEN OPENED? (Y/N)
55
CHECK VOLTAGE IMBALANCE
LINE-TO-LINE VOLTS: AB V AC V BC V
(AB + AC + BC)/3 = AVERAGE VOLTAGE = V
MAXIMUM DEVIATION FROM AVERAGE VOLTAGE = V
VOLTAGE IMBALANCE = 100 X (MAX DEVIATION)/(AVERAGE VOLTAGE) =
IF OVER 2% VOLTAGE IMBALANCE, DO NOT ATTEMPT TO START SYSTEM!
CALL LOCAL POWER COMPANY FOR ASSISTANCE.
CHECK INDOOR UNIT FAN SPEED AND RECORD.
CHECK OUTDOOR UNIT FAN SPEED AND RECORD.
AFTER AT LEAST 10 MINUTES RUNNING TIME, RECORD THE FOLLOWING MEASUREMENTS:
SUCTION PRESSURE CIR 1: CIR 2:
38AU
SUCTION LINE TEMP CIR 1: CIR 2:
LIQUID PRESSURE CIR 1: CIR 2:
LIQUID LINE TEMP CIR 1: CIR 2:
ENTERING OUTDOOR UNIT AIR TEMP
LEAVING OUTDOOR UNIT AIR TEMP
INDOOR UNIT ENTERING-AIR DB (dry bulb) TEMP
INDOOR UNIT ENTERING-AIR WB (wet bulb) TEMP
INDOOR UNIT LEAVING-AIR DB TEMP
INDOOR UNIT LEAVING-AIR WB TEMP
COMPRESSOR 1 AMPS (L1/L2/L3) / /
COMPRESSOR 2 AMPS (L1/L2/L3) / /
NOTES:
Copyright 2010 Carrier Corp. D 7310 W. Morris St. D Indianapolis, IN 46231 Printed in U.S.A. Edition Date: 11/10
Manufacturer reserves the right to change, at any ti me, specifications and designs without notic e and without obligations.
56
Catalog No: 38AU--- 09SI
Replaces: 38AU ---07SI
Loading...