Carrier 38AU User Manual

38AU

Air-Cooled Condensing Units 50 Hz

with Puron

(R-410A) Refrigerant

Sizes 07 - 14

Installation, Start-Up and

Service Instructions

CONTENTS

SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . 1

INSTALLATION GUIDELINES. . . . . . . . . . . . . . . . . . . . . . . 2

INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-19

Step 1 – Plan for Unit Location . . . . . . . . . . . . . . . . . . . 9

Step 2 – Complete Pre-Installation Checks. . . . . . . . . . 9

Step 3 – Prepare Unit Mounting Support . . . . . . . . . . 9

Step 4 – Rig and Mount the Unit . . . . . . . . . . . . . . . . . . 9

Step 5 – Complete Refrigerant Piping Connections

Step 6 – Install Accessories. . . . . . . . . . . . . . . . . . . . . . 14

Step 7 – Complete Electrical Connections . . . . . . . . . 14

PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Turn On Crankcase Heater . . . . . . . . . . . . . . . . . . . . . . 19

Preliminary Charge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

START-UP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 -25

38AU Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

OPERATING SEQUENCE. . . . . . . . . . . . . . . . . . . . . . . . . . 26

Indoor (Supply) Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Cooling, Unit Without Economizer . . . . . . . . . . . . . . . . 26

Cooling, Unit With Economizer. . . . . . . . . . . . . . . . . . . 26

Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

ROUTINE SYSTEM MAINTENANCE. . . . . . . . . . . . . . . 26

Quarterly Inspection (and 30 days after initial start)

Seasonal Maintenance . . . . . . . . . . . . . . . . . . . . . . . . 26

SERVICE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 - 33

Refrigeration System . . . . . . . . . . . . . . . . . . . . . . . . . 27

Compressor Oil. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Servicing Systems on Roofs with

Synthetic Materials. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Liquid Line Filter Drier . . . . . . . . . . . . . . . . . . . . . . . . . 27

Filed Refrigerant Access Ports . . . . . . . . . . . . . . . . . 27

Factory High-flow Access Ports . . . . . . . . . . . . . . . . 27

Comfort Alert Diagnostic Module. . . . . . . . . . . . . . . 28

Crankcase Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Compressor Protection. . . . . . . . . . . . . . . . . . . . . . . . . . 30

Low-Pressure Switches . . . . . . . . . . . . . . . . . . . . . . . . . 30

High-Pressure Switches. . . . . . . . . . . . . . . . . . . . . . . . . 30

Outdoor Fans. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

NOVATION™ Coil Cleaning and Maintenance . . . . 33

. . 10

. . 26

Repairing NOVATION Condenser Tube Leaks . . . . 33

Replacing NOVATION Condenser Coil . . . . . . . . . . 33

Service Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333

Fastener Torque Values . . . . . . . . . . . . . . . . . . . . . . . 333

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . 34 -35

APPENDIX A

Air Conditioner and Heat Pump with Puron

Quick Reference Guide . . . . . . . . . . . . . . . . . . . . . . . 36

APPENDIX B

Wiring Diagram List. . . . . . . . . . . . . . . . . . . . . . . . . 36

APPENDIX C

Motormaster Sensor Locations. . . . . . . . . . . . . . . . . 37

START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . .CL-1, CL-2

–

SAFETY CONSIDERATIONS

Improper installation, adjustment, alteration, service, maintenance, or use can cause explosion, fire, electrical shock or other conditions which may cause personal injury or property damage. Consult a qualified installer, service agency, or your distributor or branch for information or assistance. The qualified installer or agency must use factory-authorized kits or accessories when modifying this product. Refer to the individual instructions package

Follow all safety codes. Wear safety glasses and work gloves. Use quenching cloths for brazing operations and have a fire extinguisher available. Read these instructions thoroughly and follow all warnings or cautions attached to the unit. Consult local building codes for special requirements. In absence of local codes, it is recommended that the (USA standard ANSI/ NFPA70, National Electrical Code (NEC), be followed.

It is important to recognize safety information. This is the safety-alert symbol . When you see this symbol on the unit and in instructions or manuals, be alert to the potential for personal injury.

Understand the signal words DANGER, WARNING, CAUTION, and NOTE. These words are used with the safetyalert symbol. DANGER identifies the most serious hazards which will result in severe personal injury or death. WARNING signifies hazards which could result in personal injury or death. CAUTION is used to identify unsafe practices, which may result in minor personal injury or product and property damage. NOTE is used to highlight suggestions which will result in enhanced installation, reliability, or operation.

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could cause personal injury or death.

Before performing service or maintenance operations on unit, always turn off main power switch to unit and install lockout tag. Unit may have more than one power switch.

UNIT OPERATION AND SAFETY HAZARD

Failure to follow this warning could cause personal injury, death and/or equipment damage.

Puron® (R-410A) refrigerant systems operate at higher pressures than standard R-22 systems. Do not use R-22 service equipment or components on Puron refrigerant equipment.

PERSONAL INJURY AND ENVIRONMENTAL HAZARD

Failure to follow this warning could cause personal injury or death.

Relieve pressure and recover all refrigerant before system repair or final unit disposal.

Wear safety glasses and gloves when handling refrigerants. Keep torches and other ignition sources away from refrigerants and oils.

CUT HAZARD

Failure to follow this caution may result in personal injury. Sheet metal parts may have sharp edges or burrs. Use care

and wear appropriate protective clothing, safety glasses and gloves when handling parts and servicing 38AU units.

INSTALLATION GUIDELINE

Replacement /Retrofit – R22 to Puron

Replacement/retrofit installations require change-out of outdoor unit, metering device, and filter driers. Change-out of indoor coil (evaporator) and interconnecting tubing is recommended.

Existing evaporator coil – If the existing evaporator coil may be re-used, check with the coil manufacturer to verify the coil construction is suitable for operation with the higher pressures of Puron is compatible with R-410A, replace if necessary. The minimum factory test pressure rating must be 1725 kPa (250 psig). Existing coil will need to be purged with Nitrogen to remove as much mineral oil as possible to eliminate cross contamination of oils.

(R-410A). Also determine if the existing TXV valve

Acid test – If the existing system is being replaced because of a compressor electrical failure, assume acid is in system. If system is being replaced for any other reason, use an approved acid test kit to determine acid level. If even low levels of acid are detected, install a 100 percent activated alumina suctionline filter drier in addition to the replacement liquid-line filter drier. Remove the suction line filter drier as soon as possible, with a maximum of 72 hr of operation. Recommendation: Install a ball valve in the liquid line at the filter drier location when installing a suction filter in the suction line (to facilitate evacuation of the system’s low side when suction filter-drier is removed).

Installation –

1. Remove the existing evaporator coil or fan coil and install the replacement coil when appropriate.

2. Drain oil from low points and traps in suction line tubing (and hot gas bypass tubing if appropriate) and evaporator if they were not replaced. Removing oil from evaporator coil may require purging of the tubing with dry nitrogen.

3. Unless indoor unit is equipped with a Puron® approved metering device, change the metering device to a thermal expansion valve (TXV) designed for Puron® (R-410A).

4. Remove the existing outdoor unit. Install the new outdoor unit according to these installation instructions.

5. Install a new field-supplied liquid-line filter drier at the indoor coil just upstream of the TXV or fix orifice metering device.

6. If a suction line fil.ter-drier is also to be installed, install the suction line filter-drier immediately upstream of the suction line service valve at the outdoor unit. Note the recommendation above regarding use of ball valve in the liquid line.

UNIT DAMAGE HAZARD

Failure to follow this caution may result in equipment damage or improper operation.

Never install suction-line filter drier in the liquid-line of a

Puron

system.

7. If required, install a 100% activated alumina suction line filter drier at the outdoor unit.

8. Evacuate and charge the system according to the instructions in this installation manual.

9. Operate the system for 10 hr. Monitor the pressure drop across the suction line filter drier. If pressure drop exceeds 21kPa (3 psig), 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.

UNIT

Standard

Weight

Corner

Center of Gravity Unit Height

lbs. kg. lbs. kg. lbs. kg. lbs. kg. lbs. kg. X Y Z H

38AUZ*07

328 149 128 58 68 31 62 28 70 32

21.00

[533.4]

19.00

[482.6]

13.00

[330.2]

42.36

[1076.0]

38AUZ*08

353 160 138 63 72 33 65 29 78 35

19.00

[482.6]

23.00

[584.2]

13.00

[330.2]

42.36

[1076.0]

38AUD*12

499 226 193 88 111 50 72 38 123 56

20.000 [508.0]

23.00

[584.2]

15.00

[381.0]

50.36

[1279.2]

38AUD*14

505 229 190 86 88 40 76 34 151 68

20.000 [508.0]

24.00

[609.6]

15.00

[381.0]

50.36

[1279.2]

Fig. 1 — 38AU*07-14 Unit Dimensions

Table 1A — Physical Data — 38AUZ*07-08 Units — 50 Hz English

UNIT SIZE 38AU Z*07 Z*08 NOMINAL CAPACITY (tons) OPERATING WEIGHTS (lb)

Aluminum-Fin Coils 328 353

REFRIGERANT TYPE

Operating Charge, Typical (lb)

‡

†

Shipping Charge (lb) 4.4 4.9

COMPRESSOR

Qty...Type 1...Scroll

OUTDOOR FANS

Qty...Rpm 2...1100 Motor Hp Diameter 22 Nominal Airflow (Cfm Total) 6000 Watts (Total) 610

OUTDOOR COIL (Qty)

Face Area (sq ft total) 17.5 20.5 Rows/Fins per inch (FPI) 1/17 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 1...1 Qty...Liquid

67.5

R-410A

9.0 12.3

1...NOVATION

1...

1...11/

1...1/

LEGEND ODS — Outside Diameter Sweat (socket)

‡ Unit is factory-supplied with partial charge only. † Typical operating charge with 25 ft of interconnecting piping.

Table 1B — Physical Data — 38AUZ*07-08 Units — 50 Hz SI

UNIT SIZE 38AU Z*07 Z*08 NOMINAL CAPACITY (kW) OPERATING WEIGHT (kg)

Aluminum-Fin Coils 149 160

REFRIGERANT TYPE

Operating Charge, Typical (kg)

‡

†

Shipping Charge (kg) 2.0 2.2

COMPRESSOR

Qty...Type 1...Scroll

OUTDOOR FANS

Qty...r/s 2...18 Motor Hp NEMA

Diameter (mm) 560 Nominal Airflow (L/s) 2832 Watts (Total) 610

OUTDOOR COIL (Qty)

Face Area (sq m total) 1.6 1.9 Rows/Fins per Meter (Fins/m) 1...670 1...670

CONTROLS

Pressurestat Settings (kPa)

High Cutout 4347 ± 70

Cut-in 3482 ±138

Low Cutout 372 ± 21

Cut-in 807 ± 34

PIPING CONNECTIONS (in. ODS)

Qty...Suction 1...1 Qty...Liquid

21.1 26.4

R-410A

4.1 5.6

1...NOVATION

1...

1...11/

1...1/

LEGEND

NEMA — National Electrical Manufacturers Association ODS — Outside Diameter Sweat (socket)

‡ Unit is factory-supplied with partial charge only. † Typical operating charge with 7.62 m of interconnecting piping.

Table 2A — Physical Data — 38AUD*12-14 Units — 50 Hz English

UNIT SIZE 38AU D*12 D*14 NOMINAL CAPACITY (tons) OPERATING WEIGHTS (lb)

Aluminum-Fin Coils 418 431

REFRIGERANT TYPE

Operating Charge A/B, Typical (lb)

‡

†

Shipping Charge A/B (lb) 3.0/3.1 3.7/3.9

COMPRESSOR

Qty...Type 2...Scroll

OUTDOOR FANS

Qty... RPM 2...1100 Motor Hp Diameter (in) 22 Nominal Airflow (Cfm Total) 6,000 Watts (Total) 610

OUTDOOR COIL (Qty)

Face Area (sq ft total) 25.0 31.8 Rows/Fins per inch (FPI) 1/17 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 A/B 1...1 Qty...Liquid A/B

10 12.5

R-410A

7.5/7.5 11.2/11.2

1...NOVATION

1...

/8 /1...11/

/8 /1...3/

1...13/8 /1...13/

1...1/2 /1...1/

LEGEND ODS — Outside Diameter Sweat (socket)

‡ Unit is factory-supplied with partial charge only. † Typical operating charge with 25 ft of interconnecting piping.

Table 2B — Physical Data — 38AUD*12-14 Units — 50 Hz SI

UNIT SIZE 38AU D*12 D*14 NOMINAL CAPACITY (kW) OPERATING WEIGHT (kg)

Aluminum-Fin Coils 190 196

REFRIGERANT TYPE

Operating Charge A/B, Typical (kg)

‡

†

Shipping Charge A/B (kg) 1.3/1.4 1.7/1.8

COMPRESSOR

Qty...Model 2...Scroll

OUTDOOR FANS

Qty... r/s 2...18 Motor Hp NEMA Diameter (mm) 560 Nominal Airflow (Cfm Total) 6,000 Watts (Total) 610

OUTDOOR COIL (Qty)

Face Area (sq m total) 2.3 3.0 Rows/Fins per Meter (Fins/m) 1...670 1...670

CONTROLS

Pressurestat Settings (kPa)

High Cutout 4347 ± 70

Cut-in 3482 ±138

Low Cutout 372 ± 21

Cut-in 807 ± 34

PIPING CONNECTIONS (in. ODS)

Qty...Suction A/B 1...1 Qty...Liquid A/B

35.1 44

R-410A

3.4/3.4 5.1/5.1

1...NOVATION

1...

/8 /1...11/

/8 /1...3/

1...13/8 /1...13/

1...1/2 /1...1/

LEGEND

NEMA — National Electrical Manufacturers Association ODS — Outside Diameter Sweat (socket)

‡ Unit is factory-supplied with partial charge only. † Typical operating charge with 7.62 m of interconnecting piping.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

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POSITION NUMBER TYPICAL

Year of manufacture (”09” = 2009)3−4

38AUZA07A0G9–0A0A0

_____________ ____

Model Type Packaging

38AU= Carrier Condensing Unit Puronr

R---410A Refrigerant

0=Standard

1=LTL

Type o f Co il

Z = Single Circuit, A/C Scroll Compressor D = Dual Circuit, A/C Scroll Compressor

Refrigerant Options

A = None B = Low Ambient

Nominal Tonnage

07 = 6 Tons 08 = 7.5 Tons 12 = 10 Tons 14 = 12.5 Tons

Factory Assigned

A=Default

Factory Assigned

0=Default

Coil Options (Condenser)

G = Al/Al Standard K = E-Coated Al/Al T = Al/Al with Louvered Hail Guard W = E-Coated Al/Al with Louvered Hail Guard

Electrical Options

A=None

C = Non-Fused Disconnect

Service Options

1= 0=None

Factory Assigned

A = Default

Base Unit Controls

0 = Electro-Mechanical Controls

Design Rev

--- = Catalog Model Number A = Initial Rev (Discrete Model Number)

Voltage

9 = 400/3/50

Fig. 2 — Model Number Nomenclature

Fig. 3 — Serial Number Nomenclature

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.

Before unpacking this new 38AU model, compare the evaporator coil design to the 38AU model.

Table 3 — Evaporator Coil Connections

Evaporator Coil has Connect to Model Notes

Single Circuit 38AUZ ONLY

Manifold evaporator circuits into single piping system

Use two separate piping systems

Two Circuits

38AUZ

38AUD

INSTALLATION

Jobsite Survey

Complete the following checks before installation.

1. Consult local building codes or the U.S. A. National Electrical Code (Ref: ANSI/NFPA 70 [American National Standards Institute/National Fire Protection Association], latest version) 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 minimum working space, clearances between live electrical components and nearest barriers (grounded or ungrounded), clearances for unit performance and service access below, around and above unit as specified in unit drawings. See Fig. 4.

NOTE: Local codes may require different clearances than specified in Fig. 4. It is the responsibility of installers to be knowledgeable in local codes and to modify the recommended clearances to satisfy local codes.

NOTE: Consider also the effect of adjacent units on airflow performance and control box safety clearance.

Do not install the outdoor unit in an area where fresh air supply to the outdoor coil may be restricted or when recirculation from the condenser fan discharge is possible. Do not locate the unit in a well or next to high walls.

Evaluate the path and required line length for interconnecting refrigeration piping, including suction riser requirements (outdoor unit above indoor unit), liquid line lift (outdoor unit below indoor unit) and hot gas bypass line. Relocate sections to minimize the length of interconnecting tubing.

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.

RIGHT:

REAR: Min 457 mm (18”) requried for service

LEFT: Min 457 mm (18”) requried for service

Note: Observe requirements for 914 mm (39”) operating clearance on either Left or Rear coil opening.

Fig. 4 — Service Clearance Dimensional Drawing

Min 457 mm (18”) requried for service

FRONT: 1067 mm (42”)

Step 2 — Complete Pre-Installation Checks

CHECK UNIT ELECTRICAL CHARACTERISTIC — Confirm before installation of unit that voltage, amperage and circuit protection requirements listed on unit data plate agree with power supply provided.

— UNCRATE UNIT — Remove unit packaging except for the top skid assembly, which should be left in place until after the unit is rigged into its final location.

INSPECT SHIPMENT — File a claim with shipping company if the shipment is damaged or incomplete.

CONSIDER SYSTEM REQUIREMENTS

• Consult local building codes and National Electrical Code (NEC, U.S.A.) for special installation requirements.

• Allow sufficient space for airflow clearance, wiring, refrigerant piping, and servicing unit. See Fig.1 for unit dimensions and weight distribution data.

• Locate the unit so that the outdoor coil (condenser) airflow is unrestricted on all sides and above.

• The unit may be mounted on a level pad directly on the base channels or mounted on raised pads at support points. See Tables 1A through 2B for unit operating weights. See Fig. 1 for weight distribution based on recommended support points.

NOTE: If vibration isolators are required for a particular installation, use the data in Fig. 1 to make the proper selection.

Step 3 — Prepare Unit Mounting Support Slab Mount —

Provide a level concrete slab that extends a minimum of 150 mm (6 in.) beyond unit cabinet. Install a gravel apron in front of condenser coil air inlet to prevent grass and foliage from obstructing airflow.

Step 4 — Rig and Mount the Unit

UNIT DAMAGE HAZARD

Failure to follow this caution may result in equipment damage.

All panels must be in place when rigging. Unit is not designed for handling by fork truck.

RIGGING — These units are designed for overhead rigging. Refer to the rigging label for preferred rigging method. Spreader bars are not required if top crating is left on the unit. All panels must be in place when rigging. As further protection for coil

faces, plywood sheets may be placed against the sides of the unit, behind cables. Run cables to a central suspension point so that the angle from the horizontal is not less than 45 degrees. Raise and set the unit down carefully.

If it is necessary to roll the unit into position, mount the unit on longitudinal rails, using a minimum of 3 rollers. Apply force to the rails, not the unit. If the unit is to be skidded into position, place it on a large pad and drag it by the pad. Do not apply any force to the unit.

Raise from above to lift the unit from the rails or pad when unit is in its final position.

After the unit is in position, remove all shipping materials and top crating.

Step 5 — Complete Refrigerant Piping Connections

IMPORTANT: Do not bury refrigerant piping underground.

IMPORTANT: A refrigerant receiver is not provided with the unit. Do not install a receiver.

PROVIDE SAFETY RELIEF — The 38AU unit is provided with a fusible joint in the suction line in accordance with applicable UL standards for pressure relief. If local codes dictate an additional safety relief device, purchase locally and install locally. Installation will require the recovery of the factory shipping charge before the factory tubing can be cut and the supplemental relief device is installed.

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 Tub e OD

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%

31 1.41.6

41.4 1.9 2 5 1.7 2.3 2.6 7 2.3 3.1 3.3

82.6 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 9.

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.

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 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.

Table 5 — 38AUZ 07-08 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

Model Typ Linear ft 0-25 25-50 50-75 75-100 100-125 38AUZ*07 Liquid Line

Max Lift 25 42 50 75 90 100 86 101 Suction Line

1-1/

1-1/81-1/

1-1/

Charge (lbs) 8.4 9.6 11.1 13.1 15.0 18.8 16.9 22.6

38AUZ*08 Liquid Line

Max Lift 25 50 75 100 112 Suction Line

1-1/81-1/

1-1/

Charge (lbs) 11.8 9.6 12.9 16.8 18.7

Legend:

Length Equiv Equivalent tubing length, including effects of refrigeration specialties devices Liquid Line Tubing size, inches OD. Max Lift

Cooling

Heating 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 (where

NOTE:

Maximum liquid lift at maximum permitted liquid line pressure drop

• Indoor unit ABOVE outdoor unit

• Indoor unit BELOW outdoor unit

applicable) For applications with linear length greater than 100 ft (30.5 m), contact your local Carrier representative.

Table 6 — 38AUD 12-14 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

Model Typ Linear ft 0-25 25-50 50-75 75-100 100-125 38AUD*12 Liquid Line

Max Lift 25 50 28 75 100 99 Suction Line

11/

Charge ea. (lbs) 7.1 8.1 9.6 11.9 13.8 15.8

38AUD*14 Liquid Line

Max Lift 25 50 48 75 100 122 Suction Line

11/

Charge ea. (lbs) 9.7 10.7 12.2 14.5 16.4 18.4

Legend:

Length Equiv Equivalent tubing length, including effects of refrigeration specialties devices Liquid Line Tubing size, inches OD. Max Lift

Cooling

Heating 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 (where

NOTE:

Maximum liquid lift at maximum permitted liquid line pressure drop

• Indoor unit ABOVE outdoor unit

• Indoor unit BELOW outdoor unit

applicable) For applications with linear length greater than 100 ft (30.5 m), contact your local Carrier representative.

Table 7 — 38AU Maximum Suction Pipe Size

Model: Unit Size Maximum Tube Size

38AUZ 07 1

08 15/

38AUD 12 13/

14 15/

INSULATE SUCTION LINES — Apply closed-cell tubular

Circuit A

Connections

Circuit B

Connections

FIRST ON/LA ST OFF = B

VERTICAL INSTALLATION

FIRS T ON/LAST OF F = A

HORIZONTAL INSTALLATION

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 fieldsupplied and installed in the compressor discharge line. Run a ½-in OD line between outdoor unit and evaporator coil inlet. Install an Auxiliary Side Connector at the evaporator between TXV and distributor (follow instructions for the side connector part). Insulate the hot gas line.

38AUD: Generally only one hot gas bypass system will be applied on a two-circuit unit. Connect the hot gas bypass system to Circuit A (first-on/last-off, connected to the evaporator coil’s bottom circuit).

38AUD PIPING CONNECTIONS – The 38AUD’s two circuits are designated Circuit A and Circuit B. Circuit A is controlled by the thermostat’s Y1 (or TC1) contact and will be the first circuit on and last circuit off. Circuit B is controlled by the thermostat’s Y2 (or TC2) contact and this circuit is always the “lag” circuit.

See Fig. 5 for location of the Circuit A and Circuit B service valves and field piping connections. Circuit A is on the righthand side of the service valve compartment; Circuit B is on the left.

40RU Arrangement

Vertical

Horizontal

Cooling

Stage

Y1 Y2

40RU Coil

Segment

B A

A B

Connect to

38AUD

Circuit A Circuit B

Fig 5 - 38AUD Service Valve Locations

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 A so that the evaporator’s lower coil segment is first-on/last-off (to avoid re-evaporation of condensate on dry lower coil segments).

Plan the Circuit A and Circuit B 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 12, 14 and 16 is a face-split coil design that also has its circuits designated as A and B. See Fig. 6. 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 B; this segment should be connected to the 38AUD’s Circuit A. In a horizontal arrangement, the 40RU’s lower segment is now segment A; this segment should be connected to the 38AUD’s Circuit A.

Fig. 6 — Typical Evaporator Coil Connections (40RU)

Note that refrigerant suction piping should be insulated. INSTALL FILTER DRIER(S) AND MOISTURE

INDICATOR(S) — 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.

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.

Table 8 — Puron-duty Filter Drier(s)

Model-Size Qty

38AUZ*07 1 38AUZ*08 1 38AUD*12 2 38AUD*14 2

Liquid

Line OD

/8-in 8 cu. in. KH43LG091

/2-in 16 cu. in. KH43LG085

/8-in 8 cu. in. KH43LG091

/2-in 16 cu. in. KH43LG085

Desiccant

Vol ume

Part

Number Ref

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.

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