Page 1: Table Of Contents
38AU Air Cooled Condensing Units 60 Hz With Puron (R---410A) Refrigerant Sizes 16---25 Installation, Start---Up and Service Instructions CONTENTS SAFETY CONSIDERATIONS ....
Page 2: Safety Considerations
. When you see this symbol on the glasses and gloves when handling parts and servicing unit and in instructions or manuals, be alert to the 38AU units. potential for personal injury. Understand the signal words DANGER, WARNING, CAUTION, and NOTE. These words are used with the INSTALLATION GUIDELINE safety-alert symbol.
Page 3 Same tube sizes are capable of handling higher flowrates 5. Install a new field-supplied liquid-line filter drier at (expressed as tons of cooling capacity) with Puron the indoor coil just upstream of the TXV or fix orifice refrigerant compared to R- - 22 at constant pressure drops. metering device.
Page 4 [482.6] [381] [1279.2] 38AUD*16 65.5 (MCHX) [965.2] [482.6] [381] [1279.2] 38AUZ*16 (RTPF) [965.2] [482.6] [431.8] [1279.2] 38AUD*16 (RTPF) [965.2] [482.6] [431.8] [1279.2] LEGEND: MCXH = Novation™ coil RTPF = Round Tube/Plate Fin coil Fig. 1 - - 38AU**16 Unit Dimensions...
Page 5 Corner Corner Unit UNIT Center of Gravity Weight Height lbs. lbs. lbs. lbs. lbs. 38AUZ*25 (RTPF) [965.2] [584.2] [431.8] [1279.2] 38AUD*25 (RTPF) [965.2] [584.2] [431.8] [1279.2] LEGEND: RTPF = Round Tube/Plate Fin coil Fig. 2 - - 38AU**25 Unit Dimensions...
Page 6 Table 1A — Physical Data — 38AUZ*16-25 Units — 60 Hz English UNIT SIZE 38AU Z*16 Z*25 NOMINAL CAPACITY (tons) OPERATING WEIGHTS (lb) NOVATION™ Coil (Al Tube) Round Tube/Plate Fin Coil (Cu/Al) ‡ REFRIGERANT TYPE R-410A † NOVATION Operating Charge, Typical (lb) 24.6...
Page 7 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) Round Tube/Plate Fin Coil (Cu/Al) ‡ REFRIGERANT TYPE R-410A † NOVATION Operating Charge, Typical (kg) 11.1...
Page 8 Table 2A — Physical Data — 38AUD*16-25 Units — 60 Hz English UNIT SIZE 38AU D*16 D*25 NOMINAL CAPACITY (tons) OPERATING WEIGHTS (lb) NOVATION™ Coil (Al Tube) Round Tube/Plate Fin Coil (Cu/Al) ‡ REFRIGERANT TYPE R-410A † NOVATION Operating Charge A/B, Typical (lb) 12.0 / 12.0...
Page 9 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) Round Tube/Plate Fin Coil (Cu/Al) ‡ REFRIGERANT TYPE R-410A R-410A †...
Page 10 10 11 12 13 14 15 16 17 18 3 8 A U Z A 2 5 A 0 G 6 A 0 A 0 A 0 Model Type Packaging 38AU= Carrier Condensing Unit 0 = Standard Puron ® R--- 410A Refrigerant...
Page 11: Installation
C10201 Fig. 5 - - Service Clearance Dimensional Drawing piping systems Step 2 — Complete Pre-Installation Checks Before unpacking this new 38AU model, compare the evaporator coil design to the 38AU model. Check Unit Electrical Characteristics: Confirm before installation of unit that voltage, amperage and circuit...
Page 12: Step 3 - Prepare Unit Mounting Support
Refer to Part 3 of the Carrier System Design the factory tubing can be cut and the supplemental relief Manual for additional data and information on equivalent device is installed.
Page 13 Check Table 7 for maximum suction tube size for 38AU valve. This effect reduces the length of liquid lift (feet of units at minimum load conditions. Consider suction speed elevation) that a liquid line size can accommodate.
Page 14 38AUD’s Circuit 1 so that the during low load conditions and then to oil slugging as evaporator load increases.) Model 38AU units do not include evaporator’s lower coil segment is first-on/last-off (to avoid a hot gas stub connection; a tee must be field-supplied and...
Page 15 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.
Page 16 SOLENOID VALVE SENSING FILTER CIRCUIT 2 BULB DRIERS 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 AIRFLOW 15 DIAMS CKT 1...
Page 17: Step 6 - Install Accessories
Preliminary Charge — High-Flow Access Port Before starting the unit, charge R-410A liquid refrigerant into the high side of each 38AU circuit through the liquid Service Valve service valve(s). The amount of refrigerant added must be with Stem Cap Sweat...
Page 18: Step 7 - Complete Electrical Connections
Step 7 — Complete Electrical Connections WARNING WARNING FIRE HAZARD Failure to follow this warning could cause in personal ELECTRICAL SHOCK HAZARD injury, death and/or equipment damage. Failure to follow this warning could result in personal Do not connect aluminum wire between disconnect injury or death.
Page 19 Locate its disconnect switch, if appropriate, and open it. Tag-out this switch, if necessary. 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)
Page 20 Field Control Wiring — checked and de-energization is confirmed. Observe National Electrical Code Article 210, Branch Circuits, 38AU unit control voltage is 24 v. See Fig. 29 (38AUZ) for use of convenience outlets. and Fig. 30 (38AUD) for typical field control connections and the unit’s label diagram for field-supplied wiring...
Page 21 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. (Note 1) The 38AUZ is a single-circuit, two- - stage cooling unit.
Page 22 NO C.O. or UNPWRD C.O. NOMINAL VOLTAGE POWER RANGE UNIT No. 1 No. 2 POWER SUPPLY DISCONNECT SIZE SUPPLY SIZE FUSE or 38AU V--- Ph--- Hz HACR (ea) BRKR 208/230---3---60 25.0 25.0 60.8/60.8 80/80 63/63 337/337 D*16 460 ---3 ---60 12.2...
Page 23: Pre-Start-Up
CAUTION START-UP UNIT DAMAGE HAZARD 38AU Units: The compressor crankcase heater must be on Failure to follow this caution may result in equipment for 24 hours before start-up. After the heater has been on damage. for 24 hours, the unit can be started. If no time elapsed...
Page 24: Start Unit
Close becomes excessive, and automatically resets when the the 38AU disconnect switch. Only the crankcase heater internal temperature drops to a safe level. This overload will be energized.
Page 25 38AUZ*25 Check Compressor Oil Level — IMPORTANT: Oil level should only be checked when the compressors are off. After adjusting the refrigerant charge, allow the unit to run fully loaded for 20 minutes. Stop the compressors and Add oil only if necessary to bring the oil into view in the check the oil level.
Page 26 (CIRCUIT 1) (CIRCUIT 2) C10946 Fig. 24 - - 38AUD*16 Charging Chart (Novation)
Page 27 C10947 Fig. 25 - - 38AUZ*16 Charging Chart (RTPF) C10948 Fig. 26 - - 38AUZ*25 Charging Chart (RTPF)
Page 28 C10949 Fig. 27 - - 38AUD*16 Charging Chart (RTPF)
Page 29 (CIRCUIT 1) (CIRCUIT 2) C10950 Fig. 28 - - 38AUD*25 Charging Chart (RTPF)
Page 30 C10212A Fig. 29 - - Typical 38AUZ Wiring Diagram - (15 Ton 230V Tandem Unit Shown)
Page 31 C10213A Fig. 30 - - Typical 38AUD Wiring Diagram - (15 Ton 230V Dual Unit Shown)
Page 32: Operating Sequence
OPERATING SEQUENCE On a thermostat calling for Stage 2 Cooling, thermostat output Y2 is energized; terminal Y2 at 38AUD unit Base Unit Controls receives 24-v. 24-v received at CADM2 terminal Y. If anti-recycle time delay period has not expired, CADM2 —...
Page 33: Routine System Maintenance
ROUTINE SYSTEM MAINTENANCE SERVICE Refrigeration System These items should be part of a routine maintenance program, to be checked every month or two, until a specific CAUTION schedule for each can be identified for this installation: Quarterly Inspection (and 30 days after initial start) — EQUIPMENT DAMAGE HAZARD Indoor section Failure to follow this caution may result in damage to...
Page 34: Liquid Line Filter Drier
Liquid Line Filter Drier — Factory High-Flow Access Ports — The factory-provided filter drier is specifically designed to There are two additional access ports in the system - on ® operate with Puron . Replace the filter drier with the suction tube between the compressor and the suction factory-authorized components only with a filter drier service valve and on the liquid tube near the liquid service with desiccant made from 100% molecular sieve grade...
Page 35: Comfort Alert Diagnostic Module
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.
Page 36 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 Compressor protector is open Red “TRIP” Thermostat demand signal LED On Solid Y is present, but the com- Condensing unit power disconnect is open pressor is not running.
Page 37: Compressor Protection
TRIP LED is on but system Verify Y terminal is wired properly per the 38AU wiring diagram (see Fig. 29 and Fig. 30). Verify and compressor check OK voltage at contactor coil falls below 0.5VAC when off. Verify 24VAQC is present across Y and C when thermostat demand signal is present.
Page 38 Condenser Fans/Motors Access Panel - Control Box & Compressors Service Valves C10087 Fig. 34 - - 38AUD Size 16 Cabinet C10095 Fig. 35 - - 38AUD*16 Piping...
Page 39 Equalization Oil Equalizer Line C10079 Fig. 36 - - 38AUZ*16 Compressor Assembly (Rear View) C10214 Fig. 37 - - 38AUD*16 Compressor Assembly (Rear View)
Page 40 Condenser Fans/Motors Access Panel - Control Box & Compressors Service Valves C10089 Fig. 38 - - 38AUZ,D Size 25 Cabinet C10090 Fig. 39 - - 38AUD*25 Piping...
Page 41 C10215 Fig. 40 - - 38AUZ*25 Compressor Assembly (Rear View) C10091 Fig. 41 - - 38AUD*25 Compressor Assembly (Rear View)
Page 42: Coil Type Identification
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.
Page 43: Replacing Novation Condenser Coil
RTPF coils. This UNIT RELIABILITY HAZARD cleaner is available from Carrier Replacement parts division Failure to follow this caution may result in reduced as part number P902-0301 for a one gallon container, and unit performance.
Page 44: Service
FASTENER TORQUE VALUES 7. Hold garden sprayer nozzle close to finned areas and apply cleaner with a vertical, up-and-down motion. Table 13 – Torque Values Avoid spraying in horizontal pattern to minimize po- Compressor mounting bolts 65--- 75 in–lbs tential for fin damage. (734–847 N–cm) 8.
Page 45: Troubleshooting
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.
Page 46: Air Conditioner & Heat Pump With Puron
APPENDIX A S POE oils absorb moisture rapidly. Do not expose oil to ® Air Conditioner & Heat Pump with PURON atmosphere. — Quick Reference Guide S POE oils may cause damage to certain plastics and ® S Puron (R-410A) refrigerant operates at 50 percent to roofing materials.
Page 47: Low Ambient Option - Factory Installed
APPENDIX C Low Ambient Option — Factory Installed Troubleshooting — OBSERVATION POSSIBLE REMEDY Units with the factory installed low ambient option are Fans won’t start All fans: equipped with a Motormaster solid- - state head pressure Check power & wiring control which regulates fan speed.
Page 48 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 C10093 C10094 Fig. 44 - - Motormaster Sensor Location: Fig.
Page 49 Table 14 – Wind Baffle Dimension DIMENSIONS --- INCHES UNIT BAFFLE LEFT SIDE 38AUZ*16 BACK 38AUD*16 RIGHT SIDE (MCHX) FRONT LEFT SIDE 38AUZ*16 BACK 38AUD*16 RIGHT SIDE (RTPF) FRONT LEFT SIDE 38AUZ*25 BACK 38AUD*25 RIGHT SIDE (RTPF) FRONT DIMENSIONS --- MM UNIT BAFFLE LEFT SIDE...
Page 54 Catalog No: 38AU ---09SI 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 time, specifications and designs without notice and without obligations.
Page 55: Start-Up Checklist
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)
Page 56 COMPRESSOR 2 AMPS (L1/L2/L3) NOTES: Catalog No: 38AU ---09SI 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 time, specifications and designs without notice and without obligations.

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Carrier 38AU Installation, Start-Up And Service Instructions Manual

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