Carrier Gemini 38AX 16 Series Installation, Start-Up And Service Instructions Manual
Carrier Gemini 38AX 16 Series Installation, Start-Up And Service Instructions Manual

Carrier Gemini 38AX 16 Series Installation, Start-Up And Service Instructions Manual

Air-cooled condensing units with puron advance (r-454b) refrigerant
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Installation, Start-Up and Service Instructions
CONTENTS
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 1
Detection of Flammable Refrigerants . . . . . . . . . . . . 2
Ignition Source Mitigation . . . . . . . . . . . . . . . . . . . . . 2
Ventilation Requirements . . . . . . . . . . . . . . . . . . . . . . 2
INSTALLATION GUIDELINES . . . . . . . . . . . . . . . . . . . 3
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Rated Indoor Airflow (cfm) . . . . . . . . . . . . . . . . . . . . . 3
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Jobsite Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Step 1 - Plan for Unit Location . . . . . . . . . . . . . . . . 8
Step 4 - Rig and Mount the Unit . . . . . . . . . . . . . . . . . . 8
Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Step 8 - Install Accessories . . . . . . . . . . . . . . . . . . 21
PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Turn On Crankcase Heater . . . . . . . . . . . . . . . . . . . . 27
Preliminary Charge . . . . . . . . . . . . . . . . . . . . . . . . . . 27
START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Preliminary Checks . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Start Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
OPERATING SEQUENCE . . . . . . . . . . . . . . . . . . . . . 33
Base Unit Controls . . . . . . . . . . . . . . . . . . . . . . . . . . 33
All Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
(and 30 days after initial start) . . . . . . . . . . . . . . . 34
Seasonal Maintenance . . . . . . . . . . . . . . . . . . . . . . . 34
SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Refrigeration System . . . . . . . . . . . . . . . . . . . . . . . . 35
Comfort Alert Diagnostic Module . . . . . . . . . . . . . . 40
Compressor Protection . . . . . . . . . . . . . . . . . . . . . . 42
Coils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Fastener Torque Values . . . . . . . . . . . . . . . . . . . . . . 43
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . 43
DECOMMISSIONING . . . . . . . . . . . . . . . . . . . . . . . . . 46
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 04-53380059-01
with Puron Advance™ (R-454B) Refrigerant
Printed in U.S.A.
Form No. 38AX-16-28-01SI
Air-Cooled Condensing Units
Page
APPENDIX B - WIRING DIAGRAMS. . . . . . . . . . . . .48
START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . . . CL-1

SAFETY CONSIDERATIONS

Improper
installation,
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
packaged with the kits or accessories when installing.
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
U.S.A., ANSI/NFPA70, National Electrical Code (NEC); in
Canada, CSA C22.1) for special requirements.
It is important to recognize safety information. This is the safety-
alert symbol
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 will result in personal injury or
death.
Before performing service or maintenance operations on unit,
turn off main power switch to unit and install lock(s) and
lockout tag(s). Ensure electrical service to rooftop unit agrees
with voltage and amperage listed on the unit rating plate. Do
not check compressor ohms at compressor terminals. Unit
may have more than one power switch.
38AX*16/25/28
adjustment,
alteration,
. When you see this symbol on the unit and in
DANGER
Pg 1
1-25
Gemini™
service,
Replaces: NEW

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Summary of Contents for Carrier Gemini 38AX 16 Series

  • Page 1: Table Of Contents

    Gemini™ 38AX*16/25/28 Air-Cooled Condensing Units with Puron Advance™ (R-454B) Refrigerant Installation, Start-Up and Service Instructions CONTENTS APPENDIX A — AIR CONDITIONER AND HEAT PUMP WITH PURON ADVANCE™ — QUICK REFERENCE Page GUIDE ........47 SAFETY CONSIDERATIONS .
  • Page 2: Cut Hazard

    Unit Label Safety Symbols WARNING This symbol shows that the appliance UNIT OPERATION AND SAFETY HAZARD used a flammable refrigerant. If the WARNING refrigerant is leaked and exposed to an Failure to follow this warning could cause personal injury, ignition source, there is a risk of fire death and/or equipment damage.
  • Page 3: Installation Guidelines

    INSTALLATION GUIDELINES GENERAL INSTALLATION See Fig. 1 for 38AX model number nomenclature. For date of unit manufacture see Fig. 2 serial number nomenclature. For unit di- Remove the existing evaporator coil or fan coil and install the mensions see Fig. 3. For corner weights see Table 4. For physical replacement coil when appropriate.
  • Page 4 10 11 12 13 14 15 16 17 18 3 8 A X D T 1 6 A 0 A 6 A 0 A 0 A 0 Model Type Packaging 38AX = Carrier Condensing Unit 0 = Standard Puron Advance™ R-454B Refrigerant Electrical Options Type of Coil...
  • Page 5 Fig. 3 — 38AXD/Z 16 Base Unit Dimensions...
  • Page 6 Fig. 4 — 38AXZ 25 / 38AXD 25-28 Base Unit Dimensions...
  • Page 7 Table 4 — 38AXZ*16/25 Physical Data UNIT 38AXZ(M,N)16 38AXZ(M,N)25 NOMINAL CAPACITY (TONS) OPERATING WEIGHT (lb) Refrigeration System No. Circuits / No. Comp. / Type 1 / 2 / Scroll 1 / 2 / Scroll Refrigerant Type R-454B R-454B R-454B Shipping Charge A/B (lb) System Charge w/ Fan Coil 34.0 36.5...
  • Page 8: Installation

    • Pipework must be protected from potential damage during INSTALLATION normal operation, service or maintenance. Jobsite Survey Although unit is weatherproof, avoid locations that permit water Complete the following checks before installation. from higher level runoff and overhangs to fall onto the unit. Consult local building codes and the NEC (National Electrical Step 2 —...
  • Page 9: Step 5 - Check Refrigerating Equipment

    Refer to Part 3 of the force to the unit. Carrier System Design Manual for additional data and information on equivalent lengths. Raise from above to lift the unit from the rails or pad when unit is in its final position.
  • Page 10 Table 7 — Suction Line Diameter — Condenser Above Evaporator a,b,c LINEAR LENGTH (ft) 0-25 26-50 51-75 76-100 101-125 126-150 151-175 176-200 SUCTION NOMINAL UNIT CIRCUITS RISER EQUIV. LINEAR TONNAGE 0-37 38-74 75-112 113-149 150-187 188-224 225-262 263-300 TYPE LENGTH (ft) Nominal Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Suction Line Dia.
  • Page 11 Table 7 — Suction Line Diameter — Condenser Above Evaporator a,b,c (cont) LINEAR LENGTH (ft) 0-25 26-50 51-75 76-100 101-125 126-150 151-175 176-200 SUCTION NOMINAL UNIT CIRCUITS RISER EQUIV. LINEAR TONNAGE 0-37 38-74 75-112 113-149 150-187 188-224 225-262 263-300 TYPE LENGTH (ft) Nominal Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Suction Line Dia.
  • Page 12 Table 7 — Suction Line Diameter — Condenser Above Evaporator a,b,c (cont) LINEAR LENGTH (ft) 0-25 26-50 51-75 76-100 101-125 126-150 151-175 176-200 SUCTION NOMINAL UNIT CIRCUITS RISER EQUIV. LINEAR TONNAGE 0-37 38-74 75-112 113-149 150-187 188-224 225-262 263-300 TYPE LENGTH (ft) Nominal Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Suction Line Dia.
  • Page 13 Table 8 — Liquid Line Diameter — Condenser Above Evaporator LINEAR LENGTH (ft) 0-25 26-50 51-75 76-100 101-125 126-150 151-175 176-200 NOMINAL UNIT CIRCUITS EQUIV. LINEAR TONNAGE 0-37 38-74 75-112 113-149 150-187 188-224 225-262 263-300 LENGTH (ft) Nominal Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Liquid Line Dia.
  • Page 14 Table 9 — Liquid Line Diameter — Condenser Below Evaporator LINEAR LENGTH (ft) 0-25 26-50 51-75 76-100 101-125 126-150 151-175 176-200 NOMINAL UNIT CIRCUITS TONNAGE EQUIV. LINEAR 0-37 38-74 75-112 113-149 150-187 188-224 225-262 263-300 LENGTH (ft) Nominal Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Liquid Line Dia.
  • Page 15 Table 10 — Suction Line Diameter — Condenser Level or Below Evaporator LINEAR LENGTH (ft) 0-25 26-50 51-75 76-100 101-125 126-150 151-175 176-200 NOMINAL UNIT CIRCUITS TONNAGE EQUIV. LINEAR 0-37 38-74 75-112 113-149 150-187 188-224 225-262 263-300 LENGTH (ft) Nominal Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Nominal Allowable Suction Line Dia (in.) 1-3/8 1-3/8...
  • Page 16: Liquid Lift

    LIQUID LIFT A liquid lift condition exists when the outdoor unit is located be- low 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 sub-cooling at the evaporator coil’s thermal expansion valve.
  • Page 17: Install Filter Drier(S) And Moisture  Indicator(S)

    as the arrangement of the 40RL changes. In a vertical arrange- ment, the 40RL unit’s lower coil segment is segment 2; this segment should be connected to the 38AXD unit’s Circuit 1. In a horizontal arrangement, the 40RL unit’s lower segment is now segment 1;...
  • Page 18: Install Liquid Line Solenoid Valve

    Refer to Table 13 for recommendations on refrigeration unit to the outdoor unit before opening the liquid and suction lines specialties. at the outdoor unit. INSTALL LIQUID LINE SOLENOID VALVE Table 12 — Puron Advance™-Duty Filter Drier(s) It is recommended that a solenoid valve be placed in the main liq- PART LIQUID LINE DESICCANT...
  • Page 19 Solenoid Drop Control Wiring EQUALIZER LINE Control the power to the liquid line solenoid through a Solenoid INDOOR SENSING SIGHT GLASS COIL CKT Valve Relay (SVR) in all units. Use part number HN61PC005 BULB A LOCATION FILTER DRIER (field-supplied, installed). 38AXZ unit requires one SVR; 38AXD A LOCATION unit requires two relays.
  • Page 20: Selecting An Accumulator

    GTAC II, Module 4, System For linear line lengths longer than 125 ft (38 m), contact your local Dehydration. Carrier representative for system charge value. A2L CHARGING REQUIREMENTS WARNING In addition to conventional charging procedures, the following re- quirements shall be followed.
  • Page 21: Step 8 - Install Accessories

    • Ensure that the refrigerating system is earthed prior to charging the system with refrigerant. • Label the system when charging is complete (if not already). • Extreme care shall be taken not to overfill the refrigerating system. Prior to recharging the system, it shall be pressure-tested with the appropriate purging gas.
  • Page 22: Units With Factory-Installed Non-Fused Disconnect

    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 1/4-in. female spade connector Electric from the 230-v connection and moving it to the 208-v 1/4-in.
  • Page 23 Fuse on power type: The factory fuse is a Bussman™ “Fusetron™ ” T-15, non-renewable screw-in (Edison base) type Convenience plug fuse. Outlet GFCI WARNING Pwd-CO Fuse Switch ELECTRICAL OPERATION HAZARD Pwd-CO Failure to follow this warning could result in personal injury or Transformer death.
  • Page 24: Field Control Wiring

    Figures 21 (38AXZ) and 22 (Note 2) (38AXD) depict typical connections to a Carrier 40RL fan coil unit. Plan for field connections carefully and install control wir- ing correctly per the project plan. Additional components and supplemental transformer accessory may be required.
  • Page 25: External Devices

    will include the indoor fan motor contactor (or control relay) or unit control board in the fan coil unit. These devices may also in- clude liquid line solenoid valve (two on 38AXD model), econo- mizer control relay, supplemental electric heater contactors or control relays and other devices selected by system designer.
  • Page 26 Table 17 — 38AXD Unit Electrical Data NOMINAL COMPRESSOR NO C.O. OR POWERED C.O. VOLTAGE POWER RANGE UNIT NUMBER No. 1 No. 2 Power Supply Disconnect Size SUPPLY SIZE Fuse or 38AXD STAGES V-Ph-Hz HACR (ea) Breaker 208/230-3-60 26.9 29.2 68/68 90/90 70/70...
  • Page 27: Step 10 - Wind Baffles For Low Ambient Control

    Step 10 — Wind Baffles for Low Ambient Control CAUTION Units with low ambient control (either as factory-installed option or field-installed accessory) require the addition of wind baffles to UNIT DAMAGE HAZARD ensure full range low ambient operation. Material data and dimen- Failure to follow this caution may result in equipment damage.
  • Page 28: Start Unit

    See Fig. 25. Refer to Cooling Charging Charts, Fig. 27-31. For applications with line lengths greater than 125 ft (38 m), contact Carrier rep- To manually reset ASTP, the compressor should be stopped and resentative. Make sure that all condenser fans are operating be- allowed to cool.
  • Page 29: Charging Chart

    15 Tons Dual Stage R-454B CHARGING CHART (Unit must run both compressors and outdoor fans on high speed) 59.9 48.8 Add Charge if Above the Curve 37.7 26.6 Remove Charge if Below the Curve 15.5 -6.7 1034 1379 1723 2068 2413 2758 3102...
  • Page 30 15 Tons Circuit B R-454B CHARGING CHART 15 Tons Circuit A R-454B CHARGING CHART (Unit must run both compressors and (Unit must run both compressors and outdoor fans on high speed) outdoor fans on high speed) 59.9 59.9 Add Charge if Above the Curve Add Charge if Above the Curve 48.8 48.8...
  • Page 31 20 Tons Circuit A R-454B CHARGING CHART 20 Tons Circuit B R-454B CHARGING CHART (Unit must run both compressors and (Unit must run both compressors and outdoor fans on high speed) outdoor fans on high speed) 59.9 59.9 Add Charge if Above the Curve Add Charge if Above the Curve 48.8 48.8...
  • Page 32 25 Tons Circuit A R-454B CHARGING CHART 25 Tons Circuit B R-454B CHARGING CHART (Unit must run both compressors and (Unit must run both compressors and outdoor fans on high speed) outdoor fans on high speed) 59.9 59.9 Add Charge if Above the Curve Add Charge if Above the Curve 48.8 48.8...
  • Page 33: Operating Sequence

    24-v received at CADM2 terminal Y. If anti-recycle time delay pe- OPERATING SEQUENCE riod has not expired, CADM2 relay will remain open, de-energiz- Base Unit Controls ing Solenoid Valve Relay 2 (SVR2) and preventing compressor start. When safety pressure switches are closed and CADM2 time INDOOR (SUPPLY) FAN delay expires, CADM2 relay closes, SVR2 and compressor con- If the thermostat fan operation is selected as Continuous the in-...
  • Page 34: Quarterly Inspection  (And 30 Days After Initial Start)

    Seasonal Maintenance a. The above list may not include all maintenance items. Inspection intervals may vary depending on climate and opening hours. Consult your Carrier dealer These items should be checked at the beginning of each season (or about a service contact for seasonal inspections.
  • Page 35: Refrigeration System

    Synthetic Roof Precautionary Procedure: SERVICE Cover extended roof working area with an impermeable Refrigeration System polyethylene (plastic) drop cloth or tarp. Cover an approxi- mate 10 x 10 ft (3.3 x 3.3 m) area. Cover area in front of the unit service panel with a terry cloth WARNING shop towel to absorb lubricant spills and prevent run-offs, and UNIT OPERATION AND SAFETY HAZARD...
  • Page 36 Condenser Fans/Motors Outdoor Fan 1 Outdoor Fan 2 Outdoor Fan 3 Access Panel - Control Box and Compressors Service Valves Fig. 32 — 38AXZ/D Size 16 Cabinet Fig. 33 — 38AXD*16 Piping...
  • Page 37 Suction Equalizer Oil Equalizer Line Fig. 34 — 38AXZ*16 Compressor Assembly (Rear View) Fig. 35 — 38AXD*16 Compressor Assembly (Rear View)
  • Page 38 Condenser Fans/Motors Outdoor Outdoor Fan 1 Fan 4 Outdoor Fan 2 Outdoor Fan 3 Access Panel - Control Box & Compressors Service Valves Fig. 36 — 38AXZ/D Size 25/28 Cabinet Fig. 37 — 38AXD*25/28 Piping...
  • Page 39 Fig. 38 — 38AXZ*25 Compressor Assembly (Rear View) Fig. 39 — 38AXD*25/28 Compressor Assembly (Rear View)
  • Page 40: Comfort Alert Diagnostic Module

    Comfort Alert Diagnostic Module Power The Comfort Alert Diagnostic Module (CADM) monitors and an- (GRN) Comfort Alert ™ alyzes data from the Copeland™ Scroll three-phase compressor Commercial Diagnostics POWER and the thermostat demand. The CADM also provides a 3-minute Green LED - 24VAC Power Yellow LED - Flash Code System Pressure Trip anti-recycle time delay to compressor cycling.
  • Page 41: Status Led Description

    Table 22 — LED Status Codes STATUS LED STATUS LED STATUS LED TROUBLESHOOTING INFORMATION DESCRIPTION Green “POWER” Module has power Supply voltage is present at module terminals 1. Compressor protector is open Thermostat demand 2. Condensing unit power disconnect is open signal Y is present, but 3.
  • Page 42: Compressor Protection

    (ASTP) cleaner is essential to extend the life of RTPF coils. This cleaner is available from Carrier Replacement parts division as part number See “Advanced Scroll Temperature Protection (ASTP)” on P902-0301 for a one gallon container, and part number P902-0305 page 28.
  • Page 43: Fastener Torque Values

    TOTALINE ENVIRONMENTALLY BALANCED COIL NOTE: Use of a water stream, such as a garden hose, against sur- face loaded coil will drive the fibers and dirt into the coil, making CLEANER APPLICATION EQUIPMENT cleaning efforts more difficult. Surface loaded fibers must be com- •...
  • Page 44 Table 25 — 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.
  • Page 45 Table 25 — Troubleshooting (cont) PROBLEM SOLUTION COMPRESSOR RUNNING BUT COOLING INSUFFICIENT 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.
  • Page 46: Evacuation, Removal, And Recovery

    EVACUATION, REMOVAL, AND RECOVERY DECOMMISSIONING When breaking into the refrigerant circuit to make repairs - or for Before carrying out this procedure, it is essential that the techni- any other purpose - conventional procedures shall be used. How- cian is completely familiar with the equipment and all its detail. It ever, for flammable refrigerants it is important that best practice be is recommended good practice that all refrigerants are recovered followed, since flammability is a consideration.
  • Page 47: Appendix A - Air Conditioner And Heat Pump With Puron Advance™ - Quick Reference Guide

    APPENDIX A — AIR CONDITIONER AND HEAT PUMP WITH PURON ADVANCE™ — QUICK REFERENCE GUIDE • Puron Advance™ (R-454B) refrigerant operates at 50 per- • POE oils may cause damage to certain plastics and roofing cent to 70 percent higher pressures than R-22. Be sure that materials.
  • Page 48: Appendix B - Wiring Diagrams

    APPENDIX B — WIRING DIAGRAMS ELECTRICAL UNIT DIAGRAM NUMBER PAGE NUMBER CHARACTERISTICS 575-3-60 38AU002435 38AXD*16 208/230-3-60 38AU002436 460-3-60 38AU002437 575-3-60 38AU002442 38AXD*25 208/230-3-60 38AU002443 460-3-60 38AU002444 575-3-60 38AU002446 38AXD*28 208/230-3-60 38AU002447 460-3-60 38AU002448 575-3-60 38AU002432 38AXZ*16 208/230-3-60 38AU002433 460-3-60 38AU002434 575-3-60 38AU002439 38AXZ*25...
  • Page 49 APPENDIX B — WIRING DIAGRAMS (cont) Fig. A — Dual Circuit/Three Stage Wiring Diagram, 15 Ton — 575-3-60 Unit...
  • Page 50 APPENDIX B — WIRING DIAGRAMS (cont) Fig. B — Dual Circuit/Three Stage Wiring Diagram, 15 Ton — 208/230-3-60 Unit...
  • Page 51 APPENDIX B — WIRING DIAGRAMS (cont) Fig. C — Dual Circuit/Three Stage Wiring Diagram, 15 Ton — 460-3-60 Unit...
  • Page 52 APPENDIX B — WIRING DIAGRAMS (cont) Fig. D — Dual Circuit/Three Stage Wiring Diagram, 20 Ton — 575-3-60 Unit...
  • Page 53 APPENDIX B — WIRING DIAGRAMS (cont) Fig. E — Dual Circuit/Thee Stage Wiring Diagram, 20 Ton — 208/230-3-60 Unit...
  • Page 54 APPENDIX B — WIRING DIAGRAMS (cont) Fig. F — Dual Circuit/Three Stage Wiring Diagram, 20 Ton — 460-3-60 Unit...
  • Page 55 APPENDIX B — WIRING DIAGRAMS (cont) Fig. G — Dual Circuit/Three Stage Wiring Diagram, 25 Ton — 575-3-60 Unit...
  • Page 56 APPENDIX B — WIRING DIAGRAMS (cont) Fig. H — Dual Circuit/Three Stage Wiring Diagram, 25 Ton — 208/230-3-60 Unit...
  • Page 57 APPENDIX B — WIRING DIAGRAMS (cont) Fig. I — Dual Circuit/Three Stage Wiring Diagram, 25 Ton — 460-3-60 Unit...
  • Page 58 APPENDIX B — WIRING DIAGRAMS (cont) Fig. J — Single Circuit/Two Stage Wiring Diagram, 15 Ton — 575-3-60 Unit...
  • Page 59 APPENDIX B — WIRING DIAGRAMS (cont) Fig. K — Single Circuit/Two Stage Wiring Diagram, 15 Ton — 208/230-3-60 Unit...
  • Page 60 APPENDIX B — WIRING DIAGRAMS (cont) Fig. L — Single Circuit/Two Stage Wiring Diagram, 15 Ton — 460-3-60 Unit...
  • Page 61 APPENDIX B — WIRING DIAGRAMS (cont) Fig. M — Single Circuit/Two Stage Wiring Diagram, 20 Ton — 575-3-60 Unit...
  • Page 62 APPENDIX B — WIRING DIAGRAMS (cont) Fig. N — Single Circuit/Two Stage Wiring Diagram, 20 Ton — 208/230-3-60 Unit...
  • Page 63 APPENDIX B — WIRING DIAGRAMS (cont) Fig. O — Single Circuit/Two Stage Wiring Diagram, 20 Ton — 460-3-60 Unit...
  • Page 64: Operation

    APPENDIX C — LOW AMBIENT OPTION Units with the factory installed low ambient option are equipped Troubleshooting with a solid-state head pressure control which regulates fan speed. OBSERVATION POSSIBLE REMEDY A temperature sensor, mounted on either circuit 1 (38AXZ units) or both circuits 1 and 2 (38AXD units) of the outdoor coil controls All fans: Check power and wiring...
  • Page 65 APPENDIX C — LOW AMBIENT OPTION (cont) Low Ambient Sensor 2 Must Be Positioned On Vapor Stub (Fourth From Top) Low Ambient Sensor 1 Must Be Positioned On Vapor Stub (Fourth From Top) Circuit 2 Circuit 1 Fig. P — 38AXD*16 Low Ambient Sensor Locations Low Ambient Sensor 2 Must Be Positioned On Vapor Stub...
  • Page 66: Dimensions (Mm)

    APPENDIX C — LOW AMBIENT OPTION (cont) Low Ambient Sensor Must Be Positioned On Vapor Stub (Fourth From Top) Fig. R — 38AXZ*16/25 Low Ambient Sensor Location (Circuit 1 Only) Table A — Wind Baffle Dimension DIMENSIONS (in.) UNIT BAFFLE LEFT SIDE 10-3/4 11-1/2...
  • Page 67 APPENDIX C — LOW AMBIENT OPTION (cont) NOTE: Dimensions are in inches. Fig. S — Wind Baffles – Fabrication...
  • Page 68 APPENDIX C — LOW AMBIENT OPTION (cont) NOTE: Dimensions are in inches. Fig. T — 15 Ton Wind Baffle Brackets – Fabrication...
  • Page 69 APPENDIX C — LOW AMBIENT OPTION (cont) TOP BRACKETS FRONT BOTTOM BRACKET BACK LEFT RIGHT Fig. U — Wind Baffle Installation – 15 Ton Units...
  • Page 70 BACK RIGHT Fig. V — Wind Baffle Installation – 20 and 25 Ton Units © 2025 Carrier Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations. Catalog No. 04-53380059-01 Printed in U.S.A.
  • Page 71: Preliminary Information

    START-UP CHECKLIST (Remove and use for Job File) NOTE: To avoid injury to personnel and damage to equipment or property when completing the procedures listed in this start-up checklist, use good judgment, follow safe practices, and adhere to the safety considerations/information as outlined in preceding sec- tions of this Installation, Start-Up, and Service document.
  • Page 72 ________________________________________________________________________________________________________ ________________________________________________________________________________________________________ ________________________________________________________________________________________________________ ________________________________________________________________________________________________________ ________________________________________________________________________________________________________ ________________________________________________________________________________________________________ © 2025 Carrier Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations. Catalog No. 04-53380059-01 Printed in U.S.A. Form No. 38AX-16-28-01SI Pg CL-2...

This manual is also suitable for:

Gemini 38ax 25 seriesGemini 38ax 28 series

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