Carrier CAS072 - User Manual

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CAS-072-153-01SI Rev. A 1-23

Installation, Start-Up and Service Instructions

CONTENTS

Page

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

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

Replacement/Retrofit — R-22 to R-410A

Refrigerant . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Rated Indoor Airflow (cfm) . . . . . . . . . . . . . . . . . 2

Matching CAS Model to Evaporator Coil . . . . . 3

INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Jobsite Survey . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Step 1 — Plan for Unit Location . . . . . . . . . . . . 6

Step 2 — Complete Pre-Installation Checks . . 7

Step 3 — Prepare Unit Mounting Support . . . . 7

Rig and Mount the Unit . . . . . . . . . . . . . . . . . . . 7

Step 4 — Determine Refrigerant Line Sizes . . . 7

Suction Riser . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Step 5 — Complete Refrigerant Piping

Connections . . . . . . . . . . . . . . . . . . . . . . . . . 10

Step 6 — Install Accessories . . . . . . . . . . . . . . 13

Step 7 — Complete Electrical Connections . . 13

Step 8 — Wind Baffles for Low Ambient

Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . 18

System Check . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Turn On Crankcase Heater . . . . . . . . . . . . . . . 18

Preliminary Charge . . . . . . . . . . . . . . . . . . . . . . 18

START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Preliminary Checks . . . . . . . . . . . . . . . . . . . . . 18

Start Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

OPERATING SEQUENCE . . . . . . . . . . . . . . . . . 25

Base Unit Controls . . . . . . . . . . . . . . . . . . . . . . 25

All Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . 26

Quarterly Inspection

(and 30 days after initial start) . . . . . . . . . . . 26

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

SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

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

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

Compressor Protection . . . . . . . . . . . . . . . . . . 31

Routine Cleaning of Round-Tube Plate Fin

(RTPF) Coils . . . . . . . . . . . . . . . . . . . . . . . . . 31

Fastener Torque Values . . . . . . . . . . . . . . . . . . 32

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . 32

APPENDIX A — AIR CONDITIONER AND HEAT

PUMP WITH R-410A –

QUICK REFERENCE GUIDE . . . . . . . . . . . . . 35

APPENDIX B — WIRING DIAGRAMS . . . . . . . 35

APPENDIX C — LOW AMBIENT OPTION . . . . 50

START-UP CHECKLIST . . . . . . . . . . . . . . . . . CL-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 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 . 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

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.

DANGER

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.

WARNING

UNIT OPERATION AND SAFETY HAZARD

Failure to follow this warning could cause personal

injury, death and/or equipment damage.

R-410A refrigerant systems operate at higher pressures

than standard R-22 systems. Do not use R-22 service

equipment or components on R-410A refrigerant

equipment.

CAS072-153

Air-Cooled Condensing Units

with R-410A Refrigerant

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This document provides installation, start-up, and service instructions for CAS072-153 Air-Cooled Condensing Units with R-410A Refrigerant.

Function Description:

The CAS072-153 series comprises air-cooled condensing units designed for outdoor installation, utilizing R-410A refrigerant. These units are primarily used for air conditioning (cooling only) and are available in single-circuit (CAS072/091/121/151) and dual-circuit (CAS123/153) configurations, offering various cooling capacities. The units are designed to work with indoor evaporator coils and require proper refrigerant piping, electrical connections, and control systems. Key features include scroll compressors, condenser fan motors, and a Comfort Alert Diagnostic Module (CADM) for system monitoring and troubleshooting. Some models offer low ambient control options, which may require the installation of wind baffles.

Important Technical Specifications:

Refrigerant Type: R-410A. It operates at 50-70% higher pressures than R-22 systems. R-410A refrigerant cylinders are rose-colored.
Compressor: Scroll type. Single-circuit units (CAS072/091/121/151) have one compressor, while dual-circuit units (CAS123/153) have two compressors.
Oil Type: Polyolester (POE) oil, which is highly hygroscopic and absorbs water readily.
Cooling Capacity:
- CAS072: 6 Tons (2 stages)
- CAS091: 7.5 Tons (2 stages)
- CAS121: 10 Tons (2 stages)
- CAS123: 10 Tons (3 stages)
- CAS151: 12.5 Tons (2 stages)
- CAS153: 12.5 Tons (3 stages)
Rated Indoor Airflow (CFM):
- CAS072-F*X072: 2400
- CAS091-F*X091: 3000
- CAS121-F*X120: 4000
- CAS151-F*S/H150: 4400
- CAS123-F*X120: 4000
- CAS153-F*S/H150: 4400
Condenser Fan/Motor: All units feature direct-drive fan motors.
- CAS072/091/121/151: 2 fans, 1/4 HP, 1100 RPM, 22-inch diameter, 6,000 CFM nominal airflow, 610 total watts.
- CAS123/153: 2 fans, 1/4 HP, 1100 RPM, 22-inch diameter, 6,000 CFM nominal airflow, 610 total watts.
Piping Connections:
- CAS072: Suction 1-1/8 in. ODS, Liquid 3/8 in. ODS.
- CAS091: Suction 1-1/8 in. ODS, Liquid 1/2 in. ODS.
- CAS121: Suction 1-3/8 in. ODS, Liquid 1/2 in. ODS.
- CAS151: Suction 1-3/8 in. ODS, Liquid 5/8 in. ODS.
- CAS123: Suction 2 x 1-1/8 in. ODS, Liquid 2 x 3/8 in. ODS.
- CAS153: Suction 2 x 1-3/8 in. ODS, Liquid 2 x 1/2 in. ODS.
Electrical: 208/230-3-60, 460-3-60, or 575-3-60 V-Ph-Hz. Control voltage is 24V.
Safety Devices: High-pressure and low-pressure switches (fixed, non-adjustable), compressor over-temperature internal protection, Advanced Scroll Temperature Protection (ASTP).
Filter Drier: R-410A-duty filter drier with 100% molecular sieve grade XH-11 desiccant is required for every unit. Dual-circuit models require two filter driers.
Solenoid Valve: Recommended for liquid lines exceeding 75 ft (23 m) to prevent refrigerant migration.

Usage Features:

Installation: Units are designed for outdoor installation only. Proper clearances for airflow and service access must be maintained. Rigging requires all panels to be in place.
Refrigerant Piping: Use R-410A compatible equipment. Do not bury refrigerant lines. Suction lines must be insulated. Dual-circuit units (CAS123/153) require two separate piping systems.
Electrical Connections: Confirm voltage, amperage, and circuit protection requirements match the unit data plate. Ensure proper grounding. Units may have multiple power switches.
Crankcase Heater: Must be energized for 24 hours before starting the compressor to prevent damage.
Compressor Rotation: For 3-phase units, verify correct compressor rotation by checking suction and liquid pressures after energizing. Reverse any two power leads if rotation is incorrect.
Charging: Charge R-410A liquid refrigerant into the high side of the system through the liquid service valve. Do not charge liquid into the low-pressure side. Use charging charts for correct subcooling.
Comfort Alert Diagnostic Module (CADM): Monitors compressor and thermostat data, provides a 3-minute anti-recycle time delay, and detects electrical/system failures. Flashing LEDs communicate alert codes for troubleshooting.
Low Ambient Control: Optional feature that regulates fan speed to maintain constant head pressure at low outdoor temperatures. May require field-fabricated wind baffles.

Maintenance Features:

Quarterly Inspection (and 30 days after initial start):
- Outdoor Unit: Clear debris/vegetation, inspect cabinet for damage, check electrical disconnect/wiring/connections, check refrigerant system subcooling/superheat, inspect inside of unit for debris, inspect/clean condenser coil (rinse with fresh water, avoid harsh chemicals), inspect motor/fan for damage.
- Indoor Section: Check condenser coil cleanliness, replace return air filter, clean outdoor hood inlet filters, check fan shaft bearing locking collar tightness, check condensate drain.
- Heating: Check power wire connections, fuses, manual-reset limit switch.
Seasonal Maintenance:
- Air Conditioning: Check condenser fan motor mounting bolts, compressor mounting bolts, condenser fan blade positioning, control box cleanliness/wiring, wire terminal tightness, refrigerant charge level, evaporator coil cleaning, evaporator blower motor amperage.
Refrigeration System:
- Filter Drier Replacement: Replace the filter drier whenever the refrigerant system is opened. Use a tubing cutter to remove; do not unsweat.
- Access Ports: Field service access ports are 1/4-in. SAE Flare couplings with Schrader check valves. Ensure service caps are in place and secure after service.
Coil Cleaning: Periodic cleaning of Round-Tube Plate Fin (RTPF) coils with Totaline® environmentally balanced coil cleaner is essential. Avoid harsh chemicals, high-pressure washers, and poor quality water. Follow specific instructions for application and rinsing.
Fastener Torque Values: Specific torque values are provided for compressor mounting bolts, condenser fan motor mounting bolts, fan hub setscrews, high-flow service port, Schrader-type service check valve, compressor oil sight-glass thread, compressor to compressor rail, and compressor rail to base pan.