Carrier N4A4 - User Manual

Installation Instructions
NOTE: Read the entire instruction manual before starting the installation.
SAFETY CONSIDERATIONS
IMPORTANT: This appliance shall only be installed by EPA qualified
personnel having appropriate certification. This appliance is not
intended for use by persons (including children) with reduced physical,
sensory or mental capabilities or lack of experience and knowledge,
unless they have been given supervision or instruction concerning use of
the appliance by a person responsible for their safety.
Improper installation, adjustment, alteration, service, maintenance, or
use can cause explosion, fire, electrical shock, or other conditions which
may cause death, 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, protective clothing, and
work gloves. Use quenching cloth for brazing operations. Have fire
extinguisher available. Read these instructions thoroughly and follow all
warnings or cautions included in literature and attached to the unit.
Consult local building codes and current editions of the National
Electrical Code (NEC) NFPA 70. In Canada, refer to current editions of
the Canadian electrical code CSA 22.1.
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 these signal words;
DANGER, WARNING, and CAUTION. 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 would 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.
GENERAL
NOTE: In some cases noise in the living area has been traced to gas
pulsations from improper installation of equipment.
1. This unit is intended to be installed in a location that is 10,000 feet
(3000 meters) above sea level or lower.
2. Locate unit away from windows, patios, decks, etc. where unit
operation sound may disturb customer.
3. Ensure that vapor and liquid tube diameters are appropriate for unit
capacity.
4. Run refrigerant tubes with no bends with centerline bend radius less
than 2.5 times the external pipe diameter.
5. Leave some slack between structure and unit to absorb vibration.
6. When passing refrigerant tubes through the wall, seal opening with
RTV or other pliable silicon-based caulk. (See Fig. 1.)
7. Avoid direct tubing contact with water pipes, duct work, floor
joists, wall studs, floors, and walls.
8. Do not suspend refrigerant tubing from joists and studs with a rigid
wire or strap which comes in direct contact with tubing (see Fig. 1).
9. Ensure that tubing insulation is pliable and completely surrounds
vapor tube.
10. When necessary, use hanger straps which are 1 in. (25 mm) wide
and conform to shape of tubing insulation. (See Fig. 1.)
11. Isolate hanger straps from insulation by using metal sleeves bent to
conform to shape of insulation.
12. Provision shall be made for expansion and contraction of long runs
of piping.
13. Piping and fittings shall be protected as far as possible against
adverse environmental effects. For example, the accumulation of
dirt and debris.
14. Piping should be installed to reduce the likelihood of hydraulic
shock damaging the system.
15. Certified piping and components must be used in order to protect
against corrosion.
16. Flexible pipe elements shall be protected against mechanical
damage, excessive stress by torsion, or other forces. They should be
checked for mechanical damage annually.
17. Piping material, routing, and installation shall be include protection
from physical damage in operation and service, and be in
compliance with the national and local codes and standards of the
installation site.
18. When setting up refrigerant piping, precautions shall be taken to
avoid excessive vibration or pulsation
N4A4, N4A5S
SPLIT-SYSTEM AIR CONDITIONERS
WITH R-410A REFRIGERANT
WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury or death.
Before installing, modifying, or servicing system, main electrical
disconnect switch must be in the OFF position. There may be more than
1 disconnect switch. Lock out and tag switch with a suitable warning
label.
WARNING
!
EXPLOSION HAZARD
Failure to follow this warning could result in
personal injury or death.
Never use air or any gas containing oxygen for leak
testing or operating refrigerant compressors. Never
allow compressor suction pressure to operate in a
vacuum with service valves closed. See service
manual for pump-down instructions.

Summary

Safety Considerations

General Safety Precautions

Covers EPA qualifications, signal words, and general installation advice.

Electrical Shock Hazard Warning

Emphasizes disconnecting power before system installation or service.

Explosion Hazard Warning

Warns against using oxygen for leak testing and operating in vacuum.

General Installation Guidelines

Unit Location and Operating Limits

Site selection, altitude, noise considerations, and tube diameter.

Refrigerant Tubing Installation Best Practices

Guidance on bends, slack, contact, insulation, and expansion.

Piping Protection and Support

Protecting piping from environmental effects, stress, and corrosion.

Installation Procedures and Site Preparation

Cut Hazard Warning

Caution about sharp sheet metal edges and necessary protective gear.

Equipment Inspection and Mounting Pad Requirements

Unpacking, inspection, and ensuring a solid, level mounting pad.

Clearance and Operating Ambient

Specifies required clearances and minimum outdoor operating ambient temperature.

Refrigerant Handling Safety

Personal injury and environmental hazards associated with refrigerant handling.

Refrigerant System Installation Details

Refrigerant Tubing Burial and Protection

Guidelines for burying lines and preventing contamination.

Outdoor to Indoor Unit Connection

Connecting outdoor units to factory-approved indoor units and checking charge.

Refrigerant Tube Connections

Proper connection of liquid and vapor tubes to service valves.

Brazing Safety Precautions

Steps for brazing to prevent hazards and damage.

System Checks and Evacuation

Liquid-Line Filter Drier Installation

Required installation and brazing of the filter drier.

Evacuating Refrigerant Tubing and Coil

Importance and methods for deep vacuum evacuation.

Pressure Proof and Leak Checks

Procedures for verifying system integrity and detecting leaks.

Final Tubing and Piston Installation

Checking tubing security and installing indoor pistons.

Refrigerant Charge Adjustment Procedures

Replacement Unit Piston Adjustment

Adjusting piston size for replacement component installations.

TXV Unit Charging (Subcooling Method)

Procedure for charging units with TXVs using subcooling.

Piston Unit Charging (Superheat Method)

Procedure for charging units with pistons using superheat.

Electrical Connections and Wiring

Power and Ground Wire Connections

Connecting the main power and ground wires to the unit.

Control Wiring Installation

Routing and connecting low-voltage control wires to the thermostat.

Wiring Diagram Overview

Illustrative diagrams for typical unit wiring configurations.

Final Checks and System Start-Up

Pre-Start Wiring and Component Checks

Ensuring wiring is secure and checking components like crankcase heater.

System Start-Up Procedure

Step-by-step guide for initial system operation.

3-Phase Monitor and Operation Sequence

Explains the 3-phase monitor and the unit's operating sequence.

Charge Verification and Accessory Usage

Factory Charge and Adjustment Guidance

How to check and adjust refrigerant charge based on site conditions.

Required Accessory Guidance

Information on accessories needed for specific applications like long lines or low ambient.

General Hazard Warning on Parts

Warning about using non-manufacturer approved parts and accessories.

Post-Installation and Maintenance

Final Job Completion Checklist

Tasks to ensure the installation is complete and correct.

Refrigerant Circuit Repair Procedures

Steps for safely working on the refrigerant system.

Periodic Maintenance Importance

Emphasizing the need for regular maintenance for optimal performance.

Overview

1. Function Description
2. Important Technical Specifications
3. Usage Features
4. Maintenance Features

This document provides installation instructions for N4A4 and N4A5S split-system air conditioners with R-410A refrigerant. It emphasizes safety considerations, proper installation procedures, and maintenance guidelines to ensure optimal performance and longevity of the unit.

Function Description

The N4A4 and N4A5S are split-system air conditioners designed for residential applications, utilizing R-410A refrigerant. These units are intended to provide cooling by transferring heat from the indoor environment to the outdoors. The "split-system" designation indicates that the unit consists of an outdoor condensing unit and an indoor evaporator coil, connected by refrigerant tubing. The system operates by circulating R-410A refrigerant, which absorbs heat indoors and releases it outdoors, thereby cooling the indoor air. The installation instructions cover critical steps from site preparation and piping connections to electrical wiring, charging, and final checks, ensuring the system operates efficiently and safely.

Important Technical Specifications

• Refrigerant: R-410A.
• Installation Altitude: Intended for installation at locations 10,000 feet (3000 meters) above sea level or lower.
• Refrigerant Tube Diameters: Specific vapor and liquid tube diameters are recommended based on unit capacity. For 18, 24, 30, 36, 42, 48, and 60 size units, the liquid line connection and maximum tube diameter is 3/8 inch. Vapor line connection and tube diameters vary: 3/4 inch for 18, 24, 30 size units; 7/8 inch for 36, 42, 48 size units; and 7/8 inch connection with 1-1/8 inch tube diameter for 60 size units. These specifications are for units rated with a 25 ft (7.6 m) lineset.
• Refrigerant Tubing Lengths: Recommended up to 80 ft (24 m) for rated tubing diameters. For lengths beyond 80 ft (24 m) or vertical differentials of 35 ft (11 m) or more, refer to the Residential Piping and Long Line Guideline. Buried lines are limited to 36 inches (914 mm) with a 6-inch (152 mm) vertical rise at the service valve.
• Clearance Requirements: A minimum of 24 inches (610 mm) clearance is required at the service end of the unit, and 48 inches (1219 mm) above the unit. For proper airflow, 6 inches (152 mm) clearance on one side and 12 inches (305 mm) on all remaining sides must be maintained. For units with wire grille coil guards, an 18-inch (457 mm) clearance option is approved, otherwise 24 inches (610 mm) is required. Rooftop units must be at least 6 inches (152 mm) above the roof surface.
• Minimum Outdoor Operating Ambient: 55°F (13°C) in cooling mode without accessories.
• Electrical Wiring: Field wiring must comply with local and national fire, safety, and electrical codes. Use copper wire only between the disconnect switch and the unit. No. 18 AWG color-coded, insulated (35°C minimum) wire is recommended for control wiring up to 100 ft (30 m); No. 16 AWG for longer runs. Control power requires a 24V/40VA minimum transformer.
• Pressure Proof Check: A nitrogen charge of approximately 200 psi is required, which must not decrease in pressure for 1 hour.
• Vacuum Level: System must be evacuated to 500 microns. Pressure rise should not exceed 1500 microns in 10 minutes after isolation from the pump.

Usage Features

• Quiet Operation: Units should be located away from windows, patios, and decks to minimize operational sound disturbance. Proper installation, including leaving slack between the structure and unit to absorb vibration and avoiding direct tubing contact with building elements, helps reduce noise.
• Piping Installation: Refrigerant tubes should be run with no bends having a centerline bend radius less than 2.5 times the external pipe diameter. Openings through walls for refrigerant tubes should be sealed with RTV or other pliable silicon-based caulk. Hanger straps, 1 inch (25 mm) wide, should conform to the shape of tubing insulation and be isolated from insulation using metal sleeves.
• Mounting: Units must be installed on a solid, level mounting pad, within ±2° (±3/8 in./ft.±9.5 mm/m) per compressor manufacturer specifications. Tie-down bolts should be used if required by local codes or conditions, fastened through knockouts in the unit base pan.
• Refrigerant Charging:
  • Units with Cooling Mode TXV: Charge by the subcooling method. Operate the unit for at least 15 minutes before checking the charge. Measure liquid service valve pressure and liquid line temperature. Adjust refrigerant based on the required subcooling temperature from the unit rating plate, with a tolerance of ±3°F (±1.7°C).
  • Units with Indoor Piston: Charge by the superheat method. Operate the unit for at least 15 minutes. Measure suction pressure, suction temperature, outdoor air dry-bulb temperature, and indoor air wet-bulb temperature. Adjust refrigerant based on the superheat value from the provided chart. If the indoor piston needs replacement, use a back-up wrench, hand tighten the hex nut, then tighten with a wrench 1/2 turn (not exceeding 30 ft-lbs). Ensure the Teflon ring is properly seated.
• 3-Phase Monitor (for 3-phase units): A factory-installed circuit board monitors line voltage. A flashing LED indicates a reversed phase, requiring the interchange of 2 field-wiring leads on the unit contactor. A solid ON LED indicates normal operation.
• Crankcase Heater: If equipped, power must be supplied to the crankcase heater for a minimum of 24 hours before starting the unit, especially if refrigerant tubing is longer than 80 ft (24 m) or if the outdoor unit is 35 ft (6 m) below the indoor unit.

Maintenance Features

• Periodic Maintenance: To maintain high performance and minimize equipment failure, periodic maintenance is required. The frequency of maintenance may vary based on geographic areas and coastal applications. Refer to the Owner's Manual for detailed information.
• Filter Drier Installation: A liquid-line filter drier must be installed indoors. It should be wrapped in a heat-sinking material (e.g., a wet cloth) while brazing to prevent damage. The flow arrow on the drier must point towards the indoor coil.
• Evacuation: Refrigerant tubes and the indoor coil must be evacuated to 500 microns using the deep vacuum method to eliminate contamination and moisture. The system should hold a vacuum of 1000 microns for approximately 7 minutes. Never use the system compressor as a vacuum pump.
• Leak Testing: After piping connections and filter drier installation, the system must undergo leak testing. This involves a pressure proof check with nitrogen and then a vacuum check to ensure no leaks are present.
• Refrigerant Recovery: When breaking into the refrigerant circuit for repairs or disposal, safely remove refrigerant using a recovery pump certified for flammable refrigerants. Purge the circuit with nitrogen gas, evacuate to 1500 microns, and break the vacuum with a nitrogen purge before opening the circuit.
• Final Checks: Before leaving the job site, ensure all wiring is routed correctly, secured, and away from sharp edges. All panels and covers must be securely fastened. Service valve stem caps must be tightened to 1/12-turn past finger tight. The Owner's Manual should be left with the customer, and the Dealer Installation Checklist completed.

Carrier N4A4 Specifications