Carrier GH7T User Manual

Installation Instructions
NOTE: Read the entire instruction manual before starting the installation.
SAFETY CONSIDERATIONS
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.
Installation Recommendations
NOTE: In some cases noise in the living area has been traced to gas
pulsations from improper installation of equipment.
1. Locate unit away from windows, patios, decks, etc. where unit
operation sound may disturb customer.
2. Ensure that vapor and liquid tube diameters are appropriate for unit
capacity.
3. Run refrigerant tubes as directly as possible by avoiding
unnecessary turns and bends.
4. Leave some slack between structure and unit to absorb vibration.
5. When passing refrigerant tubes through the wall, seal opening with
RTV or other pliable silicon-based caulk. (See Fig. 1.)
6. Avoid direct tubing contact with water pipes, duct work, floor
joists, wall studs, floors, and walls.
7. 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.)
8. Ensure that tubing insulation is pliable and completely surrounds
vapor tube.
9. When necessary, use hanger straps which are 1 in. (25.4 mm) wide
and conform to shape of tubing insulation. (See Fig. 1.)
10. Isolate hanger straps from insulation by using metal sleeves bent to
conform to shape of insulation.
A07588
Fig. 1 – Piping Installation
When outdoor unit is connected to factory-approved indoor unit, outdoor
unit contains system refrigerant charge for operation with AHRI rated
indoor unit when connected by 15 ft. (4.57 m) of field-supplied or
factory accessory tubing. For proper unit operation, check refrigerant
charge using charging information located on control box cover and/or
in the Check Charge section of this instruction.
IMPORTANT: Maximum liquid-line size is 3/8-in. OD for all
residential applications including line line.
IMPORTANT: Always install the factory-supplied liquid-line filter
drier. Obtain replacement filter driers from your distributor or branch.
GH7T
SPLIT-SYSTEM 2-STAGE HEAT PUMP
WITH R-410A REFRIGERANT
2-5 TONS
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
death, serious personal injury, death, and/or
property damage.
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.

Carrier GH7T Specifications

General

Brand	Carrier
Model	GH7T
Category	Heat Pump
Language	English

Summary

Safety Considerations

Electrical Shock Hazard

Warning about personal injury or death from electrical shock during installation or servicing.

Explosion Hazard

Warning about potential explosion or injury due to improper handling of air or oxygen with refrigerant.

Installation Recommendations

Piping Installation

Guidance on routing refrigerant tubes to minimize noise, avoid contact, and properly seal wall penetrations.

Installation Precautions and Steps

Cut Hazard

Caution regarding sharp edges on sheet metal parts during handling.

Check Equipment and Job Site

Instructions for unpacking, inspecting, and verifying unit rating plate information.

Install on Solid, Level Mounting Pad

Requirements for securing the unit to a level pad, including tie-down methods.

Clearance Requirements

Specifications for maintaining adequate space around the unit for airflow, wiring, and service.

Unit Operation Hazard

Caution to ensure unit stability in all circumstances, including adverse weather.

Elevate Unit

Caution to elevate the unit for drainage and to prevent water/ice buildup in the base pan.

Accessory Usage and Piping Connections

Accessory Usage Table

Table detailing required accessories for low ambient, long line, and sea coast applications.

Install Liquid-Line Solenoid Valve (LSV)

Instructions for installing the LSV kit in long-line applications for proper operation.

Make Piping Connections

Safety warnings and procedures for making refrigerant piping connections.

Brazing and Filter Drier Installation

Brazing Connections

Safety warnings and procedures for brazing refrigerant lines and components.

Install Liquid Line Filter Drier

Instructions for installing the required filter drier, including heat sinking during brazing.

Evacuation and Electrical Connections

Evacuate Refrigerant Tubing and Indoor Coil

Procedure for evacuating the system to 500 microns using the deep vacuum method.

Route Ground and Power Wires

Instructions for routing and connecting ground and power wires to the unit control box.

Connect Ground and Power Wires

Safety warning and diagram for connecting system ground and power wiring.

Connect Control Wiring

Guidelines for connecting 24v control wires to the thermostat and unit.

Thermostat Wiring and Airflow Selection

Thermidistat Wiring Diagrams

Wiring diagrams for connecting thermostats to fan coil and variable speed furnace units.

Final Wiring Check

Important checks to ensure secure wiring and proper routing before closing panels.

Compressor Crankcase Heater

Requirements for powering the crankcase heater before unit startup.

Airflow Selections (ECM Furnaces)

Instructions for selecting proper airflows for high and low stage cooling on ECM furnaces.

Airflow Selection for Variable Speed Furnaces

Instructions for setting DIP switches to match airflow for variable speed furnaces.

System Start-Up and Operation

Start-Up Procedure

Step-by-step instructions for starting up the system after installation.

Sequence of Operation

Explanation of how the unit operates in cooling and heating modes.

Compressor Operation

Details on the 2-stage compressor's internal unloading mechanism and capacity modulation.

Quiet Shift-2

Explanation of the Quiet Shift-2 mode for reducing noise during defrost cycles.

Defrost Control and Charge Check

Defrost Control

Description of the defrost control board's time/temperature settings and operation.

Defrost Speedup

Procedure for initiating a forced defrost cycle using speedup pins.

Check Charge

Procedure for checking and adjusting refrigerant charge based on subcooling method.

Heating Check Chart Procedure

Guidance on using the heating check chart to verify system operation.

Verify Proper Switching Between Stages

Checks for proper suction pressure and current changes during stage switching.

Unloader Test and Final Checks

Unloader Test Procedure

Methods to verify the operation of the compressor's unloader mechanism.

Final Checks

Final important checks before leaving the job site, including wiring, security, and documentation.

Troubleshooting

Table and notes for troubleshooting compressor winding resistance.