Lennox MHA012S4S-1P User Manual

1
MINI-SPLIT SYSTEMS SERVICE MANUAL
MHA Series Unit Information
CORP1913-L8
11/2020
Table of Contents
1. Indoor Units ................................................3
1.1. ModelNumberIdentication ..................................... 3
1.2. IndoorUnitSpecications ......................................... 3
1.3. IndoorUnitDimensions ............................................4
1.4. IndoorUnitClearances ............................................. 4
1.5. IndoorUnitWallMounts ...........................................5
1.6. Indoor/OutdoorMatches ........................................... 5
2. Air Throw Data ...........................................6
3. Power and Communication Wiring for
Systems .....................................................7
3.1. Overview ...................................................................7
3.2. WireGauge...............................................................7
3.3. TerminalConnections ...............................................8
4. Indoor Unit Diagrams ................................8
5. Wireless Remote ........................................ 9
5.1. Requirements ...........................................................9
5.2. RemoteControlSpecications .................................9
6. Connection to Centralized Controller .... 11
6.1. SetIndoorUnitAddressforCentralizedControl(Used
withVRFOnly) ........................................................ 11
6.2. IndoorUnitConnectionPointsforCentralized
Controller ................................................................12
6.3. DryModeOperation-IndoorUnits .........................12
6.3.1. Procedure .................................................12
6.3.2. DryModeOperationSequence ................13
6.4. TestRun-IndoorUnits ........................................... 13
6.4.1. TestRunInstructions ................................13
6.4.2. BeforeTestRun ........................................13
6.5. Double-CheckPipeConnections ............................13
6.6. AmbientTemperatureisBelow63°F(17°C) ........... 13
7. Single Zone Outdoor Units .....................15
7.1. ModelNumberIdentication ................................... 15
7.2. Specications..........................................................15
7.3. CoolingandHeatingCapacities .............................16
7.3.1. Cooling-009(115V) ................................16
7.3.2. Heating-009(115V) ................................17
7.3.3. Cooling-009(208/230V) .........................17
7.3.4. Heating-009(208/230V) ......................... 18
7.3.5. Cooling-012(115V) ................................18
7.3.6. Heating-012(115V) ................................19
7.3.7. Cooling-012(208/230V) .........................19
7.3.8. Heating-012(208/230V) ......................... 20
7.3.9. Cooling-018(208/230V) .........................20
7.3.10. Heating-018(208/230V) ......................... 21
7.3.11. Cooling-024(208/230V) .........................21
7.3.12. Heating-024(208/230V) ......................... 22
MHA Single Zone Air
Conditioning Outdoor Unit
MWHA Wall Mount Single Zone
Air Conditioning Indoor Unit
Please refer to Corp1914-L8 for indoor and outdoor unit error codes and component diagnostics.

Lennox MHA012S4S-1P Specifications

General

Cooling Capacity (BTU/hr)	12, 000
Voltage (V)	208/230
Phase	1
Cooling Capacity	12, 000 BTU/hr
Refrigerant Type	R-410A
Voltage	208/230V

Summary

Indoor Units

1.2. Indoor Unit Specifications

Details technical specifications, including power, dimensions, and capacities for indoor units.

1.6. Indoor/Outdoor Matches

Table matching indoor units with compatible outdoor units and performance ratings.

Power and Communication Wiring for Systems

3.2. Wire Gauge

Details recommended wire gauges and conductor requirements for system connections.

3.3. Terminal Connections

Diagrams illustrating terminal connections for indoor and outdoor units.

Wireless Remote

Connection to Centralized Controller

6.1. Set Indoor Unit Address for Centralized Control

Instructions on setting unique addresses for indoor units in a centralized system.

6.2. Indoor Unit Connection Points for Centralized Controller

Identifies connection points on indoor units for centralized control wiring.

6.4. Test Run - Indoor Units

Instructions and checklist for performing a test run of the indoor unit after installation.

6.5. Double-Check Pipe Connections

Guidance on re-inspecting refrigerant pipe connections for leaks during operation.

Single Zone Outdoor Units

7.2. Specifications

Presents technical specifications for various single zone outdoor unit models.

7.3. Cooling and Heating Capacities

Provides detailed cooling and heating capacity data across different temperature conditions.

7.5. Outdoor Unit Clearances

Specifies the minimum required clearances for single zone outdoor unit installation.

Refrigeration Pipe Work

8.2. Single-Zone Piping Limitations

Outlines the maximum allowable lengths and elevation differences for refrigerant piping.

Outdoor Unit Connections and Line Set Usage

9.2. Torque Requirements

Installation Requirements

12.1. Gas Leak Check with Soap Water

12.2. Air and Moisture

12.3. Air Purging using a Vacuum Pump

Step-by-step guide for evacuating the system using a vacuum pump.

12.4. Adding Refrigerant if Pipe Length Exceeds Charge Less Pipe Length

12.5. Add Refrigerant after Long-Term System Operation

12.6. Servicing Indoor Unit Refrigeration Circuit

Procedures for servicing the refrigeration circuit within the indoor unit.

12.7. Evacuation after Servicing the Outdoor Unit Refrigeration Circuit

Steps for evacuating and charging the system after servicing the outdoor unit.

Adding Refrigerant - Single-Zone Systems

Specifications and Operations

Main Protection Features

Communication Protection

16.1. Cooling Chart

16.2. Heating Chart

16.3. Capacity Request Calculations

Methodology for calculating required system capacity based on unit codes and operating conditions.

16.4. Outdoor Fan Control

Indoor and Outdoor Unit Disassembly

Outdoor Unit Electronic Components Disassembly

Outdoor Unit Fan Disassembly

Outdoor Unit Four-Way Valve Removal

Outdoor Unit Compressor Removal

Detailed instructions for recovering refrigerant and removing the compressor from the outdoor unit.