Lennox MWCA012S4-1P

1
MINI-SPLIT SYSTEMS SERVICE MANUAL
MCA Series Unit Information
CORP1907-L5
11/2020
Supersedes 8/2019
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 ........................................... 5
1.5. IndoorUnitWallMounts ......................................... 5
2. Indoor/Outdoor Matches ...........................6
3. Air Throw Data ...........................................6
4. Power and Communication Wiring for
Systems .....................................................7
4.1. Overview ................................................................. 7
4.2. WireGauge............................................................. 7
4.3. TerminalConnections ............................................. 8
5. Indoor Unit Diagrams ................................8
6. Wireless Remote ...................................... 10
6.1. Requirements ....................................................... 10
6.2. RemoteControlSpecications ............................. 10
6.3. FunctionButtons ................................................... 11
6.4. Display .................................................................. 12
6.5. Operations ............................................................ 12
6.5.1. Start/StopOperation.............................. 12
6.5.2. Select Fahrenheit or Celsius ............... 12
6.5.3. Cool/Fan mode ..................................... 12
6.5.4. DryMode ................................................ 12
6.5.5. TimerOperation ..................................... 12
6.5.6. TimerONOperation ............................... 12
6.5.7. TimerOFFOperation ............................. 13
6.5.8. ModifyTimerON/OFFsettings ............... 13
7. Connection to Centralized Controller ....13
7.1. SetIndoorUnitAddressforCentralizedControl
(UsedwithVRFOnly) ........................................... 13
7.2. IndoorUnitConnectionPointsforCentralized
Controller .............................................................. 14
7.3. DryModeOperation-IndoorUnits ....................... 14
7.3.1. Procedure ............................................... 14
7.3.2. DryModeOperationSequence .............. 14
7.4. TestRun-IndoorUnits ......................................... 14
7.4.1. TestRunInstructions .............................. 14
7.4.2. BeforeTestRun ...................................... 14
7.5. Double-CheckPipeConnections .......................... 15
7.6. AmbientTemperatureisBelow63°F(17°C) ......... 15
8. Single Zone Outdoor Units .....................16
8.1. ModelNumberIdentication ................................. 16
8.2. Specications........................................................ 16
8.3. CoolingCapacity................................................... 17
8.3.1. -009(208/230V) .................................... 17
8.3.2. -012(115V) ............................................ 18
8.3.3. -012(208/230V) .................................... 18
MCA Single Zone Air
Conditioning Outdoor Unit
MCWA Wall Mount Single Zone
Air Conditioning Indoor Unit
Please refer to Corp1908-L5 for indoor and outdoor unit error codes and component diagnostics.

Lennox MWCA012S4-1P Specifications

General

Brand	Lennox
Model	MWCA012S4-1P
Category	Air Conditioner
Language	English

Summary

Power and Communication Wiring for Systems

4.1. Overview

4.2. Wire Gauge

4.3. Terminal Connections

Wiring diagrams for indoor and outdoor unit terminal connections.

Wireless Remote

6.3. Function Buttons

6.5. Operations

Detailed operation procedures and settings via remote.

Single Zone Outdoor Units

8.2. Specifications

8.3. Cooling Capacity

Cooling capacity data based on indoor and outdoor temperatures.

Refrigeration Pipe Work

Installation Requirements

13.1. Gas Leak Check with Soap Water

Method for checking pipe connections for gas leaks.

13.3. Air Purging using a Vacuum Pump

Procedure for evacuating the system using a vacuum pump.

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

Procedure for adding refrigerant based on pipe length.

Servicing Indoor Unit Refrigeration Circuit

13.6.1. Collecting Refrigerant into Outdoor Unit

Steps to recover refrigerant into the outdoor unit.

13.6.2. Air Purging with Vacuum Pump

Detailed procedure for air purging using a vacuum pump.

Evacuation after Servicing the Outdoor Unit Refrigeration Circuit

13.7.1. Evacuation of the Complete Refrigeration Circuit, Indoor and Outdoor Unit

Evacuation procedure for the entire refrigeration circuit.

13.7.2. Refrigerant Charging

Process for charging the system with refrigerant.

Adding Refrigerant - Single-Zone Systems

Specifications and Operations

17.1. Cooling Chart

Table of cooling performance based on temperature conditions.

17.2. Capacity Request Calculations

Outdoor Fan Control

17.3.1. Cooling Mode

Indoor and Outdoor Unit Disassembly

18.1. Indoor Unit (All Models)

General disassembly procedures for indoor units.

18.2. Outdoor Unit

General disassembly procedures for outdoor units.