Lennox MLB018S4M - User Manual

1
MINI-SPLIT SYSTEMS SERVICE MANUAL
Indoor and Outdoor Unit Information
100029
5/2022
Table of Contents
Indoor Unit Information ...................................3
1. M22A and M33C Cassette Non-Ducted Indoor Units ............... 3
1.1. ModelNumberIdentication ........................................................3
1.2. M22AIndoorUnitSpecications ..................................................3
1.3. M33CIndoorUnitSpecications .................................................4
1.4. M22AIndoorUnitDimensions .....................................................5
1.5. M33CIndoorUnitDimensions .....................................................6
1.6. M22AandM33CIndoorUnitClearances ....................................7
1.7. M22AandM33CIndoorUnitControlBoardSwitches
Location .......................................................................................8
1.8. M22AandM33CCondensateDrainTestProcedure ...................9
2. MMDB Ducted Indoor Units ......................................................10
2.1. MMDBModelNumberIdentication ..........................................10
2.2. MMDBIndoorUnitSpecications .............................................. 11
2.3. IndoorUnitBlowerData ............................................................12
2.4. MMDBIndoorUnitDimensions .................................................18
2.5. MMDBIndoorUnitClearances ..................................................19
2.6. CondensatePumpLift-MMDBandM22A/M33C .....................20
2.7. MMDBCondensateDrainTestProcedure.................................20
2.8. MMDBIndoorUnitGravityDrain ...............................................21
3. MWMC and 3WMC-036 Wall Mounted Indoor Units ............... 22
3.1. ModelNumberIdentication ......................................................22
3.2. IndoorUnitSpecications(009-012Ton)Units ......................23
3.3. IndoorUnitSpecications(018-030Ton)Units .......................23
3.4. IndoorUnitSpecications(3WMC) ...........................................23
3.5. IndoorUnitDimensions(MWMCand3WMC) ...........................24
3.6. IndoorUnitClearances(AllModelsandSizes) .........................25
3.7. MWMCand3WMC036S4UnitControlBoardSwitches
Location .....................................................................................25
3.8. DryModeOperation-MWMCand3WMC ................................26
3.9. TestRun-MWMCand3WMC ..................................................26
3.10. Double-CheckPipeConnections ...............................................26
3.11. AmbientTemperatureisBelow63°F(17°C) .............................27
4. MCFA and MCFB Ceiling / Floor Indoor Units ........................28
4.1. ModelNumberIdentication ......................................................28
4.2. IndoorUnitSpecications(018-048Ton)Units .......................28
4.3. IndoorUnitDimensions .............................................................29
4.4. IndoorUnitClearances ..............................................................30
4.5. MCFAandMCFBIndoorUnitControlBoardSwitches
Location .....................................................................................31
5. MFMA Floor Indoor Unit ...........................................................32
5.1. ModelNumberIdentication ......................................................32
5.2. IndoorUnitSpecications(012Ton)Unit ..................................32
5.3. IndoorUnitDimensions .............................................................33
5.4. IndoorUnitClearances ..............................................................33
6. Indoor and Outdoor Power and Communication
Wiring Requirements ............................................................... 34
6.1. Overview ....................................................................................34
6.2. WiringGuide ..............................................................................35
MCFA and MCFB
M22A and M33C
MMDB
MWMC and 3WMC036
MPC, 3PC, and MLB
Single Zone
MLB and MPC
Multi-Zone
MFMA
Please refer to service manual 100030 for indoor and
outdoor unit error codes and component diagnostics.

Lennox MLB018S4M Specifications

General

Refrigerant	R-410A
Phase	1
Type	Air Conditioner
Cooling Capacity	18, 000 BTU
Power Supply	208-230V, 60Hz
Voltage	208-230V

Summary

Indoor Unit Information

1. M22 A and M33 C Cassette Non-Ducted Indoor Units

Details on M22A/M33C cassette indoor units, including specs and dimensions.

2. MMDB Ducted Indoor Units

Information on MMDB ducted indoor units, including specifications and dimensions.

3. MWMC and 3 WMC-036 Wall Mounted Indoor Units

Information on MWMC and 3WMC wall-mounted indoor units, specs, and dimensions.

4. MCFA and MCFB Ceiling; Floor Indoor Units

Information on MCFA/MCFB ceiling/floor indoor units, specs, and dimensions.

5. MFMA Floor Indoor Unit

Wiring Requirements

6.2. Wiring Guide

Detailed wiring guide for single-zone and multi-zone systems, including wire types and gauges.

Outdoor Unit Information

9. Single and Multiple Zone Outdoor Units

11. Refrigeration Pipe Work

Installation Requirements

18.2.1. Additional Refrigerant Charge

18.2.4. Air Purging using a Vacuum Pump

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

18.2.8. Evacuation after Servicing the Outdoor Unit Refrigeration Circuit

Operations and Specifications

24.1. Cooling Charts

Provides cooling charge pressure data based on indoor and outdoor temperatures.

24.2. Heating Chart

Provides heating charge pressure data based on indoor and outdoor temperatures.

24.3. Capacity Request Calculations

24.4. Defrost Control

24.9. Electronic Expansion Valve (EXV) Control