Lennox MLB018S4S-1P 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 MLB018S4S-1P Specifications

General

Cooling Capacity	18, 000 BTU
Voltage	208/230V
Phase	1
Refrigerant Type	R-410A
Fan Speed	Variable

Summary

M22A and M33C Cassette Non-Ducted Indoor Units

M22A and M33C Model Number Identification

Explains the model number breakdown for M22A/M33C cassette non-ducted indoor units.

M22A Indoor Unit Specifications

Details specifications for M22A series cassette non-ducted indoor units.

M33C Indoor Unit Specifications

Details specifications for M33C series cassette non-ducted indoor units.

M22A Indoor Unit Dimensions

M33C Indoor Unit Dimensions

M22A and M33C Indoor Unit Clearances

Specifies minimum clearance requirements for M22A and M33C cassette indoor units.

M22A and M33C Indoor Unit Control Board Switches Location

Locates control board switches and DIP switches for M22A/M33C indoor units.

M22A and M33C Condensate Drain Test Procedure

Outlines the procedure for testing condensate drainage on M22A/M33C indoor units.

MMDB Ducted Indoor Units

MMDB Model Number Identification

Explains the model number breakdown for MMDB ducted indoor units.

MMDB Indoor Unit Specifications

Details specifications for MMDB ducted indoor units across various capacities.

MMDB Indoor Unit Dimensions

MMDB Indoor Unit Clearances

Specifies minimum clearance requirements for MMDB ducted indoor units.

MMDB Condensate Drain Test Procedure

Outlines the procedure for testing condensate drainage on MMDB units.

MWMC and 3WMC-036 Wall Mounted Indoor Units

MWMC and 3WMC Model Number Identification

Explains model number breakdown for MWMC and 3WMC wall mounted indoor units.

MWMC Indoor Unit Specifications (009 - 012 Ton)

Details specifications for MWMC 009-012 Ton wall mounted indoor units.

MWMC Indoor Unit Specifications (018 - 030 Ton)

Details specifications for MWMC 018-030 Ton wall mounted indoor units.

3WMC Indoor Unit Specifications

Details specifications for the 3WMC wall mounted indoor unit.

MWMC and 3WMC Indoor Unit Dimensions

MWMC and 3WMC Indoor Unit Clearances

Specifies minimum clearance requirements for MWMC/3WMC units.

MWMC and 3WMC036S4 Control Board Switches Location

Locates control board switches for MWMC and 3WMC036S4 units.

MCFA and MCFB Ceiling / Floor Indoor Units

MCFA and MCFB Model Number Identification

Explains the model number breakdown for MCFA/MCFB ceiling/floor indoor units.

MCFA and MCFB Indoor Unit Specifications (018 - 048 Ton)

Details specifications for MCFA/MCFB ceiling/floor units (018-048 Ton).

MCFA and MCFB Indoor Unit Dimensions

MCFA and MCFB Indoor Unit Clearances

Specifies clearance requirements for MCFA/MCFB units in various applications.

MCFA and MCFB Control Board Switches Location

MFMA Floor Indoor Unit

MFMA Model Number Identification

MFMA Indoor Unit Specifications (012 Ton)

Details specifications for the MFMA012S4 floor indoor unit.

MFMA Indoor Unit Dimensions

MFMA Indoor Unit Clearances

Indoor and Outdoor Power and Communication Wiring Requirements

Wiring Requirements Overview

Single Zone Mini-Split Wiring Guide

Provides wiring guides for single-zone mini-split systems.

Connection to Centralized Controller, ON/OFF and Alarm Devices

Set Indoor Unit Address for Centralized Control

Single and Multiple Zone Outdoor Units

Outdoor Unit Model Number Identification

MPC Single-Zone Specifications (0.75 - 1.5 Ton)

Details specifications for MPC single-zone units (0.75-1.5 Ton).

MPC Single-Zone Specifications (2 - 4 Ton)

Details specifications for MPC single-zone units (2-4 Ton).

3PC Single-Zone Specifications

MLB Single-Zone Specifications (0.75 - 2 Ton)

Details specifications for MLB single-zone units (0.75-2 Ton).

MLB Single-Zone Specifications (3 - 4 Ton)

Details specifications for MLB single-zone units (3-4 Ton).

MPC Multi-Zone Specifications (1.5 - 2.5 Ton)

Details specifications for MPC multi-zone units (1.5-2.5 Ton).

MPC Multi-Zone Specifications (3 - 4 Ton)

Details specifications for MPC multi-zone units (3-4 Ton).

MLB Multi-Zone Specifications (1.5 - 3 Ton)

Details specifications for MLB multi-zone units (1.5-3 Ton).

MLB Multi-Zone Specifications (4 Ton)

Details specifications for MLB multi-zone units (4 Ton).

Single-Zone Outdoor Unit Dimensions

Multi-Zone Outdoor Unit Dimensions

Single Outdoor Unit Clearances

Multiple Outdoor Unit Clearances

Indoor / Outdoor Unit Combinations

MPC Multi-Zone System Combinations

Lists capacity combinations for MPC multi-zone systems.

MLB Multi-Zone System Combinations

Lists capacity combinations for MLB multi-zone systems.

Refrigeration Pipe Work

Single-Zone Piping Limitations

Multi-Zone Piping Limitations

MPC Multi-Zone Outdoor Unit Connections and Line Set Usage

MPC018S4M Outdoor Unit Connection Sizes

MPC024S4M Outdoor Unit Connection Sizes

MPC030S4M Outdoor Unit Connection Sizes

MPC036S4M Outdoor Unit Connection Sizes

MPC036S4M Outdoor Unit Connection Sizes (Continued)

MPC048S4M Outdoor Unit Connection Sizes

MPC048S4M Outdoor Unit Connection Sizes (Continued)

MLB Multi-Zone Outdoor Unit Connections and Line Set Usage

MLB018S4M Outdoor Unit Connection Sizes

MLB030S4M Outdoor Unit Connection Sizes

MLB030S4M Outdoor Unit Connection Sizes (Continued)

MLB036S4M Outdoor Unit Connection Sizes

MLB048S4M Outdoor Unit Connection Sizes

MLB048S4M Outdoor Unit Connection Sizes (Continued)

Power and Communication Wiring for Systems

Installation Requirements

Torque Requirements for Pipe Connections

Pipe Length and Elevation Details

Additional Refrigerant Charge Calculation

Guidance on calculating and adding refrigerant charge.

Air Purging using a Vacuum Pump Procedure

Adding Refrigerant Based on Pipe Length

Instructions for adding refrigerant based on pipe length.

Evacuation of Refrigeration Circuit

Start-Up

Adding Refrigerant - Single-Zone Systems

Calculating additional refrigerant required for single-zone systems.

Adding Refrigerant - Multi-Zone Systems

Calculating additional refrigerant required for multi-zone systems.

Specifications and Operations

Main Protection Features

Pressure on Service Port

Cooling Charts and Pressure

Heating Charts and Pressure

Capacity Request Calculations

Defrost Control Conditions

Outdoor Fan Control in Cooling Mode

Outdoor Fan Control in Heating Mode

Electronic Expansion Valve (EXV) Control

EXV Control Logic for Cooling Mode

EXV Control Logic for Heating Mode