Lennox MCB012S4S-1L - User Manual

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INSTALLATION INSTRUCTION &

SERVICE INFORMATION

2021 Lennox Industries Inc.

Dallas, Texas, USA

WARNING

Improper installation, adjustment, alteration, ser vice

or maintenance can cause property damage, personal

injury or loss of life.

Installation and service must be performed by a li-

censed professional HVAC installer (or equivalent) or a

service agency.

CAUTION

In order to avoid injury, take proper precaution when

lifting heavy objects.

General

Refer to the Product Specications bulletin (EHB) for

additional product information. These instructions are

intended as a general guide and do not supersede local or

national codes in any way. Authorities having jurisdiction

should be consulted before installation.

This wall-mounted indoor unit is matched with an outdoor

air conditioner unit to create a mini-split system that uses

HFC-410A refrigerant.

Use of Mini-Split System During

Construction

Lennox does not recommend the use of its mini-split

systems during any phase of construction. Very low return

air temperatures, harmful vapors and operation of the unit

with clogged or misplaced lters will damage the system.

However, mini-split systems may be used for cooling of

buildings under construction, if the following conditions

are met:

• Air lter must be installed in the system and must be

maintained during construction.

• Air lter must be replaced upon construction comple-

tion.

• The indoor wall unit assembly must be thoroughly

cleaned following nal construction clean-up.

• All mini-split operating conditions must be veried ac-

cording to these installation instructions.

MCB and MWCB Series Units

SINGLE-ZONE MINI-SPLIT SYSTEM

(115V and 208/230V)

508241-01 12/2021

Table of Contents

General ..........................................................................1

Use of Mini-Split System During Construction ..........1

Included Parts ...............................................................2

Model Number Identication .......................................3

Typical System Components .......................................4

System Dimensions .....................................................4

Outdoor Units ..............................................................4

Indoor Units .................................................................5

Indoor Unit Wall Mounts ..............................................5

System Clearances.......................................................5

Outdoor Unit ................................................................5

Indoor Unit ...................................................................5

Multiple Outdoor Units .................................................6

Torque Requirements for Caps and Fasteners ..........6

Indoor Unit Installation ................................................6

Unit Placement Considerations ...................................6

Determining Wall Mounting Plate Location ..................7

Installation of Wall Mounting Plate...............................7

Installation of Wall Sleeve............................................7

Installation of Indoor Unit on Wall Mounting Plate .......8

Indoor Unit Condensate Piping Connections ...............8

Outdoor Unit Installation .............................................8

Placement Considerations ...........................................8

Direct Sunlight and Rain Protection .............................9

Buried Refrigerant Pipe Protection ..............................9

Securing the Outdoor Unit ...........................................9

Refrigerant Piping Connections ................................10

Adding Refrigerant for Longer Line Set ...................12

Leak Test and Evacuation ..........................................12

Leak Test ...................................................................12

Triple Evacuation Procedure......................................12

Wiring Connections ....................................................12

Outdoor Unit .............................................................13

Indoor Unit .................................................................13

Unit Start-Up ...............................................................14

Service Information ....................................................14

Indoor Unit Alert Codes and Outdoor Unit LED .........14

Test Run ....................................................................15

Double-Check Line Set Connections .........................15

Ambient Temperature is Below 60ºF (16ºC) ..............15

Indoor Unit Wiring Diagrams .....................................16

Outdoor Unit Wiring Diagrams ...................................17

THIS MANUAL MUST BE LEFT WITH THE OWNER

FOR FUTURE REFERENCE

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Summary

Indoor Unit Installation

Condensate Piping

Connecting the drain line for condensate removal from the indoor unit.

Refrigerant Piping Connections

Making Connections

Steps for connecting refrigerant lines to the indoor and outdoor units.

Leak Test and Evacuation

Leak Testing

Steps to test the system for refrigerant leaks using nitrogen.

Evacuation Procedure

Procedure to remove air and moisture from the refrigerant system.

Wiring Connections

Outdoor Unit Wiring

Electrical power wiring connections for the outdoor unit.

Indoor Unit Wiring

Communication, power, and ground wiring for the indoor unit.

Service and Start-Up

Error Codes and LEDs

Table of error codes and LED indicators for system diagnostics.

Start-Up Procedure

Step-by-step guide to safely start up the mini-split system.

Test Run and Operation

Test Run Pre-Checks

Safety and system checks required before performing a test run.

Test Run Procedure

Steps to run the system and verify its operation.

This document is an installation and service information manual for Lennox MCB and MWCB Series Single-Zone Mini-Split Systems (115V and 208/230V). It provides detailed instructions for the installation, operation, and maintenance of these HVAC units.

Function Description

The Lennox MCB and MWCB Series units are single-zone mini-split air conditioning systems designed for residential or light commercial applications. They consist of an indoor wall-mounted unit matched with an outdoor air conditioner unit, using HFC-410A refrigerant. The system provides cooling and, depending on the model, may also offer heating capabilities. The manual emphasizes proper installation to ensure optimal performance, safety, and longevity of the system.

Important Technical Specifications

Model Number Identification: The manual includes detailed model number identification charts for both outdoor single-zone air conditioner units and wall-mounted indoor units.

Series Type: M = Mini-Split
Unit Type: C = Air Conditioner (Outdoor), WC = Wall-Mounted Non-Ducted Unit (Indoor)
Major Design Sequence: B = Second Generation
Nominal Cooling Capacity:
- 009 = 0.75 ton
- 012 = 1 ton
- 018 = 1.5 tons
- 024 = 2 tons
Refrigerant Type: 4 = HFC-410A
Cooling Efficiency: S = Standard Efficiency
Voltage:
- L = 115V-1 phase-60Hz
- P = 208/230V-1 phase-60Hz
Minor Design Sequence: 1 = 1st Revision
Refrigerant Circuits: S = Single Circuit

System Dimensions (Inches (mm)):

09 and 12K Outdoor Units:
- Top View: 28-5/8 (727)
- Front View: 17-3/4 (451) H x 28-3/8 (720) W
- Side View: 19-1/2 (495) D
18K Outdoor Units:
- Top View: 30-7/8 (784)
- Front View: 17-3/4 (451) H x 30-1/8 (765) W
- Side View: 21-7/8 (556) D
24K Outdoor Units:
- Top View: 32-1/8 (816)
- Front View: 20-1/8 (511) H x 31-3/4 (806) W
- Side View: 21-7/8 (556) D
Indoor Units (A x B x C):
- 9K: 27-3/4 (730) x 11-1/2 (292) x 8-1/8 (207)
- 12K: 31-3/4 (806) x 11-5/8 (295) x 7-7/8 (200)
- 18K: 38-1/4 (972) x 12-3/4 (324) x 9-1/8 (232)
- 24K: 42-5/8 (1083) x 13-1/4 (337) x 9-3/8 (238)

System Clearances:

Outdoor Unit: Minimum rear clearance of 6 inches (152 mm) when mounted on brackets. Air inlet clearance 12 inches (305 mm), air outlet clearance 24 inches (610 mm).
Indoor Unit: Minimum clearance from ceiling 6 inches (152 mm), from side walls 5 inches (127 mm). Minimum vertical clearance to floor 72 inches (1829 mm), recommended 96 inches (2438 mm).

Refrigerant Piping and Indoor Unit Connection Sizes:

9K, 12K, 18K: Liquid Line 1/4 inch, Suction Line 3/8 inch (9K), 1/2 inch (12K, 18K).
24K: Liquid Line 3/8 inch, Suction Line 5/8 inch.

Line Set Length and Elevation Parameters:

Maximum Line Set Length: 82 feet (25m) for 009, 012 models; 98 feet (30m) for 018, 024 models.
Maximum Elevation Outdoor Unit BELOW Indoor Unit: 82 feet (25m) for 009, 012 models; 98 feet (30m) for 018, 024 models.
Maximum Elevation Outdoor Unit ABOVE Indoor Unit: 33 feet (10m) for 009, 012 models; 66 feet (20m) for 018, 024 models.
Additional Refrigerant for Longer Line Set: 0.161 oz. for 1/4" liquid line and 0.322 oz. for 3/8" liquid line per foot.

Electrical Specifications (Minimum Circuit Amps (MCA) and Max Fuse):

MCB012S4S-1L (115V): MCA 18, Max Fuse 30.
MCB009S4S-1P, MCB012S4S-1P (208/230V): MCA 11, Max Fuse 15.
MCB018S4S-1P, MCB024S4S-1P (208/230V): MCA 16, Max Fuse 20.

Refrigerant Oil: The compressor uses PVE oil (Polyvinylether), formulated for HFC-410A refrigerants. Mixing with mineral-based oil or POE oil is not recommended.

Usage Features

Wireless Remote Control: The system includes a wireless controller for operation. Indoor Unit Display: The indoor unit LED displays alert codes and operational status codes for troubleshooting. Manual Control Button: In situations where the ambient temperature is below 60°F (16°C) and the wireless remote control cannot activate the COOL function, a manual control button on the indoor unit can be used for testing.

Maintenance Features

Air Filter Maintenance:

Air filters must be installed and maintained during construction.
Air filters must be replaced upon construction completion.
The indoor wall unit assembly must be thoroughly cleaned after construction.

Leak Test and Evacuation:

The manual provides a detailed procedure for leak testing the refrigerant system using oxygen-free nitrogen (OFN) and a triple evacuation procedure to remove non-condensables and moisture.
Pressure test specifications are provided (e.g., 45 psig for 1 hour stress test, 32 psig for 24 hours lower pressure test).

Torque Requirements:

Specific torque values are provided for caps and fasteners (e.g., service valve cap 8 ft.-lb. (11 Nm), compressor bolts 7 ft.-lb. (10 Nm), gauge port seal cap 8 ft.-lb. (11 N*m)).
Flare nut torque recommendations are given for different pipe diameters to ensure leak-free joints (e.g., 1/4" pipe 15 ft.-lb. (20 N), 3/8" pipe 26 ft.-lb. (35 N), 1/2" pipe 41 ft.-lb. (56 N), 5/8" pipe 48 ft.-lb. (65 N)).

Troubleshooting (Indoor Display Alert and Status Codes): The manual lists various error codes and their descriptions, displayed on the indoor unit LED or outdoor unit:

System Error Codes: Indoor unit EEPROM error (EH 00), Communication error (EL 01), Indoor fan speed error (EH 03), Indoor room/coil temperature sensor error (EH 60, EH 61), Refrigerant leakage detection (EL OC), Outdoor current overload protection (PC 08), Outdoor ambient/coil/discharge temperature sensor error (EC 53, EC 52, EC 54), Outdoor unit EEPROM error (EC 51), Outdoor unit fan speed error (EC 07), Inverter module IPM error (PC 00), High or Low voltage protection (PC 01), Outdoor low ambient temperature protection (PC 0L), Compressor drive error (PC 04), Communication error between main control board and display board (EH 0b).
Operational Status Codes: Force Cooling (FC), Remote or Wired controller Lock (LL), Active clean (CL), Time On/Off (On/OF), Remote On/Off (CP), ECO mode (On display 3 seconds).
Outdoor Unit LED: Slow flash (1Hz) for standby, LIT for normal operation, FAST FLASH (2Hz) for outdoor unit error.

Construction Usage Guidelines: Lennox advises against using mini-split systems during construction due to potential damage from low return air temperatures, harmful vapors, and clogged filters. If used, specific conditions must be met: air filter installation and maintenance, filter replacement after construction, thorough cleaning of the indoor unit, and verification of all operating conditions.