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Marvair MGA3090-3180 Wall Mount AC I&O Manual 05/2023 Rev.14
WARNING
• If the information in these instructions are not followed exactly, a fire may result causing
property damage, personal injury or loss of life.
• Read all instructions carefully prior to beginning the installation. Do not begin
installation if you do not understand any of the instructions.
• Improper installation, adjustment, alteration, service or maintenance can cause property
damage, personal injury or loss of life.
• Installation and service must be performed by a qualified installer or service agency in
accordance with these instructions and in compliance with all codes and requirements
of authorities having jurisdiction.
INSTALLER:
Affix the instructions on the inside of the building adjacent to the
thermostat.
END USER:
Retain these instructions for future reference.
Table of Contents
Chapter 1 Air Conditioner Description & Specifications
1.1 General Description .................................................................................................................................5
1.2 Model Identification .................................................................................................................................6
1.3 Serial Number Date Code ........................................................................................................................6
1.4 Capacities, Weights and Filter Sizes ........................................................................................................6
1.5 General Operation ..................................................................................................................................10
1.6 Programmable Logic Controller (PLC) .................................................................................................10
1.7 Unit Operation ........................................................................................................................................12
1.8 Optional Controls and Packages ............................................................................................................13
1.9 Electrical Operation ...............................................................................................................................14
Chapter 2 Electronic Control Board
2.1 Introduction ............................................................................................................................................16
2.2 Installation and Replacement .................................................................................................................17
2.3 PCB Details and Information .................................................................................................................17
2.4 Operation ................................................................................................................................................17
2.5 Sequence of Operation ...........................................................................................................................21
Chapter 3 Installation
3.1 Equipment Inspection .............................................................................................................................33
3.2 Installation Requirements .......................................................................................................................33
3.3 Installation Materials .............................................................................................................................34
3.4 Porting and Duct Work ..........................................................................................................................36
3.5 Top Flange Installation ..........................................................................................................................36
3.6 Installing the Lifting Brackets ................................................................................................................37
3.7 Mounting the Unit .................................................................................................................................37
3.8 Electrical Connections ...........................................................................................................................38
Chapter 4 Start-Up
4.1 Check-Out of Cooling Cycle .................................................................................................................42
4.2 Check-Out of Heating Cycle ..................................................................................................................42
