Marvair MAA/MGA Wall Mount AC Installation & Operation Manual
05/2023 Rev.21
5
Chapter 1 Description & Specifications
1.1 General Description
The Marvair MAA and MGA are a series of vertical wall-mounted air conditioning systems that provide
heating, cooling, and ventilation for electronic equipment shelters, process control centers, and other
applications with high internal heat gains. The series includes multiple sizes and nominal cooling
capacities from 18,000 to 72,000 BTUH. Resistance heating elements are available in various wattages.
MAA modes are available with cooling capacities of 18,000 to 60,000 BTUH and EER’s of 11.00 to
11.50. MGA models have 72,000 BTUH (6 ton) capacity and are 10 EER. The Marvair Product Data
Sheets have detailed information on the capacities and efficiencies for each model.
See Appendix A for instructions on field installation of electric heat.
Marvair air conditioners feature an exclusive electronic control board. The control board consolidates
several of the electrical components and improves the air conditioner’s reliability. The control board
replaces the blower relay, the lockout relay, the compressor time delay and the timed low pressure
bypass. In addition, the control board has LED’s to indicate operating status and fault conditions to
assist the service technician. A complete description of functions of the control board is in Chapter 2.
All models are designed for easy installation and service. Major components are accessible for service
beneath external panels.
All units have internal disconnects (optional on 380V and 575V). Follow local codes for external
disconnect requirements.
Marvair wall mount air conditioners have a 0-15% manual outside air damper as standard equipment.
All models are available with an optional factory installed economizer for 100% free cooling with
outside air.
