Airxcel Marvair MGA3090A Bedienungsanleitung

Marvair MGA3090-3210 Wall Mount AC I&O Manual 03/2021 Rev.6

Part #03836

IMPORTANT

This manual may include information for options and features which may not be

included on the unit being installed. Refer to the unit data label or Model Identication

to determine which features and options this unit is equipped with.

INSTALLER: Afx the instructions on the inside of the building adjacent to the thermostat.

END USER: Retain this manual for future reference.

Manufactured By:

Marvair Division of the AIRXCEL®Commercial Group

P.O. Box 400 • Cordele, Georgia 31010 • 156 Seedling Drive • Cordele, Georgia 31015

(229) 273-3636 • Fax (229) 273-5154

www.Marvair.com

The most current version of this manual can be found at www.Marvair.com.

MODELS:

MGA3090A & MGA3120A

(Dual Compressor)

Installation & Operation Manual

10 EER Vertical Wall-Mount Air Conditioners

Installation & Operation Manual

10EER 7.5 & 10 Ton Vertical Wall Mount

Air Conditioners

Marvair MGA3090-3120 I&O Manual 03/2021 Rev.6

How To Use This Manual

This manual is intended to be a guide to Marvair's line of vertical air conditioners. It contains installation, troubleshoot-

ing, maintenance, warranty, and application information. The information contained in this manual is to be used by the

installer as a guide only. This manual does not supersede or circumvent any applicable national or local codes.

If you are installing the air conditioner rst read Chapter 1 and scan the entire manual before beginning the installation

as described in Chapter 2. Chapter 1 contains general, descriptive information and provides an overview which can speed

up the installation process and simplify troubleshooting.

If a malfunction occurs, follow this troubleshooting sequence:

1. Make sure you understand how the air conditioner works (Chapters 1 & 3).

2. Identify and correct installation errors (Chapter 2).

3. Refer to the troubleshooting information in Chapter 4.

If you are still unable to correct the problem, contact the Factory at 1-229-273-9558 for additional assistance.

Please read the following “Important Safety Precautions” before beginning any work.

Important Safety Precautions

1. USE CARE when LIFTING or TRANSPORTING equipment.

2. TRANSPORT the UNIT UPRIGHT. Laying it down on its side may cause oil to leave the compressor and breakage

or damage to other components.

3. TURN ELECTRICAL POWER OFF AT THE breaker or fuse box BEFORE installing or working on the equipment.

LINE VOLTAGES ARE HAZARDOUS or LETHAL.

4. OBSERVE and COMPLY with ALL applicable PLUMBING, ELECTRICAL, and BUILDING CODES and ordi-

nances.

5. SERVICE may be performed ONLY by QUALIFIED and EXPERIENCED PERSONS.

* Wear safety goggles when servicing the refrigeration circuit

* Beware of hot surfaces on refrigerant circuit components

* Beware of sharp edges on sheet metal components

* Use care when recovering or adding refrigerant

6. Use COMMON SENSE - BE SAFETY-CONSCIOUS

This is the safety alert symbol . When you see this symbol on the air conditioning unit and in the instruction

manuals be alert to the potential for personal injury. Understand the signal word DANGER, WARNING and

CAUTION. These words are used to identify levels of the seriousness of the hazard.

DANGER Failure to comply will result in death or severe personal injury and/or property damage.

WARNING Failure to comply could result in death or severe personal injury and/or property damage.

CAUTION Failure to comply could result in minor personal injury and/or property damage.

IMPORTANT Used to point out helpful info that will result in improved installation, reliability or operation.

SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE.

3Marvair MGA3090-3120 I&O Manual 03/2021 Rev.6

WARNING

• If the information in these instructions are not followed exactly, a re 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 qualied installer or service agency in

accordance with these instructions and in compliance with all codes and requirements

of authorities having jurisdiction.

INSTALLER: Afx 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 & Specications

1.1 General Description .................................................................................................................................5

1.2 Model Identication .................................................................................................................................6

1.3 Serial Number Date Code ........................................................................................................................6

1.4 Capacities, Weights and Filter Sizes ........................................................................................................6

1.5 General Operation ....................................................................................................................................9

1.6 Programmable Logic Controller (PLC) ...................................................................................................9

1.7 Unit Operation........................................................................................................................................11

1.8 Optional Controls and Packages ............................................................................................................13

1.9 Electrical Operation ...............................................................................................................................13

Chapter 2 Electronic Control Board

2.1 Introduction ............................................................................................................................................15

2.2 Installation and Replacement .................................................................................................................16

2.3 Operation................................................................................................................................................16

2.4 Sequence of Operation ...........................................................................................................................20

Chapter 3 Installation

3.1 Equipment Inspection.............................................................................................................................26

3.2 Installation Requirements.......................................................................................................................26

3.3 Installation Materials .............................................................................................................................27

3.4 Porting and Duct Work ..........................................................................................................................29

3.5 Top Flange Installation ..........................................................................................................................29

3.6 Installing the Lifting Brackets................................................................................................................30

3.7 Mounting the Unit .................................................................................................................................30

3.8 Electrical Connections ...........................................................................................................................31

Chapter 4 Start-Up

4.1 Check-Out of Cooling Cycle .................................................................................................................35

4.2 Check-Out of Heating Cycle..................................................................................................................35

Marvair MGA3090-3120 I&O Manual 03/2021 Rev.6

Table of Contents

Chapter 5 Troubleshooting

5.1 Overview ................................................................................................................................................36

5.2 Failure Symptoms Guide........................................................................................................................37

5.3 Compressor Troubleshooting .................................................................................................................37

Chapter 6 Maintenance

6.1 Scheduled Maintenance .........................................................................................................................39

Chapter 7 Warranty

7.1 Limited Product Warranty ......................................................................................................................40

Chapter 8 Start-Up Check List

8.1 Start-Up Check List................................................................................................................................41

Illustrations

Figure 1. PLC ............................................................................................................................................10

Figure 2. Typical Electrical Schematic......................................................................................................14

Figure 3a. Setting the Speed for the Y1 and Y2 Operation for Indoor Motor ............................................17

Figure 3b. Second Stage Cooling Speed .....................................................................................................17

Figure 4. Output Termination for Indoor Motor Control Signal ...............................................................18

Figure 5. Outdoor Motor Speed Setting ....................................................................................................18

Figure 6. Output Termination for Outdoor Motor Control Signal.............................................................18

Figure 7. Communications SetUp .............................................................................................................19

Figure 8. Top Flange and Lifting Bracket Installation ..............................................................................30

Figure 9. Wall Mounting Detail.................................................................................................................31

Figure 10a. Thermostat Connection Diagram ...............................................................................................34

Figure 10b. CommStat™ 3 Wiring Detail.....................................................................................................34

Tables

Table 1 Efciency and Capacity Ratings at ANSI/AHRI Standard 390..................................................... 7

Table 2 Sensible Capacities - Single Compressor ...................................................................................... 7

Table 3 Sensible Capacities - Dual Compressor......................................................................................... 7

Table 4 Single Compressor Cooling Performance (BTUH) at Various Outdoor Temperatures ................. 8

Table 5 Dual Compressor Cooling Performance (BTUH) at Various Outdoor Temperatures.................... 8

Table 6 Economizer Cooling Performance................................................................................................. 8

Table 7 Return Air Filter Sizes ................................................................................................................... 8

Table 8 Shipping Weights & Dimensions............................................................................................................. 8

Table 9 MODBUS Network Address DIP Swith Positions ...................................................................... 20

Table 10a. MODBUS Discrete Registers ...................................................................................................... 24

Table 10b. MODBUS Registers..................................................................................................................... 25

Table 11 Minimum Clearances................................................................................................................... 27

Table 12 Voltage Limitations ...................................................................................................................... 27

5Marvair MGA3090-3120 I&O Manual 03/2021 Rev.6

Chapter 1 Description & Specications

1.1 General Description

The Marvair MGA3090A & MGA3120A are a series of vertical wall-mounted air conditioning

systems that provide heating, cooling, and ventilation for telecommunication shelters, and other

applications with high internal heat gains. The series is available in nominal cooling capacities of

90,000-120,000 BTUH. A factory installed economizer, resistance heating elements and reverse ow

congurations are available.

All Marvair MGA wall mount air conditioners feature an exclusive electronic control board or PLC-

based controls.

The control board and PLC consolidate several of the electrical components, improves the air

conditioner’s reliability and has LED’s to indicate operating status and fault conditions to assist the

service technician. A complete description of functions is in Section 1.6

Other standard components include:

• Hot gas by-pass valve to allow operation in cold temperatures

• Thermal expansion valve to improve both efciency and capacity over a wide range of ambient

temperatures

• Phase monitor to prevent operation if the unit is not properly phased

Marvair air conditioners are designed for easy installation and service. Major components are accessible

for service beneath external panels.

All units have internal disconnects. Depending upon state and local code requirements, this feature

may eliminate the need for an external breaker or disconnect.

Marvair MGA3090-3120 I&O Manual 03/2021 Rev.6

1.2 Model Identication

The model identication number is found on the data sticker. Rating plate located on side panel.

Example M G A 3 0 9 0 A D 1 5 0 C + + + + 1 C A + A 1 1 + + + + + +

Position 1234567891011 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

1Unit Designation/Family M = Marvair Wall Mount

2Energy Efciency Ratio (EER) G = 10

3Refrigerant Type A = R-410a

4Compressor Type/

Quantity

1 = Single

3 = Dual Compressors

5Unit Capacity/Nominal

Cooling (BTUH)

090 = 90,000

120 = 120,000

8System Type A = Air Conditioner

9Power Supply

(Volts-Phase-Hz)

A= 208/230-1-60

C= 208/230-3-60

D= 460-3-60

E= 380-3-50 - 4 Wire

F= 220-1-50

Z= 575-3-60

10 Heat Designation

@ Rated Voltage

KW = Kilowatt

000 = No Heat

050 = 5KW

090 = 9KW

150 = 15KW

180 = 18KW

13 Ventilation

Conguration

A = Solid Front Door

C = Economizer

D = Motorized Damper w/Pressure Relief

E = Motorized Damper w/Pressure

Relief & Independent Motorized

Damper Control

F = No Free Cooling, 100% Emergency

Ventilation Only w/Independent Control

14 Dehumidication

R = Electric Reheat

T = Electric Reheat w/Humidity Control

+ = None

15 Controls

A = Power Fail Alarm w/Additional Lockouts

C = 24V EMS Relay Kit

D = 24V EMS Relay Kit

w/Factory Installed T-Stat

E = Factory Installed T-Stat

F = ModBus Interface

G = ModBus Interface

w/Factory Installed T-Stat

H = Bac-Net

J = Bac-Net Controls

w/Factory Installed T-Stat

+ = None

16 Operating Condition

A = Evaporator Freeze Sensor (EFS)

C = EFS w/Hot Gas Bypass

M = Extreme Duty w/Hard Start & EFS

N = Hard Start

P = Hard Start w/Low Ambient & CCH

Q = Hard Start w/Low Ambient &

Fan Cycle Control (FCC)

R = Crank Case Heater (CCH)

T = Hard Start w/EFS

U = Hard Start w/Hot Gas Bypass

V = Hard Start w/Low Ambient &

CCH & EFS

W = Low Ambient w/CCH

X = Hot Gas Bypass

Y = Low Ambient w/CCH & FCC

Z = Low Ambient w/CCH & EFS

1 = Low Ambient w/FCC

2 = Low Ambient w/FCC & EFS

3 = CCH w/Hot Gas Bypass

+ = None

17 Indoor Air Quality

Features

D = Dry Bulb Sensor

E = Dry Bulb Sensor w/Dirty Filter

G = Dirty Filter Sensor

+ = None

18 Air Flow 1 = Top Supply/Bottom Return

2 = Center Supply (Reverse)

19 Compressor

Location

C = Center

D = Left Hand

E = Right Hand

20 Filter Option

A = 2” Pleated (MERV 8, AC/HP-C)

C = 2” Charcoal

D = MERV 11 High Filtration Package

E = MERV 13 High Filtration Package

F = Filter Access Through Return Air Grille

W = Aluminum Washable

+ = None

21 Corrosion

Protection

A = Condenser Coil Only

C = Evaporator Coil Only

D = Both Coils Condenser & Evaporator

E = All Coils Cond/Evap/Reheat

F = Coat All

K = Coastal Package

+ = None

$ = Special

22 Engineering

Revision Level A1

24 Cabinet Color

1 = Marvair Beige

2 = Gray

3 = Carlsbad Canyon

4 = White

5 = Stainless Steel Exterior

6 = Dark Bronze

7 = .050 Aluminum Stucco

8 = Mesa Tan

9 = Pebble Gray

A = Stainless Steel - Unit

$ = Custom Color (Powder Coat)

25 Sound Attenuation 2 = Compressor Blanket

+ = None

26 Security Option A = Lockable Access Plate/Tamper Proof

+ = None

27 Fastener/Drain Pan

Option

A = Stainless Steel Fasteners

C = Stainless Steel Drain Pan

D = Stainless Steel Fasteners & Drain Pan

E = IP55 Ingress

+ = None

28 Unused + = None

$ = Special

29 Unused + = None

$ = Special

30 Special Variation

+ = None

$ = Special Conguration Not Covered by

Model Nomenclature

1.3 Serial Number Date Code

20 = 2020 01 = January 05 = May 09 = September

21 = 2021 02 = February 06 = June 10= October

22 = 2022 03= March 07 = July 11 = November

23 = 2023 04 = April 08 = August 12 = December

1.4 Capacities, Weights and Filter Sizes

See the Product Data Sheet for complete electrical and performance specications and dimensional

drawings.

7Marvair MGA3090-3120 I&O Manual 03/2021 Rev.6

Note: Follow local codes and standards when designing duct runs to deliver the required airow.

Minimize noise and excessive pressure drops caused by duct aspect ratio changes, bends, dampers and

outlet grilles in duct runs.

Basic Model Cooling BTUH1EER2Rated Air Flow (CFM)3

MGA3090A 89,000 10 3,500

MGA3120A 118,000 10 4,000

1Cooling rated at 95°F (35°C) outdoor and 80°F DB/67° WB (26.5°C DB/19.5°C WB) return air. 2EER=Energy Efciency Ratio

3CFM=Cubic Feet per Minute

Ratings are with no outside air. Performance will be affected by altitude.

Ratings are at 230 volts for 208/230 volt units (“A” & “C” models) and 460 volts for “D” models. Operation of units at a different voltage

from that of the rating point will affect performance and air ow.

Table 1. Efficiency and Capacity Ratings at ANSI/AHRI Standard 390

MGA3090A (Stage 1)

Return Air DB/WB Sensible Cooling

Capacity

Outside Air Temperature ºF (ºC)

75 (24) 80 (27) 85 (30) 90 (32) 95 (35)

79/66

BTUH

40,953 40,416 39,874 39,339 38,800

75/61 42,039 40,581 39,164 37,706 36,248

80/63 43,700 42,201 40,662 39,164 37,665

85/65 45,320 43,781 42,201 40,662 39,083

MGA3120A (Stage 1)

Return Air DB/WB Sensible Cooling

Capacity

Outside Air Temperature ºF (ºC)

75 (24) 80 (27) 85 (30) 90 (32) 95 (35)

79/66

BTUH

68,061 65,732 63,372 61,043 58,684

75/61 61,999 59,848 57,758 55,608 53,457

80/63 64,448 62,238 59,968 57,758 55,548

85/65 66,837 64,567 62,238 59,968 57,638

Table 2. Sensible Capacities - Single Compressor Operation

MGA3090A (Stage 2)

Return Air

DB/WB

Sensible Cooling

Capacity

Outside Air Temperature ºF (ºC)

75 (24) 80 (27) 85 (30) 90 (32) 95 (35) 100

(38)

105

(41)

110

(43)

115

(46)

120

(49)

125

(52)

130

(54)

79/66*

BTUH

74,445 73,149 71,827 70,547 69,274 67,701 66,718 65,451 64,829 64,256 63,684 63,114

75/61 77,983 76,678 75,416 74,126 72,843 71,567 70,298 69,071 68,443 66,928 65,326 63,724

80/63 87,060 85,763 84,439 83,158 81,884 79,477 76,184 72,802 71,200 69,598 67,996 66,394

85/65 96,006 94,720 92,738 89,356 85,885 82,414 79,032 75,561 73,870 72,268 70,666 69,064

MGA3120 (Stage 2)

Return Air

DB/WB

Sensible Cooling

Capacity

Outside Air Temperature ºF (ºC)

75 (24) 80 (27) 85 (30) 90 (32) 95 (35) 100

(38)

105

(41)

110

(43)

115

(46)

120

(49)

125

(52)

130

(54)

79/66*

BTUH

99,115 97,304 95,482 93,696 91,900 90,117 88,369 86,611 85,748 84,954 84,162 83,373

75/61 103,575 101,753 99,994 98,197 96,412 94,639 92,878 91,178 90,307 89,440 88,462 86,293

80/63 115,351 113,540 111,693 109,907 108,134 106,373 103,166 98,586 96,417 94,247 92,078 89,909

85/65 126,948 125,152 123,321 121,003 116,303 111,602 107,023 102,322 100,032 97,863 95,694 93,524

Table 3. Sensible Capacities - Dual Compressor Operation

Marvair MGA3090-3120 I&O Manual 03/2021 Rev.6

Basic Model Outdoor Temperature

75ºF / 24ºC 80ºF / 26.5ºC 85ºF / 29ºC 90ºF / 32ºC 195ºF / 35ºC

MGA3090A 46,980 45,360 43,740 42,120 40,500

MGA3120A 69,286 66,896 64,507 62,118 59,729

1Based upon ANSI/AHRI std. 390 return air conditions of 80°F DB/67° WB (26.5°C DB/19.5°C WB) at various outdoor temperatures.

Table 4. Single Compressor Cooling Performance (BTUH) at Various Outdoor Temperatures

Basic Model Outdoor Temperature

75ºF / 24ºC 80ºF / 26.5ºC 85ºF / 29ºC 90ºF / 32ºC 195ºF / 35ºC

MGA3090A 103,240 99,680 96,120 92,560 89,000

MGA3120A 139,804 134,984 130,163 125,342 120,521

1Based upon ANSI/AHRI std. 390 return air conditions of 80°F DB/67° WB (26.5°C DB/19.5°C WB) at various outdoor temperatures.

Table 5. Dual Compressor Cooling Performance (BTUH) at Various Outdoor Temperatures

Basic Model Fan Watts Fan CFM EER @ 55 F OAT Outside Air Temperature ºF (ºC)

50 (10) 55 (13) 60 (16) 65 (18) 70 (21)

MGA3090A 730 3,500 125 110,128 91,140 72,153 53,165 34,178

MGA3120A 967 4,000 108 125,860 104,160 82,460 60,760 39,060

Based upon indoor setpoint temperature of 79 (26).

Table 6. Economizer Cooling Performance

Model Description INCHES MILLIMETERS PART NO. FILTERS PER UNIT MERV RATING

MGA3090A Exterior Access Return Air Filter 25" x 16" x 2" 635 x 406 x 51 80137 3 8

Interior Access Return Air Filter 15" x 20" x 2" 381 x 508 x 51 92365 3 8

MGA3090A

Reverse Flow

Exterior Access Return Air Filter 25” x 16” x 2” 635 x 406 x 51 80137 3 8