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7

Marvair MGA3090-3180 Wall Mount AC I&O Manual 05/2023 Rev.14

Note: 

Follow local codes and standards when designing duct runs to deliver the required airflow. 

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

outlet grilles in duct runs.

Model Number

Cooling BTUH

1

EER

2

Rated Air Flow (CFM)

3

MGA3090A

89,000

10

3,500

MGA3120A

118,000

10

4,000

MGA3150A

146,000

10

4,500

MGA3180A

182,000

10

6,000

1

Cooling rated at 95°F (35°C) outdoor and 80°F DB/67° WB (26.5°C DB/19.5°C WB) return air.   

2

EER=Energy Efficiency Ratio   

3

CFM=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 flow.

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

Model Number

IWG Static Pressure

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

2.2

MGA3090A

3,846

3,570

3,286

3,003

2,722¹

2,515¹

2,164¹

1,888¹

1,612¹

1,338¹

1,065¹

794¹

MGA3120A

4,301

4,064

3,808

3,533

3,238

2,924¹

2,590¹

2,237¹

1,865¹

1,472¹

1,061¹

630¹

MGA3150A

4,801

4,564

4,308

4,033

3,738

3,424

3,090

2,737

2,365

1,972

1,561

1,130

MGA3180A

6,876

6,622

6,378

6,143

5,916

5,686

5,487

5,285

5,090

4,902

4,721

4,547

¹Operation in the shaded area is not recommended 

Table  2. SCFM @ Various External Static Pressures

Model 

Number

Return 

Air 

DB/WB 

°F (°C)

Outdoor Temperature

Cooling  

Capacity 

BTUH

75°F 

(24°C)

80°F 

(27°C)

85°F 

(30°C)

90°F 

(32°C)

95°F 

(35°C)

100°F 

(38°C)

105°F 

(41°C)

110°F 

(43°C)

115°F 

(46°C)

120°F 

(49°C)

125°F 

(52°C)

130°F 

(54°C)

MGA3090A

72/61 

(22/16)

Total

42,039 40,581 39,164 37,706 36,248 34,790 33,332 31,914 31,185 30,456 29,727 28,998

Sensible

37,564 37,021 36,494 35,953 35,414 34,790 33,332 31,914 31,185 30,456 29,727 28,998

76/63 

(24/17)

Total

43,700 42,201 40,662 39,164 37,665 36,167 34,668 33,129 32,400 31,671 30,942 30,213

Sensible

41,395 40,856 40,305 39,164 37,665 36,167 34,668 33,129 32,400 31,671 30,942 30,213

80/67 

(27/19)

Total

46,980 45,360 43,740 42,120 40,500 38,192 37,260 35,640 34,830 34,101 33,372 32,643

Sensible

40,841 40,300 39,761 39,224 38,688 37,926 37,260 35,640 34,830 34,101 33,372 32,643

84/71 

(29/22)

Total

50,261 48,519 46,818 45,077 43,335 41,594 39,852 38,151 37,260 36,531 35,802 35,073

Sensible

40,097 39,560 39,037 38,503 37,970 37,438 36,908 36,392 36,122 35,901 35,681 35,073

MGA3120A

72/61 

(22/16)

Total

61,242 59,118 57,053 54,929 52,805 50,681 48,557 46,492 45,430 44,368 43,306 42,244

Sensible

61,242 59,118 57,053 54,929 52,805 50,681 48,557 46,492 45,430 44,368 43,306 42,244

76/63 

(24/17)

Total

63,661 61,478 59,236 57,053 54,870 52,687 50,504 48,262 47,200 46,138 45,076 44,014

Sensible

63,661 61,478 59,236 57,053 54,870 52,687 50,504 48,262 47,200 46,138 45,076 44,014

80/67 

(27/19)

Total

68,440 66,080 63,720 61,360 59,000 56,640 54,280 51,920 50,740 49,678 48,616 47,554

Sensible

68,440 66,080 63,720 61,360 59,000 56,640 54,280 51,920 50,740 49,678 48,616 47,554

84/71 

(29/22)

Total

73,219 70,682 68,204 65,667 63,130 60,593 58,056 55,578 54,280 53,218 52,156 51,094

Sensible

72,324 70,682 68,204 65,667 63,130 60,593 58,056 55,578 54,280 53,218 52,156 51,094

MGA3150A

72/61 

(22/16)

Total

75,809 73,180 70,623 67,994 65,365 62,736 60,107 57,550 56,236 54,921 53,607 52,292

Sensible

75,809 73,180 70,623 67,994 65,365 62,736 60,107 57,550 56,236 54,921 53,607 52,292

76/63 

(24/17)

Total

78,803 76,101 73,326 70,623 67,921 65,219 62,517 59,741 58,427 57,112 55,798 54,483

Sensible

78,803 76,101 73,326 70,623 67,921 65,219 62,517 59,741 58,427 57,112 55,798 54,483

80/67 

(27/19)

Total

84,719 81,798 78,876 75,955 73,034 70,112 67,191 64,269 62,809 61,494 60,180 58,865

Sensible

84,374 81,798 78,876 75,955 73,034 70,112 67,191 64,269 62,809 61,494 60,180 58,865

84/71 

(29/22)

Total

90,635 87,494 84,427 81,286 78,146 75,005 71,865 68,798 67,191 65,876 64,562 63,247

Sensible

83,360 82,358 81,383 80,389 78,146 75,005 71,865 68,798 67,191 65,876 64,562 63,247

MGA3180A

72/61 

(22/16)

Total

94,458 91,182 87,997 84,721 81,445 78,169 74,893 71,708 70,070 68,432 66,794 65,156

Sensible

94,458 91,182 87,997 84,721 81,445 78,169 74,893 71,708 70,070 68,432 66,794 65,156

76/63 

(24/17)

Total

98,189 94,822 91,364 87,997 84,630 81,263 77,896 74,438 72,800 71,162 69,524 67,886

Sensible

98,189 94,822 91,364 87,997 84,630 81,263 77,896 74,438 72,800 71,162 69,524 67,886

80/67 

(27/19)

Total

105,560 101,920 98,280 94,640 91,000 87,360 83,720 80,080 78,260 76,622 74,984 73,346

Sensible

105,560 101,920 98,280 94,640 91,000 87,360 83,720 80,080 78,260 76,622 74,984 73,346

84/71 

(29/22)

Total

112,931 109,018 105,196 101,283 97,370 93,457 89,544 85,722 83,720 82,082 80,444 78,806

Sensible

108,205 106,965 105,196 101,283 97,370 93,457 89,544 85,722 83,720 82,082 80,444 78,806

Table 3.  Single Compressor Cooling Performance (BTUH) at Various Outdoor Temperatures

Summary of Contents for Marvair MGA3090A

Page 1: ...ide of the building adjacent to the thermostat END USER Retain this manual for future reference Manufactured By Marvair An ACS Brand P O Box 400 Cordele Georgia 31010 156 Seedling Drive Cordele Georgi...

Page 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 in...

Page 3: ...cent 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...

Page 4: ...ting Detail 38 Figure 7a Humidistat Wiring to a Marvair Air Conditioner with Reheat 40 Figure 7b Thermostat Connection Diagram 41 Figure 7c CommStat 4 Wiring Detail 41 Tables Table 1 Efficiency and Ca...

Page 5: ...ols 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...

Page 6: ...ter 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 L...

Page 7: ...9 037 38 503 37 970 37 438 36 908 36 392 36 122 35 901 35 681 35 073 MGA3120A 72 61 22 16 Total 61 242 59 118 57 053 54 929 52 805 50 681 48 557 46 492 45 430 44 368 43 306 42 244 Sensible 61 242 59 1...

Page 8: ...18 92 033 90 966 89 904 88 845 87 790 76 63 24 17 Total 157 606 152 202 146 651 141 247 135 842 130 438 125 033 119 483 116 854 114 224 111 595 108 966 Sensible 115 990 113 761 111 489 109 294 107 115...

Page 9: ...508 x 51 92365 3 8 Economizer Pre filter 9 25 x 37 x 375 235 x 940 x 10 92127 1 N A MGA3120A MGA3150A Exterior Access Return Air Filter 25 x 16 x 2 635 x 406 x 51 80137 3 8 Interior Access Return Air...

Page 10: ...r operation is desired the factory installed jumper between terminals 1 and 2 of the low voltage terminal strip must be removed The 1st stage cooling input is terminal 1 of the low voltage terminal st...

Page 11: ...compressor and fans will also de energize PMF Phase monitor fault to monitor phase operation for 3 phase systems light is on when 3 phase power is powered and connected correctly PLC Outputs The PLC...

Page 12: ...urned off the alarm output is energized and the status LED s will blink to indicate which fault has occurred If there is a call for air flow the indoor blower will remain energized When the lockout co...

Page 13: ...ts and sheet metal Note the internal sheet metal which is insulated and the internal control box are not coated Dirty Filter Indicator Adiaphragm type of indicator measures the air pressure on either...

Page 14: ...l PTC crankcase heater that functions as long as primary power is available The heater drives liquid refrigerant from the crankcase and prevents loss of lubrication caused by oil dilution Power must b...

Page 15: ...3 Rev 14 RELAY OUTPUTS X12 DQ a 1L 0 1 2 3 4 2L 5 6 7 0 1 DQ b CPU 1215C DC DC RLY L M X12 24VDC 24VDC L M 1M 0 1 2 3 4 5 6 7 0 1 2 3 4 5 2M 0 1 Dl a Dl b 24VDC INPUTS 3M 0 1 X11 AQ ANALOG OUTPUTS INP...

Page 16: ...rmation to the end user Special features include 2 Stage operation with varying speed control to optimize latent and sensible capacity built in remote communication Modbus for monitoring and or contro...

Page 17: ...23 Control Board Power Indicator LED 2 2 Installation and Replacement The PCB is factory installed To install a replacement PCB use the six mounting holes along with the appropriate screw size to fir...

Page 18: ...off delay in seconds 4 IBM Y1 Set 80 40 100 G Fan only and Y1 1st Stage Cooling Indoor Blower Speed Setting 5 IBM Y2 Set 100 40 100 Y2 2nd Stage Cooling Indoor Blower Speed Setting 6 OFM Select P P dC...

Page 19: ...sureorhigh pressurelockout 6 OFM Select This setting allows the IBM Indoor Blower control signal to be configured for PWM or 0 10vdc control The default control output signal is PWM 7 OFM Set This is...

Page 20: ...ill default to compressor cooling if any sensor becomes disconnected or faulty ChangingtheECONOSelecttoN no willdisableeconomizeroperationandtheeconomizer function will be ignored 13 SensorType Thisse...

Page 21: ...ftware Version Number The software version of the 92589 control board will be displayed on the seven segment display This is for informational purposes only 2 4 Operation Power The Marvair PCB require...

Page 22: ...Pumps 5 0 Dehumidification Operation AC HP 5 1 Hot Gas Reheat 5 2 Electric Reheat 6 0 Refrigeration Protection 6 1 High Pressure lockout 6 2 Low Pressure Lockout Freeze Protection 6 3 Anti Short Cycl...

Page 23: ...ity This means that in any combination involving the G input the speed associated to Fan Only will never take precedence The priority list from Highest to Lowest goes as follows 1 Y2 Request 2 Y1 Requ...

Page 24: ...l the switch reopens at 290 PSIG These outputs function as described until the Cooling setpoint is satisfied This is considered as ON OFF fan cycle control and the PSC motor will not modulate Note Sin...

Page 25: ...ed since Y2 has higher priority These outputs remain energized until the cooling setpoint is satisfied Once the setpoint is satisfied the Compressor and the Outdoor fan outputs are de energized The In...

Page 26: ...g the testing of the air conditioner at the factory the control board has been configured for the sensor type used in the system There should be no need to change the sensor configuration If an enthal...

Page 27: ...nd provides a signal to the economizer controller for modulating the position of the damper The default supply air temperature is 55F in economizer cooling and is not adjustable A disconnected or faul...

Page 28: ...tiate a defrost cycle based on the time selected in the control board configuration menu setting 8 The defrost time intervals selections are 30 60 and 90 minutes and the factory default setting is 30...

Page 29: ...remain off as long as the request for W2 is active Once the request for W2 satisfies the compressor will be allowed to operate The default setting for SCKT is N No the electric heat and compressor wil...

Page 30: ...erature of 80F and 115F Systems with PSC Outdoor Motors utilizes a Fan Cycle Switch which closes at 400 PSIG to energize the OFR outdoor fan relay to start the outdoor fan which runs until the switch...

Page 31: ...ecting it from excessive short cycling When the compressor goes off due to any fault emergency or if the cooling heat pump heating setpoint is satisfied a built in 3 minute timer locks the compressor...

Page 32: ...odbus and the system will operate in normal cooling mode until the request for FC is satisfied Once satisfied the system will be allowed to return to economizer operation if conditions are favorable 7...

Page 33: ...rimary power turned on 2 Attempt to start the compressor after 24 hours 3 If the compressor will not start makes excessive noise or will not pump return the unit to the freight carrier 3 2 Installatio...

Page 34: ...cm 24 inches 61 cm 120 inches 305 cm MGA3120A MGA3150A MGA3180A Table 10 Minimum Clearances 6 Codes Make sure your installation conforms to all applicable electrical plumbing building and municipal c...

Page 35: ...cinstallationconditions Theinstallationoftheairconditioner to the building must take in to account all of these factors and follow best industry practices to provide a safe and secure attachment to th...

Page 36: ...National Fire Protection Association Standards 90A and 90B before designing and installing duct work The duct system must be engineered to insure sufficient air flow through the unit to prevent over h...

Page 37: ...iring into the back of unit locate the lower of the two knockouts on the wall side of the unit Drill a one inch hole in the shelter wall to match this opening Allow sufficient clearance to run 3 4 con...

Page 38: ...units may incorporate an internal crankcase heater for compressor protection The crankcase heater must be energized for at least 24 hours prior to starting the compressor Scrollcompressors likesevera...

Page 39: ...y cause serious injury and damage the panel DANGER NEVER open all four hinges simultaneously The panel should ONLY be opened by using the two hinges on the left side OR the two hinges on the right sid...

Page 40: ...ubbase assembly See Figure 4a for connections to various thermostats 2 Mount the thermostat on the wall of the shelter The thermostat should be located so that the supply air from the unit does NOT bl...

Page 41: ...m e o t n i m e t s y s e h t s e c r o f t u p t u o R A M e h T s r e z i m o n o c e h t i w s m e t s y s n o d e s u y l n o s i R A M l a n i m r e t 4 t a t S m m o C e h T 4 t l u a f n e g o...

Page 42: ...Nothing should operate at this time 3 Set the time delay in the control box to three minutes See Section 1 6 4 Slowly lower the thermostat s cooling set point temperature until the switch closes The...

Page 43: ...ng transportation However the great majority of problems result from installation errors If you experience difficulties with the unit please review the installation steps in Chapter 2 Much time can be...

Page 44: ...n in refrigerant circuit 2 Check for blockage or restriction especially filter drier and capillary tube assembly 3 Refrigerant overcharge following field service 3 Evacuate and recharge to factory spe...

Page 45: ...mpressor to see if it has overheated If it is hot the internal overload may be open You may have to wait several hours for it to reset 3 MotorWinding Resistances Using a digital volt ohm meter VOM mea...

Page 46: ...ged door or from the return grille on the inside of the building Evaporator If the evaporator becomes clogged or dirty it may be cleaned by careful vacuuming or with a com mercial evaporator cleaning...

Page 47: ...other material charges 2 Damages caused by shipping accident abuse negligence misuse fire flood or Acts of God 3 Damages caused by operating or staging the unit in a corrosive environment 4 Damages ca...

Page 48: ..._____________ Address ________________________________________State________________________ City ___________________________________________ Marvair Air conditioner Model No __________________________...

Page 49: ...olts L1 L2_______V L1 L3 ________V L2 L3______V L1 L2 L1 L3 L2 L3 3 Avg Voltage _______________ Max Deviation from avg voltage ______________volts Voltage imbalance 100 x Max Deviation avg Voltage ___...

Page 50: ...Amps L2 ________ ________ Heater Contactor Amps L3 ________ ________ E Cooling Mode Check Record Refrigerant Pressures Recheck voltage imbalance in cooling mode Measured Line to Line Volts L1 L2_____...

Page 51: ...______________________________________________________________ _________________________________________________________________________ _______________________________________________________________...

Page 52: ...SCALE DRAWN BY APPROVED BY TITLE DATE DRAWING NUMBER TOLERANCES EXCEPT AS NOTED DECIMAL FRACTIONAL ANGULAR This drawing contains confidential information of Marvair a Division of AIRXCEL Inc This inf...

Page 53: ...he bottom front panel To access the hood remove the screws that hold the front panel The air flow can be adjusted from no 0 fresh air to approximately 15 of rated air flow of fresh air in 5 increments...

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