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Marvair MAA/MGA Wall Mount AC Installation & Operation Manual

05/2023 Rev.21

Item Description

1

Economizer Actuator Output 2-10 VDC

2

Outdoor Motor Control Output 0-10 VDC or PWM

3

Indoor Motor Control Output 0-10 VDC or PWM

4

Enthalpy Sensor Signal Input 4-20mA

5

Outdoor Sensor Signal 10K NTC (Heat Pumps) / Dry Bulb Sensor Signal Input 10K NTC                                                

(Systems Equipped with Dry Bulb Economizer)

6

Supply Air Sensor Signal Input 10K NTC (Systems Equipped with Economizer)

7

Defrost Sensor Signal Input 10k NTC (Heat Pumps Only)

8

Head Pressure Control Sensor Signal 10k NTC (ECM Motors)

9

Control Board Menu/Fault Display

10

Menu/Up/Down Selection Buttons

11

Modbus RJ11 Communications Ports

12

Low Pressure / Freeze Sensor Signal Input 10k NTC 

13

High Pressure Switch Input (Normally Closed) 

14

Thermostat Inputs/Alarm And Status Terminals

15

24 VAC To Power Board (18 VAC To 30 VAC)

16

Indoor Blower Output 24 VAC (PSC Motors)

17

Reheat Output 24 VAC (Hot Gas Or Electric Reheat Dehumidification)

18

Reversing Valve Output 24 VAC (Heat Pumps Only)

19

Electric Heat Output 24 VAC

20

Outdoor Fan Output 24 VAC (PSC Motors)

21

Compressor 1/1st Stage Output 24 VAC (Single Stage Compressor)

22

Compressor 2/2nd Stage Output 24 VAC (Dual Compressor System 2nd Compressor) 

(Single Compressor 2nd Stage)

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 firmly secure the board to the control box. After this is achieved, follow the 

wiring diagram and menu configuration for the respective system for appropriate operation. Ensure 

that the terminals used do not make any unwanted electrical connection (via strands etc.) with any 

other terminals. Please allow a 1” creepage distance between the board and all other adjacent electrical 

components.

2.3  PCB Details and Information

The  PCB  is  equipped  with  an  on  board  seven-segment  display  (Item  #9)  for 

configuring various settings and displaying faults. During normal operation the 

display remains off unless the configuration menu is accessed or a fault has occurred. 

Faults will be annunciated on the display as shown below:

Display

Displayed Faults

AS-F

 Supply Air Sensor Fault (Sensor Disconnected Or Faulty) If Equipped

DB-F

Dry Bulb / Outdoor Sensor Fault (Sensor Disconnected Or Faulty) If Equipped

DS-F

Defrost Sensor Fault (Sensor Disconnected Or Faulty) Heat Pumps Only

ES-F

Enthalpy Sensor Fault (Sensor Disconnected Or Faulty) If Equipped

LP-1

Low Pressure Lockout Compressor Circuit 1 

LP-2

Low Pressure Lockout Compressor Circuit 2

HP-1

High Pressure Lockout Compressor Circuit 1

HP-2

High Pressure Lockout Compressor Circuit 2

03

Low Voltage "Brownout" 16VAC or Less for 10 Minutes

Summary of Contents for Marvair MAA1018A

Page 1: ...f this manual can be found at www Marvair com 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...

Page 2: ...T 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...

Page 3: ...on the inside of the building adjacent to the thermostat END USER Retain these instructions for future reference Table of Contents Chapter 1 Marvair Wall Mount Air Conditioner Description Specificatio...

Page 4: ...omizer 14 Figure 1d Typical Electrical Schematic Model MAA Alternate Construction with Economizer 15 Figure 1e Typical Electrical Schematic Model MAA Alternate Construction with Economizer 16 Figure 2...

Page 5: ...x 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 a...

Page 6: ...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 Y Low Ambient w CCH FCC Z Low Ambient w CCH EFS 1 Low Ambient w FCC 2 Lo...

Page 7: ...del INCHES MILLIMETERS PART NUMBER FILTERS PER UNIT MERV RATING MAA1018A 14 x 12 1 356 x 305 x 25 P 80122 1 N A MAA1020A 1024A 16 x 25 x 2 406 x 635 x 51 80137 1 8 MAA1024A 1030A 1036A B2 INTERNAL 16...

Page 8: ...of outside air into the enclosure when the outdoor air conditions are suitable to reduce the need for mechanical cooling save energy and extend compressor life Depending upon the options selected the...

Page 9: ...nly Used in specialty applications i e Magnetic Resonance Imaging MRI buildings to prevent magnetic voltage disturbance caused by compressor cycling Two hot gas bypass option packages are available to...

Page 10: ...s performance in hot ambient temperatures High Filtration Selected units are built with larger blowers motors for use with higher efficiency filters with MERV ratings of 11 13 and 14 when tested to AS...

Page 11: ...el Two stainless steel cabinet constructions are available the complete cabinet including most internal sheet metal or only the exterior sheet metal 1 7 Electrical Operation The compressor and condens...

Page 12: ...O C L L A N O D E R I U Q E R E B T O N Y A M R E T A E H E S A C K N A R C 3 T U O K C O L L L I W T I N U E H T D N A E C I W T D E N E P O S A H S P H E H T N E H W T L U A F E R U S S E R P H G I...

Page 13: ...E R I W P A T R E M R O S N A R T E G N A R O D N A D E R S R O S S E R P M O C L L A N O D E R I U Q E R E B T O N Y A M R E T A E H E S A C K N A R C 3 T U O K C O L L L I W T I N U E H T D N A E C...

Page 14: ...14 Marvair MAA MGA Wall Mount AC Installation Operation Manual 05 2023 Rev 21 Figure 1c Typical Electrical Schematic Economizer Model MAA Alternate Construction...

Page 15: ...Marvair MAA MGA Wall Mount AC Installation Operation Manual 05 2023 Rev 21 15 Figure 1d Typical Electrical Schematic Economizer Model MAA Alternate Construction...

Page 16: ...16 Marvair MAA MGA Wall Mount AC Installation Operation Manual 05 2023 Rev 21 Figure 1e Typical Electrical Schematic Economizer Model MAA Alternate Construction...

Page 17: ...le information 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...

Page 18: ...d Stage 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...

Page 19: ...Blower 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...

Page 20: ...ow pressureorhigh 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 T...

Page 21: ...ystem will default to compressor cooling if any sensor becomes disconnected or faulty ChangingtheECONOSelecttoN no willdisableeconomizeroperationandtheeconomizer function will be ignored 13 SensorType...

Page 22: ...n 25 Software 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...

Page 23: ...DD Heat 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 Sho...

Page 24: ...t priority 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...

Page 25: ...ns until 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 N...

Page 26: ...Y1 speed 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...

Page 27: ...e During 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...

Page 28: ...cture and 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...

Page 29: ...ill initiate 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...

Page 30: ...r will 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 compres...

Page 31: ...ne temperature 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...

Page 32: ...by protecting 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 comp...

Page 33: ...Modbus 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...

Page 34: ...pressor will not start makes excessive noise or will not pump return the unit to the freight carrier 3 2 Installation Requirements General 1 Inspect unit for completeness Check for missing parts e g h...

Page 35: ...m 24 inches 61 cm 6 inches 15 cm 1030A 1036A 30 inches 76 cm 18 inches 46 cm 24 inches 61 cm 6 inches 15 cm 1042A 1048A 1060A 2060A 30 inches 76 cm 30 inches 76 cm 24 inches 61 cm 6 inches 15 cm 1072A...

Page 36: ...an Non volatile program memory P N 50107 Grilles Wall Sleeves Supply Grilles For MAA1018A 17 x 5 432 mm x 127 mm P N 80682 For MAA1020A MAA1024A MAA1024A B2 20 x 8 508 mm x 203 mm P N 80674 For MAA103...

Page 37: ...his manual is intended for use by a qualified service agency that is experienced in such work is familiar with all precautions and safety procedures required in such work and is equipped with the prop...

Page 38: ...m of the unit Galvanized metal duct extensions should be used to simplify connections to duct work and grilles Use fabric boots to prevent the transmission of vibration through the duct system The fab...

Page 39: ...d on the wall You must stabilize the unit on the bracket with the lifting device or by some other means the bracket alone is not sufficient 3 Make sure that the duct flanges are properly aligned with...

Page 40: ...ressure drops and the discharge pressure rises when the compressor is energized An alternate method of verification for self contained system with small critical refrigerant charges where the installa...

Page 41: ...t meter set to the 300 volt scale measure voltage between terminal L1 on the compressor contactor of unit 1 and terminal L1 on the compressor contactor of unit 2 If voltage is present units are wired...

Page 42: ...industry set points to facilitate installation If desired each of the set points can be quickly and easily changed in the field by the installer It can be used with Marvair s unique vertical packaged...

Page 43: ...4 t l u a f n e g o r d y h a n o p u e d o m n o i t a l i t n e v k c a b d e e f s i h T C A V H d e t c e n n o c e h t m o r f g n i r o t i n o m s u t a t s r e z i m o n o c e r o f d e s u e...

Page 44: ...omizer Equipped models only To check the system operation under different ambient conditions the air temperature and enthalpy sensors must be tricked When outdoor ambient condi tions are higher than t...

Page 45: ...ays please exercise caution and good judgement when servicing the unit Use only safe and proven service techniques Use refrigeration goggles when servicing the refrigeration circuit WARNING The refrig...

Page 46: ...iction 2 Obstruction or leak in condensate pan 2 Check pan for leak or blockage 3 Unit is not level 3 Level unit F No space heating or reduced heating units equipped with resistance ele ments 1 Defect...

Page 47: ...rcuit 1 LP 2 Low Pressure Lockout Compressor Circuit 2 HP 1 High Pressure Lockout Compressor Circuit 1 HP 2 High Pressure Lockout Compressor Circuit 2 03 Low Voltage Brownout 16VAC or Less for 10 Minu...

Page 48: ...before restarting Condenser Periodicallyinspecttheoutdoorcondensercoilandthecabinetairreliefsfordirtorobstructions Remove foreign objects such as leaves paper etc If the condenser coil is dirty it ma...

Page 49: ...or any 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 Da...

Page 50: ...__________________________ Compressor Model No ______________________________________________ Serial No ______________________________________________ B Pre Start Up Is there any shipping damage Yes N...

Page 51: ...Deviation from avg voltage ______________volts Voltage imbalance 100 x Max Deviation avg Voltage ___________ A voltage deviation greater than 2 with the unit running should be addressed and corrected...

Page 52: ...ir DB Temp ________ ________ Evap Leaving Air WB Temp ________ ________ Heater Contactor Amps L1 ________ ________ Heater Contactor Amps L2 ________ ________ Heater Contactor Amps L3 ________ ________...

Page 53: ...__ Compressor Amps L3 ________ ________ Notes _________________________________________________________________________ _________________________________________________________________________ ______...

Page 54: ...the supply outlet duct flange on the unit The 1 25 4 mm clearance must extend on all sides of the supply duct for the first 3 feet 1 meter from the unit IMPORTANT Marvair requires a minimum of 1 25 4...

Page 55: ...ters 6 Install the two No 10 screws in the heater assembly plate 7 Install wire harness in hole provided in drain pan and then through filter bracket and then into control box 8 Wire the heater as sho...

Page 56: ...56 Marvair MAA MGA Wall Mount AC Installation Operation Manual 05 2023 Rev 21...

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