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Single Stage Models:

MAA1042H • MAA1048H • MAA1060H

2-Stage Models:

MMA2042H • MAA2048H • MAA2060H

Installation & Operation Manual 

3.5, 4 & 5 Ton Vertical Wall-Mount Heat Pumps

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 Identification 

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

INSTALLER:  

Affix the instructions on the inside of the building adjacent to the thermostat.

END USER:  

Retain this manual for future reference.

Heat Pump Product Manual

Vertical Wall-Mount Heat Pumps

Manufactured By:

A 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

E-mail: [email protected] • Internet: www.Marvair.com

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

Marvair Wall Mount Heat Pump I&O Manual

11/2021 New

An AirX Climate Solutions Brand

Summary of Contents for MAA1042H

Page 1: ...is equipped with INSTALLER Affix the instructions on the inside of the building adjacent to the thermostat END USER Retain this manual for future reference Heat Pump Product Manual Vertical Wall Moun...

Page 2: ...ure to follow these rules may result in death serious bodily harm property damage and damage to the equipment Important Safety Precautions 1 USE CARE when LIFTING or TRANSPORTING equipment 2 TRANSPORT...

Page 3: ...ve 26 3 4 Ventilation System Set Up 28 Chapter 4 Troubleshooting 4 1 Overview 30 4 2 Failure Symptoms Guide 31 4 3 Compressor Troubleshooting 32 4 4 Electric Heat Control 33 Chapter 5 Electrical Schem...

Page 4: ...stat Connection Diagram 24 Figure 6 Temperature Sensor Wires Modulating HGR Valve 27 Figure 7 Desired Temperature Set Point Modulating HGR Valve 27 Figure 8 Damper Adjustment 28 Figure 9 Damper Air Pa...

Page 5: ...requirements For school classrooms models are available to comply with the ASHRAE 62 1999 standard Ventilation for Acceptable Indoor Air Quality Where cooling is required during cool or cold weather...

Page 6: ...w 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 Special 17 Indoor Air Qua...

Page 7: ...on Economizer Base Unit 20 F 131 F 7 C 55 C Economizer Equipped Base Unit 40 F 131 F 29 C 55 C An Optional FCC switch is required for the cooling Mode Heating mode ratings are 47 F Outdoor Temperature...

Page 8: ...operate during Hydrogen Fault Emergency Ventilation Thermostat must provide the fan G signal to HVAC to activate the indoor blower Forced Mechanical Cooling When 24VAC is applied to the FC input of t...

Page 9: ...selectable 30 60 or 90 minute delay period Factory set at 60 minutes If the sensor is still calling for defrost at the end of this delay period it will de energize the outdoor fan and energize the re...

Page 10: ...o the proper operation of the heat pump The control board has four operational modes that can be defined by the installer These modes are selected with jumpers See Figure 1 for location of the jumpers...

Page 11: ...lso incorporate a fixed hard start time of one second during which the condenser fan motor will turn on full speed for one second at start up High Pressure Switch HPS The high pressure switch is mount...

Page 12: ...n there is a 24 VAC signal present at the Y terminal W2 The W2 terminal is the electric heat input from the thermostat When the control receives a call for W2 from the thermostat it will energize the...

Page 13: ...erse acting high pressure switch to cycle the condenser fan motor according to liquid refrigerant pressure conditions Switch closure and fan operation occurs when the pressure reaches 400 PSIG The swi...

Page 14: ...ator is a motor that modulates the position of the damper blade It is controlled by the enthalpy controller and powered by the 24 VAC control transformer It is capable of driving a full 90 degrees wit...

Page 15: ...r The mixed air sensor is a thermistor mounted on a bracket adjacent to the right side of the blower assembly The thermistor senses the air temperature entering the structure and provides a signal to...

Page 16: ...24 hours with primary 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 operate return the unit to the freight carri...

Page 17: ...mum clearances required for proper operation and service Tables 4a 4b below MODEL Min Clearance From the Front Min Clearance Around Sides Single Unit Min Clearance Between Sides Two Units Min Space Ab...

Page 18: ...1042H 1048H 1060H MAA2042H 2048H 2060H Double Deflection Aluminum Supply Grille 30 x 10 762mm x 254mm 80676 Aluminum Return Grille 30 x 16 762mm x 406mm 80679 Return Filter Grille 30 x 16 762mm x 406m...

Page 19: ...or the first three feet from the unit The duct must be constructed of galvanized steel with a minimum thickness of 019 Minimum Airflow Requirements WARNING The duct system must be engineered to assure...

Page 20: ...To provide fresh air remove the two screws on either side of the hood and reposition as desired Figure 3 Fresh Air Hood Damper Adjustment 2 6 Bottom Bracket Installation 1 Remove and discard the 4 x 4...

Page 21: ...erly aligned with the wall opening Adjust as necessary 5 Note the holes in each side bracket Using the holes for guides drill holes through the wall with a 3 8 inch drill bit Insert the 3 8 bolts or l...

Page 22: ...liefs CAUTION Note Power supply service must be within allowable range 10 5 of rated voltage stamped on the unit rating plate To operate nominal 230 208V unit at 208V change the transformer line tap f...

Page 23: ...e unit and reverse L1 L2 at the disconnect 4 Install the ground wire on the ground lug 5 Units designed to operate on 460v have a step down transformer for 230v motors Low Voltage Wiring 1 Pull the lo...

Page 24: ...24 Marvair Wall Mount Heat Pump I O Manual 11 2021 New Figure 5a Humidity Control Wiring Detail Heat Pumps Figure 5b Thermostat Connection Diagram...

Page 25: ...owlylowerthethermostatcoolingsetpointtemperature Once the indoor fan turns on allow approximately three minutes for the compressor and outdoor fan to start For units equipped with the low ambient cont...

Page 26: ...ps with an economizer and optional on all other Marvair units has cycled 3 Move the system switch to the Off position All functions should stop The Blower Timed Delay Relay BTR keeps the blower runnin...

Page 27: ...F Insert the probes of the meter into the negative black and positive red set point test terminals on the board Carefully and in small increments turn the blue knob on the potentiometer until the vol...

Page 28: ...the return air from the supply air The difference is the amount of fresh air c Loosen the set screw that holds the collar onto the rod connected to the damper Move the collar and tighten the set screw...

Page 29: ...ure of the indoor return air Multiply the temperature of the indoor air by B d Calculate what the Tmix should be with the desired quantity of outside air Measure the actual temperature of Tmix at the...

Page 30: ...fter making this initial inspection The troubleshooting information in this manual is basic The troubleshooting section contains problem solution charts for general problems followed by a compressor s...

Page 31: ...ation 4 Check air filter s Check blower operation Remove airflow restriction C Unit cycles on high pressure or loss of charge 1 Loss or restriction of airflow 2 Restriction in refrigerant circuit 3 Re...

Page 32: ...failures before condemning the compressor The following electrical tests will aid diagnosis on single phase units 1 Start Up Voltage Measure the voltage at the compressor contactor during start up Th...

Page 33: ...the heater assembly the switch will have to be replaced by qualified service personnel after the source of the overheat problem is resolved In addition to the thermal cut out switch described above t...

Page 34: ...ilable The heater drives liquid refrigerant from the crankcase and prevents loss of lubrication caused be oil dilution Power must be applied to the unit for 24 hours before starting the compressor Not...

Page 35: ...35 Marvair Wall Mount Heat Pump I O Manual 11 2021 New Figure 11a Typical 1 Electrical Schematic Diagram Heat Pump Models MAA with Manual Outside Air Damper...

Page 36: ...36 Marvair Wall Mount Heat Pump I O Manual 11 2021 New Figure 11b Typical 208 230v 3 Electrical Schematic Diagram Heat Pump Models MAA...

Page 37: ...37 Marvair Wall Mount Heat Pump I O Manual 11 2021 New Figure 11c Typical 460v 3 Electrical Schematic Diagram Heat Pumps Models MAA with the PC Control Board...

Page 38: ...rical components Be sure the unit has dried before restarting Use a fin comb of the correct spacing to straighten mashed or bent fins Outdoor Coil Periodically inspect the outdoor coil and the cabinet...

Page 39: ...arges 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 caused by improper...

Page 40: ...ly 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 mm from...

Page 41: ...heaters 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...

Page 42: ...42 Marvair Wall Mount Heat Pump I O Manual 11 2021 New...

Page 43: ...________________________________________________ Compressor Serial No _ ________________________________________________________ D Pre Start Up Is there shipping damage Yes No If so describe _________...

Page 44: ...age Voltage L1 L2 L1 L3 L2 L3 3 _______________V Deviation Difference Average Voltage Maximum Deviation ______________V Voltage Imbalance Deviation Difference x 100 Average Voltage ___________ A Volta...

Page 45: ...g voltage that is Not between the Minimum and Maximum listed on the unit Data Label Must be addressed and corrected before starting unit Improper voltage can cause the compressor to overheat and cause...

Page 46: ...n installed wired to the Dehumidification input Yes No Has the Humidistat Control been properly setup for dehumidification Yes No Adjust the cooling setpoint so there is No demand for cooling Adjust t...

Page 47: ...mizer Control Board been properly wired to the Control Yes No Has the Economizer Control Board Ambient selections been properly setup Yes No Has the Economizer Control Board Minimum Opening selection...

Page 48: ...eating Heat Pump Check and Record Readings After about 10 minutes of operating in the heating mode check and record the following data points Inside Temperature IAT F Outside Temperature OAT F Enterin...

Page 49: ...door blower motor IBM On Yes No Is the Compressor Off Yes No Is the Condenser Fan CFM Off Yes No Is the Heater On Clamp an AmpProbe on one leg of the heater contactor to verify Yes No Heating Check an...

Page 50: ...utdoor Thermostat is 0 F to 50 F Is the indoor blower motor IBM On Yes No Is the Compressor On Yes No Is the Condenser Fan CFM On Ambient conditions may be delay CFM Yes No Is the Heater Off Clamp an...

Page 51: ...__ ____________________________________________________________________________________ ____________________________________________________________________________________ ___________________________...

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