11 eer vertical wall-mount air conditioners (66 pages)
Summary of Contents for ACS Marvair MGA3090A
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INSTALLER: Affix the instructions on the inside 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, Georgia 31015 (229) 273-3636 • Fax (229) 273-5154 www.Marvair.com...
Porting and Duct Work ..........................29 Top Flange Installation ..........................29 Installing the Lifting Brackets ........................30 Mounting the Unit ..........................30 Electrical Connections ...........................31 Chapter 4 Start-Up Check-Out of Cooling Cycle .........................35 Check-Out of Heating Cycle ........................35 Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
Chapter 1 Description & Specifications General Description The Marvair MGA3090A, MGA3120A & MGA3150A 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 90,000-150,000 BTUH.
11 = November 23 = 2023 04 = April 08 = August 12 = December Capacities, Weights and Filter Sizes See the Product Data Sheet for complete electrical and performance specifications and dimensional drawings. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
1 of the low voltage terminal strip and the 2nd stage cooling input is terminal 2 of the low voltage terminal strip. The thermostat must be programmed for 2 stage cooling operation when 2 stage compressor operation is desired. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
PLC to the air conditioner, to the thermostat or to the customer. PLC Inputs The PLC inputs are powered by 24 VDC. The inputs are: • Y – Compressor • Y2 – Dual Compressor Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
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The PLC has indicator LED’s that show the status of all thermostat inputs and outputs. For example, if the “G” LED is on, this means that voltage is present from the “G” terminal on the thermostat. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
Emergencey Management System fault • Delay on Make – On initial power up or on resumption of power, the air conditioner will wait 3 minutes from a call for cooling before allowing the contactor to energize. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
Power must be applied to the unit for 24 hours before starting the compressor. The condenser (outside fan) motor is energized by the same contactor. The indoor evaporator fan motor is controlled by the fan purge on the electronic control board. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
MODBUS. This chapter provides the necessary information for installing and operating the Marvair PCB. The diagram below identifies the inputs, outputs and connections for the Marvair PCB. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
Low pressure switch has opened twice Status 2 3 Blinks Freeze stat (optional) - Indoor coil temperature is below 35°F (1°C) Continuous Flash of Both LEDs Insufficient voltage to the board. Less than 20 Volts Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
To set second stage cooling (Y2 request) speed, put Bridge Jumper on the “Y2 pin and center pin” shown in the figure below. Use the potentiometer marked “IBM SPEED” to set the required speed. Bridge Jumper Position For Setting Y2 Speed IBM SPEED Potentiometer Figure 3b. Second Stage Cooling Speed Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
Outdoor Motor PWM Signal Output. One Wire Connected to “GND” and the Other Connected to “PWM” Outdoor Motor 0-10V Signal Output. One Wire Connected to “GND” and the Other Connected to “0-10V” Figure 6. Output Termination for Outdoor Motor Control Signal Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
5.0 Refrigeration Protection 5.1 High Pressure Lockout 5.2 Low Pressure Lockout 5.3 Low Voltage 5.4 Anti-short Cycle 6.0 Additional Features 6.1 MODBUS communication 6.2 Modulating Head Pressure Control 6.3 Freeze Stat Operation 6.4 Onboard Thermostat Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
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Indoor Fan Motor, that is proportional to the “Y1” speed setting on the board or via MODBUS. It also outputs a request dependent (based on FCC IN) control signal for the Outdoor Fan Motor. In Stage 1 Cooling operation, the compressor Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
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(based on “FCC IN” Input) and outputs a signal proportional to board or MODBUS setting when the “FCC IN” input is High. The board continues to produce these outputs until the Dehumidification request is dropped. Once this request is dropped, the Indoor Fan Motor continues to run for 90 seconds. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
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The sequence of operation is the same as described above for the various operation, but Indoor Motor speeds for various operation, Outdoor Motor Speed, Heating Setpoint and Cooling Setpoint (if applicable) has to be configured via MODBUS. See MODBUS register tables at the end of this section. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
D) When installing multiple units, please note the recommended clearances noted in Table 4. 4. Airflow Requirements: Maximum Static Pressures MGA3090A MGA3120A MGA3150A Keep duct lengths as short as possible. Do not obstruct airflow through the unit. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
Before installing the unit, remove the bracket and reattach as described in Section 2.5 The Lifting brackets are shipped attached to the back panel of the unit. These brackets provide a method for lifting it. The installation of the brackets is described in Section 2.6. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
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The information contained in this 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 proper tools and test instruments. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
Remove the 4 screws in these holes and use these screws to attach the top flange to the air conditioner. 3. Apply a bead of silicone sealer on the wall side of the bottom support brackets on the unit. Circle the mounting holes with the silicone bead. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
7. Check the fit of each sleeve to its mating flange for possible air leaks. Apply silicone sealer to close any gaps. Install the air return and supply grilles. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
Verification of proper rotation is made by observing that the suction pressure 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 Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
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Insulate the orange lead. CAUTION The external breaker(s) that provide power to the air conditioner must be sized per the maximum Fuse Size (MFS) shown on the Unit's data label. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
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Continuous fan operation: For continuous indoor fan operation on single units, install a jumper between terminals 8 and 3. CommStat 4 Lead /Lag Controller Please refer to the Product Data sheet for the CommStat 4 controller for complete instructions on installing and programming this controller. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
1. Raise the heating set point temperature to a setting which is higher than the ambient temperature. The fan and electric heat should immediately cycle on. 2. Move the system switch to the "OFF" position. All functions should stop. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
Use refrigeration goggles when servicing the refrigeration circuit. WARNING The refrigerant circuit has hot surfaces, and the electrical voltages inside of the unit may be hazardous or lethal. SERVICE MAY BE PERFORMED ONLY BY QUALIFIED AND EXPERIENCED PERSONS. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
3. Defective heater contactor. 3. Check relay for proper operation. Replace if defective. Compressor Troubleshooting NOTE: It is important to rule out other component failures before condemning the compressor. The following electrical tests will aid diagnosis: Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
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A short circuit at high voltages indicates a motor defect. Do not do this test under vacuum. 5. On single phase models, check the capacitor by substitution. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
Some solvents can cause the drain pan to corrode. Lubrication The condenser fan motor(s) and the evaporator blower motor(s) never require oiling. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, AND YOU MAY ALSO HAVE OTHER RIGHTS WHICH VARY FROM STATE-TO- STATE. Some states do not allow limitations or exclusions, so the above limitations and exclusions may not apply to you. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
Are all wiring terminals (including main power supply) tight? ❒Yes ❒No If unit has a crankcase heater, has it been energized for 24 hours? ❒Yes ❒No On a 208/230 v. units is control transformer (24 AC) wired for correct voltage? ❒Yes ❒No Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
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L1 & L3 = 243 Volts = 717 / 3 = 239 Average Voltage L2 & L3 = 233 Volts 239 - 233 = 6 100 x 6/239 =2.5% Voltage Unbalance Three phase units only check fan & compressor rotation. Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
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Measured Line to Line Volts 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 = ___________% Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
Appendix A Fresh Air Damper Installation Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
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15% of rated air flow of fresh air, in 5% increments. The hood is shipped from the factory in the closed position (no fresh air). To provide fresh air, remove the two screws on either side of the hood and reposition as desired. Fresh Air Hood Damper Marvair MGA3090A-3150A I&O Manual 08/2022 Rev.12...
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