Ac powered cabinet climate control air conditioner (21 pages)
Summary of Contents for Airxcel Marvair 8AA1024A-8AA1060A
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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: A Division of the AIRXCEL Commercial Group ® P.O. Box 400 • Cordele, Georgia 31010 • 156 Seedling Drive • Cordele, Georgia 31015 (229) 273-3636 •...
WARNING • If the information in these instructions are not followed exactly, a fire 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. •...
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Compressor Troubleshooting .........................43 Control Board Diagnosis ........................44 Chapter 6 Maintenance Scheduled Maintenance .........................45 Chapter 7 Warranty Airxcel Commercial Group Limited Product Warranty .................46 Chapter 8 Start-Up Checklist Start-Up & Commissioning Form ......................47 Appendix A Installation Instructions for Field Installed Electric Heaters ................51 Illustrations Figure 1a.
Chapter 1 Description & Specifications General Description The Marvair 8AA are a series of vertical wall-mounted air conditioning systems that provide heating, cooling, and ventilation for electronic equipment shelters, process control centers, and other applications with high internal heat gains. The series includes multiple sizes and nominal cooling capacities from 24,000 to 60,000 BTUH.
Model Identification Example Position 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Unit Designation/Family 8 = Marvair Wall Mount D = Dry Bulb Sensor E = Dry Bulb Sensor w/Dirty Filter Energy Efficiency Ratio A = 11 17 Indoor Air Quality Features...
to repeat the cycle. Heating Mode A wall-mounted thermostat controls the heating cycle of models which incorporate resistance heating ele- ments. On a call for heat, the thermostat closes the heat relay to energize the indoor fan and the resistance elements.
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pigment) technology. The Coat all Package includes all of the above, plus: • Protective coating on the evaporator coil (Luvata Insitu®) contains ES2 (embedded stainless steel pigment) technology • Protective coating on exterior and interior components and sheet metal. (Note: the internal sheet metal which is insulated, bottom outside panel, and the internal control box are not coated) Hot Gas Bypass (Non-Economizer Models Only) Used in specialty applications;...
drops below the set point, a red LED is illuminated. The set point is adjustable. Protective Coil Coatings Either the condenser or evaporator coil can be coated, however, coating of the evaporator coil is not common. For harsh conditions, e.g., power plants, paper mills or sites were the unit will be exposed to salt water, the condenser coil should be coated.
Economizer Components (Economizer Equipped Models Only) Damper Actuator: The damper actuator is a 24V motor that modulates the position of the damper blade. It is capable of driving a full 90 degrees within 90 seconds. The assembly has a spring return to close the damper during power outage.
Figure 2. Dry Bulb Sensor Once either the enthalpy or dry bulb sensor has determined that the outside air is suitable for cooling, the damper will open. The mixed air sensor will limit the air temperature delivered to the space by modulating the damper blade to mix warm indoor air with cooler outdoor air to provide a constant 50°F to 56°F (10°C to 13.5°C) Mixed Air Sensor:...
Brand of Sensor Selection (W3 jumper) Honeywell enthalpy and dry bulb sensors are currently the only brand of sensors used in the air conditioners. Jumper W3 allows us to use alternative brands at a future date. On all current air conditioners, pins 1 &...
Chapter 2 Electronic Control Board Introduction WARNING Failure to observe the instructions contained in this document may result in personal injury and/or property damage and may void the warranty. Read this manual before installing, replacing or using this product. Marvair’s proprietary Printed Circuit Board (PCB) sets the standard for the industry in flexibility, reliability and performance.
Item Description Outdoor Motor Control Signal Output Indoor Motor Control Signal Output P 1/2- Pressure for Circuit 1 and Circuit 2 (Respectively) FS1 – Freeze Stat for Circuit 1 FS2 – Indoor Temperature Input Modbus Communication 3 Wire [A, B, COM] and Parallel RJ-11 Port Fan Cycle Control Input (only Applicable for EC Outdoor Motors) Hum –...
Power The Marvair PCB requires 24 VAC to operate. When the board is sufficiently powered, the “PWR” status light on the PCB illuminates “Green.” If there is insufficient power to the board, the “STATUS 1” and “STATUS 2” flashes continuously. Insufficient power to the board will result in no outputs being energized.
Output Termination for Indoor Motor Control Signal Note: Follow data (wiring and signal control signal type) of the appropriate motor to setup the PCB Indoor Motor PWM Signal Output. Reference Wire Connected to “GND” and the Signal Connected to “PWM” Indoor Motor 0-10V Signal Output.
Communication The Marvair PCB comes equipped with MODBUS communication standard. There are 2 adjacent MODBUS communication ports connected in parallel. That is, both ports transmit the same information. The difference between the ports is the physical connection. One port is for RS-485 (3 wire shielded cable is recommended) and the other port is RJ-11.
Address DIP Switch 1 DIP Switch 2 DIP Switch 3 DIP Switch 4 0 [Local Control] Table 5. MODBUS Network Address DIP Swith Positions Sequence of Operation IMPORTANT All equipment should go through the recommended commissioning/start up sequence to ensure safety and system reliability. This document is only valid if the system is used as intended.
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Equipment, devices and necessary system components are specified in the respective section. Note: 1. All inputs on the Controller go through a 5 seconds Time-On Delay to prevent nuisance request. Compressor Outputs go through 5 seconds staggered Time On delay to prevent nuisance tripping of breaker due to the inrush associated with these large inductive loads.
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and the indoor fan remains on continuously but the outdoor fan cycles based on head pressure. The Fan Cycle Control Switch (Low Ambient Control Switch) closes at 400 PSIG to set the “FCC IN” input High which in turn outputs a speed proportional to the “OFM Speed” setting on the board or by MODBUS.
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5.0 – Refrigeration Protection 5.1– High Pressure Lockout This condition describes the abnormal rise in Head Pressure pass the system acceptable limit of 660 PSI (+/-20PSI). The fault will only be active when the High-Pressure Switch (Normally Closed) opens during a request for Cooling. The first time this fault condition occurs, the system cuts the compressor off WITHOUT locking out.
5.2 – Modulating Head Pressure Control A 10K Nominal NTC Thermistor is connected to the “P1” and “P2” inputs for circuit 1 and circuit 2 respectively. When this sensor is connected, the “FCC IN” is ignored and the thermistor value is used as the process variable when controlling the head pressure.
Registers: Read with Function Code 04, Write to RW or WO registers with Function Code 06 Description Size Data Format Heat Setpoint 16 Bit 45º-100º F Cool Setpoint 16 Bit 45º-100º F 0-20, 10 is default. Less Temperature Calibration 16 Bit than 10 is a negative offset, 11-20 is a positive offset 0-100, 80 is default.
Chapter 3 Installation WARNING Failure to observe and follow Warnings and Cautions and these Instructions could result in death, bodily injury or property damage. Read this manual and follow its instructions and adhere to all Cautions and Warnings in the manual and on the unit.
the heater element. This includes proper supply duct sizing, sufficient quantity of supply registers, and adequate return and filter areas. Duct work must be of correct material and must be properly insulated. Duct work must be constructed of galvanized steel with a minimum thickness of .019 inches.
Installation Materials Installation Kits Marvair air conditioners are shipped with one 12 Ga. "L" shaped bottom bracket. If you have not yet unpacked the unit, follow the instructions in section 2.1. All units have built-in full length mounting flanges. Therefore, use of mounting brackets is not required. Kit Components: 1.
Additional Items Needed: Additional hardware and miscellaneous supplies (not furnished by Marvair ) are needed for installation. ® For example, the list below contains approximate quantities of items typically needed for mounting a unit on a wood frame wall structure. Concrete or fiberglass structures have different requirements. (10) 3/8"...
When installing the wall sleeve, the supply opening must be on top. The supply opening is smaller than the return air opening. Ducting Extensions should be cut flush with the inside wall for applications without duct work. Applications using duct work should be designed and installed in accordance with all applicable safety codes and standards.
Bracket Installation 1. All models have built-in mounting flanges. 2. 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. 3. Refer to Figure 4. Attach the bottom support bracket to the wall using appropriate 3/8" diameter hardware.
Electrical Connections WARNING ELECTRICAL SHOCK HAZARD Failure to follow safety warnings exactly could result in serious injury, death, and/or property damage. Turn off electrical power at fuse box or service panel BEFORE making any electrical connections and ensure a proper ground connection is made before connecting line voltage.
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2. Connect the wires to the input side of the internal breaker or terminal block (L1 & L2 for single- phase units; L1, L2, & L3 for three-phase models). 3. Install the ground wire on the ground lug. 4. For units designed for operation on 208/230V, 60Hz power supply, the transformer is factory wired for a 230V power supply.
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. CommStat 3 Controller (See Figure 8c) The CommStat 3 Controller is a solid state control package designed to operate a fully or partially redundant air conditioning system for a telecommunication cabinet or shelter.
Chapter 4 Start-Up Check-Out of Cooling Cycle Important: Be sure that the crankcase heater (if used) has been energized for at least 24 hours before starting the unit(s). Double-check all electrical connections before applying power. Marvair air conditioners with scroll compressors running on 3Ø power must be checked for proper rotation during the initial start-up.
Chapter 5 Troubleshooting Overview A comprehensive understanding of the operation of the air conditioner is a prerequisite to troubleshooting. Please read the Chapter 1 for basic information about the unit. Marvair air conditioners are thoroughly tested before they are shipped from the factory. Although unlikely, it is possible that a defect may escape undetected, or damage may have occurred during transportation.
PROBLEM/SYMPTOM LIKELY CAUSE(S) CORRECTION C. Unit cycles on high/low pressure 1. Loss or restriction of airflow. 1. Check blower assembly for proper operation. Look limit. for airflow restrictions, e.g.. the air filter. Check blower motor and condenser fan. 2. Restriction in refrigerant circuit. 2.
3. Motor Winding Resistances: Using a digital volt-ohm meter (VOM), measure the resistance across the compressor windings as shown below. SINGLE THREE PHASE PHASE > R > R Resistance can be measured as shown above. Any deviation from above values could indicate a defective compressor.
Chapter 6 Maintenance Scheduled Maintenance Airxcel Commercial Group strongly recommends that the air conditioner be serviced a minimum of twice a year – once prior to the heating season and once prior to the cooling season. At this time the filters, evaporator coil, condenser coil, the cabinet, and condensate drains should be serviced as described below.
Chapter 7 Warranty Marvair, Inc. Limited Product Warranty Marvair Inc., warrants its products to be free from defects in materials and workmanship under normal use to the original purchaser for the period of time in the table below. If any part of your product fails within 12 months from start-up, or 18 months from shipment from the factory, whichever comes first, Marvair, Inc.
Chapter 8 Start-Up Check List Start-Up & Commissioning Form Please complete the information on this form and return to Marvair by mail or fax. The mailing address and fax number can be found at the end of the form. A. Equipment Information Date: ________________Equipment Owner _______________________________________ Installing Company: _____________________________Installer: ____________________ Address: _______________________________________State _______________________...
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C. Check Rated Voltage at Terminal Block for Imbalance before starting of Unit. ❒208/230V 1 Phase ❒208/230V 3 Phase ❒460V 3 Phase ❒380V 3 Phase 50Hz. ❒575 3 Phase 60 Hz. Measured Line to Line Volts L1&L2_______V. L1&L3 ________V. L2&L3______V. (L1&L2 + L1&L3 + L2&L3)/3 = Avg.
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D. Heating Mode Check & Record Readings Circuit 1 Circuit 2 (if applicable) Room Temperature ________ ________ Outside Temperature ________ ________ Evap. Entering Air DB Temp ________ ________ Evap. Entering Air WB Temp ________ ________ Evap. Leaving Air DB Temp ________ ________ Evap.
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After 10 minutes of compressor operation, record the following: Circuit 1 Circuit 2 (if applicable) Room Temperature ________ ________ Outside Temperature ________ ________ Suction Pressure ________ ________ Suction Line Temperature ________ ________ Discharge Pressure ________ ________ Discharge Line Temperature ________ ________ Entering Condenser Air ________...
Note: The following instructions are for general guidance only. Due to the wide variety of installation possibilities, specific instructions will not be given. When in doubt, follow standard and accepted installation practices, or contact Airxcel Commercial Group for additional assistance. Wall Openings Measure the dimensions of the supply and return ports on the unit.
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WARNING ELECTRICAL SHOCK HAZARD Failure to follow safety warnings exactly could result in serious injury, death, and/or property damage. Turn off electrical power at fuse box or service panel BEFORE making any electrical connections and ensure a proper ground connection is made before connecting line voltage.
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