Marvair Scholar III VAISA Installation And Start-Up Instructions Manual Download Page 2

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Marvair Scholar III™ VAISA I&S Manual 03/2019 Rev. 8

How To Use This Manual

This manual is intended to be a guide to the Marvair

Scholar III™ line of vertical packaged heat pumps and

air conditioners. This manual covers the installation and start-up of the Scholar III heat pumps and air conditioners,

models VAISA, with two stage compressors. It contains installation, troubleshooting, maintenance, warranty, and

application information. The information contained in this manual is to be used by the installer as a guide only. This

manual does not supersede or circumvent any applicable national or local codes.

If you are installing the Scholar III™ heat pump or air conditioner, first read the entire manual and Appendices

for any of the options and accessories before beginning the installation. The Appendices describe the installation of

the base stand, the plenum, trim strips, wall brackets and outdoor louvers.

If a malfunction occurs, follow this troubleshooting sequence:

1. Make sure you understand how the Scholar III™ unit works.

2. Identify and correct installation errors.

3. If you are still unable to correct the problem, contact the Factory at 1-800-841-7854 for additional

assistance.

Please read the following “Important Safety Precautions” before beginning any work. Failure to follow

these rules may result in death, serious bodily harm, property damage and damage to the equipment.

Important SafetyPrecautions

1. USE CARE when LIFTING or TRANSPORTING equipment.
2. TRANSPORT the UNIT UPRIGHT. Laying it down on its side may cause oil to leave the compressor, re-

sulting in DAMAGE upon START-UP.

3. TURN ELECTRICAL POWER OFF AT THE breaker or fuse box BEFORE installing or working on the

equipment. LINE VOLTAGES ARE HAZARDOUS or LETHAL.

4. OBSERVE and COMPLY with ALL applicable PLUMBING, ELECTRICAL, and BUILDING CODES &

ordinances.

5. SERVICE may be performed ONLY by QUALIFIED and EXPERIENCED PERSONS.
*

Wear safety goggles when servicing the refrigeration circuit

* Beware of hot surfaces on refrigerant circuit components

* Beware of sharp edges on sheet metal components

* Use care when reclaiming or adding refrigerant

Use COMMON SENSE - BE SAFETY CONSCIOUS

This is the safety alert symbol

. When you see this symbol on the air conditioning unit and in the instruction

manuals be alert to the potential for personal injury. Understand the signal word DANGER, WARNING and

CAUTION. These words are used to identify levels of the seriousness of the hazard.

DANGER

Failure to comply will result in death or severe personal injury and/or property damage.

WARNING

Failure to comply could result in death or severe personal injury and/or property damage.

CAUTION

Failure to comply could result in minor personal injury and/or property damage.

IMPORTANT

Used to point out helpful info that will result in improved installation, reliability or

operation.

Specifications subject to change without notice.

, Division of AIRXCEL

™

, Inc.

Summary of Contents for Scholar III VAISA

Page 1: ...Do not begin installation if you do not understand any of the instructions Improper installation adjustment alteration service or maintenance can cause property damage personal injury or loss of life Installation and service must be performed by a qualified installer or service agency in accordance with these instructions and in compliance with all codes and requirements of authorities having juri...

Page 2: ... damage to the equipment Important SafetyPrecautions 1 USE CARE when LIFTING or TRANSPORTING equipment 2 TRANSPORT the UNIT UPRIGHT Laying it down on its side may cause oil to leave the compressor re sulting in DAMAGE upon START UP 3 TURN ELECTRICAL POWER OFF AT THE breaker or fuse box BEFORE installing or working on the equipment LINE VOLTAGES ARE HAZARDOUS or LETHAL 4 OBSERVE and COMPLY with ALL...

Page 3: ... and Preparation 10 1 06 Power and Control Wiring Rough In 11 1 07 Condensate Drain Line Rough In 13 1 08 Wet Heat Rough In 13 1 09 Preparation of the Scholar III Units 13 1 10 Installation Through the Outside Wall 15 1 11 Electric Condensate and Wet Heat Hook ups 17 1 12 Ventilation System Calibration 23 1 13 Control Adjustments 25 1 14 Remote Thermostat Installation 32 1 15 Start up Procedure 34...

Page 4: ... Backing for Scholar III Wall Interface 1 02 INSPECTION UNPACKING HANDLING A The Scholar III heat pumps and air conditioners are shipped to the job site on 4x4 wood base framing and enclosed in shrink wrap Freeblow and ducted plenums are shipped on wooden skids and enclosed in shrink wrap Outdoor louvers collar assemblies louvers and collars are shipped in corrugated containers Base stands are shi...

Page 5: ... REQUIRED FOR THE ACTUAL MOVING PROCESS IF THE SCHOLAR III UNIT HAS BEEN PLACED ON ITS SIDE DO NOT ATTEMPT TO START THE UNIT UNTIL THE UNIT HAS BEEN UPRIGHT FOR AT LEAST 24 HOURS C Note the unit identification label is located on the right side cabinet panel at the lower front corner The identification label has the model and serial number on it and the type of refrigerant and amount of refrigeran...

Page 6: ...number is located as shown in Figure 1 Source Vertical Air Indoor Nominal Cooling System Type HP Heat Pump AC Air Conditioner Power Supply A 208 230V 1 60Hz C 208 230V 3 60Hz D 460V 3 60Hz Configuration N Manual Damper std H GreenWheel ERV B Motorized Damper J Power Vent with Motorized Damper Special Options G Hot Gas Reheat Dehumidification VAI III Configuration III Scholar III 2 Stage Compressor...

Page 7: ...om 30 to 90 minutes in one minute increments BAS Control Relay Provides 24 VAC coil to control operation from Building Automation System BAS Note an additional BAS control relay can be added when 120 or 240 VAC coils are required B High and Low Refrigerant Pressure and Loss of Charge Switches These switches render the compressor and outdoor fan motor inoperative whenever the limits of the pressure...

Page 8: ...SUB BASES A Thermostats for Air Conditioners and Heat Pumps with two stages heating 1 Digital 7 day 5 2 and 5 1 1 day programmable thermostat Two stage heat Two stage cool Manual or auto changeover Fan Auto On Permanent retention of setting on power loss Field adjustable temperature calibration Adjustable max setpoint for heating and min adjustable setpoints for cooling Adjustable temperature diff...

Page 9: ... with Electric reheat or Hot Gas Reheat must have a method of signaling the reheat function If a DDC system is not being used a Humidity Controller must be installed Digital Humidity Controller Programmable dehumidistat humidistat and ventilation control Time of day can be set for dehumifier humidifier or ventilation to run Auto changeover for humidification or dehumidification Permanent memory re...

Page 10: ...mponents Do not put anything immovable in front of the Scholar III unit To remove carpet from where the footprint of the unit will be when installed carefully measure cut and remove carpet from an area based on the dimensions of the Scholar III cabinet as described in Figure 3 and allowing for any offset or standoff from the finished interior surface of the wall Prior to installation of the Schola...

Page 11: ...ined Six feet of power line should be available inside the cabinet for routing and connecting the power lines after the Scholar III unit is installed If entry is from bottom the stub out should be no higher than 1 2 from the classroom floor to allow the unit to slide into the wall opening IMPORTANT IF S CIRCUIT POSITION IS SELECTED ON THE ELECTRIC HEAT CONTROL SEE ARTICLE 1 11 LOWER MINIMUM CIRCUI...

Page 12: ...Marvair Scholar III VAISA I S Manual 03 2019 Rev 8 12 Figure 3 Scholar III Heat Pump and Air Conditioner Dimensional Data ...

Page 13: ...art up The following items are to be completed prior to final installation A Remove the two shipping screws that at the top and bottom of the front door B Open the front door for access to the lag bolts that hold the shipping skids in place Unscrew the 4 lag screws Note access to the back right lag screw is easier through the the condensate opening in the back panel beneath the outdoor air box Rem...

Page 14: ... of galvanized steel with a minimum thickness of 019 Ductwork must be firmly attached secured and sealed to prevent air leakage Do not use duct liner on inside of supply duct within four feet of the unit Galvanized metal duct extensions should be used to simplify connections to ductwork and grilles Use fabric boots to prevent the transmission of vibration through the duct system The fabric must be...

Page 15: ...nside finished wall flush or offset Be sure the surface is level or provisions are made to level the unit upon installation M If the outdoor air box was removed reinstall it prior before placing the Scholar III unit in its final position Install the outdoor air box onto the back of the Scholar III heat pumps or air conditioners before sliding the unit into position Apply a weather proof sealant i ...

Page 16: ... field supplied fasteners through the four 1 2 diameter through holes in the base E If the Scholar III heat pump or air conditioner is offset from the outside wall trim strips should be installed at this time Check instructions that come with trim strips for installation or see Appendix D at end of this manual F If appropriate install wall brackets to the inside surface of the outside wall and to ...

Page 17: ...door Figure 6 shows typical control centers for the Scholar III heat pump and air conditioner Figures 7 and 8 show typical single and three phase wiring diagrams for the Scholar III heat pump and air conditioner 2 Power supply service must be with the allowable voltage range stamped on the identification plate To operate a nominal 230 208V model on 208V change the transformer line tap from 240V to...

Page 18: ...ity caused by operating three phase compressors in the reversed direction for a short duration of time usually defined as less than one hour However after several minutes of operation the compressor s internal protector will trip The compressor will then cycle on the protector until the phasing is corrected Reverse operation for longer than one hour may have a negative impact on the bearings B 1 L...

Page 19: ...tilation Filters and GreenWheel ERV Figure 6 Typical Control Center Layout for Scholar III VENTILATION FILTERS PLC ELECTRICAL CONTROL BOX UNIT DISCONNECT Due to the variety of options the control center in your unit may be different from the photo Always refer to the electrical schematic in your unit ...

Page 20: ...Marvair Scholar III VAISA I S Manual 03 2019 Rev 8 20 Figure 7 Typical Wiring Schematic for Heat Pump Single Phase Power ...

Page 21: ...21 Marvair Scholar III VAISA I S Manual 03 2019 Rev 8 Figure 8 Typical Wiring Schematic for Heat Pump Three Phase Power ...

Page 22: ...n the field supplied contacts between E1 and E2 are closed the system will shut down The unit control system is factory wired to energize the ventilation package anytime the Indoor Fan Blower is energized If additional control of the ventilation package is desired it may be accomplished by the following The Controls Contractor must remove the factory installed jumper between terminals V1 and V2 th...

Page 23: ...ater heating the plenum is equipped with a coil and a freeze protection thermostat embedded in the coil An optional diverter valve may also be factory installed The front and top panels of the plenums are removable to access the coil and make piping and wiring connections Consult hot water plenum installation instructions for installation details or see Appendix C in back of this manual 1 12 VENTI...

Page 24: ...dependent control allows positive pressurization of the classroom i e more outside air can be brought into the classroom than what is exhausted The fresh air door is opened and closed by the motorized drive Calibration as shown in Figure 10 will ensure the required amount of air up to a maximum of 450 CFM is delivered to the classroom Follow the directions in Figure 11 to ensure the proper air flo...

Page 25: ...ENTS A Scholar III Heat Pump and Air Conditioner PLC Programmable Logic Controller Microprocessor Essential to the operation of the Scholar III heat pump and air conditioner is a factory installed PLC microprocessor The PLC controller improves reliability due to a reduction of components and simplification of the control panel wiring The PLC is able to Provide various control functions Show operat...

Page 26: ...wdriver The indicator on the knob is the gap between the two protrusions with the hollow centers on the knob See drawing below For both control timers turning the knob clockwise increases the time period NOTE Scholar III air conditioners do not have the defrost function The micro switch has three positions RUN TERM STOP The switch should be in the RUN position during normal operation Term is for o...

Page 27: ...only is located next to the three position micro switch The defrost control is based upon both time and temperature The DFT initiates a defrost cycle whenever the outdoor coil temperature is 28 F or below and the selected time interval from the previous defrost cycle has been exceeded Select the desired time interval by turning the DFT knob When turned completely to the left counterclockwise the t...

Page 28: ...ured to allow simultaneous operation of the electric heat and the compressor heat pump only SCKT S Circuit Signal that indicates the electric heat and the compressor can never operate simultaneously This function is controlled by the electric heat control toggle switch in the control center The LED should be ON if Y is ON the electric heat is on and the toggle switch is in the S circuit position h...

Page 29: ... off non operational When the micro switch is in the STOP position this LED should be lit Operation Guide Cooling Mode During normal operation of the system the thermostat calls for cooling by turning on the G Y and O inputs to the system This request will be indicated on the G Y and O indicators at the bottom of the unit If the compressor has been off for a least the amount of time interval set o...

Page 30: ...rmal heating mode By having a maximum time for the Defrost Cycle to operate the system will not go into Defrost and remain in Defrost mode if a Defrost Switch malfunctions If the Electric Heat During Defrost EHDD function has been selected the Heat Contactor HTR will come on to supply supplemental heat during the Defrost Cycle Low Pressure Lockout The Low Pressure Switch is designed to guard again...

Page 31: ...l Normal Operation The High Pressure Switch HPS and Low Pressure Switch LPS should be on all the time An exception will be during a low temperature start up during which the LPS should come on within a few moments of start up The chart below shows the standard inputs and what functions should be on as a result 2 Outdoor Thermostat heat pump only Factory set at 40 F this thermostat determines the o...

Page 32: ...ic heaters from operating during the defrost mode For operation during defrost a wire is moved from one terminal to another in the control box 1 14 REMOTE THERMOSTAT INSTALLATION A Locate the thermostat about five feet above the floor on an inside wall Avoid the following Hot Spots Cold Spots Dead Spots Concealed Pipes or Duct Concealed Pipe or Ducts Behind Doors Registers Stairwells Drafts Corner...

Page 33: ...STAT CONNECTION DIAGRAM FOR MARVAIR CLASSIC I CLASSIC II SCHOLAR HEAT PUMPS POWER FAN COMPRESSOR AUX HEAT COMMON REVERSING VALVE LOCK OUT LOCK OUT LOW VOLTAGE TERMINAL BOARD LOW VOLTAGE TERMINAL BOARD THERMOSTAT PART NUMBER 50121 SC2010 SL 50122 SC2210 SL 50107 SC5811 SL CLASSIC I SCHOLAR W O REHEAT CLASSIC II WITH ECONOMIZER W O REHEAT R G Y1 W2 C W B O B H R C 50252 SC4811 SL ...

Page 34: ...action to supply sufficient voltage to the Scholar III disconnect Figure 13 Voltage Limitations 4 Turn the Scholar III heat pump disconnect to ON position 5 Please refer to the thermostat instructions for configuration and start up of units with 2 stage compressors a Check to see that when the heat pump comes on that the air coming out the discharge grille is cooling Let unit run for five minutes ...

Page 35: ...tric supplemental heat will turn on at the same time c Lowering the set point slowly should turn the electric heat off The indoor blower will turn off 90 seconds later 7 Automatic Changeover For an automatic changeover remote thermostat the proper functioning of the system can be checked for cooling and heating by using the same sequence as detailed above with the thermostat system switch put in A...

Page 36: ...lts 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 Qty per unit Size Type MERV1 Rating Return Air Filter 2 46 x 24 x 2 Pleaded disposable 72 Fresh Air Ventilation Filter 1 12 x 20 x 1 Fiberglass disposable N A Exhaust Air Vent...

Page 37: ...MINE VISIBLE AND CONCEALED DAMAGE ALL DAMAGE MUST BE REPORTED TO THE FREIGHT CARRIER WITHIN 15 DAYS ON THE FREIGHT CARRIER S FORM The label on the base stand identifies the part number of the base stand Base Stand Height Part Number 2 S 06849 4 S 06850 Remove the shrink wrap from the base stand and dispose of the wooden skid Retain the bag of 5 16 bolts and flat washers to fasten the cabinet to th...

Page 38: ...own in the Installation and Start Up Manual Figures 3 and 4 IMPORTANT STUBOUTS SHOULD BE LOCATED FROM THE FLOOR OR WALL TO ALIGN WITH SELECTED CABINET KNOCK OUT ON THE CABINET AS SHOWN IN FIGURE3 THIS IS A REQUIREMENT IF A BASE STAND IS TO BE INSTALLED AND STUBOUTS ARE COMING THROUGH THE FLOOR Lastly remeasure to be sure that the wall opening for the Scholar III heat pump and air conditioner air b...

Page 39: ... the instructions provided in Appendix C WARNING WHEN MOVING RAISING THE SCHOLAR III CABINET UTILIZE ADEQUATE RESOURCES TO HANDLE THE 1 100 LB CABINET THIS IS TO AVOID PERSONAL INJURY OR DAMAGE TO THE EQUIPMENT FACILITIES With appropriate resources to lift the Scholar III unit place it on the base stand while guiding the air box through the wall opening and maintaining clearance between the plenum...

Page 40: ...BE REPORTED TO THE FREIGHT CARRIER WITHIN 15 DAYS ON THE FREIGHT CARRIER S FORM WARNING THIS EQUIPMENT MUST BE INSTALLED IN CONFORMANCE WITH ALL APPLICABLE LOCAL AND NATIONAL ELECTRICAL PLUMBING AND BUILDING CODES THIS EQUIPMENT SHOULD BE INSTALLED AND SERVICED ONLY BY A TRAINED PROFESSIONAL HEAT PUMP SERVICE PERSON WARNING BEFORE INSTALLING SERVICING OR MAINTAINING THIS EQUIPMENT SWITCH THE ELECT...

Page 41: ...stalled 2 On the top panel of the Scholar III unit locate the 6 holes that correspond with the six holes in the plenum 3 After the front panel has been removed lift the plenum onto the top of the Scholar III unit WARNING THE PLENUM IS HEAVY USE CARE WHEN PLACING THE PLENUM ON TOP OF THE SCHOLAR III HEAT PUMP OR AIR CONDITIONER REMOVE AND RETAIN SCREWS REMOVE AND RETAIN SCREWS REMOVE AND RETAIN SCR...

Page 42: ...tatic pressure to a minimum Applications using duct work should be designed and installed in accordance with the current edition of the National Fire Protection Association codes and standards 90A and 90B The duct system must be engineered to insure sufficient air flow through the unit to prevent over heating of the heater element This includes proper supply duct sizing sufficient quantity of supp...

Page 43: ...ets with up to a 9 inch offset from the wall Trim strips are packaged in corrugated marked on the outside with part number 03027 and strapped to a skid for shipment to the job site They are painted to match the cabinet color The finished painted surfaces have a protective white film on the surface to protect the surfaces from damage Leave the film on the painted surfaces until the strips have been...

Page 44: ...ound transmission through the trim strips apply acoustical insulation on the side of the strips that face the outdoor air box Debur all field cut or sawed metal edges IMPORTANT CAREFULLY MARK INDENT AND DRIVE SCREWS THROUGH THE TRIM STRIPS TO AVOID DAMAGING THE PAINTED SURFACES Field supplied screws should be self tapping zinc coated sheet metal type 1 2 long with head color of satin aluminum to m...

Page 45: ...are to be handled as fragile items IMPORTANT IMMEDIATELY UPON RECEIPT INSPECT THIS EQUIPMENT TO DETERMINE VISIBLE AND CONCEALED DAMAGE ALL DAMAGE MUST BE REPORTED TO THE FREIGHT CARRIER WITHIN 15 DAYS ON THE FREIGHT CARRIER S FORM A The following louver collar assemblies louvers and collars are suitable for all Scholar III units Part Number Description 81161 Clear anodized louver collar assembly 8...

Page 46: ...re 1 Figure 1 Dimension between Scholar III Air Box and Finished Outside Wall for Outdoor Louver Collar Assembly Installation FREEBLOW PLENUM SCHOLAR III HEAT PUMP OR AIR CONDITIONER DISTANCE INCHES BETWEEN AIR BOX AND OUTSIDE FINISHED WALL LOUVER COLLAR OUTSIDE WALL NOTE TO PREVENT RAIN WATER FROM RUNNING DOWN THE INTERIOR OF THE WALL INSTALL FLASHING UNDER THE OUTDOOR AIR BOX OVER THE SILL OF TH...

Page 47: ...e exterior wall Installer must drill required holes in the collar as located in Figure 1 1 AIR BOX IS RECESSED 1 1 4 TO 1 3 8 FROM FINISHED OUTSIDE WALL TO ACCEPT LOUVER COLLAR ASSEMBLY OUTSIDE LOUVER WITH COLLAR not to block the weep holes on the bottom flange To ensure proper fit up of the collar to the outside wall surface be sure the unit is positioned as shown in Figure 1 After the six screws...

Page 48: ...de the GeoScholar unit in the lower left side Use care when handing the heaters The heaters are wrapped in brown paper for protection during transit Remove the paper before installing the heaters The heater s elements are fragile and can break and the support frames can bend when handled improperly Make sure that the heater s elements are not touching the frame 1 03 MOUNTING THE ELECTRIC HEATERS T...

Page 49: ...Make sure that the elements are not broken or bent when sliding the assembly into position C Secure the assembly with two screws D Pull the power wires from inside the heat pump through the electrical bushing Connect the wires as shown in the electrical diagram that is on the heat pump E Check to see that all connections are secure and replace the front cover of the plenum ...

Page 50: ... Air Conditioning Choice Please consult the Marvair website at www marvair com for the latest product literature Detailed dimensional data is available upon request A complete warranty statement can be found in each product s Installation Operation Manual on our website or by contacting Marvair at 229 273 3636 As part of the Marvair continuous improvement program specifications are subject to chan...

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Marvair Scholar III VAISA, Installation And Start-Up Instructions Manual

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