Marvair Scholar QV VACA Instructions and recipes

Scholar QV™
Heat Pump & Air Conditioner
(CSI 15740)
Marvair Scholar QV™ VACA/VAHA I&S Manual 3/2019 Rev.18
P/N 01274
MODEL NO.: ______________________ SERIAL NO.: _________________
DATE OF START-UP.:_______________
Models VACA/VACSA & VAHA/VAHSA
2, 2.5, 3, 3.5, 4 & 5 Tons
INSTALLATION AND
START-UP
WARNING
SAFETY REQUIREMENTS
• If the information in these instructions
are not followed exactly, a re 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.
• 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 qualied installer or service agency in
accordance with these instructions and in
compliance with all codes and requirements
of authorities having jurisdiction.
• Follow all safety codes.
Manufactured By:
Marvair Division of the AIRXCEL®
P.O. Box 400 • Cordele, Georgia 31010 • 156 Seedling Drive • Cordele, Georgia 31015
[phone] • Fax [phone]
www.Marvair.com
The most current version of this manual can be found at www.Marvair.com.
Scholar QV™

Marvair Scholar QV™ VACA/VAHA I&S Manual 03/2019 Rev.18 15700 - 2
How To Use This Manual
This manual is intended to be a guide to the Marvair®Scholar QV™ line of vertical packaged heat pumps and
air conditioners. 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 QV™ heat pump or air conditioner, rst 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, outdoor louvers and the sound reduction panel.
If a malfunction occurs, follow this troubleshooting sequence:
1. Make sure you understand how the Scholar QV™ 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
6. Use COMMON SENSE - BE SAFETY CONSCIOUS
This is the safety alert symbol . When you see this symbol on the Scholar 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.
Specications subject to change without notice.
© 3/2019 Marvair®, Division of AIRXCEL®, Inc.

15700 - 3 Marvair Scholar QV™ VACA/VAHA I&S Manual 03/2019 Rev.18
SECTION 15700
HEATING, VENTILATING AND AIR CONDITIONING EQUIPMENT
INSTALLATION AND START-UP INSTRUCTIONS
FOR SCHOLAR QV™ HEAT PUMPS AND AIR CONDITIONERS (15740)
TABLE OF CONTENTS
Article Description Page
1.01 Tools/Field Furnished Supplies ......................................................4
1.02 Inspection/Unpacking/Handling......................................................4
1.03 Standard Controls ..........................................................................7
1.04A Thermostats & Sub-bases..............................................................8
1.04B Optional Controls .........................................................................10
1.05 Location Preparation....................................................................12
1.06 Power and Control Wiring (Rough-In)..........................................13
1.07 Condensate Drain Line (Rough-In) ..............................................16
1.08 Wet Heat (Rough-In)....................................................................16
1.09 Preparation of the Scholar QV™ Units ........................................16
1.10 Installation Through the Outside Wall ..........................................18
1.11 Electric, Condensate and Wet Heat Hook-ups.............................19
1.12 Ventilation System Calibration .....................................................30
1.13 Control Adjustments.....................................................................32
1.14 Remote Thermostat Installation ...................................................42
1.15 Start-up Procedure.......................................................................43
1.16 Exploded Views and Parts Lists...................................................45
Appendix A Ratings and Data .........................................................................46
Appendix B Base Stand Installation ................................................................47
Appendix C Wet Heat/Plenum Installation.......................................................51
Appendix D Trim Strip Installation ...................................................................57
Appendix E Wall Bracket Installation...............................................................59
Appendix F Outdoor Louver/Collar Installation................................................61
Appendix G Sound Reduction Panel ...............................................................65

Marvair Scholar QV™ VACA/VAHA I&S Manual 03/2019 Rev.18 15700 - 4
SECTION 15700
HEATING, VENTILATING AND AIR CONDITIONING EQUIPMENT
1.01 TOOLS/FIELD FURNISHED SUPPLIES
WARNING
TO AVOID PERSONAL INJURY, ADEQUATE PROTECTIVE CLOTHING MUST BE WORN
AND PRECAUTIONS IN HANDLING AND INSTALLING THIS EQUIPMENT MUST BE
PRACTICED AT ALL TIMES.
•Power Drill/Driver & Extension
•T25 TORX Bits
•Needle Noise Pliers
•Wire Stripper/Cutter
•Spirit Level
•Tape Measure
•Screwdriver with Slotted Bit
•Caulk Gun
•Sealant Caulk (tube)
•Wire Nuts for Power and Control Wiring Gauges
•Supplies to Install PVC Condensate Drain
•Floor Fasteners for Cabinet (4 required for 1/2” pass through holes) - Appropriate Drivers
for Floor Fasteners
•Supplies to Install Wet Heat Coil (Hot Water) (if appropriate)
•25 Ft. of Polyurethane Foam Strips, 1” Wide x 1/2” Thick, Adhesive Backing, for Scholar
QV/Wall Interface.
1.02 INSPECTION/UNPACKING/HANDLING
A. The Scholar QV™ 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 shipped on a wooden skid and are enclosed in shrink wrap.
Trim pieces are enclosed in corrugated carton and strapped to a wooden skid.
The sound reduction panel is shipped in a wooden crate after being shrink wrapped.

15700 - 5 Marvair Scholar QV™ VACA/VAHA I&S Manual 03/2019 Rev.18
B. Immediately upon delivery to the jobsite, each Scholar QV™ heat pump or air
conditioner and the appropriate additional accessories should be inspected for
visible and concealed damage. All damage must be reported to the freight car-
rier within 15 days, on the freight carrier’s form.
The Scholar QV™ heat pump or air conditioner and additional accessories should be
stored inside and not exposed to outdoor weather conditions. Do not remove equip-
ment from packing until it is ready to be installed.
WARNING
DO NOT STACK THE UNIT OR ANY ACCESSORIES ON TOP OF ONE ANOTHER.
THE UNITS SHOULD ALWAYS REMAIN IN THE UPRIGHT POSITION WHEN BEING
SHIPPED, STORED, HANDLED OR INSTALLED.
DO NOT STORE THE UNIT OR ACCESSORIES IN OUTDOOR
WEATHER CONDITIONS.
IF IT IS NECESSARY TO TILT THE SCHOLAR QV™ HEAT PUMP OR AIR CONDITIONER
WHILE MOVING IT DURING INSTALLATION, BE SURE THE TOP END IS ALWAYS ABOVE
THE BOTTOM BY AT LEAST 30 INCHES. THE UNIT SHOULD NOT BE ALLOWED TO
REMAIN IN THE TILTED POSITION ANY LONGER THAN REQUIRED FOR THE ACTUAL
MOVING PROCESS.
C. Note the unit identication label is located on left side cabinet panel at the lower front
corner, as shown in Figure 1. The identication label has the model and serial num-
ber on it and the type of refrigerant and amount of refrigerant charge.
IMPORTANT
WHEN THE HEAT PUMP OR AIR CONDITIONER IS INSTALLED, MODEL NUMBER AND
SERIAL NUMBERS ARE TO BE RECORDED ON THE COVER OF THIS
MANUAL AND MAINTAINED IN A LOCATION FOR IMMEDIATE ACCESS, WHEN
REQUESTING FURTHER INFORMATION CONCERNING THIS EQUIPMENT.
Serial Number Date Code
A = January E = May J = September D = 2014 H = 2018
B = February F = June K = October E = 2015 I = 2019
C = March G = July L = November F = 2016 J = 2020
D = April H = August M = December G = 2017 K = 2021

Marvair Scholar QV™ VACA/VAHA I&S Manual 03/2019 Rev.18 15700 - 6
For the Scholar QV™ heat pump or air conditioner system, the identication number-
ing system is shown below. The model identication number is located as shown in
Figure 1.
Vertical Air
Indoor Source
Nominal CoolingCompressor Option
System Type
HP = Heat Pump
AC = Air Conditioner
C= Standard
Efficiency
H= High
Efficiency
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
• • • • •
VA • •QV
Configuration
QV
Refrigerant
R-410A
A
24 = 24,000 BTUH
30 = 29,600 BTUH
36 = 35,000 BTUH
40 = 39,500 BTUH
49 = 46,000 BTUH
60 = 54,000 BTUH
S= 2-Stage
Heat – kW
000 - No Heat
050 = 5 kW
075 = 7.5 kW
100 = 10 kW
150 = 15 kW
990 = Hot Water
Series
1= Revision #1
•
S
Figure 1. General External Component Identication and Access to Scholar QV™
Heat Pump or Air Conditioner
Front Air Supply Grille Side Air Supply Grille
Scholar QV
Heat Pump
Model VACA
Freeblow Plenum
(shipped separately)
Air Return Grille
Exhaust Air Grille
Identication Plate
(lower front corner)
Access to:
• electrical
control center
• ventilation system
• disconnect
• condensate disposal
Upper Front Panel

15700 - 7 Marvair Scholar QV™ VACA/VAHA I&S Manual 03/2019 Rev.18
1.03 STANDARD CONTROLS
A. Programmable Logic Controller (PLC) Microprocessor
Scholar QVTM heat pumps use a factory installed PLC microprocessor to control the
operation, the safety switches and function options. LED’s show operational status
and provide assistance with diagnosis if troubleshooting is ever required. Various
control functions are eld selectable. The PLC is also capable of communicating to
PLC’s in other Scholar units to allow run time leveling and does not require additional
equipment installed in the Scholar QV unit. The PLC microprocessor provides im-
proved reliability because of the reduction of components, the components utilized
are more durable and the control box wiring has been simplied. Pertinent statistical
data about the life of the refrigeration system can be accessed through the PLC.
The PLC microprocessor provides for the following control and operation functions:
• Anti-Short Cycle Timer - Prevents the compressor from destructive short cy-
cling due to momentary power interruptions. One of three time intervals can be
eld selected.
• Defrost Timer (heat pumps only) - Adjustable defrost control that is based
upon both time and temperature. The time interval is adjustable from 30 to 90
minutes in one minute increments.
• BAS Control Relay - Provides 24 VAC coil to control operation from Build-
ing 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 switches are exceeded. In the event of high pressure, the
Scholar QVTM heat pump or air conditioner will turn off and lockout.
The low pressure (A/C) and loss of charge (HP) switch is bypassed for 8-1/2 minutes
during each start-up. The system will lockout if the low pressure switch opens three
times within one hour or if it does not reset within 8-1/2 minutes of the Scholar QVTM
heat pump or air conditioner start-up.
The high and low pressure and loss of charge switches are resettable at the wall
thermostat or by turning power off and then on to the Scholar QVTM heat pump or air
conditioner. A fault LED located on the PLC indicates that a lockout has occurred
and whether it is due to high or low refrigerant pressure.
C. Heat Related Controls
The outdoor thermostat (heat pump only), factory set at 40°F, determines the tem-

Marvair Scholar QV™ VACA/VAHA I&S Manual 03/2019 Rev.18 15700 - 8
perature at which the supplemental electric heat (or wet heat) turns on to heat the class-
room. The temperature set point can be adjusted in the eld for local conditions. When
the outdoor thermostat activates wet heat, the compressor simultaneously turns off.
The electric heat control (heat pump only) allows the user to select whether the
electric heat operates simultaneously with the compressor. On the 2, 2 ½, 3 and 3
½ ton heat pumps, the units are wired at the factory for simultaneous operation. For
non-simultaneous operation, a wire is moved from one terminal to another in the con-
trol box. On 4 & 5 ton units, a toggle switch in the control box controls this function. In
the “NORM” position, electric heat can operate simultaneously with the compressor.
In the “S circuit” position, electric heat does not operate any time the compressor is
operating.
The electric heat during defrost (heat pump only) allows the user to select
whether electric heat operates when the heat pump enters into the defrost mode. On
the 2, 2 ½, 3 and 3 ½ ton heat pumps, the units are wired at the factory to prevent
the electric heaters from operating during the defrost mode. For operation during
defrost, a wire is moved from one terminal to another in the control box. On 4 & 5 ton
units, a toggle switch in the control box controls this function. In the “EHDD” position,
electric heat will operate in the defrost mode. In the “NORM” position, electric heat
does not operate in the defrost mode. NOTE: for operation of the electric heat during
defrost, the electric heat control must be congured to allow simultaneous operation
of the electric heat and the compressor.
D. The indoor blower fan speed control provides adjustable air volume from the
indoor blower.
IMPORTANT
MINIMUM AIR FLOW IS REQUIRED FOR PROPER OPERATION.
E. The motorized fresh air damper with PowerVent and GreenWheel® ERV ventila-
tion options are equipped with a fresh air fan speed control. The fresh air fan speed
control controls both the ventilation intake and exhaust blowers together, automati-
cally balancing the intake and exhaust cfm up to 450 cfm.
1.04A THERMOSTATS, THERMOSTAT GUARDS AND HUMIDITY CONTROLLERS
A. Scholar QV™ heat pumps with two stages of heat have the following thermostats
available.
1. Digital, 7 day, 5-2 and 5-1-1 day programmable thermostat (p/n 50107).
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 differential. Keypad lockout. Status LED. °F or
°C selectable. Title 24 compliant.
2. Digital, non-programmable thermostat (p/n 50252) Two stage heat/Two
stage cool. Manual or auto changeover. Fan: Auto & On. Permanent retention

15700 - 9 Marvair Scholar QV™ VACA/VAHA I&S Manual 03/2019 Rev.18
of setting on power loss. Field adjustable temperature calibration. Adjustable
max. setpoint for heating and min. adjustable setpoints for cooling. Adjustable
temperature differential. Keypad lockout. Status LED. °F or °C selectable.
3. Internal electronic programmable thermostat (p/n S/02792) (factory installed)
with automatic changeover, has two stages of heating and one stage of cooling
and a fan switch. System mode switch has OFF, COOL, AUTO, HEAT, and
EM.HT. settings. Fan mode switch has OFF and AUTO settings. This thermostat
may be used with systems that have no heat, electric resistance, a hot water coil
coil.
4. Digital, 7 day, 2 occupied & 2 unoccupied periods for each day of the week
programmable thermostat (p/n 50248). Three stage heat/Three stage cool.
Manual or auto changeover. Fan: Auto & On. Ten year retention of programming
settings and 48 hour clock and day settings on power loss. Adjustable max. set-
point for heating and min. adjustable setpoints for cooling. Adjustable temperature
differential. Keypad lockout. Status LED. °F or °C selectable. Optional remote
sensors for outdoor air, supply air and humidity. Title 24 compliant.
5. The direct digital control (DDC) interfaces with the building automation system
(BAS) is to be dened by the specier, in consultation with the Marvair® sales
representative. Marvair will factory install the DDC sent by the DDC manufactur-
er, and purchased by the customer. Due to the specialized nature of DDC con-
trols applied to specic building automation systems, pricing for the Scholar QV™
Heat Pump with custom controls will be based on the customer requirements for
additional controls components (materials and installation) and engineering by
Marvair.
6. MAR7000 Energy Management System provides a number of functions while remaining
extremely cost sensitive. For a complete description of the operation and features of the
MAR7000 EMS, please see the MAR7000 Product Data Sheet.
B. Scholar QV™ air conditioners or heat pumps with one stage of heat.
1. Digital, non-programmable thermostat (p/n 50121). One stage heat, one
stage cool. Fan switch: Auto & On. Manual changeover system switch: Cool-Off-
Heat. Low temperature protection. °F or °C selectable. Thirty minute power loss
memory retention.
2. Digital, seven day programmable thermostat (p/n 50123). One stage heat, one
stage cool. Fan switch: Auto & On. Auto-changeover. Keypad lockout. Non-volatile
program memory. Title 24 compliant.
3. Digital, non-programmable thermostat (p/n 50186). One stage cool/one stage
heat. Manual or auto changeover. Fan mode: Auto or On. Permanent retention
of settings upon power loss. Field adjustable temperature calibration. Max heat
and minimum cool set points. Adjustable temperature differential. Remote sensor
capable. Keypad lock out. Status LED. °F or °C selectable.

Marvair Scholar QV™ VACA/VAHA I&S Manual 03/2019 Rev.18 15700 - 10
C. Thermostat guards.
1. Clear thermostat guard with keylock & clear plastic cover & base (p/n
50092). For use with 50121, 50123, 50186, 50107 & 50252 thermostats.
2. Clear thermostat guard with keylock & clear plastic cover & base (p/n 50119).
For use with 50248 thermostat.
D. Humidity Controller
1. Digital humidity controller, (p/n 50254). To be used with units with hot gas or
electric reheat. Programmable dehumidistat, ventilation control. Time of day can
be set for dehumidifier or ventilation to run. Permanent memory retention of set
points. Humidity sensor can be field calibrated. High & low dehumidification set
points. Outdoor temperature and humidity sensor included. ºF or ºC selectable.
1.04B OPTIONAL CONTROLS
A. All units have the following control options available.
1. The spring wound timer is a eld installed kit used to enable operation of the
heat pump for up to six hours, or override the building automation system. (p/n
08557)
2. The hard start kit is eld installed and used on single phase power models to
overcome hard starting conditions. Note: Hard start kits are generally not recom-
mended for use on scroll compressors.
3. The motorized fresh air damper with PowerVent and GreenWheel® ERV
ventilation options can be equipped with an exhaust fan air speed control, which
controls the ventilation exhaust blower independent of the fresh air intake blower.
4. The condensate pan and drain line heaters are required for heat pump instal-
lations north of the 34° latitude line (see gure below) and other sites where
condensate may freeze. The pan heaters prevent the condensate from freezing
in the condensate pan and the drain line heaters prevent it from freezing in the
drain lines. These heaters are factory installed and no eld installation is
required. See price pages for part numbers.