Marvair GeoScholar Series User manual

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.
MODEL NO.: ______________________ SERIAL NO.: _________________
DATE OF START-UP.:_______________
INSTALLATION AND
START-UP
GeoScholar
Heat Pump
(CSI 15740)
MODELS VWIA, VWISA and VWCA, VWCSA
2, 2.5, 3, 3.5, 4 & 5 Tons
Part # 01516
GeoScholar IS Manual 03/2019
Rev. 2
P.O. Box 400 • Cordele, GA 31010
156 Seedling Drive • Cordele, GA 31015
[phone] • Fax: [phone]
Email: [email protected]
Internet: www.marvair.com

GeoScholar (I&S) 03/2019 15700 - 2 HVAC Equipment
How To Use This Manual
This manual is intended to be a guide to the Marvair®GeoScholar line of vertical packaged heat
pumps. 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 GeoScholar heat pump, 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 GeoScholar 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. Denitions identifying hazard labels are shown below.
Failure to comply will result in death or severe personal injury and/or
property damage.
Failure to comply could result in death or severe personal injury and/or
property damage.
Failure to comply could result in minor personal injury and/or property
damage.
Important Safety Precautions
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 compres-
sor, resulting 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
Specications subject to change without notice.
© Marvair®, Division of AIRXCEL®, Inc.
!IMPORTANT
!WARNING
!CAUTION
!DANGER
!WARNING

GeoScholar (I&S) 03/2019 15700 - 3 HVAC Equipment
SECTION 15700
HEATING, VENTILATING AND AIR CONDITIONING EQUIPMENT
INSTALLATION AND START-UP INSTRUCTIONS
FOR GEOSCHOLAR HEAT PUMP (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
1.04 Controllers......................................................................................8
1.05 Options.........................................................................................10
1.06 Location Preparation.................................................................... 11
1.07 Power and Control Wiring (Rough-In).......................................... 11
1.08 Condensate Drain Line (Rough-In) ..............................................16
1.09 Wet Heat (Rough-In) ....................................................................16
1.10 Preparation of the GeoScholar Units ...........................................16
1.11 Installation Through the Outside Wall ..........................................19
1.12 Electric, Condensate, Water and Wet Heat Hook-ups .................20
1.13 Ventilation System Calibration .....................................................29
1.14 Control Adjustments.....................................................................31
1.15 Remote Thermostat Installation ...................................................36
2.01 Start-up Procedure.......................................................................37
Appendix A Ratings and Data ....................................................................... A-1
Appendix B Base Stand Installation .............................................................. B-1
Appendix C Free Blow and Wet Heat Plenum Installation for VWCA............ C-1
Appendix D Free Blow Plenum Installation for VWIA .................................... D-1
Appendix E Trim Strip Installation ................................................................. E-1
Appendix F Wall Bracket Installation............................................................. F-1
Appendix G Outdoor Louver/Collar Installation..............................................G-1
Appendix H Sound Reduction Panel ............................................................. H-1
Appendix I Electric Heat Installation ..............................................................I-1
Appendix J Check, Test and Start Form ........................................................J-1

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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
GeoScholar /Wall Interface.
1.02 INSPECTION/UNPACKING/HANDLING
A. The GeoScholar heat pumps 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 (models VWCA & VWCSA only) is shipped in a wooden
crate after being shrink wrapped.
!

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B. Immediately upon delivery to the jobsite, each GeoScholar heat pump and
the appropriate additional accessories should be inspected for visible and
concealed damage. All damage must be reported to the freight carrier within 15
days, on the freight carrier’s form.
The GeoScholar heat pump and additional accessories should be stored inside and
not exposed to outdoor weather conditions. Do not remove equipment from packing
until it is ready to be installed.
CAUTION
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 GEOSCHOLAR HEAT PUMP 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. The identication label has the model and serial number on it and the type of
refrigerant and amount of refrigerant charge.
IMPORTANT
WHEN THE HEAT PUMP 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 G = July L = 2000 T = 2006
B = February H = August M = 2001 U = 2007
C = March J = September N = 2002 V = 2008
D = April K = October P = 2003 Y = 2009
E = May L = November R = 2004 Z = 2010
F = June M = December S = 2005 A = 2011
!

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For the GeoScholar heat pump system, the identication numbering system is
shown below. The model identication number is located as shown in Figure 1.
Models with an “S” indicate a 2-stage compressor. Installation is identical for the
heat pumps regardless of the type of compressor. However, a 2-stage cooling
thermostat must be used with all 2-stage compressor units.
VWI = GeoScholar III Series
VWC - GeoScholar QV Series
Power Vent with
Motorized Damper Special Options
G =Hot Gas Reheat/Dehumidification
VW•
40 =39,000 BTUH
48 =47,000 BTUH
60 =56,500 BTUH
System Ty pe
J =
Nominal Cooling
24 =23,500 BTUH
30 =30,000 BTUH
36 =35,000 BTUH
HP = Heat Pump
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
Heat – kW
00 15
05
7.5
99 (Hot Water)
10
•••• •
HP
GG = Tw o Stage Hot Gas Reheat
Refrigerant
A = R-410A
Refrigerant
A
S = 2-Stage Compressor
S
Figure 1. General External Component Identication and Access to GeoScholar
QV Series Heat Pump

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1.03 CONTROLS
1.03A. STANDARD CONTROLS
1. Programmable Logic Controller (PLC) Microprocessor
GeoScholar 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 GeoScholar units to allow run time leveling and does not require
additional equipment installed in the GeoScholar unit. The PLC microprocessor
provides improved 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
cycling due to momentary power interruptions. One of three time intervals can
be eld selected.
• 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.
2. High and Low Refrigerant Pressure and Loss of Charge Switches
These switches render the compressor and pump inoperative whenever the limits of
the pressure switches are exceeded. In the event of high pressure, the GeoScholar
heat pump will turn off and lockout.
The low pressure (A/C) and loss of charge (HP) switch render the compressor and
pump inoperative whenever the limit of the switch is exceeded after one minute.
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 GeoScholar heat pump. A fault
LED located on the PLC indicates that a lockout has occurred and whether it is due
to high or low refrigerant pressure.
3. The indoor blower fan speed control (VWCA models only) provides adjustable air
volume from the indoor blower.
4. The motorized fresh air damper with PowerVent and GreenWheel® ERV
ventilation 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,
automatically balancing the intake and exhaust cfm up to 450 cfm.

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5. Fresh water/anti-freeeze solution switch. This two position selector switch must be
set based upon the liquid used for the heat source. If the system is using fresh water,
select fresh water. If the system is using an antifreeze solution, e.g. glycol, select
anti-freeze solution. Brine or salt solutions should NOT be used due to corrosion of
the heat exchanger.
6. Freeze Stat. A thermostat clamped to the outlet water line of the water coil senses
the temperature of the water. If the sensor detects water temperature of 37°F or lower
and the compressor and pump are on, the compressor is turned off, but the pump will
continue to run. If the compressor and pump are off when a temperature of 37ºF is
detected, the pump will be turned on. The freeze stat is disabled (not operable) if the
antifreeze solution position is selected in “F” above.
1.03B OPTIONAL CONTROLS
1. All units have the following control options available.
A. 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)
B. 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.
1.04 CONTROLLERS
1.04A THERMOSTATS & SUB-BASES
1. GeoScholar™ heat pumps with one stage of heat. All units with 2-stage compressors
require a two stage cool thermostat.
A. 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.
B. 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.
C. 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.
IMPORTANT
MINIMUM AIR FLOW IS REQUIRED FOR PROPER OPERATION.

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2. Thermostat guards.
A. Clear thermostat guard with keylock & clear plastic cover & base (p/n
50092). For use with 50121, 50123, 50186, 50107 & 50252 thermostats.
B. Clear thermostat guard with keylock & clear plastic cover & base (p/n 50119).
For use with 50248 thermostat.
1.04B HUMIDITY CONTROLLERS
1. Humidity Controller
A. Digital humidity controller, (p/n 50254). To be used with units with hot gas or
electric reheat. Programmable dehumidistat, humidistat and ventilation control.
Time of day can be set for dehumidifier, humidifier or ventilation to run. Auto
changeover for humidification or dehumidification. 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.
1.04C ENERGY MANAGEMENT SYSTEMS
1. MAR5000 Energy Management System provides a number of functions while
remaining extremely cost sensitive. For a complete description of the operation and
features of the MAR5000 EMS, please see the MAR5000 Product Data Sheet. The
MAR5000 features:
• Temperature control.
• Dynamic recovery time.
• Run time limitation of heat pump to minimize energy costs.
• Humidity measurement and direct control of the dehumidication function.
• Seven relays for interfacing with the HVAC system or external devices.
• Ventilation control.
• One dry contact set of inputs enables data feed from any dry contact output
device, e.g., a door switch.
• Support for peak load shedding.
• A precise time clock that will keep accurate time for lengthy power outages
(at least 2 1/2 weeks).
• Intelligent occupancy and departure anticipation.
Options include:
• Unoccupied continuous fan shutoff.
2. 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 manufacturer,
and purchased by the customer.

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1.05 OPTIONS
1.05A TWO STAGE COMPRESSOR
1. Models with a “S” in the in the 5th letter of the model number have a 2-stage
compressor. A two stage compressor is able to maintain more precise temperature
control and humidity levels. The 2-stage operation is only operational in the cooling
mode-heating and dehumidication are 1-stage.
Installation of heat pumps with a 2-stage is identical to hose with a 1-stage
compressor. However, a 2-stage cooling thermostat must be used. Do not use the
Mar5000 controller with a unit with a 2-stage compressor.
1.05B WATER SIDE ECONOMIZER (VWIA MODELS ONLY)
1. A water side economizer is a factory installed option that can reduce the cost of
cooling the classroom. The water side economizer is a set of water coils installed
in the plenum. If the loop water is sufciently cool and cooling is required by the
room thermostat, a valve opens to allow the cool water to ow into the coils.
Simultaneously, the indoor blower turns on to pull the air across the coils and into the
classroom. When either the room temperature is satised or the entering water rises
above the set point, the economizer operation is terminated. The following schematic
shows the internal water piping for the waterside economizer.
Figure 2. Water Side Economizer
L
oop
W
a
t
er
Senso
r
Notes:
PLENUM - WATERSIDE ECONOMIZER
Hose
FlexibleFlexible
COIL-NC
Connect to Hi
g
h Pressure
1" MPT Water Out
Pressure-Actuated
1" MPT Water In
Water-Regulating
Valve
24 Vol
t
2-WAY
Signal
Heating
3
Refrigerant Liquid Line
LH WATERSIDE ECONOMIZER
Hose
Co-Axial
1
RH WATERSIDE ECONOMIZER
3-WAY
COIL-NC
Heat Exchanger
2
Tem
p
erature
Controller
DASHED LINES ( ) REPRESENT EVERYTING INSIDE OF PLENUM