Marvair AVPA 12 series User manual

MODELS:
AVPA 12-20-24-30-36-42-48-60
Installation & Operation Manual
9 EER Vertical Wall-Mount Air Conditioners
Manufactured By:
A Division of the AIRXCEL®Commercial Group
P.O. Box 400 • Cordele, Georgia 31010 • 156 Seedling Drive • Cordele, Georgia 31015
[phone] • Fax [phone]
E-mail: [e-mail] • Internet: www.Marvair.com
The most current version of this manual can be found at www.Marvair.com.
Air Conditioner Product Manual
Vertical Wall-Mount Air Conditioners
with Front Control Box Panel
IMPORTANT
This manual may include information for options and features which may not be
included on the unit being installed. Refer to the unit data label or Model Identication
to determine which features and options this unit is equipped with.
INSTALLER: Afx the instructions on the inside of the building adjacent to the thermostat.
END USER: Retain this manual for future reference.
Marvair ModPac Installation & Operation Manual 11/2017 Rev. 8
Part #01690

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Marvair ModPac Installation & Operation Manual
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Specications subject to change without notice.
© 11/2017 Airxcel Commercial Group
How To Use This Manual
This manual is intended to be a guide to the Marvair® ModPac family of vertical 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 ModPac unit, rst read Chapter 1 and scan the entire manual before beginning the
installation as described in Chapter 2. Chapter 1 contains general, descriptive information and provides an
overview which can speed up the installation process and simplify troubleshooting.
If a malfunction occurs, follow this troubleshooting sequence:
1. Make sure you understand how the ModPac unit works (Chapters 1 & 3).
2. Identify and correct installation errors (Chapter 2).
3. Refer to the troubleshooting information in Chapter 4.
If you are still unable to correct the problem, contact the Factory at 1 [phone] for additional assistance.
Please read the following “Important Safety Precautions” before beginning any work.
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 compressor and
breakage or damage to other components.
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
and 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 recovering or adding refrigerant
6. Use COMMON SENSE - BE SAFETY-CONSCIOUS
This is the safety alert symbol . When you see this symbol on the ModPac 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.

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Table of Contents
Chapter 1. ModPac Description & Specications
1.1 General Description..................................................................................................................................5
1.2 Model Identication .................................................................................................................................5
1.3 Serial Number Date Code ........................................................................................................................5
1.4 General Operation ....................................................................................................................................6
1.5 M5 Conguration .....................................................................................................................................6
1.6 A2 Internal Disconnect.............................................................................................................................6
1.7 Elcontronic Control Board Modes of Operation ......................................................................................6
1.8 Electrical Diagrams ..................................................................................................................................8
Chapter 2. Installation
2.1 Equipment Inspection.............................................................................................................................10
2.2 Installation Requirements.......................................................................................................................10
2.3 Installation Materials..............................................................................................................................12
2.4 Porting and Duct Work...........................................................................................................................14
2.5 Fresh Air Hood Installation ....................................................................................................................15
2.6 Bottom Bracket Installation ...................................................................................................................15
2.7 Mounting the Unit ..................................................................................................................................16
2.8 Electrical Connections............................................................................................................................17
Chapter 3. Start-Up
3.1 Check-Out of Cooling Cycle .................................................................................................................20
3.2 Check-Out of Heating Cycle ..................................................................................................................20
Chapter 4. Troubleshooting
4.1 Overview ................................................................................................................................................21
4.2 Failure Symptoms Guide........................................................................................................................22
4.3 Compressor Troubleshooting .................................................................................................................23
4.4 Electric Heat Controls ............................................................................................................................24
Chapter 5. Ratings & Specications
5.1 Ratings & Specications .......................................................................................................................25
Chapter 6. Maintenance
6.1 Scheduled Maintenance..........................................................................................................................26
WARNING
• 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.

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Chapter 7. Warranty Information
7.1 Airxcel Commercial Group Limited Product Warranty Statement ........................................................27
Exploded Views & Parts Lists .......................................................................................................................28
Appendix A - Installation Instructions of Field Installed Electric Heat ........................................................28
Illustrations
Figure 1. Typical Electrical Schematic for Units with the PC Board .....................................................9
Figure 2. Damper Air Path ....................................................................................................................12
Figure 3a. Fresh Air Hood Adjustment for Models AVPA20-60 ............................................................15
Figure 3b. Fresh Air Hood Adjustment for AVPA12...............................................................................15
Figure 4. Wall Mounting Detail.............................................................................................................16
Figure 5. Thermostat Connection Diagram...........................................................................................19
Figure 6. Typical Conguration for Single Element Heater..................................................................24
Tables
Table 1. Minimum Clearances............................................................................................................. 11
Table 2. Voltage Limitations................................................................................................................ 11
Table 3. Maximum Static Pressure ......................................................................................................15
Table 4. CFM @ ESP...........................................................................................................................25
Table 5. Filter Sizes .............................................................................................................................25
Table 6. Shipping Weights ...................................................................................................................25

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Chapter 1. Description & Specications
1.1 General Description
The Marvair® ModPac air conditioner line is a series of vertical wall-mounted air conditioning systems
that provide heating and cooling for modular construction ofces and classrooms. The series includes
four cabinet sizes and nominal cooling capacities from 12,000 to 56,500 BTUH. Resistance heating
elements are available in various wattages. See Appendix A for instructions on eld installation of
electric heat.
Marvair's ModPac models are designed for easy installation and service. Major components are accessible
for service beneath external panels.
1.2 Model Identication
AVP A •AC •••• M5 •••••• •••
Air Source
Vertical Package
Nominal Cooling
12 = 12,000 BTUH
20 = 20,000 BTUH
24 = 24,000 BTUH
30 = 29,000 BTUH
36 = 35,000 BTUH
42 = 42,000 BTUH
48 = 46,500 BTUH
60 = 56,000 BTUH
System Type
Air Conditioner
Power Supply
A = 208/230V,1ø,60Hz
C = 208/230V,3ø,60Hz
D = 460V,3ø,60Hz
Configuration
M5 =PC Board &
Square Cornered
Cabinet
Electric Heat – kW
000 = No Heat 080 = 8 kW
036 = 3.6 kW 090 = 9 kW
040 = 4 kW 100 = 10 kW
050 = 5 kW 120 = 12 kW
060 = 6 kW 150 = 15 kW
Ventilation Code
N = 0-15% fresh air with manual damper,
no pressure relief)
All Models
B = Motorized two position damper
(open & closed) capable of 0
to 450 cfm (up to 40% of rated
air flow) of outside air, includes
pressure relief) Models AVPA30-
60 only
Z = Manual damper, field adjustable with
pressure relief
Y = Manual damper, field adjustable, no
pressure relief
A = R410
Refrigerant
Special Option Code
U = Scroll Compressor
A1 = PC Board
K = Coastal Environmental
Package
R = Electric Reheat
Color Code
800 = Mesa Tan
200 = Grey
400 = White
A5 = Built in
compliance with
UL 1995, 4th
edition
Brand Designation
Unused = Marvair
ModPac
EUB = Eubank
WalPac
1.3 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

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1.4 General Operation
Refrigerant Cycle (Cooling Mode)
The ModPac uses R-410A refrigerant in a conventional vapor-compression refrigeration cycle to transfer
heat from air in an enclosed space to the outside. A double blower assembly blows indoor air across
the evaporator. Liquid refrigerant passing through the evaporator is boiled into gas by heat removed
from the air. The warmed refrigerant gas enters the compressor where its temperature and pressure are
increased. The hot refrigerant gas condenses to liquid as heat is transferred to outdoor air blown across
the condenser by the condenser fan. Liquid refrigerant is metered into the evaporator through capillary
tubes to repeat the cycle.
Heating Mode
A wall-mounted thermostat controls the heating cycle of models which incorporate resistance heating
elements. On a call for heat, the thermostat closes the heat relay to energize the indoor fan and the
resistance elements. Please see Appendix A for instructions on eld installing electric heaters.
Ventilation Options
• Manual damper capable of up to 15% of rated airow of outside air; eld adjustable, no pressure
relief. (Standard - Ventilation Conguration N)
• Motorized, two position damper (open and closed) capable of 0 to 450 cfm (maximum of 40% of
rated airow) of outside air; includes pressure relief. A 24-volt actuated motor controls the damper
from an external input such as: a time clock, CO2 sensor, energy management system or manual
switch. (Optional - Ventilation Conguration B) - AVPA20-60 only.
• Field adjustable manual damper capable of up to 450 cfm (maximum 40% of rated airow) of outside
air; includes pressure relief. (Ventilation Conguration Z) – AVPA20-60 only.
• Field adjustable manual damper capable of up to 450 cfm (maximum 40% of rated airow) of outside
air. Does not include pressure relief. (Ventilation Conguration Y) – AVPA20-60 only.
1.5 M5 Conguration
The M5 conguration of the ModPac conditioners include a factory installed PC board.
The internal control board in the M5 conguration simplies wiring, consolidates several of the electrical
functions onto one device and improves the reliability of the air conditioner. In addition, the control
board has LED’s that indicate operational status and fault conditions.
1.6 A2 Internal Disconnect
To meet the current U.L. 1995 Safety Standard, the electric heating elements are installed on a separate
electrical circuit. Single phase, 240 volt electric heating elements which exceed 48 amps (12 and 15
kW) require two electrical circuits.
1.7 Electronic Control Board Modes of Operation
Normal
24 VAC power must be continuously applied to “R” and “C”. Upon a call for cooling “Y” and with the
high pressure switch (HPS) closed, the compressor will be energized. (Note: See the delay on make
feature.) The compressor will remain energized during the 3 minute timed low pressure by-pass cycle. If
the low pressure switch (LPS) is open after the 3 minute by-pass cycle, the compressor will de-energize.

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Lock-out
If either of the fault conditions (LPS or HPS) occurs twice during the same call for cooling, the control
board will enter into and indicate the lockout mode. In the lockout mode, the compressor is turned off.
If there is a call for indoor air ow “G”, the blower remains energized, the alarm output is energized and
the status LED will blink to indicate which fault has occurred. When the lockout condition is cleared,
the unit will reset if the demand for the thermostat is removed or when the power is reset. With the
control board, the user can now have either normally closed or normally open contacts by moving a
wire on the control board. ComPac air conditioners are factory wired to be normally open.
Delay on Break
If the compressor is de-energized due to a loss of a cooling “Y” call or the rst fault, the unit re-start
will be delayed 3 minutes from the time the contactor is de-energized. (Note: There is no delay on break
if the lockout condition is reset.)
Delay on Make
On initial power up only, the unit will wait 0.03 to 10 minutes from the cooling “Y” call before
allowing the contactor to energize. The delay can be adjusted by the DOM wheel on the board. Factory
recommended wait is 3 minutes.
Low Pressure By-Pass Time
When starting, the low pressure switch (LPS) fault condition will be by-passed for 3 minutes before
the contactor is de-energized.
Post Purge
Upon a call for indoor airow “G” the blower will energize immediately. When in the cooling mode,
the blower will remain energized for 10 to 90 seconds (adjustable) after the compressor has been de-
energized. The time period can be changed by fan purge wheel on the board. Factory setting is 90 seconds.
LED Indicator Lights
COLOR TYPE STATUS DESCRIPTION
Green Power Contstant On 24 VAC power has been applied
Red Status Contstant On Normal operation
Red Status 1 Blink High pressure switch has opened twice
Red Status 2 Blinks Low pressure switch has opened twice
High Pressure Switch
The high pressure switch is mounted on the compressor liquid line. It is electrically connected to a
lockout relay which shuts down the system if the refrigerant pressure rises to 650 PSIG. This protects
the unit if airow through the condenser is blocked or if the outdoor fan motor fails. Although the
contacts of the high pressure switch close when the refrigerant pressure falls to approximately 450 PSIG,
the system must be manually reset once the lockout relay is activated. A manual reset is necessary to
prevent harmful short-cycling. To reset switch, turn primary power off, then back on or turn thermostat
system switch off, then back on.
Low Pressure Switch
The low pressure switch is mounted on the compressor suction line. It is designed to open if the refrigerant
pressure drops to 40 PSIG; it resets when the pressure rises to 60 PSIG. The switch protects the unit if
airow through the indoor blower is impeded, if the blower motor fails, or if there is a loss of refrigerant.

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LEDs POST PURGE WHEEL DELAY ON MAKE
(COMPRESSOR TIME DELAY) WHEEL
1.8 Electrical Diagrams
The compressor incorporates an internal PTC crankcase heater that functions as long as primary power
is available. The heater drives liquid refrigerant from the crankcase and prevents loss of lubrication
caused by oil dilution. Power must be applied to the unit for 24 hours before starting the compressor.
The compressor is energized with a contactor controlled by a 24 VAC pilot signal (see Figure 1). The
evaporator blower motor is cycled by the blower time delay relay.
IMPORTANT
The ModPac incorporates a 90 second purge cycle that runs the evaporator
blower after the thermostat is satised.
To meet the current U.L. 1995 Safety Standard, the electric heating elements are installed on a separate
electrical circuit. Single phase, 240 volt electric heating elements which exceed 48 amps (12 and 15
kW) require two electrical circuits. The compressor and all other motors are on separate electrical circuit
which do not contain any electrical heating elements. The incoming power for units without electric heat
can be wired directly to the unit mounted circuit breaker. The incoming power for units with electric
heat can be wired to the unit mounted terminal block. The external or wall mounted breaker must be
sized for the load of the unit's electrical circuit(s). The required minimum circuit ampacity (MCA)and
maximum fuse size (MFS) for this breaker will be marked on the unit's Data Info in the single point
power entry (SPPE) column.

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Figure 1. Typical Electrical Schematic for Air Conditioners with the PC Board

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Chapter 2. 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.
2.1 Equipment Inspection
Concealed Damage
Inspect all cartons and packages upon receipt for damage in transit. Remove cartons and check for
concealed damage. Important: keep the unit upright at all times. Remove access panels and examine
component parts. (Note: the bottom bracket for Models AVPA20-60 are stored in the condenser air
compartment. Remove a side screen to retrieve them and then replace the side screen). The AVP12 does
not require a bottom bracket. Inspect refrigerant circuit for fractures or breaks. The presence of refrigerant
oil usually indicates a rupture. If damage is apparent, immediately le a claim with the freight carrier.
Units that have been turned on their sides or tops may have concealed damage to compressor motor
mounts or to the oil system. If the unit is not upright, immediately le a claim for concealed damages
and follow these steps:
1. Set unit upright and allow to stand for 24 hours with primary power turned on.
2. Attempt to start the compressor after 24 hours.
3. If the compressor will not start, makes excessive noise, or will not pump, return the unit to the
freight carrier.
2.2 Installation Requirements
General
1. Inspect unit for completeness. Check for missing parts (e.g. hardware). Refer to the installation
kit information in section 2.3.
2. Remove access panels and check for loose wires. Tighten screw connections if necessary.
3. Complete and mail the warranty registration card.
You must consider all of the following when choosing the installation site:
1. Noise: Install the unit so that the least amount of noise will be transmitted to inhabited spaces.
2. Condensate Drainage: Condensate produced during operation must be discharged to a suitable drain.
3. Placement:
A) Place the unit in a shaded area, if possible.
B) Install it above ground for protection against ooding.
C) The unit exhausts air. Be sure that the airow is not impeded by shrubbery or other obstructions.
4. Airow Requirements: Note the minimum CFM requirements (section 2.4). Keep duct lengths as
short as possible. Do not obstruct airow through the unit.
Applications using duct work should be designed and installed in accordance with all applicable safety