Marvair AVP 24 Product manual

ComPac® I and ComPac® II
Air Conditioner Product Manual
Vertical Wall-Mount Air Conditioners
with Front Control Box Panel
Models AVP24-30-36-42-48-60-72
Chapter 1 Description....................................... 5
Chapter 2 Installation..................................... 18
Chapter 3 Start-Up......................................... 30
Chapter 4 Troubleshooting............................. 32
Chapter 5 Maintenance................................... 35
Chapter 6 Warranty........................................ 36
Parts List & Exploded Views............................... 38
Manufactured By:
Marvair® Division of AIRXCEL®, Inc.
P.O. Box 400 • Cordele, Georgia 31010
156 Seedling Drive • Cordele, Georgia 31015
(229) 273-3636 • Fax (229) 273-5154
E-mail: marvairtech@airxcel.com • Internet: www.marvair.com
P/81024 6/09-18
supersedes 10/07-17
How To Use This Manual
This manual is intended to be a guide to Marvair's ComPac® line 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 ComPac® unit, first 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 ComPac® 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 1-800-841-7854 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 ComPac 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 is used to point out helpful suggestions that will result in improved installation, reliability or operation.
SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE.
© 6/09 Marvair® Div. Airxcel®, Inc.
ComPac 6/09-18
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.
• 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 jurisdiction.
INSTALLER: Affix the instructions on the inside of the building adjacent to the
thermostat.
END USER: Retain these instructions for future reference.
Table of Contents
Chapter 1ComPac® A/C Description & Specifications
1.1 General Description..................................................................................................................................5
1.2 Model Identification..................................................................................................................................5
1.3 Serial Number Date Code.........................................................................................................................5
1.4 Ratings and Specifications........................................................................................................................6
1.5 General Operation.....................................................................................................................................9
1.6 Electronic Control Board Mode of Operation.........................................................................................10
1.7 Optional Controls....................................................................................................................................12
1.8 Electrical Diagrams.................................................................................................................................13
1.9 Economizer Components........................................................................................................................16
Chapter 2 Installation
2.1 Equipment Inspection..............................................................................................................................18
2.2 Installation Requirements........................................................................................................................18
2.3 Installation Materials . ...........................................................................................................................19
2.4 Porting and Duct Work . .........................................................................................................................21
2.5 Fresh Air Hood Installation . ..................................................................................................................22
2.6 Bracket Installation ................................................................................................................................23
2.7 Mounting the Unit ..................................................................................................................................23
2.8 Electrical Connections............................................................................................................................24
Chapter 3 Start-Up
3.1 Check-Out of Cooling Cycle . ................................................................................................................30
3.2 Check-Out of Heating Cycle...................................................................................................................30
3.3 A/C Testing with LL357D4.....................................................................................................................31
Chapter 4 Troubleshooting
4.1 Overview.................................................................................................................................................32
4.2 Failure Symptoms Guide.........................................................................................................................32
4.3 Compressor Troubleshooting..................................................................................................................33
4.4 Control Board Diagnosis.........................................................................................................................34
ComPac 6/09-18
Table of Contents
Chapter 5 Maintenance
5.1 Scheduled Maintenance..........................................................................................................................35
Chapter 6 Warranty
6.1 Limited Product Warranty.......................................................................................................................36
6.2 Optional Silver Service Program............................................................................................................37
Parts List and Exploded Views......................................................................................................................38
Illustrations
Figure 1a.
1b.
1c.
Figure 2.
Figure 3a.
3b.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Figure 8a.
Figure 8b.
Figure 8c.
Figure 8d.
ComPac® I & II A/C Dimensions - Models 24-36................................................................... 7
ComPac® I & II A/C Dimensions - Models 42-60.................................................................... 7
ComPac® I & II A/C Dimensions - Model 72........................................................................... 8
Refrigerant Circuit.................................................................................................................... 9
Typical Electrical Schematic-ComPac® I A/C Models 24-72 w/ Electronic Control Board... 14
Typical Electrical Schematic-ComPac® II A/C Models 24-72 w/ Electronic Control Board 15
H205A Temperature Control Points........................................................................................ 16
H205A Control Point Adjustment........................................................................................... 17
Fresh Air Hood Installation..................................................................................................... 22
Wall Mounting Detail - ComPac® A/C AVP24-72.................................................................. 23
Thermostat Wiring Details...................................................................................................... 27
Thermostat Connection Diagram............................................................................................ 28
LL357D4 Wiring Detail.......................................................................................................... 28
CommStat 3™ Wiring Detail.................................................................................................. 29
Tables
Table 1
Table 2
Table 3
Table 4
Table 5
Table 6
CFM @ External Static Pressure.............................................................................................. 6
Ship Weight............................................................................................................................... 6
Standard Filter Size................................................................................................................... 6
Minimum Clearances.............................................................................................................. 19
Voltage Limitations................................................................................................................. 19
Maximum Static Pressure....................................................................................................... 22
ComPac 6/09-18
Chapter 1 Description & Specifications
1.1 General Description
Marvair's ComPac® lines 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 72,000 BTUH. Resistance heating elements are available in various wattages.
Marvair’s ComPac® I & ComPac® II air conditioners, models AVP24-72, feature an exclusive electronic
control board. The control board consolidates several of the electrical components and improves the air
conditioner’s reliability. The control board replaces the blower relay, the lockout relay, the compressor
time delay and the timed low pressure bypass. In addition, the control board has LED’s to indicate
operating status and fault conditions to assist the service technician. A complete description of functions
of the control board is in Section 1.6.
The ComPac® I & ComPac® II models are designed for easy installation and service. Major components
are accessible for service beneath external panels.
All units have internal disconnects (optional on 460V). Depending upon state and local code requirements, this feature may eliminate the need for an external breaker or disconnect.
The ComPac® I A/C has a 0-15% manual outside air damper and the ComPac® II A/C has a factory
installed economizer for 100% free cooling with outside air.
1.2
Model Identification
The model identification number is found on the data sticker. Rating plate located on side panel.
AVP ** AC * * * *
Special Option Code
R = Electric Reheat
U = Scroll Compressor
Configuration
N = ComPac® I A/C
C = ComPac® II A/C
Electric Heat (kW)
00, 04, 05, 06, 08, 09, 10, 15
Power Supply
A = 208/230V, 1ø, 60 Hz
C = 208/230V, 3ø, 60 Hz
D = 460V, 3ø, 60 Hz
E = 380V, 3ø, 50 Hz
F = 220V, 1ø, 50 Hz
G = 220V, 3ø, 50 Hz
System Type = Air Conditioner
Nominal Cooling*
24 = 24,000 BTUH
48 = 48,000 BTUH
30 = 29,400 BTUH
60 = 55,000 BTUH
36 = 35,000 BTUH
72 = 72,000 BTUH
42 = 41,500 BTUH
Air Source Vertical Package
*Ratings at 60 Hz.
1.3
Serial Number Date Code
A = January
B = February
C = March
D = April
E = May
F = June
G = July
H = August
J = September
K = October
L = November
M = December
L = 2000
M = 2001
N = 2002
P = 2003
R = 2004
S = 2005
T = 2006
U = 2007
V = 2008
Y = 2009
ComPac 6/09-18
1.4
Ratings & Specifications
MODEL
24
30
36
42
48
60
72
0.10
860
1100
1310
0.20
810
1000
1220
1650
1900
1900
2100
0.25
740
960
1185
1585
1830
1830
1950
0.30
670
920
1150
1520
1760
1760
1800
0.40
0.50
810
1060
1450
1700
1700
1730
1360
1620
1620
1660
Table 1. CFM @ External Static Pressure (Wet Coil) (IWG)
24
LBS/KG
274/125
286/130
MODEL
COMPAC® I A/C
COMPAC® II A/C
30/36
LBS/KG
355/160
365/170
42
LBS/KG
495/225
527/240
48
LBS/KG
521/240
552/250
60
LBS/KG
535/245
565/260
72
LBS/KG
625/284
640/290
Table 2. Ship Weight
MODEL
FILTER SIZE (inches)
FILTER SIZE (mm)
*Two filters required.
24
16 x 25 x 2
406 x 635 x 51
30/36
16 x 30 x 2
406 x 762 x 51
42/48/60
22 x 36-1/2 x 2
559 x 927 x 51
72
18 x 24 x 2*
452 x 610 x 51
Table 3. Filter Size
ComPac 6/09-18
Figure 1a. ComPac® I & ComPac® II A/C Dimensions- Models AVP20-36 (in inches)
Figure 1b. ComPac® I A/C & ComPac® II A/C Dimensions- Models AVP42-60 (in inches)
ComPac 6/09-18
Figure 1c. ComPac® I A/C & ComPac® II A/C Dimensions- Models AVP72 (in inches & mm)
ComPac 6/09-18
1.5
General Operation
Refrigerant Cycle (Cooling Mode)
The ComPac® I & ComPac® II A/C use R-22 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. Cold 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 drawn across the condenser by the condenser fan. Liquid refrigerant is metered into the evaporator
through capillary tubes to repeat the cycle.
Evaporator (Indoor Coil)
Distributor &
Capillary
Tubes
Filter
Drier
Twin Blowers
Suction
Line
Compressor
Discharge Line
Condenser Fan
Condenser (Outdoor Coil)
Figure 2. Refrigerant Circuit
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. Except on units with the optional dehumidification kit, the compressor is locked
out during the heating cycle.
Economizer Operation (ComPac® II A/C Only)
The economizer is a regulated damper system with controls. The damper regulates the circulation
of outside air into the enclosure (when the outdoor air conditions are suitable) to reduce the need for
mechanical cooling, save energy, and extend compressor life.
Depending upon the options selected, the damper responds to the enthalpy of the outdoor air. On a call
for cooling from a space thermostat, it operates as follows:
When the enthalpy of the outdoor air is below the set point, the outdoor air damper is proportionally open (and return air damper is proportionally closed) to maintain between 50°F and 56°F at the
mixed/discharge air sensor. Integral pressure relief allows the indoor air to exit the shelter through the
air conditioner.
When the enthalpy of the outdoor air is above the set point, the outdoor air damper closes to its minimum
position. A call for cooling from the space thermostat brings on mechanical cooling.
An optional built-in adjustable minimum position potentiometer (part number 70012) controls the
amount of outdoor air admitted to meet minimum ventilation requirements.
ComPac 6/09-18
1.6Electronic Control Board Mode of Operation (AVP24-72)
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.
Lock-out
If either of the fault conditions (LPS or HPS) occurs twice, 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
flow “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.
The 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 first 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 airflow “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 Green
Red
Red
Red
TYPE Power Status Status Status
STATUS Constant On
Constant On
1 Blink
2 Blinks
DESCRIPTION 24 VAC power has been applied
Normal operation
High pressure switch has opened twice
Low pressure switch has opened twice
10
ComPac 6/09-18
Low Ambient Control
The low ambient control permits cooling when outdoor ambient temperatures are low. The control
uses a reverse-acting high pressure switch to cycle the condenser fan motor according to liquid refrigerant pressure conditions. Switch closure and fan operation occurs when the pressure reaches 250
PSIG. The switch opens again when the refrigerant pressure falls to 190 PSIG. Therefore, the outdoor
fan always starts after the compressor, and it will cycle frequently during normal operation at low
outdoor conditions.
High Pressure Switch
The high pressure switch is mounted on the compressor discharge line. It is electrically connected to a
lockout relay which shuts down the system if the refrigerant pressure rises to 400 PSIG (AVP60 setting
is 450 PSIG). This protects the unit if airflow 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 300 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 35 PSIG; it resets when the pressure rises to 60 PSIG. The switch protects
the unit if airflow through the indoor blower is impeded, if the blower motor fails, or if there is a loss
of refrigerant.
POST PURGE
WHEEL
LEDs
11
DELAY ON MAKE
(COMPRESSOR TIME DELAY)
WHEEL
ComPac 6/09-18
1.7Optional Controls & Packages
Hard Start Kit
Used on single phase equipment to give the compressor higher starting torque under low voltage conditions. Generally not recommended on units with scroll compressors.
Extreme Duty Package
The Extreme Duty Package allows selected Marvair® ComPac® I & ComPac® II air conditioners to
operate in extremely cold and hot ambient conditions. The Extreme Duty Kit is always factory installed
and is available on all ComPac® air conditioners. ComPac® I air conditioners (non-economizer units)
will operate from 0° F to 130° F (-18° to 54°C). ComPac® II air conditioners (economizer units) will
operate from -20° F to 130° F (-29° to 54°C).
The Extreme Duty Package includes a suction line accumulator, thermal expansion valve (TXV),
crankcase heater, hard start kit, an auto reset, adjustable high pressure switch and an outdoor thermostat
and fan cycle switch. The fan cycle control is standard on all ComPac® air conditioners and operates
based upon the liquid line pressure. The outside thermostat closes whenever the outside temperature is
below 50°F (10°C) and opens when the outside temperature is 50° F (10°C) or higher. Whenever the
temperature is below 50°F (10°C), the fan cycle switch is in the circuit; when temperatures are 50° F
(10°C) or higher, the fan cycle switch is not in the circuit. The fan cycle control is used with a TXV to
prevent excessive cycling or "hunting" of the TXV.
Coastal Environmental (ComPac® I A/C Only)
Recommended for units to be installed near an ocean or on seacoast. Includes corrosion resistant
fasteners, sealed condenser fan motor, protective coating applied to all exposed internal copper in the
condenser section and a protective coating on the condenser coil.
Stainless Steel Cabinet (ComPac® I A/C Only)
All sheet metal constructed of stainless steel.
Hot Gas Bypass (ComPac® I A/C Only)
Used in specialty applications; i.e., Magnetic Resonance Imaging (MRI) buildings, to prevent magnetic
voltage disturbance caused by compressor cycling. Two hot gas bypass option packages are available
to allow operation to 20°F (-7°C) or minus 20°F (-29°C). Please refer to Hot Gas Bypass Application
Bulletin for details.
Electric Reheat Dehumidification
A humidity controller (p/n 50057) allows electric heat and cooling to operate simultaneously. Marvair®
air conditioners equipped with the dehumidification option allow the indoor humidity of the controlled
environment to be maintained at or below a certain humidity set point. These units do not have the
ability to add humidity to the building.
IMPORTANT: The electrical wire and breaker or fuses must be sized for simultaneous operation
of the electric heater and the air conditioner. Refer to the data sticker on the unit or the ComPac®
Air Conditioner Product Data Sheet for the sizing information.
Dehumidification is achieved by operating mechanical cooling in conjunction with electric reheat. The
strip heat is sized approximately to the sensible capacity of the total tonnage of the machine (i.e., on a
24,000 BTU unit the strip heat is sized at approximately 20,000 BTU). Because the strip heat is sized
to the approximate sensible cooling capacity, only selected models are available.
Operation:
When the humidity rises above the set point on the humidity controller both mechanical cooling and
12
ComPac 6/09-18
electric reheat operate to temper the air and lower the humidity. If the temperature in the controlled
environment rises above the set point of the thermostat and the unit is operating in the dehumidification
mode, the call for cooling will override the call for dehumidification and the strip heat is disengaged
until the thermostat is satisfied. This assures the environment temperature is maintained as first priority
and humidity control is second.
In applications where a shelter has redundant air conditioning units and is controlled by a lead lag
controller (Marvair's LL357D4 or CommStat3™ Controller), most times the dehumidification option
is only necessary on one of the two units. It is possible for one unit to be operating in the cooling mode
while the unit with dehumidification is operating at the same time. If the cooling unit does not maintain
the shelter temperature set point, the unit with dehumidification will go into the cooling mode. It does
not matter whether the unit with dehumidification is the lead or lag unit.
Three Phase Voltage Monitor, Marvair®
Continuously measures the voltage of each of the three phases. The monitor separately senses low
and high voltage, voltage unbalance including phase loss and phase reversal. An LED indicator glows
when all voltages are acceptable. Automatically resets when voltages and phases are within operating
tolerances.
Dirty Filter Indicators
A diaphragm type of indicator measures the air pressure on either side of the filter and when the pressure
drops below the set point, an LED is illuminated.
Minimum Potential Potentiometer
Used in the ComPac® II units with the factory installed economizer. The potentiometer prevents the
economizer from closing completely, assuring that outside air will be brought into the shelter and exhausted whenever the indoor blower is operating. This prevents negative pressurization of the building.
The minimum potential potentiometer is adjustable.
1.8Electrical Diagrams
The compressor and condenser fan are energized with a contactor controlled by a 24 VAC pilot signal.
Some compressors incorporate 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 condenser (outside fan) motor is energized by the same contactor. However, the motor is cycled
on and off by the low ambient control (see low ambient control 1.6).
The indoor evaporator fan motor is controlled by the fan purge on the electronic control board.
13
ComPac 6/09-18
TRANSFORMER
6
5
Figure 3a. Typical Electrical Schematic - ComPac® I A/C, Models AVP24-72
with Electronic Control Board
14
ComPac 6/09-18
TRANSFORMER
5
OPTIONAL FIELD INSTALLED 270 OHMS MINIMUM POSITION POTENTIOMETER.
Figure 3b. Typical Electrical Schematic - ComPac® II A/C, Models AVP24-72
with Electronic Control Board
15
ComPac 6/09-18
1.9Economizer Components (ComPac® II A/C 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.
Controls:
The economizer is controlled by the H205A enthalpy control or optional dry bulb sensor.
H205A Economizer Changeover Control:
The H205A enthalpy controller responds to the total heat content of the outdoor air to provide changeover
to outside air for free cooling. The change point (factory set at "D") is adjustable from 53°F @ 50%
RH (full counterclockwise) to 78°F @ 50% RH (full clockwise). Refer to Figure 4 and Figure 5.
Once the H205A has selected outside air, the mixed air sensor will limit the air temperature delivered
to the space by modulating the damper blade to "mix in" a quantity of inside air to provide a constant
50° to 56°F. (Adjustable minimum potentiometer, part number 70012, is optional.)
CONTROL
CONTROL POINT*
CURVE AT 50% RH
A
72°F/23°C
B
68°F/20°C
C
63°F/17°C
D
58°F/14.5°C
Full CCW is 55°F
*Approximate Deg.
Figure 4. H205A Temperature Control Points
16
ComPac 6/09-18
The controller modulates the position of the outside air damper in response to input from the enthalpy
and mixed air sensors. The controller is designed to maintain the supply air temperature between 50°
to 56°F by mixing warm indoor air with cooler outdoor air.
On a call for cooling from the wall-mounted thermostat, if outdoor conditions are suitable, the controller
will open the damper and admit outside air (i.e., economizer cooling). If the outdoor ambient is too
hot or humid, the controller will place the actuator in the closed or minimum open position and activate
mechanical cooling. The compressor is locked out during the economizer cooling mode.
54.4 Degrees
Scaleplate
and Knob
Between
D
C
B
A
Index Mark
on Controller
Flat on Shaft
Perpendicular
to Index Mark
on Controller
Figure 5. H205A Control Point Adjustment
Mixed Air Sensor:
The mixed air sensor is a thermistor mounted on a bracket adjacent to the right side of the blower
assembly. The thermistor senses the air temperature entering the structure, and provides a signal to the
economizer controller for modulating the position of the damper. Nominal resistance of the sensor at
77° F is 3000 ohms.
17
ComPac 6/09-18
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 Marvair unit..
2.1Equipment 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 "L"-shaped bottombracket is stored in the condenser air compartment. Remove it before replacing the side screen). Inspect refrigerant circuit for fractures or breaks.
The presence of refrigerant oil usually indicates a rupture. If damage is apparent, immediately file 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 file 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.
2.2Installation 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.
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 flooding.
C) The unit exhausts air. Be sure that the airflow is not impeded by shrubbery or other obstructions.
D) When installing multiple units, please note the recommended clearances noted in Table 4.
4. Airflow Requirements:
Note the minimum CFM requirements (Table 6). Keep duct lengths as short as possible. Do not
obstruct airflow through the unit.
18
ComPac 6/09-18
Duct work should be designed and installed in accordance with all applicable safety codes and
standards. Marvair® strongly recommends referring to the current edition of the National Fire
Protection Association Standards 90A and 90B before designing and installing duct work. 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 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. Duct work must be firmly attached, secured, and sealed to prevent air leakage. See section
2.4 for additional duct work requirements.
5. Clearances:
Note the minimum clearances required for proper operation and service.
MIN. CLEARANCE AROUND
SIDES (SINGLE UNIT)
MIN. CLEARANCE BETWEEN
UNITS (TWO UNITS)
MIN. SPACE
ABOVE UNIT
24
30 inches
18 inches
24 inches
30/36
30 inches
18 inches
24 inches
42/48/60
30 inches
30 inches
24 inches
72
30 inches
30 inches
12 inches
MODEL
Table 4. Minimum Clearances
6. Codes:
Make sure your installation conforms to all applicable electrical, plumbing, building, and municipal
codes. Some codes may limit installation to single story structures.
7. Electrical Supply:
The power supply must have the appropriate voltage, phase, and ampacity for the model selected.
Voltage must be maintained above minimum specified values listed below. Refer to the data sticker
on the unit for ampacity requirements.
Electrical Rating Designations*
A
C
D
Nominal Voltage
208/230
208/230
460
Phase
1
3
3
Minimum Voltage
197
197
414
Maximum Voltage
253
253
506
* Letters refer to model number code designations. Refer to page 5.
Table 5. Voltage Limitations
2.3
Installation Materials (AVP24-72)
Installation Kits
The ComPac® I and ComPac® II A/C units, models AVP24-72, are shipped with one 12 Ga. "L" shaped
bottom bracket. On AVP24,30 & 36 units, there is an air intake hood packed inside each unit. 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 - Models AVP24-72:
1. One 12 Ga. "L"-shaped bottom bracket
Accessories:
The package may include other factory-supplied items (optional) as follows on the next page:
19
ComPac 6/09-18
P/N
Description
S/04581
CommStat 3™ Controller, Solid State Lead/Lag Controller
S/07529
LL357D4, Lead/Lag Controller with T'stat & Sub-Base; Controls 2 A/C Units
50123
Digital thermostat. 1 stage heat, 1 stage cool. 7 day programmable. Fan switch: Auto &
On. Auto-change over. Keypad lockout. Non-volatile program memory.
50107
Digital thermostat. 2 stage heat, 2 stage cool. 7 day programmable. Fan switch: Auto &
On. Auto-change over. Status LED’s. Backlit display. Programmable fan. Non-volatile
program memory.
80674
VPG - 20S, 20 x 8" Adjustable, Aluminum, Double Deflection Supply Grill for
AVP24
VPG - 30S, 28 x 8" Adjustable, Aluminum, Double Deflection Supply Grill for
AVP30-36
VPG - 40S, 30 x 10" Adjustable, Aluminum, Double Deflection Supply Grill for
AVP42-48-60-72
80675
80676
80677
80678
80679
VPG - 20R, 20 x 12" Aluminum Return Grill for AVP24
VPG - 30R, 28 x 14" Aluminum Return Grill for AVP30-36
VPG - 40R, 30 x 16" Aluminum Return Grill for AVP42-48-60-72
06777
Start Relay and Capacitor for AVP24-36 (Field Installed) (Not recommended for scroll
compressors.)
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.
ComPac® I and ComPac® II A/C Models 24-72
(10) 3/8" carriage head mounting bolts for unit mounting flanges. The length needed is typically
the wall thickness plus one inch.
(20) 3/8" washers
(10) 3/8" hex nuts
(6)
3/8" x 2-1/2" lag screws for bottom bracket
• Silicone Sealer to seal around cracks and openings
• 4-conductor low voltage multicolored wire cable (i.e. thermostat wire)
• Appropriate electrical supplies such as conduit, electrical boxes, fittings, wire connectors,
etc.
• High voltage wire, sized to handle the MCA (minimum circuit ampacity) listed on the data
plate.
• Over-Current Protection Device sized in accordance with the MFS (maximum fuse size) listed
on the unit data plate.
20
ComPac 6/09-18
Warning
FIRE HAZARD
Improper adjustment, alteration, service, maintenance or installation could cause serious
injury, death and/or property damage.
Installation or repairs made by unqualified persons could result in hazards to you and
others. Installation MUST conform with local codes or, in the absence of local codes, with
codes of all governmental authorities have jurisdiction.
The information contained in this manual is intended for use by a qualified service
agency that is experienced in such work, is familiar with all precautions and safety
procedures required in such work, and is equipped with the proper tools and test
instruments.
2.4Porting and Duct Work (AVP24-72)
General Information
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 Marvair® for additional assistance.
Wall Openings
Measure the dimensions of the supply and return ports on the unit.
Cut the openings in the exterior wall for the supply and return. IMPORTANT: All units with electric
heat must have one inch clearance on all four sides of the supply outlet duct flange on the unit.
The one inch clearance must extend on all sides of the supply duct for the first three feet from
the unit.
IMPORTANT: Marvair® requires a minimum of one inch from the surface of any supply ducts to
combustible material for the first three feet of the duct.
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. Marvair® strongly recommends referring to the current edition of the National
Fire Protection Association Standards 90A and 90B before designing and installing duct work. 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 supply registers,
adequate return and filter area. Ductwork 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 for the
first three feet. Ductwork must be firmly attached, secured and sealed to prevent air leakage. Do not
use duct liner on inside of supply duct within 4 feet of the unit.
Galvanized metal duct extensions should be used to simplify connections to duct work and grilles. Use
fabric boots to prevent the transmission of vibration through the duct system. The fabric must be U.L.
rated to a minimum of 197°F.
Minimum Airflow Requirements
The duct system must be engineered to assure sufficient air flow through the unit even under adverse
conditions such as dirty filters, etc. Use Table 6 below and Table 1, CFM at External Static Pressure
(Wet Coil) in section 1.4.
21
ComPac 6/09-18
BASIC MODEL
MAXIMUM TOTAL STATIC
MINIMUM FILTER AREA
24
.30
2.25 sq. ft.
30/36
.40
3.00 sq. ft.
42/48/60/72
.50
3.90 sq. ft.
Table 6. Maximum Static Pressure
(For units with 2" Pleated Filters)
2.5
Fresh Air Hood Installation (AVP24-30-36)
1. Cut and remove insulation on the inside of the lower front access panel in the shape of the rectan gular opening. See Figure 6.
2. Insert flange on hood into opening and secure using the two #8 x 1/2 sheet metal screws
supplied.
Figure 6. Fresh Air Hood Installation
2.6
Bracket Installation (AVP24-72)
1. Models AVP24-72 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 7. Attach the bottom support bracket to the wall using appropriate 3/8" diameter
hardware.
For example, on wooden structures, use 3/8" x 2-1/2" all-thread lag screws. The screws must penetrate
the center of the wall stud. Drill a pilot hole in the stud to prevent it from splitting.
22
ComPac 6/09-18
2.7
Mounting The Unit (AVP24-72)
1. For wiring into the back of unit, locate the lower of the two knockouts on the wall side of the unit.
Drill a one inch hole in the shelter wall to match this opening. Allow sufficient clearance to run
3/4" conduit through the hole and to the unit.
2. Using an appropriate and safe lifting device, set the unit on the bottom support bracket mounted on
the wall. You must stabilize the unit on the bracket with the lifting device or by some other means
- the bracket alone is not sufficient.
3. Make sure that the duct flanges are properly aligned with the wall opening. Adjust as necessary.
4. Note the holes in each side flange. Using the holes for guides, drill holes through the wall with a
3/8" drill bit. Insert the 3/8" x 5" bolts through the flanges. Install nuts and washers on the inside
of the shelter. Tighten the bolts to secure the unit.
5. Apply a bead of silicone where the mounting flange contacts the unit and the shelter wall.
6. On the inside of the shelter, install the wall sleeves in the supply and return air openings. The
sleeves may be trimmed to fit flush with the inside wall.
7. Check the fit of each sleeve to its mating flange for possible air leaks. Apply silicone sealer to close
any gaps. Install the air return and supply grilles.
GRILLE
SUPPLY AIR
DUCT EXTENSIONS (Not Supplied with Unit)
COMPAC® II A/C
ONLY
RETURN AIR
GRILLE
FOAM SEAL
Figure 7. ComPac® I and ComPac® II A/C Wall Mount Detail (AVP24-72)
23
ComPac 6/09-18
2.8Electrical 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.
Important
All electrical work must meet the requirements of local codes and ordinances. Work should be
done only by qualified persons.
The ComPac® units may incorporate an internal crankcase heater for compressor protection. The
crankcase heater must be energized for at least 24 hours prior to starting the compressor.
Scroll compressors, like several other types of compressors, will only compress in one rotational direction.
The direction of rotation is not an issue with single-phase compressors since they will always start and
run in the proper direction. However, three phase compressors will rotate in either direction depending
upon phasing of power. Since there is a 50-50 chance of connecting power in such a way as to cause
rotation in the reverse direction, it is imperative to confirm that the compressor is rotating in the proper
direction at the initial field start-up of the system. Verification of proper rotation is made by observing
that the suction pressure drops and the discharge pressure rises when the compressor is energized. An
alternate method of verification for self contained system with small critical refrigerant charges, where
the installation of gauges may be objectionable, can be made by monitoring the temperature of the
refrigerant lines at the compressor. The temperature should rise on the discharge line while the suction
line temperature decreases. Reverse rotation also results in a substantially reduced current draw when
compared to tabulated values.
Marvair units have either a reciprocating or scroll compressor. A reciprocation compressor is standard
on the AVP24, 30 & 36 units. However, a scroll compressor is an option on these ComPac® I and
ComPac® II air conditioners. Units with scroll compressors have a "U" in the model number. The scroll
compressor is standard on all AVP42, 48, 60 & 72 units.
There is no negative impact on durability 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.
High Voltage Wiring - (Single Units)
The power supply should have the proper voltage, phase, and ampacity for the selected model.
1. Size the incoming power supply lines according to Code requirements. Run the power conductors
through the knockouts on the wall side of the unit, or to those adjacent to the electrical control box.
Use appropriate conduit and strain reliefs.
2. Connect the wires to the input side of the internal breaker or terminal block (L1 & L2 for singlephase units; L1, L2, & L3 for three-phase models).
3. Install the ground wire on the ground lug.
24
ComPac 6/09-18
4. For units designed for operation on 208/230v, 60Hz power supply, the transformer is factory wired
for a 230v power supply. For a 208v power supply, remove the orange lead from the transformer
and connect the red lead. Insulate the orange lead.
Dual Unit Phasing
For applications where one controller operates two units, e.g., the CommStat 3 or LL357D.
The LL357D4 and the LL357D3 do not require unit phasing. However, if other devices are connected
to the control system, phasing of the air conditioner is required. Earlier models; i.e., LL357, LL357A,
LL357D2 require the unit to be properly phased.
1. Wire each unit as described in steps 1 through 4 above.
2. Test for proper phasing as follows:
A. Power up the units.
B. Using an AC volt meter set to the 300 volt scale, measure voltage between terminal L1 on the
compressor contactor of unit #1 and terminal L1 on the compressor contactor of unit #2 If
voltage is present, units are wired out of phase and must be rewired.
C. If units are not in phase, turn off power and reverse the field power leads connected to the
internal circuit breaker on one of the units only.
D. Restore power and retest the phase (step B). When the voltage reads "0", the units are in
phase.
E. Turn off power and proceed.
Low Voltage Wiring
1. On single units, pull the low voltage wiring (e.g., 18 gauge 4-conductor Class 2 thermostat wire)
from the ComPac® A/C into the thermostat / subbase assembly. See Figure 8d for connections to
various thermostats.
2. Mount the thermostat on the wall of the shelter. The thermostat should be located so that the supply air from the unit does NOT blow directly on to the thermostat. Connect the thermostat to the
terminal block in the ComPac air conditioner as shown in Figures 8a and 8b.
3. On dual units, refer to the Marvair® LL357D4 Lead/Lag Controller Specification Sheet or CommStat 3™ Controller Specification sheet. Level and install the LL357D4 or CommStat 3 subbase.
Wire the two ComPac® units to the Lead/Lag Controller, according to the wiring diagram on the
specification sheet and as shown in Figure 8c or 8d (note: the diagram also appears on the back
cover of the controller).
Remote Signalling: Terminals 5 & 7(N.O.) and 6 & 7 (N.C.) on the ComPac® A/C terminal board are
dry contacts which can be used for remote signalling in the event of a/c cutoff on low or high pressure
limit.
Continuous fan operation: For continuous indoor fan operation on single units, install a jumper between
terminals 8 and 3. For continuous indoor fan operation on dual units using the LL357D4, install jumper
between 8 and 3 and remove jumper between 1 and 3.
CommStat 3™ Controller (See Figure 8c)
The CommStat 3™ Controller by Marvair® is a solid state control package designed to operate a
fully or partially redundant air conditioning system for a telecommunication cabinet or shelter. The
CommStat 3 Controller is factory programmed with standard industry set points to facilitate installation. If desired, each of the set points can be quickly and easily changed in the field by the installer.
25
ComPac 6/09-18
It can be used with Marvair’s ComPac® I or II unique vertical packaged wall mount air conditioners
or Marvair’s environmental control units. See CommStat 3 Product Data Sheet for installation and
programming instructions.
LL357D4 Lead/Lag Controller (See Figure 8b)
The Marvair® LL357D4 is a complete control package designed to operate a fully or partially redundant
air conditioning system. It consists of a two-stage heat and two-stage cool electronic thermostat and
a solid state timer. It can be used with either the Marvair ComPac® I vertical packaged wall mount air
conditioner or our unique ComPac® II air conditioner with built-in economizer. The LL357D4 provides
environmental control and the security demanded by the communication shelter industry for a backup
unit. The lead/lag controller insures equal wear on both air conditioners while allowing the lag unit
to assist upon demand. The LL357D4 is factory wired, tested, and mounted in an enclosure for quick
installation. Refer to the LL357D4 Product Data Sheet for complete installation instructions.
Operational Specifications
• Thermostat Range: 45ºF to 90ºF (7ºC to 32ºC)
• Accuracy: ±1ºF (± ½ºC)
• Changeover Temperature Differential (separation between the heat set point and the cool set point):
2ºF to 9ºF (1.0ºC to 4.5ºC)
• First Stage Temperature Differential (number of degrees between the set point temperature and the
“turn on” temperature): 1ºF to 3ºF (.5ºC to 1.5ºC)
• Second Stage Temperature Differential (number of degrees between when stage 1 turns on and
when stage 2 turns on): 1ºF to 6ºF (.5ºC to 3.0ºC).
• Minimum Cool Temperature Set Point: Adjustable from 45ºF to 75ºF (7ºC to 24.0ºC).
• Maximum Heat Temperature Set Point: Adjustable from 55ºF to 90ºF (13ºC to 32.0ºC)
• Staged OFF Outputs: Air conditioners will turn off independently.
Timing Device
• Solid state timer with both 3.5 and 7 day changeover capability.
NOTE: Cut timer circuit wire to provide 3.5 day changeover. Timing accuracy ±5%.
• Momentary push button for accelerated manual timer advance. (9 seconds = 7 days)
• Light emitting diode indicates power on and identifies the lead unit.
Unit Shutdown/Fire Alarm Systems
Immediate shutdown of the air conditioning system can be accomplished by wiring the normally closed
set of contacts in the fire extinguishing or alarm system across terminals 8 and 10 on the low voltage
terminal board inside the air conditioner. Note: The factory jumper between these terminals must be
removed.
This function cannot be accomplished at the wall thermostat because the fan purge on the electronic
control board inside the unit allows the indoor blower to operate from 10 to 90 seconds following each
cool "on" cycle.
NOTE: The fan purge on the electronic control board allows the indoor fan to run for approximately
10 to 90 seconds after the compressor is off. This operation provides a small improvement in system
efficiency.
26
ComPac 6/09-18
5 WIRE WALL THERMOSTAT
G
R
*
W
Y
C
Five (5) Conductor ColorCoded 18 Gauge Thermostat
Cable (Field Supplied)
NOTE:
Terminals 5 & 7 are normally open dry
contacts and close to indicate lockout.
Terminals 6 & 7 are normally closed dry
contacts and open to indicate lockout.
2
1
4
3
6
5
8
7
10
9
COMPAC® A/C TERMINAL BLOCK
*Terminals on thermostat may have RC & RH. If so, install jumper wire between RC & RH.
O
X
Y
A
G
H
W2
E
R
Thermostat
Field Supplied
Y
A
O
G
W2
C
*A/C’s do not have “O”.
R
HEAT PUMP*LOW VOLTAGE SECTION
Humidity Controller
Seven (7) Conductor, Color Coded
18 Gauge Thermostat Cable
Figure 8a. Thermostat Wiring Details
27
ComPac 6/09-18
MARVAIR®/SIMPLE COMFORT THERMOSTAT CONNECTION DIAGRAM
FOR MARVAIR MODPAC II™, XCELPAC™ & ALL COMPAC® AIR CONDITIONERS
THERMOSTAT
PART NUMBER
W
C
O
B
50124/
SC3001
Rc
RH
G
Y
W
C
O
B
50123/
SC5011-SL
Rc
RH
G
Y
W
C
O
B
R
G
Y1
W1
C
Y2
W2
R
G
Y
W
C
LOW VOLTAGE
TERMINAL BOARD
8
3
1
4
9
1ST STAGE HEAT
Y
COMPRESSOR
G
FAN
R
POWER
50121/
SC2010-SL
MODPAC II
ALL COMPAC 10
UNITS
O/B
2
5
7
6
LOW VOLTAGE
TERMINAL BOARD
COMMON
50107/
SC5811-SL
Figure 8b. Thermostat Connection Diagram
Figure 8c. LL357D4 Wiring Diagram & Thermostat Keys
28
ComPac 6/09-18
COMMSTAT 3™
E2
E3
E1
THERMOSTAT
SWITCH TERMINALS
E4
LOR G W C Y R
LOR G W C Y R
POWER
ALARM
NC
DRY
CONTACTS
C
NO
LOW BLDG TEMP
OUTPUT
NC
DRY
CONTACTS
C
THERMISTOR CONTACTS
#1
NO
HIGH BLDG TEMP
ALARM
#2
NC
DRY
CONTACTS
C
#3
NO
#4 (FACTORY
INSTALLED)
NC
HP/LP LOCKOUT
DRY
CONTACTS
C
NO
CONNECT TO
NORMALLY CLOSED
DRY CONTACTS FROM
SMOKE ALARM
SMOKE ALARM
SMOKE
NC
JUMPER
C
DRY
CONTACTS
NO
COMPAC®
CONNECTION
DESIGNATIONS
TERMINAL BOARD
TERMINAL BOARD
UNIT 1
UNIT 2
COMPAC®
CONNECTION
DESIGNATIONS
NOTE:
1. 24 VAC connections only.
2.
For immediate shutdown of air conditioner upon a signal from the smoke alarm, the jumper between terminals 8 and 10 in the ComPac® I
and ComPac® II units must be removed and a jumper placed from terminals 8 and 3.
3.
When connecting a smoke alarm to the smoke alarm input terminals (normally closed), remove the factory installed jumper wire and
install the smoke alarm leads.
IF LINE VOLTAGE IS BELOW 220 VAC, USE THE 208 TRANSFORMER TAP.
Figure 8d. CommStat 3™ Wiring Diagram
29
ComPac 6/09-18
Chapter 3 Start-Up
3.1 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.
ComPac® air conditioners with scroll compressors running on 3Ø power must be checked for
proper rotation during the initial start-up. Please refer to Section 2.8 for determining if the 3Ø
compressors are rotating correctly. Incorrect rotation can damage the compressor and is not
covered by the warranty
Procedure:
1. Set the cooling temperature on the wall thermostat to a point higher than the ambient temperature.
Set the heating temperature to a temperature that is lower than the ambient.
2. Set the thermostat system switch in the AUTO position. Nothing should operate at this time.
3. Set the time delay in the ComPac® I or ComPac® II A/C control box to three minutes. Check the
changeover setting of the H205A or dry bulb sensor and reset it if needed (ComPac II A/C only).
See Section 1.6.
4. Slowly lower the thermostat's cooling temperature until the switch closes. The indoor fan should
operate.
Once the indoor fan turns on, allow approximately three minutes for the compressor to start. Note that
the outdoor fan may not come on immediately, because it is cycled by refrigerant pressures.
NOTE: (ComPac® II A/C only) To check the system operation under different ambient conditions, the
air temperature and enthalpy sensors must be "tricked". When outdoor ambient conditions are higher
than the control setting, a component cooler aerosol may be sprayed directly into the enthalpy sensor
to simulate low enthalpy conditions, causing the economizer damper to open.
Alternately, when outdoor conditions are lower than the set point, a source of heat such as a hair dryer
can be directed on the air temperature sensor to simulate warmer conditions, which will bring on
mechanical cooling and start the compressor.
5. To stop cooling, slowly raise the thermostat cooling to a temperature higher than the ambient.
If the unit fails to operate, refer to the troubleshooting information in Chapter 4.
Follow the same procedure for additional units.
NOTE: The fan purge allows the indoor fan to run for approximately 90 seconds after the compressor
is off. This operation provides a small improvement in system S.E.E.R.
3.2 Check-Out of Heating Cycle
Procedure: (Applies only to units with resistance elements)
1. Raise the heating temperature to a setting which is higher than the ambient temperature. The fan
and electric heat should immediately cycle on.
2. Move the system switch to the "OFF" position. All functions should stop.
NOTE: (ComPac® II A/C only) The damper blade should remain closed during the heating cycle (unless the minimum position potentiometer has been set for constant ventilation A fully counterclockwise
position corresponds to full closure of the damper.
30
ComPac 6/09-18
3.3A/C Testing with LL357D4
Note: The LL357D4 does not require the units to be in phase.
Procedure: (A/C Testing with LL357D4 Lead/Lag Control for Two Units)
Prior to testing the air conditioners, the LL357D4 must be correctly configured. Please refer to the
LL357D4 Product Data Sheet for instructions on installing and configuring the unit.
1. Set the cooling temperature on the wall thermostat to a point higher than the ambient temperature.
Set the heating temperature to a temperature that is lower than the ambient temperature. Turn the
selector switch to the “off” position.
2. Set the time delay on unit No. 1 to “3” minutes, and No. 2 to “5” minutes.
3. Set the change over setting of the enthalpy control to the “d” setting (ComPac® II A/C only).
4. Provide power to A/C units and turn disconnects on.
5. Check incoming power to each unit. For units designed for operation on 208/230v, 60hz power
supply, the transformer is factory wired for a 230 power supply. For a 208 power supply remove
the orange lead from the transformer and connect the red lead. Insulate the orange lead.
6. Cooling. Turn the selector switch on the thermostat to the “auto” position. Slowly lower the cooling
temperature until the switch closes. The indoor fan should operate on the lead unit. Once the indoor
fan turns on, allow approximately 3 to 5 minutes for the compressor to start. Note that the outdoor
fan may not come on immediately because it is cycled by refrigerant pressures. Next, lower the
temperature until the switch closes. Follow the above procedures for the lag unit.
The green light on the lead lag control should be on. One amber light will be on to identify the lead
unit. The other light should be off. If the lag unit comes on with the lead unit the light for the lag
unit will not come on. You should never have all 3 lights on at one time.
Allow the units to run for 2 to 3 minutes then check the temperature differential between the return
air and the supply air with digital thermometer. The temperature differential should be between 12
and 20 degrees depending on ambient temperature.
Next, slowly raise the cooling temperature until the switch opens. The compressor and outdoor
fan should turn off. The indoor fan will continue to run for “90” seconds until the fan purge times
out. Raise the temperature until the switch opens. The lead unit will shut down accordingly to the
same procedures as outlines above.
Note: (ComPac® II A/C only) To check the system operation under different ambient conditions,
the air temperature and enthalpy sensors must be “tricked”. When outdoor ambient conditions are
higher than the control setting, a component cooler aerosol may be sprayed directly into the enthalpy
sensor to stimulate low enthalpy conditions, causing the economizer damper to open.
Alternately, when outdoor conditions are lower than the set point, a source of heat such as a hair
dryer can be directed on the enthalpy sensor to simulate warm conditions, which will bring on
mechanical cooling and start the compressor.
7. Heating. Slowly raise the heating temperature until the switch closes. The fan and electrical heat
should immediately cycle on. The unit should start blowing warm air in 2 to 3 minutes. Next, raise
the temperature until the switch closes. Follow the above procedures for lag unit.
Hold the manual advance button in for nine seconds the lead lag lights should switch. Next, slowly
lower the temperature until the switches open. The lag unit should shut down immediately. Next,
slowly lower the temperature until the switch opens, the lead unit should shut down immediately.
8. Replace thermostat cover and panels on the unit.
31
ComPac 6/09-18
4.1
Chapter 4 Troubleshooting
Overview
A comprehensive understanding of the operation of the ComPac® A/C is a prerequisite to troubleshooting. Please read the Chapter 1 for basic information about the unit.
Marvair's ComPac® air conditioners are thoroughly tested before they are shipped from the factory.
Of course, it is possible that a defect may escape undetected, or damage may have occurred during
transportation. However, the great majority of problems result from installation errors.
If you experience difficulties with the ComPac® A/C, please review the installation steps in Chapter
2.
Much time can be saved by taking a thoughtful and orderly approach to troubleshooting. Start with a
visual check - are there loose wires, crimped tubing, missing parts, etc? Begin deeper analysis only
after making this initial inspection.
The troubleshooting information in this manual is basic. The troubleshooting section contains problem/solution charts for general problems, followed by a compressor section.
Not every problem can be anticipated. If you discover a problem that is not covered in this manual, we
would be very grateful if you would bring it to the attention of our service department for incorporation
in future revisions.
As always, please exercise caution and good judgement when servicing the ComPac® A/C. Use only safe
and proven service techniques. Use refrigeration goggles when servicing the refrigeration circuit.
WARNING
The refrigerant circuit has hot surfaces, and the electrical voltages inside of
the unit may be hazardous or lethal. SERVICE MAY BE PERFORMED ONLY BY
QUALIFIED AND EXPERIENCED PERSONS.
4.2
Failure Symptoms Guide
PROBLEM/SYMPTOM
LIKELY CAUSE(S)
A. Unit does not run.
NOTE: An internal anti-short-cycle
timer will prevent the unit
from starting for .2 to 8
minutes following start-up.
1. Check power supply for adequate phase and voltage.
Check wiring to unit and external breakers or fuses.
2. Tripped internal disconnect.
2. Check internal circuit protection devices for continuity.
3. Shut off by external thermostat or
thermostat is defective.
4. Unit off on high or low pressure limit.
5. Internal component or connection
failure.
B. Unit runs for long periods or continuously; cooling is insufficient.
CORRECTION
1. Power supply problem.
3. Check operation of wall-mounted thermostat.
4. Reset pressure switch.
5. Check for loose wiring. Check components for failure.
1. Dirty filter or reduced airflow
1. Check air filter(s). Check blower operation. Remove
airflow restriction.
2. Low refrigerant.
2. Check for proper charge and possible refrigerant leak.
3. Component failure.
3. Check internal components, especially compressor for
proper operation.
4. Unit undersized for job.
4. Add additional units for greater capacity.
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ComPac 6/09-18
PROBLEM/SYMPTOM
C. Unit cycles on high/low pressure
limit.
D. Unit blows fuses or trips circuit
breaker.
LIKELY CAUSE(S)
CORRECTION
1. Loss or restriction of airflow.
1. Check blower assembly for proper operation. Look
for airflow restrictions, e.g.. the air filter. Check blower
motor and condenser fan.
2. Restriction in refrigerant circuit.
2. Check for blockage or restriction, especially filter drier
and capillary tube assembly.
3. Refrigerant overcharge (following
field service)
3. Evacuate and recharge to factory specifications.
4. Defective pressure control.
4. Check limit cutout pressures. Control is set to actuate at
approximately 35 PSIG (low pressure) and 400 PSIG (high
pressure).
1. Inadequate circuit ampacity.
1. Note electrical requirements in Chapter 2 and correct
as necessary.
2. Short, loose, or improper connection 2. Check field wiring for errors.
in field wiring.
E. Water on floor near unit.
F. No space heating or reduced heating
(units equipped with resistance elements)
4.3
3. Internal short circuit. Loose or
improper connection(s) in unit.
3. Check wiring in unit. See wiring and schematic diagrams. Test components (especially the compressor)
for shorts.
4. Excessively high or low supply voltage or phase loss (3ø only).
4. Note voltage range limitations specific to the compressor troubleshooting section.
1. Obstruction in condensate line.
1. Check for clog or restriction.
2. Obstruction or leak in condensate
pan.
2. Check pan for leak or blockage.
3. Unit is not level.
3. Level unit.
1. Defective heating element(s).
1. Check resistance element(s) for continuity.
2. Thermal limit open.
2. Check continuity across thermal limit switch.
3. Defective heater relay.
3. Check relay for proper operation. Replace if defective.
4. Open thermal cut-out (TCO).
4. Check across TCO (adjacent to element(s)) for continuity. It is normally closed.
Compressor Troubleshooting
NOTE: It is important to rule out other component failures before condemning the compressor.
The following electrical tests will aid diagnosis:
1. Start-Up Voltage: Measure the voltage at the compressor terminals during start-up. The voltage
must exceed the minimum shown in Table 5, section 2.2, or compressor failure is likely. A low
voltage condition must be corrected.
2. Running Amperage: Connect a clip-on type ammeter to the (common) lead to the compressor.
Turn on the supply voltage and energize the unit. The compressor will initially draw high amperage;
it should soon drop to the RLA value or less. If the amperage stays high, check the motor winding
resistances.
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ComPac 6/09-18
NOTE: Feel the top of the compressor to see if it has overheated. If it is hot, the internal overload
may be open. You may have to wait several hours for it to reset.
3. Motor Winding Resistances: Using a digital volt-ohm meter (VOM), measure the resistance
across the compressor windings as shown below.
SINGLE
PHASE
C
R2
S
R1
R3
R
R3 > R2 > R1
R3 = R2 + R1
THREE
PHASE
T1
R2
T2
R1
R3
R3 = R2 = R1
T3
Resistance can be measured as shown above. Any deviation from above values could indicate a
defective compressor.
4. High Voltage/Insulation Test: Test internal leakage with a megoh­meter. Attach one lead to the
compressor case on a bare metal tube and to each compressor terminal to test the motor windings.
A short circuit at high voltages indicates a motor defect. Do not do this test under vacuum.
5. On single phase models, check the capacitor by substitution.
4.4 Control Board Diagnosis
The control board (see section 1.6a for a complete description of the control board) has a red diagnostic
LED which indicates the lockout fault. The control board will enter into and indicate lockout if either
of the fault conditions (LPS or HPS) occur twice.
The contactor must be closed before the first fault condition can be recognized by the control board.
The contactor will be closed 3 minutes after the unit is energized and only if cooling is required. The
first fault condition will open the contactor and shutdown the unit. The contactor on the unit that has
the fault condition must be closed before the second fault condition can be recognized by the control
board. The contactor on the unit with the fault condition will close after 3 minutes if the unit is still
calling for cooling and if the fault condition no longer exists. If you get a second fault condition, the
contactor will open and shutdown the unit. The “red” led will have one blink if the high pressure switch
has opened twice and will have two blinks if the low pressure switch has opened twice. The unit must
be in the cooling mode (compressor contactor Closed) before a fault condition can occur.
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ComPac 6/09-18
Chapter 5 Maintenance
5.1Scheduled Maintenance
Marvair® 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. Also at this
time, the air conditioner should be operated in the cooling and heating cycles as described in Chapter 3,
Start-Up. In addition to this seasonal check-out, the ComPac® A/C should be maintained as follows:
Air Filter
Replace the air filter whenever it is visibly dirty.
Evaporator
If the evaporator becomes clogged or dirty, it may be cleaned by careful vacuuming or with a commercial evaporator cleaning spray. DO NOT use a solvent containing bleach, acetone, or flammable
substances. Turn off power before cleaning.. Be careful not to wet any of the electrical components.
Be sure the unit has dried before restarting.
Condenser
Periodically inspect the outdoor condenser coil and the cabinet air reliefs for dirt or obstructions.
Remove foreign objects such as leaves, paper, etc.
If the condenser coil is dirty, it may be washed off with a commercial solvent intended for this purpose.
TURN OFF POWER BEFORE CLEANING! Be sure that all electrical components are thoroughly
dry before restoring power.
Cabinet
The cabinet may be cleaned with a sponge and warm, soapy water or a mild detergent. Do not use
bleach, abrasive chemicals or harmful solvents.
Drains
Regularly check the primary and secondary condensate drains. The secondary drain has a stand pipe
(on AVP24-72). An obstruction will force water to dump into the middle of the unit and drain out
the sides of the ComPac, causing discoloration of the side panels. If discoloration is noted, service
the drains.
If a commercial drain solvent is used, flush out the drain pan and system with plenty of fresh water to
prevent corrosion.
Lubrication
Oiling of the condenser fan motor or the evaporator blower motor is not recommended.
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ComPac 6/09-18
Chapter 6 Warranty
6.1Limited Product Warranty
If any part of your Marvair® Air Conditioner, Heat Pump or Unit Ventilator fails because of a manufacturing defect within fifteen months from the date of original shipment from Marvair or within twelve
months from the date of original start-up, whichever is the earlier date, Marvair will furnish without
charge, EXW Cordele, Georgia, the required replacement part. Any transportation, related service
labor, diagnosis calls, filter, driers, and refrigerant are not included. The owner must provide proof
of the date of the original start-up. The owner’s registration card filed with Marvair, the contractor’s
invoice, the certificate of occupancy or similar document are examples of proof of the date of the
original start-up.
In addition, if the hermetic compressor fails because of a manufacturing defect within sixty months
from the date of original shipment from Marvair®, Marvair will furnish without charge, EXW Cordele,
Georgia, the required replacement part. Any related service labor, diagnosis calls, filter, driers and
refrigerant are not included. Marvair will pay for non-priority shipping costs of the compressor during
the first twelve months of the warranty period. After the first twelve months of the warranty period, all
costs of shipment and risk of loss during the shipment of the compressor shall be the responsibility of
the owner.
The owner of the product may ship the allegedly defective or malfunctioning product or part to
Marvair®, at such owner’s expense, and Marvair will diagnose the defect and, if the defect is covered
under this warranty, Marvair will honor its warranty and furnish the required replacement part. All
costs for shipment and risk of loss during shipment of the product to Marvair and back to the owner
shall be the responsibility and liability of the owner. Upon written request by an owner, Marvair may
arrange for remote diagnosis of the allegedly defective or malfunctioning product or part but all costs
for transportation, lodging and related expenses with regard to such diagnostic services shall be the
responsibility and liability of the owner.
An owner requesting performance under this Warranty shall provide reasonable access to the allegedly
defective or malfunctioning product or part to Marvair® and its authorized agents and employees.
This warranty applies only to products purchased and retained for use within the U.S.A., Canada, and
Mexico. This warranty does not cover damage caused by improper installation, misuse of equipment
or negligent servicing.
THIS WARRANTY CONSTITUTES THE EXCLUSIVE REMEDY OF ANY PURCHASER OF
A MARVAIR® HEAT PUMP OR AIR CONDITIONER AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED
WARRANTY OF MERCHANTABILITY OR FITNESS FOR USE, TO THE FULLEST EXTENT
PERMITTED BY LAW. IN NO EVENT SHALL ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR USE EXCEED THE TERMS OF THE APPLICABLE WARRANTY
STATED ABOVE AND MARVAIR SHALL HAVE NO OTHER OBLIGATION OR LIABILITY. IN
NO EVENT SHALL MARVAIR BE LIABLE FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES OR MONETARY DAMAGES.
THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, AND YOU MAY ALSO HAVE
OTHER RIGHTS WHICH VARY FROM STATE-TO-STATE. Some states do not allow limitations
or exclusions, so the above limitations and exclusions may not apply to you.
36
Rev. 6/04
Supersedes 9/02
ComPac 6/09-18
6.2 Optional Silver Service
If any part of your Marvair® Heat Pump or Air Conditioner fails because of a manufacturing defect within
fifteen months from the date of original shipment by Marvair or within twelve months from the date of
original start-up, whichever is the earlier date, Marvair will furnish without charge, EXW Cordele, Georgia,
the required replacement part and pay for the related service labor to replace the failed part. The owner
must provide proof of the date of the original start-up. The owner’s registration card filed with Marvair,
the contractor’s invoice, the certificate of occupancy or similar document are examples of proof of the date
of the original start-up.
When service is required, it must be performed during normal working hours (8:00 a.m. to 5:00 p.m.) Monday
through Friday and must be performed by Marvair® personnel or their designated Service Representative.
The responsibility of the Owner of the Equipment includes the following:
1. To operate the equipment according to the manufacturer’s instructions.
2. To provide easy accessibility for service.
3. To check and reset circuit breaker(s) and disconnect before calling for service. (Circuit breaker(s) may
be in the main service panel. The disconnect is in the Marvair® unit.)
4. To keep the unit clean and free of dirt.
5. To replace filters as required. (Filters are located in the lower front panel of the Marvair® unit below the
indoor blower section.)
6. To keep the outdoor coil section clean and free of leaves, paper, etc.
7. To pay the charges incurred when any of the above have not been done.
8. To pay for repair or replacement of any material or part other than those within the Marvair® unit or
thermostat itself.
In addition, if the hermetic compressor fails because of a manufacturing defect within the second through
fifth year from the date of original shipment by Marvair®, Marvair will furnish without charge, EXW Cordele,
Georgia, the required replacement. Any transportation, related service labor, diagnosis calls, filter, driers
and refrigerant are not included.
The owner of the product may ship the allegedly defective or malfunctioning product or part to Marvair®, at
such owner’s expense, and Marvair will diagnose the defect and, if the defect is covered under this warranty,
Marvair will honor its warranty and furnish the required replacement part. All costs for shipment and risk
of loss during shipment of the product or part to Marvair and back to the owner shall be the responsibility
and liability of the owner. Upon written request by an owner, Marvair may arrange for remote diagnosis of
the allegedly defective or malfunctioning product or part but all costs for transportation, lodging and related
expenses with regard to such diagnostic services shall be the responsibility and liability of the owner.
An owner requesting performance under this Warranty shall provide reasonable access to the allegedly
defective or malfunctioning product to Marvair® and its authorized agents and employees.
This warranty only applies to products purchased and retained for use within the U.S.A. This warranty does
not cover damage caused by improper installation, misuse of equipment or negligent servicing.
THIS WARRANTY AND SERVICE POLICY CONSTITUTE THE EXCLUSIVE REMEDY OF ANY
PURCHASER OF A MARVAIR® HEAT PUMP OR AIR CONDITIONER AND IS IN LIEU OF ALL
OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION,
ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR USE, TO THE FULLEST EXTENT PERMITTED BY LAW. IN NO EVENT SHALL ANY IMPLIED WARRANTY OF
MERCHANTABILITY OR FITNESS FOR USE EXCEED THE TERMS OF THE APPLICABLE
WARRANTY STATED ABOVE AND MARVAIR SHALL HAVE NO OTHER OBLIGATION OR
LIABILITY. IN NO EVENT SHALL MARVAIR BE LIABLE FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES OR MONETARY DAMAGES.
THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, AND YOU MAY ALSO HAVE OTHER
RIGHTS WHICH VARY FROM STATE-TO-STATE. Some states do not allow limitations or exclusions,
so the above limitations and exclusions may not apply to you.
Rev. 6/04
Supersedes 9/02
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ComPac 6/09-18
EXPLODED VIEWS AND PARTS LISTS
Current parts lists and exploded views of the unit can be found on our web
site at www.marvair.com. Click on the Service and Parts in the menu on the
left hand side of the Home page. From the drop down menu, select Exploded
Views. Once here, you can select your air conditioner or heat pump. The units
are grouped by model and by the refrigerant – R-22 or R-410A.
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ComPac 6/09-18