Please read and save these instructions for future reference. Read carefully before attempting to assemble, install,
operate or maintain the product described. Protect yourself and others by observing all safety information. Failure
to comply with these instructions will result in voiding of the product warranty and may result in personal injury
and/or property damage.
Technical Support
Call: 1-866-478-2574
Email: DOAS@greenheck.com
General Safety Information
Only qualified personnel should install and maintain this
system. Personnel should have a clear understanding of
these instructions and should be aware of general safety
precautions. Improper installation can result in electric
shock, possible injury due to coming in contact with
moving parts, as well as other potential hazards. Other
considerations may be required if high winds or seismic
activity are present. If more information is needed,
contact a licensed professional engineer before moving
forward.
1. Follow all local electrical and safety codes, as well
as the National Electrical Code (NEC), the National
Fire Protection Agency (NFPA), where applicable.
Follow the Canadian Electrical Code (CEC) in
Canada.
2. All moving parts must be free to rotate without
striking or rubbing any stationary objects.
3. Unit must be securely and adequately grounded.
4. Do not spin wheel faster than maximum cataloged
fan RPM. Adjustments to fan speed significantly
affect motor load. If the fan RPM is changed, the
motor current should be checked to make sure it is
not exceeding the motor nameplate amps.
5. Verify that the power source is compatible with the
equipment.
6. Never open access doors to the unit while it is
running.
WARNING
The roof lining contains high voltage wiring. To
prevent electrocution, do not puncture the interior or
exterior panels of the roof.
DANGER
• Always disconnect power before working on or near
this equipment. Lock and tag the disconnect switch
or breaker to prevent accidental power up.
• If this unit is equipped with optional gas accessories,
turn off gas supply whenever power is disconnected.
CAUTION
This unit is equipped with a compressed refrigerant
system. If a leak in the system should occur,
immediately evacuate the area. An EPA Certified
Technician must be engaged to make repairs or
corrections. Refrigerant leaks may also cause bodily
harm.
CAUTION
When servicing the unit, the internal components may
be hot enough to cause pain or injury. Allow time for
cooling before servicing.
®
Dedicated Outdoor Air Unit1
Page 2
®
Table of Contents
General Safety Information ......................1
Factory-Installed Refrigeration System ............20
Start-Up – Unit ..............................24
Start-Up Components .........................29
Optional Polymer Energy Wheel .................32
Optional Aluminum Energy Wheel ...............34
Troubleshooting ..............................35
Routine Maintenance .........................41
Reference
Venting Connection Locations ................44
Rated Airflow ..............................46
Our Commitment ...................... Backcover
Dedicated Outdoor Air Unit2
Page 3
Receiving
This product may have been subject to road salt during
transit. If so, immediately wash off all visible white
reside from all exterior surfaces. Upon receiving the
product, check to ensure all line items are accounted
for by referencing the delivery receipt or packing list.
Inspect each crate or carton for shipping damage before
accepting delivery. Alert the carrier if any damage is
detected, do not refuse shipment. The customer shall
make notation of damage (or shortage of items) on the
delivery receipt and all copies of the bill of lading which
should be countersigned by the delivering carrier. If
damaged, immediately contact your manufacturer’s
representative. Any physical damage to the unit after
acceptance is not the responsibility of the manufacturer.
Handling
Units are to be rigged and moved by the lifting brackets
provided. Location of brackets varies by model and size.
Handle in such a manner as to keep from scratching or
chipping the coating. Damaged finish may reduce ability
of unit to resist corrosion.
Unpacking
Verify that all required parts and the correct quantity
of each item have been received. If any items are
missing, report shortages to your local representative to
arrange for obtaining missing parts. Sometimes it is not
possible that all items for the unit be shipped together
due to availability of transportation and truck space.
Confirmation of shipment(s) must be limited to only
items on the bill of lading.
Storage
Units are protected against damage during shipment. If
the unit cannot be installed and operated immediately,
precautions need to be taken to prevent deterioration of
the unit during storage. The user assumes responsibility
of the unit and accessories while in storage. The
manufacturer will not be responsible for damage during
storage. These suggestions are provided solely as a
convenience to the user.
The ideal environment for the storage of units and
accessories is indoors, above grade, in a low humidity
atmosphere which is sealed to prevent the entry of
blowing dust, rain, or snow. Units designed for outdoor
applications may be stored outdoors. All accessories
must be stored indoors in a clean, dry atmosphere.
Indoor
Maintain temperatures evenly to prevent condensation.
Remove any accumulations of dirt, water, ice, or snow
and wipe dry before moving to indoor storage. To
avoid condensation, allow cold parts to reach room
temperature. Leave coverings loose to permit air
circulation and to allow for periodic inspection.
The unit should be stored at least 3½ in. (89 mm) off
the floor. Clearance should be provided to permit air
circulation and space for inspection.
Outdoor
The unit should be placed on a level surface to prevent
water from leaking into the unit. The unit should be
elevated so that it is above water and snow levels.
Ensure sufficient support to prevent unit from settling
into soft ground. Locate parts far enough apart to
permit air circulation, sunlight, and space for periodic
inspection. To minimize water accumulation, place all
unit parts on blocking supports so that rain water will
run off.
Do not cover parts with plastic film or tarps as these
cause condensation of moisture from the air passing
through heating and cooling cycles.
Inspection and Maintenance
While in storage, inspect units once per month. Keep a
record of inspection and maintenance performed.
If moisture or dirt accumulations are found on parts,
the source should be located and eliminated. At each
inspection, rotate the fan wheel by hand ten to fifteen
revolutions to distribute lubricant on motor. If paint
deterioration begins, consideration should be given to
touch-up or repainting. Units with special coatings may
require special techniques for touch-up or repair.
Machined parts coated with rust preventive should be
restored to good condition promptly if signs of rust
occur. Immediately remove the original rust preventive
coating with petroleum solvent and clean with lint-free
cloths. Polish any remaining rust from surface with
crocus cloth or fine emery paper and oil. Do not destroy
the continuity of the surfaces. Wipe thoroughly clean
with Tectyl® 506 (Ashland Inc.) or the equivalent. For
hard to reach internal surfaces or for occasional use,
consider using Tectyl® 511M Rust Preventive, WD-40®
or the equivalent.
Removing from Storage
As units are removed from storage to be installed
in their final location, they should be protected and
maintained in a similar fashion until the equipment goes
into operation.
Prior to installing the unit and system components,
inspect the unit assembly to make sure it is in working
order.
1. Check all fasteners, set screws on the fan, wheel,
bearings, drive, motor base, and accessories for
tightness.
2. Rotate the fan wheel(s) by hand and assure no parts
are rubbing.
®
Dedicated Outdoor Air Unit3
Page 4
®
Product Overview
A horizontally configured High Percentage Outdoor
Air unit designed for installation either indoors or
outdoors. Each unit has multiple options for cooling
and/or heating. The unit is designed to replace air that
is exhausted from the building and also heat and cool,
as needed. The air volume produced by the unit is
constant, but can be optionally modulated to provide a
variable air volume (VAV) and recirculation is also offered
as an option.
Cooling
Units have the following cooling options available:
• Packaged DX
• Split DX (thermal expansion valve is field-provided)
Not available on housing sizes 10, 75/150, 110/118.
• Chilled water coil
• Air-source heat pump (ASHP)
Not available on housing sizes 10, 75/150, 110/118.
Packaged DX and air-source heat pumps are shipped
fully charged with refrigerant and are ready for operation
upon arrival.
Heating
There are four different optional heat sources that can
be ordered for this unit:
• Indirect gas-fired furnace with one or two sets of
heat exchangers
• Electric heat with infinitely variable SCR control
• Hot water coil
• Air-source heat pump (ASHP)
Not available on housing sizes 10, 75/150, 110/118.
Models and Capacities
ModelCooling Capacity
RV-10
RV-25
RV-45
RV-75
RV-110
RVE-40
RVE-85
RVE-150
RVE-180
3 to 7 tons
5 to 15 tons
15 to 30 tons
25 to 50 tons
30 to 70 tons
5 to 15 tons
15 to 30 tons
25 to 50 tons
30 to 70 tons
Airflow Arrangement
The unit is capable of Constant Air Volume (CAV),
Variable Air Volume (VAV), 100% Outdoor Air and have
recirculating air options.
Safety Listing
Models are listed per ANSI/UL 1995, Heating and
Cooling Equipment and are ETL Certified.
Dedicated Outdoor Air Unit4
Page 5
Subassemblies
Blower - Either one, two, or three plenum-type fans. All
units are equipped with a plenum fan for Supply Air and
a second may be selected for Exhaust (Relief) Air.
have either one, two or four refrigerant compressors.
Optionally, one of the compressors may be a digital or
inverter scroll type compressor. Air-source heat pump
units will have one inverter scroll compressor and may
contain a second staged compressor.
and 45/85, use furnace model PVG. Housing sizes
75/150 use furnace models PVG 600-800 or HMA 1000-
1200. Housing sizes 110/180 use furnace model HMA
600-1200.
Packaged DX System - Any unit may be ordered with
a packaged DX system. Housing size 10 will use one
compressor; housing size 25/40 will include either one
or two compressors; housing size 45/85 will include
two compressors; housing size 75/150 will include three
compressors; housing size 110/180 will include four
compressors; a condenser coil(s) and evaporator coil(s)
and all required components. Units that have packaged
DX are charged with R410A refrigerant. Do not use tools
or parts designed for other refrigerants on these units.
Air-Source Heat Pump - Units having an air-source heat
pump will include either one or two compressors, an
indoor and outdoor coil, and all required components.
Air-source heat pump units are charged with R410A
refrigerant. Do not use tools or parts designed for other
refrigerants on these units. Not available on housing
sizes 10, 75/150, 110/118.
Split DX - The unit may be ordered with a split DX
system for connection to a building cooling system.
Thermal expansion valve (TXV) is field-provided. Not
available on housing sizes 10, 75/150, 110/118.
Vestibule - Some units may be ordered with a factory-
assembled vestibule that is to be field-attached to the
side of the unit. See lifting instructions.
Energy Wheel (RVE)
(optional)
Outdoor Air Filters
(pre-wheel)
Condenser Coils
(optional)
Packaged DX
Compressors
(optional)
Furnace Vest Plate
and
Furnace Control Center
(optional)
®
Main Control
Center
Plenum-Type
Supply Air Blower
Indirect Gas-Fired Furnace
(optional)
Weatherhood Filters
(metal mesh)
Outdoor Air
Damper
Plenum-Type
Exhaust Air Blower
Recirculating
Damper
Coils
(optional)
Dedicated Outdoor Air Unit5
Page 6
®
Installation
Typical Unit Weights and Dimensions
A
A
1
3
W
5
6
H
3
W
2
1
4
L
7
B
1
2
3
5
4
7
6
H
L
W
Housing size 10
Housing size
25/40 and 45/85
A
A
H
9
8
7
6
2
3
5
4
L
H
1
5
2
3
L
W
4
7
6
Housing size 75/150
Component Access
1Optional Inverter Compressor
2Optional Compressor/Electrical
3Optional Gas Furnace/Optional Electric Heater
4Electrical
5Supply Blower
6Coil
7Filters
8*Exhaust Blower/Optional Electric Preheat
9Powered Exhaust Blower Section
* When a powered exhaust fan (or RVE) is selected, door 8 will
be to the immediate right of door 7.
Dedicated Outdoor Air Unit6
Housing size 110/180
Page 7
Installation
Typical Unit Weights and Dimensions
Nominal
Model
tonnage
(tons)
RV-103-758.144.082.2
RV-255-1559.352.598.6
Height
(H)
Width
(W)
Length
Intake
(L)
10
7
/149.5822.130.12,700
22.3NA1,180
RV-4515-3072.568.21097/163.2827.730.14,500
RV-7525-50101.398155.239/47.5
RV-11030-7099.59618545.3NA7,950
RVE-405-1559.352.5149.5/180.5
5
22.130.13,400
RVE-8515-3072.568.2163.2/197.2527.130.15,100
RVE-15025-50101.398200.447.5NA8,000Bottom End
6
RVE-18030-7099.596263
/307
5
45.3NA10,450
(A)
Condensing
Section
(B)
9
NA6,500
Nominal
weight (lbs)
Outdoor
Intake
End
End
Supply
Discharge
Bottom
or
Side
Bottom
or
Side
Return
Intake
Bottom or
2
End
Bottom,
2
End
or
1
Side
Bottom or
End
Bottom or
Side
Bottom,
2
End
or
1
Side
Bottom or
Side
Exhaust
Discharge
NA
3
End
or
1
Side
End
Side
3
End
or
1
Side
Side
All dimensions are shown in inches. Weight is shown in pounds and includes largest supply and exhaust fans, PDX with reheat, largest indirect-gas
fired furnace, and all dampers. Actual weights will vary based on the unit configuration.
1
Only available with powered exhaust
2
Only available without barometric relief
3
Only available with barometric relief
4
Above 12,000 cfm
5
Length with side return
6
Length with bottom return
7
Length with bottom or end return
8
Length with powered exhaust
9
Length with powered exhaust bumpout
10
Optional indirect gas-fired furnace bumpout
length is additional 13.3 inches
®
Dedicated Outdoor Air Unit7
Page 8
®
Installation
Service Clearances
CC
ACCESS DOOR
ACS SIDE
CONTROL
CENTER
CONDENSING SECTION
COMPRESSORS
SUPPLY FAN
HGRH COIL
NA from CS
COOLING COIL
SUPPLY FILTERS
EXHAUST AIR FILTERS
EXHAUST AIR
WEATHERHOOD
WHEEL CASSETTE
EXHAUST FAN
OUTDOOR AIR FILTERS
NA from Unit
OUTDOOR AIR
WEATHERHOOD
OAI
Model
ACS
Access
Side
ACCESS DOOR
CC
Control Cabinet End
Indoor
Other
Mounted
with IG
ACCESS DOOR
OAI
Outdoor Air Intake
Outdoor
Mounted
Indoor
Mounted
CASSETTE REMOVAL
*NA
from Unit
ACCESS DOOR
Condensing
ACCESS DOOR
NA
from
Section
from Piping
Vestibule
(not shown)
Furnace
RV-105042NA36NA24NANA
RV-254042724218241830
RV-453658724218241830
RV-754848NA87NA48NANA
RV-1104848NA60NA48NANA
RVE-404042724218241830
RVE-853658724218241830
RVE-1504848NA87NA48NANA
RVE-1804848NA60NA48NANA
All dimensions are shown in inches.
*No condensing section or piping vestibule, or unit has top condensing section.
NA
Dedicated Outdoor Air Unit8
Page 9
Installation
Additional Clearances for
Packaged DX Units
Packaged DX units require additional clearance
because they must have unrestricted air movement
around the condenser coil and condenser fans. Hot air
is being discharged from the condenser fans during
operation. Enough clearance must be provided to
avoid recirculation or coil starvation. When equipped
with condenser coils, the unit should never be placed
under an overhang or inside a building. A minimum of
48inches above the condenser fans is acceptable, but
unobstructed is strongly recommended.
Minimum 48 inches clearance
Condenser Fans
Minimum 18 inches
clearance
Condenser Coil
End view of rooftop unit with Packaged DX
Handling Concerns for
Packaged DX or Air-Source Heat Pump
Units with PDX or ASHP have a system that is
pressurized with refrigerant. If damage occurs, the
refrigerant could leak into the atmosphere or cause
bodily harm due to the extreme cold nature of
expanding refrigerant. Use protective equipment such
as gloves and safety glasses to minimize or prevent
injury in case of a system leak during installation.
Before Lifting
Before lifting, be sure that all shipping materials have
been removed from the unit.
Vestibule
Determine whether or not the unit has a vestibule that
must be field-attached to the side of the unit. Vestibules
are shipped assembled but detached from the unit.
They have lifting lugs on them so they can also be lifted
by crane, but the installed location of the unit may make
it preferable to install the vestibule on the unit prior to
lifting.
Field Power Access
Determine where high voltage and low voltage wiring is
to be brought into the cabinet. If wiring is to be brought
into the cabinet through the floor, see Alternate Supply
Entry Locations in this manual. If unit is to be installed
on a roof, cut access openings in the roof deck as
needed.
Additional Clearances for
Air Source Heat Pump
IMPORTANT
Air-source heat pumps are equipped with a defrost
cycle to remove ice from the outdoor coil. During
defrost cycles, melted water may drip from the bottom
of the refrigeration section under the outdoor coil.
In cold climates, proper drainage/heat tape must be
installed under the outdoor coil to prevent the buildup
of ice on the roof.
Air-source heat pump units require additional clearance
because they must have unrestricted air movement
around the outdoor coil and outdoor fans. Enough
clearance must be provided to avoid recirculation or
coil starvation. Air-source heat pump units should
never be placed under an overhang or inside a building.
A minimum of 48-inches above the outdoor fans is
acceptable, but unobstructed is strongly recommended.
®
Dedicated Outdoor Air Unit9
Page 10
®
Installation
W
L
L
W
Lifting
1. Ensure that all shipping materials have been
removed from unit.
2. To assist in determining rigging requirements,
weights are provided in the Unit Weights &
Dimensions section of this manual.
3. Unit must be lifted by all lifting lugs provided at top
of unit.
4. Spreader bars must span the unit to prevent
damage to the cabinet by the lift cables.
5. Never rest the spreader bar on the unit.
WARNING
Spreader bars are required to prevent damage to the
cabinet, failure to do so can result in damage that is
the installer’s responsibility.
6. Always test-lift the unit to check for proper balance
and rigging before hoisting to desired location.
7. Never lift unit by weatherhood.
8. Never lift units in windy conditions.
9. Preparation of curb and roof openings should be
completed prior to lifting unit to the roof.
10. Check to be sure that gasketing (supplied by
others) has been applied to the top of the curb
prior to lifting the unit and setting on the curb.
11. Do not use forklifts for handling unit on housing
sizes 25/40, 45/85, 75/150, or 110/180.
12. If using forklift on housing 10, use forks with 48-
inch length and ensure forks extend to opposite
side of unit using factory-installed forklift pockets
at unit base.
Roof Curb Mounting
Roof curb details, including duct locations and
dimensions, are to be found in the roof curb assembly
instructions.
Rooftop units require curbs to be mounted first. The
duct connections must be located so they will be clear
of structural members of the building.
1. Factory-supplied roof curbs. Roof curbs are model
GKD which are shipped in a knockdown kit (includes
duct adapters) and require field assembly (by others) on
all units except RV-110 and RVE-180, which are shipped
assembled. Assembly instructions are included with the
curb kit.
2. Install curb. Locate curb over roof opening and
fasten in place. Check that the diagonal dimensions are
within ± 1/8inch of each other and adjust as necessary.
For proper coil drainage and unit operation, it is
important that the installation be level. Shim the curb as
required to level. Install gasketing on top surface of curb
(provided by others).
3. Install ductwork. Installation of all ducts should
be done in accordance with SMACNA and AMCA
guidelines. Duct adapters are provided to support ducts
prior to setting the unit.
4. Set the unit. Lift unit to a point directly above the
curb and duct openings. Guide unit while lowering to
align with duct openings. Roof curbs fit inside the unit
base. Make sure the unit is properly seated on the curb
and level.
5. Fasten the unit, Fasten the unit to the curb/
equipment support(s) using appropriate methods. The
installer is responsible for determining appropriate
support and fastening methods to ensure compliance
with all applicable codes.
6. Install vestibule. If unit was ordered with a vestibule
and it has not yet been attached to the unit, caulk and
attach the vestibule at this time.
W
Dedicated Outdoor Air Unit10
Typical Unit with Condensing Section and
Factory-Supplied Curb Kit
L
Page 11
Installation
L
W
Optional Piping Vestibule
If the unit was ordered with the vestibule, the NA (NonAccess side) clearance dimension must be measured
from the vestibule.
L
W
Typical Unit with Piping Vestibule and
Factory-Supplied Curb Kit
Rail Mounting and Layout
• The units may be installed on rails provided and
installed by others. Ensure that rails are designed to
handle the weight of the unit and provide proper load
distribution on building supports.
• Make sure that rail positioning does not interfere with
the openings on the unit.
• Rails should run the width of the unit and extend
beyond the unit a minimum of 12 inches on each side.
• Set unit on rails.
Ductwork Configurations
NOTE
Downblast Discharge Ductwork - whenever
downblast discharge is used, the ductwork directly
beneath the unit must be connected with either a “T”
or an “L” configuration and the area directly beneath
the heat source must not have any openings such
as louvers or grates.
Typical Unit Installed on Rails Supplied by Others
No louvers or grates
®
Dedicated Outdoor Air Unit11
Page 12
®
Recommended Electrical and Gas Supply Entry Locations
Manufacturer recommends that electrical service and
gas supply be brought into the cabinet through the
end wall, as shown below. There are three penetrations
into the cabinet that are required; one for high voltage
supply wiring, one for low voltage control wiring and one
for either gas supply or high voltage supply wiring for an
electric heater.
Optional Unit
Disconnect
Indirect
Gas
Supply
Location
Field Wiring
Recommended Gas and Electric Supply Entry Locations
Alternate Supply Entry Locations
Each installation is unique and as a result, alternate
entry locations may be field-located. Before using any
alternate entry location, verify the suitability of the
location and ensure the use of an alternate location
does not interfere with unit wiring, components or
functionality.
Optional Gas Piping
Units with indirect gas-fired furnaces require fieldsupplied and installed gas supply piping.
Housing
Size
10
25/40
45/85
75/150
110/180
Total Heating
Capacity
(Input in MBH)
75
100
150
200
100
150
200
250
300
300
500
600
800
100
1200
6001” NPT
800
1200
Gas
Connection
Size
Max Gas
Pressure
¾” NPT14 in. wg.
¾” NPT14 in. wg.
¾” NPT14 in. wg.400
¾” NPT
14 in. wg.
1” NPT
2” NPT1000
13.5 in. wg.
Gas Connections
If this unit is equipped with an indirect gas-fired furnace,
connection to an appropriate gas supply line will be
required. For complete information on installation
procedures for the optional gas furnace, refer the
PVF/PVG Indirect Gas-Fired Heat Module Installation,
Operation, and Maintenance Manual.
Ground
Gas Cock
From Gas Supply
Bleeder Valve or
1/8 in Plugged Tap
Typical Gas Supply Piping Connection
Joint
Union
8 in. Trap
Gas to
Controls
WARNING
Never drill holes in the roof of the unit! There is high
voltage wiring located between the inner and outer
roof panels. Damage to the wiring could cause severe
bodily harm or death.
NOTE
110/180 gas furnaces are designed for gas pressure
of 5-13.5 in. wg for natural gas (6-inch minimum on
single 500 and 600 MBH furnaces) and 11-13.5 in. wg
for LP. If the gas pressure at the job location is greater
than 13.5 in. wg, an additional regulator is required
to reduce pressure. For other RV and RVE models,
reference the Model PVF and PVG IOM.
Dedicated Outdoor Air Unit12
Page 13
Piping Installation
Optional Coil Piping
Factory-installed cooling and heating components are
mounted in the coil section of the unit. The coil section
is downstream of the energy wheel on the supply air
side of the unit. Note the coil connection locations on
the picture. Coil connections are located external to the
unit.
Note: DX coil liquid connection is internal to units.
Water Coils
1. Piping should be in accordance with accepted
industry standards. Pipework should be supported
independently of the coils. When installing couplings,
do not apply undue stress to the connection
extending through the unit. Use a backup pipe
wrench to avoid breaking the weld between coil
connection and header.
2. Connect the water supply to the bottom connection
on the air leaving side and the water return to the
top connection on the air entering side. Connecting
the supply and/or return in any other manner will
result in very poor performance. Be sure to replace
factory-installed grommets around coil connections
if removed for piping. Failure to replace grommets
will result in water leakage into the unit and altered
performance.
3. Water coils are not normally recommended for
use with entering air temperatures below 40°F. No
control system can be depended on to be 100% safe
against freeze-up with water coils. Glycol solutions
or brines are the only safe media for operation of
water coils with low entering air conditions. If glycol
or brine solutions are not used, coils must be drained
when freezing conditions are expected. If required,
vent and drain connections must be fieldpiped, external to the unit.
4. Pipe sizes for the system must be selected on
the basis of the head (pressure) available from the
circulation pump. The velocity should not exceed
6 feet per second and the friction loss should be
approximately 3 feet of water column per 100 feet
of pipe.
5. For chilled water coils, the condensate drain
pipe should be sized adequately to ensure the
condensate drains properly. Refer to Drain Trap
section.
Direct Expansion (DX) Coils (Split DX)
1. Piping should be in accordance with accepted
industry standards. Pipework should be supported
independently of the coils. Undue stress should not
be applied at the connection to coil headers.
2. The condensate drain pipe should be sized
adequately to ensure the condensate drains properly.
Refer to Condensate Drain Trap section.
3. When connecting suction and liquid connections
make sure the coil is free from all foreign material.
Make sure all joints are tight and free of leakage. Be
sure to replace factory-installed grommets around
coil connections if removed for piping.
4. Manufacturer does not supply compressor,
condensing units, or thermal expansion valve (TXV)
with standard models. For further instruction on
DX coil installation and operation contact your
compressor and/or condenser manufacturer.
Condensate Drain Trap
This unit is equipped with a stainless steel condensate
pan with a stainless steel connection. It is important
that the drain connection be fitted with a P trap to
ensure proper drainage of condensate while maintaining
internal static pressures and to prevent migration of
sewer gas back into the unit.
A P trap assembly (kit) is
supplied with each unit and is
to be assembled and installed
as local conditions require and
according to the assembly
instructions provided with
the P trap. If local and area
codes permit, the condensate
may be drained back onto the
roof, but a drip pad should
be provided beneath the outlet. If local and area codes
require a permanent drain line, it should be fabricated
and installed in accordance with Best Practices and all
codes.
In some climates, it will be necessary to provide freeze
protection for the P trap and drain line. The P trap
should be kept filled with water or glycol solution at all
times and it should be protected from freezing to protect
the P trap from damage. If severe weather conditions
occur, it may be necessary to fabricate a Ptrap and
drain line of metal and install a heat tape to prevent
freezing.
Condensate Overflow Switch
This unit is equipped with an optional factory-mounted
condensate overflow switch. In the event that a high
level of condensate is detected, the microprocessor
controller will trigger an alarm and shutdown the unit.
®
Dedicated Outdoor Air Unit13
Page 14
®
Electrical Information
WARNING
The roof lining contains high voltage wiring. To
prevent electrocution, do not puncture the interior or
exterior panels of the roof.
WARNING
To prevent injury or death due to electrocution or
contact with moving parts, lock disconnect switch
open.
For units with a gas furnace, if you turn off the power
supply, turn off the gas.
IMPORTANT
Before connecting power to the unit, read and
understand the following instructions and wiring
diagrams. Complete wiring diagrams are attached on
the inside of the control center door(s).
IMPORTANT
All wiring should be done in accordance with the latest
edition of the National Electric Code ANSI/NFPA70
and any local codes that may apply. In Canada, wiring
should be done in accordance with the Canadian
Electrical Code.
IMPORTANT
The equipment must be properly grounded and
bonded. Any wiring running through the unit in the
airstream must be protected by metal conduit, metal
clad cable or raceways.
CAUTION
If replacement wire is required, it must have a
temperature rating of at least 105ºC, except for an
energy cut-off or sensor lead wire which must be
rated to 150ºC.
DANGER
High voltage electrical input is needed for this
equipment. This work should be performed by a
qualified electrician.
CAUTION
Any wiring deviations may result in personal injury or
property damage. Manufacturer is not responsible
for any damage to, or failure of the unit caused by
incorrect final wiring.
Determine the Size of the Main Power
Lines
The unit’s nameplate states the voltage and the unit’s
MCA. The main power lines to the unit should be sized
accordingly. The nameplate is located on the outside of
the unit on the control panel side.
Determine the Size
of Electric Heater Wiring
An optional electric heater may require a separate
power supply. The power connection should be made
to the factory-provided electric heater disconnect and
must be compatible with the ratings on the nameplate,
supply power voltage, phase and amperage. Consult
ANSI/NFPA 70 and CSA C22.1 for proper conductor
sizing.
Provide the Opening(s) for the Electrical
Connections
Electrical openings vary by unit size and arrangement
and are field-supplied.
Connect the Power Supplies
Connect the main power lines and electric heater power
lines to the disconnect switches or terminal blocks
and main grounding lug(s). Torque field connections to
manufacturer’s recommendations.
Wire the Optional Convenience Outlet
The convenience outlet requires a separate 115V power
supply circuit. The circuit must include short circuit
protection which may need to be supplied by others.
Connect Field-Wired Low Voltage
Components
Most factory-supplied electrical components are
prewired. To determine what electrical accessories
require additional field-wiring, refer to the unit-specific
wiring diagram located on the inside of the control
center access door.
The low voltage control circuit is 24 VAC and control
wiring should not exceed 0.75 ohms.
Control wires should not be run inside the same conduit
as that carrying the supply power. Make sure that
field-supplied conduit does not interfere with access
panel operation. All low voltage wiring should be run in
conduit wherever it may be exposed to the weather.
If wire resistance exceeds 0.75 ohms, an industrialstyle, plug-in relay should be added to the unit control
center and wired in place of the remote switch (typically
between terminal blocks R and G on the terminal strip.
The relay must be rated for at least 5 amps and have a
24 VAC coil. Failure to comply with these guidelines may
cause motor starters to “chatter” or not pull in which
can cause contactor failures and/or motor failures.
Field-Provided Disconnect
If field-installing an additional disconnect switch, it
is recommended that there is at least four feet of
service room between the switch and system access
panels. When providing or replacing fuses in a fusible
disconnect, use dual element time delay fuses and size
according to the rating plate.
Dedicated Outdoor Air Unit14
Page 15
Control Center Components
Main Control Center Components
Image represents a typical installation for RVE-40 or RVE-85. Components and locations will vary on other models.
Electrical Cabinet
1. Power distribution block; high voltage
supply is terminated here
2. Fuse holders
3. Phase monitor
4. Unit Disconnect
5. Condensing fan motor contactors
6. Wheel motor contactor
7. Compressor motor contactors
Controls Cabinet
8. Transformer
9. VFDs
10. Microprocessor controller
11. Monitoring points
12. Low voltage terminal strip
13. Relays
14. Dirty filter switches
15. Wheel pressure switch
16. Outdoor airflow monitor
17. Exhaust airflow monitor
18. Digital scroll controller
11
9
9
14
16
9
17
10
12
13
Controls Cabinet
Accessible via compressor door
18
15
Electrical Cabinet
Accessible via control center door
22
1
3
5
5
6
4
22
8
7
Optional Indirect Gas-Fired Furnace
Note: In some models, two furnaces are installed to provide greater output. When two furnaces are installed, they are
in parallel and both will operate at the same time and the same output. Both furnaces will have identical controls.
7
1. Single-stage valve
2. Modulating valve
4
3
5
4
3
3. PCOE expansion board
4. Ignition controller
5. Transformer
6. Combustion blower
1
2
1
2
7. Burner manifold
8. Collector box
6
8
6
For further information on the optional furnace and its control center, see the Indirect Gas-Fired Heat lOM shipped
with the unit.
7
5
8
®
Dedicated Outdoor Air Unit15
Page 16
®
Component Operation
Optional Component Operation
Phase Monitor
The unit control circuitry includes a phase monitor that
constantly checks for phase reversal, phase imbalance,
loss of phase or a power brownout. When it detects a
fault, it cuts off the 24 VAC that goes to the low voltage
terminal strip, thereby shutting off all motors.
Variable Frequency Drive (VFD)
If a VFD was provided and installed at the factory, it has
been pre-set to control the speed of the blower motor
for optimum performance. The motor speed needs to be
verified during test and balance of the unit.
If the system was configured for Constant Air Volume
(CAV), the VFD will operate in an ON/OFF fashion
and the speed of the motor will not change. If the
system was configured for Variable Air Volume (VAV),
the microprocessor will constantly monitor operating
conditions and provide a signal to the VFD, changing
the VFD output as needed.
The VFD may alternatively be connected to an external
signal such as provided by a BMS and be operated by a
0-10 VDC input.
Supply Fan VFD Sequence
Optional Room CO2 Sensor: The microprocessor will
modulate the supply fan based on a comparison of the
CO2 set point to the actual CO2 levels reported from
the sensor. Mechanical high static protection cutoffs
must be installed by others to protect the system and
equipment from over-pressurization.
Optional Duct Static Pressure Sensor: The
microprocessor will modulate the supply fan based
on a comparison of the duct static pressure set point
to the actual duct static pressure level reported from
the sensor. Mechanical high static protection cutoffs
must be installed by others to protect the system and
equipment from over-pressurization. The manufacturer
does not assume responsibility for this.
Optional Building Static Pressure Sensor: The
supply fan is modulated based upon the signal from a
building static pressure sensor. The microprocessor will
modulate the supply fan based on a comparison of the
building static pressure set point to the actual building
static pressure level reported from the sensor.
Optional Single Zone VAV: The microprocessor will
use a space mounted temp sensor to vary heating and
cooling capacity and the airflow delivered by the fan to
maintain room-air temp at a desired set point.
Optional 0-10 VDC by others to VFD: Supply fan is
modulated by a 0-10 VDC, field-provided by others.
Exhaust Fan VFD Sequence
Optional Building Static Pressure Sensor: The
exhaust fan is modulated based upon the signal from
a building static pressure sensor. The microprocessor
will modulate the exhaust fan based upon a comparison
of the building static pressure level reported from the
sensor.
Optional Outdoor Air Damper Tracking: The
microprocessor will proportionally modulate the exhaust
fan based upon the outdoor air damper position.
Optional Supply Tracking: The microprocessor will
proportionally modulate the exhaust fan based upon the
supply fan.
Optional 0-10 VDC by Others to VFD: The supply fan
is modulated by a 0-10 VDC provided by others in the
field.
Outdoor Air and Recirculated (Recirc) Air
Damper Sequence
Optional Room CO2 Sensor: The microprocessor
will proportionally modulate the OA/RA dampers based
upon a comparison of the CO2 set point to the actual
CO2 level reported from the sensor. As the CO2 level
rises, the controller will proportionally modulate the
outdoor air damper open, between the minimum and
maximum OA position.
Optional Building Pressure: The OA/RA dampers
will modulate based upon the signal from a building
static pressure sensor. The controller will modulate
the dampers, between the minimum and maximum OA
positions, based upon a comparison of the building
static pressure set point to the actual building static
pressure level reported from the sensor.
Exhaust Fan Only Power
The exhaust fan will have a dedicated power circuit
where in the case of a power outage, the exhaust fan
will still run. A phase monitor will detect an outage or
power loss and open the contact, disconnecting all
power to the unit and controller. An external signal will
need to be sent to a relay to power the exhaust fan,
enabling the fan to run at a maximum speed. This
sequence is NOT to be used for high temperature
exhaust applications.
Service Lights
Service lights provide light to each of the compartments
in the energy recovery unit. The lights are wired to a
junction box mounted on the outside of the unit. The
switch to turn the lights on is located in the unit control
center. The switch requires a separate power source
to allow for power to the lights when the unit main
disconnect is off for servicing.
Dedicated Outdoor Air Unit16
Page 17
Optional Component Operation
Electronically Commutated (EC)
Condenser Fans with Standard Scroll or
Digital Scroll Compressors
The EC condenser fan(s) will modulate up and down
to maintain the optimal liquid line pressure using built
in control sequences within the factory controller. One
pressure transducer is provided with each refrigeration
circuit for monitoring and the factory controller will ramp
condenser fan(s) up or down based on the condenser
set point.
Economizer Fault Detection Diagnostics
Provides the status and faults of the air economizer
to indicate proper economizer sequence operation.
This assures the benefits of free cooling when outdoor
conditions are suitable for economizer functions. The
fault detection diagnostics system will indicate when
free cooling is available and if the outside air damper
and recirculation damper are reacting properly. If the
dampers are not functioning correctly an alarm will be
generated.
Air-Source Heat Pump
Operating Conditions and Limitations
To operate in Cooling mode, the following conditions
must be true:
1. Supply air temperature above minimum low supply
temperature limit (35°F)
2. Outside air temperature above the cooling ambient
lockout (55°F, adj.)
To operate in Heating mode, the following conditions
must be true:
1. Supply air temperature below maximum high
supply temperature limit (120°F)
2. Supply air temperature above 35°F
3. Outside air temperature above the low ambient
lockout (10°F, adj.)
For more information on air-source heat pump
operation, reference the supplemental Reference Guide
for Microprocessor Controller.
IMPORTANT
Air-source heat pumps are equipped with a defrost
cycle to remove ice from the outdoor coil. During
defrost cycles, melted water may drip from the
bottom of the refrigeration section under the outdoor
coil. In cold climates, proper drainage/heat tape must
be installed under the outdoor coil to prevent the
buildup of ice on the roof.
IMPORTANT
Melted water from snow accumulation on the unit
roof can be sucked into outdoor fans, resulting in ice
formation on fan blades under certain conditions.
Remove snow accumulation from the unit roof and
outdoor coil section after snow storms.
Airflow Monitor
IMPORTANT
For the outdoor airflow monitoring device to perform
as intended, field calibration is required. Calibration of
the airflow monitoring device requires an independent
measurement of airflow and should be performed
when the system undergoes test and balance.
A factory-wired, mounted, and powered airflow
monitoring system is provided in the outdoor, supply,
and/or exhaust air streams. The airflow control system
displays outdoor, supply, and/or exhaust air in actual
cubic feet per minute (CFM) at factory controller or
can be read by a building management system if
communication is established.
Operation
Outdoor airflow monitoring is accomplished using two
thermal dispersion sensors that accurately measure
airflow velocity down to zero feet per minute (fpm). The
airflow controller takes the average measurement for
two sensor configurations, and determines the outdoor
airflow rate based on the effective intake area. Field
calibration of the outdoor airflow monitoring device
determines the effective intake area of the unit. For
additional information on how to navigate through the
outdoor airflow controller menus, refer to technical
manuals from GreenTrol® Automation Inc. at www.
greentrol.com.
Supply and/or exhaust airflow monitoring is
accomplished by measuring the pressure drop across
the fan inlet venture. The airflow is then calculated by
the factory controller based on the measured pressure
drop and a K-Factor specific for each fan size.
Hot Gas Reheat Valve
Units equipped with a reheat coil use a three-way
valve with actuator to control the supply air discharge
temperature of the unit during dehumidification mode.
The unit controller provides a 0-10VDC signal to control
the amount of reheat to meet the supply temperature
set point.
Controls by Others
The reheat coil needs to be purged to ensure adequate
oil return. It is recommended that every six hours of
reheat compressor run time should initiate a six minute
purge cycle. During the purge cycle, the reheat valve
should be modulated to 100% open to the reheat coil.
®
Dedicated Outdoor Air Unit17
Page 18
®
Optional Component Operation
VFD Compressor
If the VFD compressor option is included, the
compressor VFD is mounted in the end of the
condensing section. Condensing section internal
components are accessible via the access panel on the
side of the condenser coil.
Envelope Control
The unit controller tracks the operating point of the VFD
compressor within the operating envelope at all times. If
the operating point is out of the envelope, the controller
will take action to bring it back in. If unsuccessful, the
controller will shut down the compressor. DO NOT
operate the compressor VFD in hand mode because
the envelope control safeties will not be in place. Refer
to the controls IOM for more information on envelope
control.
Electronic Expansion Valve
An electronic expansion valve is provided on the VFD
compressor circuit to ensure tight superheat control
throughout the compressor modulation band. The EXV
acts as a liquid line solenoid valve when the compressor
is off to prevent refrigerant migration.
Crankcase Heat
The VFD compressor will be heated by the compressor
stator. To ensure optimal performance and reliability, do
not disable stator heat. All other compressors will be
provided with a crankcase heater.
Oil Return Management
The compressor VFD has an oil return purge cycle such
that if the compressor has been operating below a set
RPM for a set period of time, the VFD will accelerate the
compressor to ensure sufficient lubrication.
DO NOT disable the oil return management function.
DO NOT operate the compressor VFD in hand mode
because the oil return management will not be
operational.
Ultraviolet Germicidal Irradiation (UVGI)
UV-C lights are mounted in the supply blower cabinet
and provide air disinfection. The lights are factorypowered and are on when the supply blower is running.
A kill switch on the supply blower access door turns the
lights off when that door is open.
Housing 110/180 Only
UV-C lights are mounted downstream of the cooling
coil, providing coil surface and drain pan disinfection.
The lights are factory-powered and are on when there
is power to the unit disconnect. A kill switch on the coil
access door turns the lights off when that door is open.
Needlepoint Bipolar Ionization (NPBI®)
Needlepoint bipolar ionizers are mounted on the fan
inlet cone(s) and provide air disinfection. The ionizers
are factory-powered and are on when there is power to
the unit disconnect.
Frost Control
Extremely cold outdoor air temperatures can cause
moisture condensation and frosting on the energy
recovery wheel. Frost control is an optional feature that
will prevent/control wheel frosting. Three options are
available:
Polymer Energy Wheel
Available options are:
1. Timed exhaust frost control
2. Electric preheat frost control
3. Modulating wheel frost control
These options are provided with a thermodisc mounted
in the outdoor air intake compartment and a pressure
sensor to monitor pressure drop across the energy
wheel. An outdoor air temperature of below 5°F and
an increase in pressure drop indicate that frost is
occurring. Both the pressure sensor and the outdoor
air thermodisc must trigger to initiate frost control. The
two sensors together ensure that frost control is only
initiated during a real frost condition.
Timed exhaust frost control includes a timer in
addition to the thermodisc and wheel pressure sensor.
When frost control is initiated, the timer will turn the
supply blower off. The default timer setting will shut
down the supply fan for 5 minutes every 30 minutes,
allowing warm exhaust to defrost the energy wheel. Use
the test procedure in the Optional Start-Up Accessories
section for troubleshooting.
Electric preheat frost control includes an electric
heater (at outdoor air intake) in addition to the
thermodisc and wheel pressure sensor. When frost
control is initiated, the electric preheater will turn on and
warm the air entering the energy wheel. Use the test
procedure in the Optional Start-Up Accessories section
for troubleshooting.
Modulating wheel frost control includes a variable
frequency drive (VFD) in addition to the thermodisc
and wheel pressure sensor. When frost control is
initiated, the VFD will reduce the wheel speed, reducing
effectiveness and preventing condensation and frosting.
If the outdoor air temperature is greater than the frost
threshold temperature OR the pressure differential is
less than the set point, the wheel will run at full speed.
If the outdoor air temperature is less than 5°F AND
the pressure differential is greater than the set point,
the wheel will run at reduced speed until the pressure
differential falls below the set point. The VFD will be fully
programmed at the factory.
Dedicated Outdoor Air Unit18
Page 19
Optional Component Operation
Aluminum Energy Wheel
Available options are:
1. Modulating wheel frost control
2. Modulating wheel with electric preheat frost
control
These options are provided with a temperature sensor
mounted in the exhaust air discharge compartment.
Frost control will initiate when the exhaust air
temperature is below 36°F.
Modulating wheel frost control includes a variable
frequency drive (VFD) in addition to the exhaust air
temperature sensor. When frost control is initiated,
the VFD will modulate the wheel speed to maintain
36°F exhaust air temperature. The VFD will be fully
programmed at the factory.
Modulating wheel with electric preheat frost control
includes a variable frequency drive (VFD) and electric
heater (at outdoor air intake) in addition to the exhaust
air temperature sensor. When frost control is initiated,
the VFD will modulate the wheel speed to maintain 36°F
exhaust air temperature. The electric heater will turn on
when the outdoor air temperature is below 10°F. The
VFD will be fully programmed at the factory.
Rotation Sensor
The rotation sensor monitors energy wheel rotation. If
the wheel should stop rotating, the sensor will close a
set of contacts in the unit control center. Field-wiring of
a light (or other alarm) between terminals R and 12 in
the unit control center will notify maintenance personnel
when a failure has occurred.
Microprocessor Control
The microprocessor controller is specifically designed
and programmed to optimize the performance of
the unit with supplemental heating and cooling. This
option ensures that the outdoor air is conditioned to
the desired discharge conditions. The controller and
accompanying sensors are factory-mounted, wired and
programmed. Default settings are pre-programmed, but
are easily field-adjustable.
The microprocessor controller can be interfaced with
a Building Management System through LonWorks®,
BACnet®, or ModBus.
Please refer to the Installation, Operation and
Maintenance manual for detailed information.
Unoccupied Recirculation Damper
The unoccupied recirculation option provides a
recirculation damper from the return air intake to the
supply airstream. If equipped with a room temperature
and/or relative humidity sensor, the unit can cycle on to
maintain unoccupied room set points if there is a call
for unoccupied heating, cooling, or dehumidification.
During the unoccupied mode, the supply and exhaust
(if equipped) fans will be off unless there is a call for
cooling, heating, or dehumidification in the space.
Dirty Filter Sensor
Dirty filter sensors monitor pressure drop across the
outdoor air filters, exhaust air filters, or both. If the
pressure drop across the filters exceeds the set point,
the sensor will close a set of contacts in the unit control
center. Field-wiring of a light (or other alarm) to these
contacts will notify maintenance personnel when
filters need to be replaced. The switch has not been
set at the factory due to external system losses that
will affect the switch. This switch will need minor field
adjustments after the unit has been installed with all
ductwork complete. The dirty filter switch is mounted in
the exhaust inlet compartment next to the unit control
center or in unit control center.
®
Dedicated Outdoor Air Unit19
Page 20
®
Factory-Installed Refrigeration System Components
Packaged DX Cooling with Three Way Hot Gas Reheat
Dedicated Outdoor Air Unit20
Page 21
Factory-Installed Refrigeration System Components
Packaged DX Cooling with Three Way Hot Gas Reheat
1. Compressor
2. High Limit Pressure Switch
The switch opens when refrigerant pressure
increases above the set point in the discharge line.
A manual reset is then required.
3. Hot Gas Reheat Valve (optional)
Units equipped with a reheat coil use a threeway valve with actuator to control the supply
air discharge temperature of the unit during
dehumidification mode. The unit controller provides
a 0-10 VDC signal to control the amount of reheat
to meet the supply temperature set point
4. Hot Gas Reheat Coil (Optional)
5. Hot Gas Reheat Check Valve (Optional)
6. Condenser Fans
7. Condensing Coil
8. Liquid Receiver (Optional)
9. Liquid Line Filter Drier
10. Sight Glass
11. Fan Cycle Switch(es)
The switch(es) open or close based on liquid
refrigerant pressure to control the condensing fans
to maintain liquid pressure.
12. Thermostatic Expansion Valve (TXV)
Each unit is equipped with a TXV on each
refrigerant circuit. The valve controls the flow of
liquid refrigerant entering the evaporator coil by
maintaining a constant, factory-set superheat of
10°F. The valve is adjustable and is located on the
side of the evaporator coil and can be accessed
through the coil access panel.
13. Evaporative Coil
14. Low Limit Pressure Switch
The switch is installed on the suction line and
disables the DX system when the suction pressure
drops below the set point. The switch will auto reset
when the pressure rises above the auto-reset set
point.
Air-Source Heat Pump with Three Way Hot Gas Reheat
Outdoor Airflow
EXV
HCV
HRV
HPS
SV
PT
PT
LPS
ACC
Compressor
4WV
Outdoor Coil
SG
Supply
Airflow
SG
Hot Gas Reheat Coil
FDS
Indoor Coil
Outdoor Airflow
4WV
Outdoor Coil
PT
SG
TXV
Supply
Airflow
SG
Indoor Coil
FDS
ACC
LPS
SV
HPS
Compressor
Dedicated Outdoor Air Unit22
Page 23
Factory-Installed Refrigeration System Components
1. Compressor
2. High Limit Pressure Switch
The switch opens when refrigerant pressure
increases above the set point in the discharge line.
A manual reset is then required.
3. Hot Gas Reheat Valve (optional)
Units equipped with a reheat coil use a threeway valve with actuator to control the supply
air discharge temperature of the unit during
dehumidification mode. The unit controller provides
a 0-10 VDC signal to control the amount of reheat
to meet the supply temperature set point
4. Hot Gas Reheat Coil (Optional)
5. Hot Gas Reheat Check Valve (Optional)
6. Outdoor Fans
7. Outdoor Coil
8. Refrigeration Accumulator
9. Liquid Line Filter Drier
10. Sight Glass
11. Four Way Reversing Valve
Each compressor circuit is equipped with a
reversing valve to reverse the direction of refrigerant
flow, switching the unit between heating and
cooling mode.
12. Electronic Expansion Valve (EXV) or
Thermostatic Expansion Valve (TXV)
An expansion valve is provided on each refrigerant
circuit. This valve controls the flow of liquid
refrigerant entering the indoor and outdoor coils
by maintaining a constant superheat. The TXV is
adjustable. Both the EXV and TXV are located on
the side of the outdoor coil and can be accessed
through the refrigeration system access panel.
13. Indoor Coil
14. Low Limit Pressure Switch
The switch is installed on the suction line and
disables the DX system when the suction pressure
drops below the set point. The switch will auto reset
when the pressure rises above the auto-reset set
point.
15. Service Access Ports
Typical port locations are shown. Additional valves
may be present in the system.
16. Refrigerant Pressure Transducers
®
Dedicated Outdoor Air Unit23
Page 24
®
Start-Up Unit
DANGER
Electric shock hazard. Can cause injury or death.
Before attempting to perform any service or
maintenance, turn the electrical power to unit to OFF
at disconnect switch(es). Unit may have multiple
power supplies.
CAUTION
Use caution when removing access panels or other
unit components, especially while standing on a
ladder or other potentially unsteady base. Access
panels and unit components can be heavy and
serious injury may occur.
CAUTION
Do not operate without the filters and birdscreens
installed. They prevent the entry of foreign objects
such as leaves, birds, etc.
CAUTION
Do not run unit during construction phase. Damage to
internal components may result and void warranty.
WARNING
• Unit was factory tested. All blowers, fans,
and compressors are set-up to run correctly
when supplied power. If any one fan is running
backwards or the compressor is making loud
noises, immediately turn off the power. Switch two
leads on the incoming power to the disconnect.
This will ensure proper operation of the unit. Failure
to comply may damage the compressors and void
the warranty.
• Do not jumper any safety devices when operating
the unit. This may damage components within or
cause serious injury or death.
• Do not operate compressor when the outdoor
temperature is below 40ºF.
• Do not short-cycle the compressor. Allow
5 minutes between “on” cycles to prevent
compressor damage.
• DX system is charged with refrigerant. Start-up
must be performed by EPA Certified Technician.
WARNING
Prior to starting up the unit, power must be energized
for 24 hours without a call for cool to allow the
compressor crankcase heaters time to boil off any
liquid refrigerant present in the compressor.
Every installation requires a comprehensive start-up
to ensure proper operation of the unit. As part of that
process, the following checklist must be completed and
information recorded. Starting up the unit in accordance
with this checklist will not only ensure proper operation,
but will also provide valuable information to personnel
performing future maintenance. Should an issue arise
which requires factory assistance, this completed
document will allow unit experts to provide quicker
resolve. Qualified personnel should perform start-up to
ensure safe and proper practices are followed.
Unit Model No. ___________________________________
Unit Serial No. ____________________________________
Energy Wheel Date Code __________________________
Compressor 1 Model No. __________________________
Compressor 2 Model No. __________________________
Compressor 3 Model No. __________________________
Compressor 4 Model No. __________________________
Start-Up Date ____________________________________
Start-Up Personnel Name __________________________
Start-Up Company ________________________________
Phone Number ___________________________________
Dedicated Outdoor Air Unit24
Page 25
Start-Up Unit
Pre-Start-Up Checklist
o Remove any foreign objects that are located in the
unit.
o Check all fasteners, set-screws, and locking collars
on the fans, bearings, drives, motor bases and
accessories for tightness.
o Rotate the fan wheels and energy recovery wheels
by hand and ensure no parts are rubbing.
o Verify diameter seal settings on the energy recovery
wheel.
o Filters can load up with dirt during building
construction. Replace any dirty pleated filters and
clean the aluminum mesh filters in the intake hood.
o Verify that non-motorized dampers open and close
properly.
o Check the tightness of all factory wiring
connections.
o Verify proper drain trap installation.
o Check condensing fans for any damage or
misalignment. Spin the blades and make sure they
don’t contact any parts and are free turning without
any resistance.
o Look over the piping system.
o Inspect all coils within the unit. Fins may get
damaged in transit or during construction. Carefully
straighten fins with a fin comb.
Electrical
oDisconnect and lock-out all power switches.
o Verify control wire gauge.
o All field-mounted sensors and instruments are
installed and wired.
o Unit controls are off.
o Electrical service matches unit voltage.
o Electrical field wiring is complete.
o All electrical connections are tightened.
o Compressor and motor breakers or fuses are open
(disabled).
o Main power is wired to the disconnect.
o Discharge air sensor is installed per wiring
instructions.
o Space temperature and humidity sensors are
installed per if selected with unit.
Compressors
o This unit contains an external crankcase heater for
each standard or digital scroll compressor. The
variable speed compressor uses internal stator
heating. Each compressor needs power supplied to
it 24hours prior to start-up. If start-up is scheduled
in 24 hours, unlock the disconnect power and
energize unit.
oCompressor shipping brackets are removed if
provided.
IG Furnace
o If there is an indirect gas-fired furnace in this unit,
refer to the manual provided with this unit for PreStart-Up information.
o Gas piping is complete and gas lines are purged.
o Gas venting is in place.
Hot Water/Chilled Water Coils
o Chilled water piping system is complete.
o Hot water piping system is complete.
o Control valves are installed, wired, and operating
properly.
o Water coils are balanced to design GPM.
o Water system is free of air.
SPECIAL TOOLS REQUIRED
• Voltage Meter (with wire probes)
• Amperage Meter
• Pressure Gauges – (refrigerant)
• Tachometer
• Thermometer
• Incline manometer or equivalent
Start-Up Procedure
The unit will be in operational mode during start-up. Use
necessary precautions to avoid injury. All data must be
collected while the unit is running.
o Make sure Pre-Start-Up checklist is complete.
o Jumper R to G, R to Y1, and R to Y2 (if applicable)
on the control board.
o Turn the disconnect on. After 3 minutes compressors
will come on. Make sure all fans and compressors
are rotating the correct direction.
o Allow the unit to run until the refrigerant system
stabilizes. Approximately 1-2 minutes.
Voltage Imbalance
In a 3-phase system, excessive voltage imbalance
between phases will cause motors to overheat and
eventually fail. Maximum allowable imbalance is 2%.
To determine voltage imbalance, use recorded voltage
measurements in this formula.
Key: V1, V2, V3 = line voltages as measured
VA (average) = (V1 + V2 + V3) / 3
VD = Line voltage (V1, V2 or V3) that
deviates farthest from average (VA)
Formula: % Voltage Imbalance = [100 x (VA-VD)] /VA
®
Dedicated Outdoor Air Unit25
Page 26
®
Start-Up Checklist - General
Line Voltage. Check at unit disconnect.
L1-L2VoltsL2-L3VoltsL1-L3Volts
Motor Amp Draw
Supply Motor 1 AmpsL1AmpsL2AmpsL3Amps
Supply Motor 2 AmpsL1AmpsL2AmpsL3Amps
Supply Motor 3 AmpsL1AmpsL2AmpsL3Amps
Exhaust Motor 1 AmpsL1AmpsL2AmpsL3Amps
Exhaust Motor 2 AmpsL1AmpsL2AmpsL3Amps
Exhaust Motor 3 AmpsL1AmpsL2AmpsL3Amps
Fan RPMCorrect fan rotation direction?
Supply Fan RPMSupply FanYes / No
Exhaust Fan RPMExhaust FanYes / No
Energy Wheel Motor (if equipped)
L1AmpsL2AmpsL3Amps
Condensing Fans (PDX only)
Condensing Fan 1L1AmpsL2AmpsL3Amps
Condensing Fan 2L1AmpsL2AmpsL3Amps
Condensing Fan 3L1AmpsL2AmpsL3Amps
Condensing Fan 4L1AmpsL2AmpsL3Amps
Condensing Fan 5L1AmpsL2AmpsL3Amps
Condensing Fan 6L1AmpsL2AmpsL3Amps
Condensing Fan 7L1AmpsL2AmpsL3Amps
Condensing Fan 8L1AmpsL2AmpsL3Amps
Outdoor Fans (ASHP only)
Outdoor Fan 1L1AmpsL2AmpsL3Amps
Outdoor Fan 2L1AmpsL2AmpsL3Amps
Outdoor Fan 3L1AmpsL2AmpsL3Amps
Compressors (if equipped)
Outdoor Air TemperatureDeg FOutdoor Air Relative Humidity% RH
Return Air TemperatureDeg FReturn Air Relative Humidity% RH
Dedicated Outdoor Air Unit26
Page 27
Start-Up Checklist - Packaged Direct Expansion (DX)
Compressor 1Compressor 2Compressor 3Compressor 4
L1AmpsAmpsAmpsAmps
L2AmpsAmpsAmpsAmps
L3AmpsAmpsAmpsAmps
Crankcase Heater
Not present on inverter compressor
Superheat
(Housings 10, 25/40, 45/85, 75/150)
Should be between 8º and 12ºF
Subcooling
(Housings 10, 25/40, 45/85, 75/150)
Should be between 8º and 12ºF
Superheat
(Housings 110/180)
Should be between 10º and 20ºF (0% reheat)
or should be between 10º and 30ºF (100%
reheat)
Subcooling
(Housings 110/180)
Should be between 10º and 15ºF (0% reheat)
or should be between 2º and 10ºF (100%
reheat)
Discharge Pressure
Should be between 300 and 500 PSIG
Suction Line Pressure
Should be between 100 and 135 PSIG
Liquid Line Temp.Deg. FDeg. FDeg. FDeg. F
Suction Line Temp.Deg. FDeg. FDeg. FDeg. F
Moisture Indicating Sight Glass
Liquid VisibleYes / NoYes / NoYes / NoYes / No
Color of Center DotPurple / PinkPurple / PinkPurple / PinkPurple / Pink
Hot Gas Bypass OperationalYes / No / NANANANA
AmpsAmpsAmpsAmps
Deg. FDeg. FDeg. FDeg. F
Deg. FDeg. FDeg. FDeg. F
Deg. FDeg. FDeg. FDeg. F
Deg. FDeg. FDeg. FDeg. F
PSIGPSIGPSIGPSIG
PSIGPSIGPSIGPSIG
®
Dedicated Outdoor Air Unit27
Page 28
®
Start-Up Checklist - Air-Source Heat Pump (ASHP)
Compressor 1Compressor 2
Compressors
L1AmpsAmps
L2AmpsAmps
L3AmpsAmps
Crankcase Heater NAAmps
Cooling
Superheat
Should be between 10º and 20ºF (0% reheat) or
should be between 10º and 30ºF (100% reheat)
Subcooling
Should be between 10º and 15ºF (0% reheat) or
should be between 2º and 10ºF (100% reheat)
Discharge Pressure
Should be between 250 and 500 PSIG
Suction Line Pressure
Should be between 96 and 155 PSIG
Liquid Line TempDeg. FDeg. F
Suction Line TempDeg. FDeg. F
Moisture Indicating Sight Glass
Liquid VisibleYes / NoYes / No
Color of Center DotPurple / PinkPurple / Pink
Heating
Superheat
Should be between 10º and 20ºF
Subcooling
Should be between 10º and 20ºF
Discharge Pressure
Should be between 250 and 500 PSIG
Suction Line Pressure
Should be between 96 and 155 PSIG
Liquid Line TempDeg. FDeg. F
Suction Line TempDeg. FDeg. F
Moisture Indicating Sight Glass
Liquid VisibleYes / NoYes / No
Color of Center DotPurple / PinkPurple / Pink
Note: Unit may not run at 100% heating mode in ambient temperatures over 70°F (21°C). Modulate compressor as necessary to
keep unit running.
Deg. FDeg. F
Deg. FDeg. F
PSIGPSIG
PSIGPSIG
Deg. FDeg. F
Deg. FDeg. F
PSIGPSIG
PSIGPSIG
Dedicated Outdoor Air Unit28
Page 29
Start-Up Components
Fan
The fan should be checked for free rotation. If any
binding occurs, check for concealed damage and
foreign objects in the fan housing.
CAUTION
When operating conditions of the fan are to be
changed (speed, pressure, temperature, etc.), consult
manufacturer to determine if the unit can operate
safely at the new conditions.
Supply Fan (Plenum Type)
The unit contains one or two plenum supply fans
located on the end of the unit opposite the outdoor air
intake and may optionally have a relief air blower which
is referred to as an exhaust blower in this document.
Efficient fan performance can be maintained by having
the correct offset.
Offset: Proper offset, or overlap, is
adjusted by loosening the wheel hub
from the shaft and moving the wheel
to the desired position along the shaft.
The transition between the inlet cone
and the wheel should
Wheel
Offset
Inlet
Cone
be as shown; there is
a smooth feel to the
profile when moving one
component to the other.
Supply/Exhaust Fan
The optional exhaust fan is a direct-drive plenum type.
Fan speed is controlled by a VFD which, in turn, is
controlled by the microprocessor controller or by an
external signal. Motor speed will be set on the VFD
during the unit Test and Balance, but after that, the
VFD will not normally be changed. Always check the
motor amperage rating shown on the motor nameplate
when changing the fan RPM. All access doors must be
installed except the control center door.
Vibration
Vibration Causes
Off axis or loose components
Drive component unbalance
Poor inlet / outlet conditions
Foundation stiffness
including structural and/or component failure. The most
common sources of vibration are listed.
Many of these conditions can be discovered by careful
observation. Refer to the Troubleshooting section of
this manual for corrective actions. If observation cannot
locate the source of vibration, a qualified technician
using vibration analysis equipment should be consulted.
Generally, fan vibration and noise is transmitted to other
parts of the building by the ductwork. To eliminate this
undesirable effect, the use of flexible connectors is
recommended.
Excessive vibration may
be experienced during
initial start-up. Left
unchecked, excessive
vibration can cause a
multitude of problems,
Fan Size
Offset
(inches)
Tolerance
(inches)
ER35C5/32± 1/32
ER45C3/16± 1/32
ER50C13/64± 1/32
ER56C1/4± 1/32
PDL-3555/32± 1/32
PRM-4503/16± 1/32
PRM-56015/64± 1/32
Refer to the respective Installation, Operation and
Maintenance Manual shipped with this unit for additional
start-up and maintenance information regarding the
plenum fan.
Fan Wheel Rotation Direction
Check for proper wheel rotation by momentarily
energizing the fan. Rotation is determined by viewing
the wheel from the drive side and should match the
rotation decal affixed to the fan housing.
If the wheel is rotating the wrong way, direction can be
reversed by interchanging any two of the three electrical
leads. Check for unusual noise, vibration or overheating
of the bearings. Refer to the Troubleshooting portion of
this manual if a problem develops.
Discharge Air Temperature Sensor
Units are supplied with a Discharge Air Temperature
Sensor that is to be field-installed prior to unit startup. The sensor is to be installed at least three duct
diameters downstream of the
heat exchanger. The sensor
must be connected directly to
the microprocessor controller. All
other sensors and low voltage
devices are to be connected
to the low voltage terminal
strip in the control center. The
discharge air sensor is shipped loose and can be found
in the unit’s control center. See the unit-specific wiring
diagram for connection locations.
Typical Discharge Air
Temperature Sensor
®
Dedicated Outdoor Air Unit29
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®
Start-Up Components
Airflow Monitoring
For additional information on how to navigate through
the airflow controller menus, refer to technical manuals
from GreenTrol® Automation Inc. at www.greentrol.
com. Also refer to the Greenheck Reference Guide for
Microprocessor Controller.
Display and Navigation
The LCD screen will by default show the current airflow
that is being measured. To enter the menu to set up the
monitoring station the user must remove the front cover
of the GreenTrol to uncover the navigation buttons.
Press and hold the UP and DOWN keys at the same
time for 3 seconds to enter the menu.
Enter Button Function - The ENTER button allows the
user to go into the selected menu or function, as well as
save the selected value.
Up/Down Button Function - The UP/DOWN buttons
are used to navigate the menu and to change values in
the menu.
Esc Button Function - The ESC button allows the user
to exit the current menu or function.
Field Calibration
1. Press UP/DOWN = Setup
2. Press DOWN/ENTER = Setup Wizard
3. Scroll Down to Field Adjust and press ENTER
4. Run FAK wizard and press ENTER
5. Set FAW Int and press ENTER
6. FAW INT = 300 and press ENTER
7. Set number of flows and press ENTER
8. Set flow and press ENTER
9. Set flow to actual CFM measured by Test and
Balance and press ENTER
10. Wait for calibration before cycling power
11. Proceed to Communication Setup
Communication Setup
1. Press the UP and DOWN keys at the same time for
3 seconds
2. When SETUP appears on the screen press ENTER
3. Scroll DOWN (twice) to the NETWORK menu and
press ENTER
4. When NETOUT appears on the screen, press
ENTER; when SET NETOUT appears on the screen,
press ENTER again
5. Scroll UP or DOWN to set the NETOUT = MODBUS
and then press ENTER
6. Scroll DOWN to NETADDR and press ENTER,
when SET NETADDR appears on the screen press
ENTER again
7. Scroll UP or DOWN to set the NETADDR to the
same address that was listed for the airflow monitor
in the microprocessor. For instance, the Outdoor
Airflow Monitor screen above has an address of 31.
Then press ENTER.
8. Scroll DOWN to NETBAUD and press ENTER,
when SET NETBAUD appears on the screen, press
ENTER again
9. Scroll UP or DOWN until NETBAUD = 19200, then
press ENTER
10. Scroll down to PARITY and press ENTER, when
SET PARITY appears on the screen press ENTER
again
11. Scroll UP or DOWN until PARITY = NONE2, then
press ENTER
12. Once the address is set and the communication
wires are connected, “Status” LED should be a
steady green and the “RS485” LED should be a
quick blinking green LED.
Dedicated Outdoor Air Unit30
Page 31
Start-Up Components
Optional Dirty Filter Switch
To adjust the switch, the unit must be running with
all of the access doors in place, except for the
compartment where the switch is located (exhaust
intake compartment). The adjusting screw is located on
the top of the switch.
1. Open the filter compartment and place a sheet of
plastic or cardboard over 50% of the filter media.
Setscrew (on front of switch) must
be manually adjusted after the
system is in operation.
Negative pressure connection
is toward the ‘front or top’ of
the switch. (Senses pressure on
the blower side of filters)
Positive pressure connection is toward the ‘back or bottom’
of the switch. (Senses pressure at air inlet side of filters)
2. Replace the filter compartment door.
3. Check to see if there is power at the alert signal
leads (refer to electrical diagram).
4. Whether there is power or not, turn the adjustment
screw on the dirty filter gauge (clockwise if you did
not have power, counterclockwise if you did have
power) until the power comes on or just before the
power goes off.
5. Open the filter compartment and remove the
obstructing material.
6. Replace the door and check to make sure that you
do not have power at the alert signal leads. The unit
is now ready for operation.
Troubleshooting
SymptomPossible CauseCorrective Action
Refer to Adjust the Air Seals in the Optional Energy Wheel
Start-Up section.
Recheck air seals, make sure they are not too tight. See Adjust
the Air Seals in the Optional Energy Wheel Start-Up section.
Energy wheel
does NOT
turn
Energy
wheel runs
intermittently
®
Air seals are too tight.
Broken belt.Replace.
No power to wheel motor.Make sure wheel drive is plugged in. Verify power is available.
Wheel motor overloads are
tripping due to rubbing between
wheel and air seals.
Dedicated Outdoor Air Unit31
Page 32
®
Optional Polymer Energy Wheel
Start-Up
If selected, the energy wheel is installed in the unit with
one half of the wheel in the outdoor airstream and one
half in the exhaust airstream. The energy wheel includes
air eals to minimize leakage between airstreams.
Retaining
Adjustable
Air Seals
Drive Belt
Screws
Bearing
Support
Label
showing
cassette
serial # and
date code
Drive Pulley
Drive Belt
Inspect the drive belt. Make sure the belt rides smoothly
in the pulley and around the outside of the wheel. Note
the directional arrow and data information shown in the
image.
Adjust the Air Seals (Polymer wheels only)
The information below only applies to polymer wheels,
which require air seal adjustment at the time of start-up
for proper performance. Aluminum wheel air seals are
factory-set and do not require field adjustment.
Make sure the unit power supply is locked out.
Disconnect the wiring to the wheel module and pull
the wheel cassette out of the cabinet on its tracks.
Large cassettes are not removable. Then slowly rotate
the wheel by hand to make sure there is no binding or
misalignment.
There is a perimeter seal located around the outside of
the wheel and a diameter seal across the face of the
wheel on both sides. Check to make sure that all air
seals are secure and in good condition.
Adjust the air seals by loosening all the air seal retaining
screws on the bearing support. Using a piece of paper
as a feeler gauge, adjust the seals so they almost touch
the face of the wheel while tugging slightly on the paper.
When the wheel is rotated, there should be a slight tug
on the paper. Tighten the screws, repeat the steps on
the other set of seals.
Push the wheel cassette back into the unit and plug
in the power connector. Turn the main power supply
back on and then observe the operation of the wheel by
opening the wheel access door slightly. Remove filters if
necessary to observe the wheel.
Sequence of Operation
Optional Economizer - The economizer will be locked
out when: the outside air is below economizer lockout;
the unit is operating in dehumidification mode; or there
is a call for heating.
• Stop Wheel: When economizer mode is enabled
and there is a signal for cooling, the wheel will stop
rotating to allow free cooling.
• Modulate Wheel: When economizer mode is
enabled and there is a signal for cooling, the
wheel VFD modulates wheel speed to maintain the
discharge temperature set point.
Optional Frost Control - Polymer Wheel
The microprocessor controller will output a signal
when wheel frosting is occurring which is determined
by a temperature set point (OA <5°F – 2°F hysteresis,
adjustable) and wheel pressure drop increase.
• Preheat: When frosting is occurring, the preheater
is energized to defrost the wheel. Once the
pressure drop decreases below the set point, the
preheater is de-energized.
• Timed Exhaust: When frosting is occurring, the
supply blower is cycled off. The exhaust blower
shall continue to run, allowing the warm exhaust
air to defrost the wheel. After the 5 minute cycle,
the supply fan is re-energized to continue normal
operation.
• Modulating Wheel: When frosting is occuring,
the wheel VFD will reduce wheel speed to prevent
condensation and frosting. If the outdoor air
temperature is greater than the frost threshold
temperature OR the pressure differential is less
than the set point, the wheel will run at full speed.
If the outdoor air temperature is less than the frost
threshold temperature AND the pressure differential
is greater than the set point, the wheel will run at
reduced speed until the pressure differential falls
below the set point. The temperature and pressure
differential set points are set at the factory, but are
field-adjustable. The VFD will be fully programmed
at the factory.
Dedicated Outdoor Air Unit32
Page 33
Optional Polymer Energy Wheel
Maintenance
WARNING
Whenever performing maintenance or inspections,
always disconnect the power source.
Inspection
The wheel should be inspected
semiannually in accordance with the
maintenance schedule. Maintenance
of the wheel consists mainly of
inspecting the wheel for cleanliness
and then checking the drive motor,
belt, and pulley for wear. If the wheel
appears dirty, the wheel should be
disassembled and cleaned.
The wheel rotates through two
airstreams moving in opposite
directions, which means the wheel
is self-cleaning, up to a point. If the
Energy Wheel
Cassette
wheel media becomes blocked by dirt or dust, or if the
media collects a layer of smoke residue or an oily film,
the energy transfer efficiency drops.
The main factor in the frequency of cleaning is the
cleanliness of the air. If air filters are not changed
frequently, the wheel will collect contaminants and will
then have to be cleaned.
Wheel Disassembly
Wheels are part of a cassette that may be pulled from
the unit for easy access. There may be a small damper
assembly or other component that blocks removal of
the cassette. Before sliding out the cassette or any other
component, disconnect any power supply cord and
secure it so it cannot jam or otherwise get damaged.
Each wheel has removable segments that hold the
coated layers of media and each segment is held in
place with two retaining
clips located on the outer
rim of the wheel. When
removing more than one
segment, remove them in
sequence from opposite
sides of the wheel (180 degrees apart) to reduce the
imbalance. Secure the wheel against rotation. Carefully
release the two retaining clips and swing them fully
open. The segment can now be removed by pushing the
face of the segment close to the outer rim of the wheel.
Wheel segments are built to close tolerances and the
segment may have to be jiggled to remove it. Do not
use a hammer or otherwise force the segment because
these are high value items and are not built to withstand
abuse.
Segment Retaining Clip
Whenever retaining clips are opened, they should be
closed as soon as possible. If the wheel should rotate
when a clip is open, the clip will jam against the bearing
support bar and could cause damage.
Cleaning
Maintenance or cleaning of the wheel segments
should be done with the segments removed from
the wheel cassette to avoid splashing liquids or
cleaning agents inside the cabinet. If the energy wheel
appears excessively dirty, it should be cleaned to
ensure maximum operating efficiency. Only excessive
buildup of foreign materials needs to be removed.
DISCOLORATION AND STAINING OF ENERGY
RECOVERY WHEEL DOES NOT AFFECT ITS
PERFORMANCE.
Thoroughly spray the wheel matrix with a household
cleaner such as Fantastik™ or the equivalent. Gently
rinse with warm water and use a soft brush to remove
any heavy accumulations. A detergent/water solution
can also be used. Avoid aggressive organic solvents,
such as acetone. Wheel segments can be soaked in the
above solution overnight for removal of stubborn dirt or
accumulations.
After cleaning is complete, shake excess water from the
wheel or segments. Dry the wheel or segments before
putting them back into the cassette.
Reassembly
When reinstalling the segments, be sure to install them
with the correct face toward the motor side of the
cassette. Note that one face of each segment is smooth
and the other face has a reinforcing channel or support
cut into the surface.
Wheel Segment
(Pulley Side)
Wheel Segment
(Motor Side)
Wheel Belt
Inspect belts each time filters are replaced. Belts
that look chewed up or are leaving belt dust near the
motor pulley may indicate a problem with the wheel.
Be sure to inspect wheel for smooth and unrestricted
rotation. If a belt requires replacement, contact the
local manufacturer representative. Instructions for
replacement will ship with the new belt.
Wheel Bearing
In the unlikely event that a wheel bearing fails, the
bearing is behind a removable plate on the wheel
support beam (slide cassette halfway out of cabinet to
access). Contact the local manufacturer's representative
for detailed instructions on how to replace the bearing.
®
Dedicated Outdoor Air Unit33
Page 34
®
Optional Aluminum Energy Wheel
Start-Up
Optional Frost Control
The microprocessor controller will output a signal when
wheel frosting is occurring which is determined by a
temperature set point (EA < 36°F, adjustable).
• Modulating wheel frost control: When frosting is
occurring, the wheel VFD will modulate the wheel
speed to maintain 36°F exhaust air temperature.
The VFD will be fully programmed at the factory.
• Modulating wheel with electric preheat frost control: When frosting is occurring, the wheel VFD
will modulate the wheel speed to maintain 36°F
exhaust air temperature. The electric preheater
will energize when the outdoor air temperature is
below 10°F. The VFD will be fully programmed at
the factory.
Maintenance
WARNING
Whenever performing maintenance or inspections,
always disconnect the power source.
Inspection
The wheel should be inspected in accordance with
the maintenance schedule. Maintenance of the wheel
consists mainly of inspecting the wheel for cleanliness
and then checking the drive motor, belt, and pulley for
wear. If the wheel appears dirty, the wheel should be
cleaned.
The wheel rotates through two airstreams moving in
opposite directions, which means the wheel is selfcleaning up to a point. If the wheel media collects a
layer of smoke residue or an oil film, the energy transfer
efficiency drops.
The main factor in the frequency of cleaning is the
cleanliness of the air. If air filters are not changed
frequently, the wheel will collect contaminants and will
then have to be cleaned.
Wheel Belt
Inspect belts each time filters are replaced. Belts
that look chewed up or are leaving belt dust near the
motor pulley may indicate a problem with the wheel.
Be sure to inspect wheel for smooth and unrestricted
rotation. If a belt requires replacement, contact the
local manufacturer representative. Instructions for
replacement will ship with the new belt.
Wheel Bearing
In the unlikely event that a wheel bearing fails, contact
the local manufacturer's representative for detailed
instructions.
Cleaning
Accumulation of dust or particles on the surface of
the wheel can typically be vacuumed, purged with
compressed air, or wiped from the surface. In cases
when a more thorough cleaning is required, use the
following procedure.
Liberally spray 409 cleaner onto a small section of the
dirty side of the energy wheel, letting it foam to soften
debris and residue. Blow approximately 90 psi of
compressed air and from the opposite side of the wheel,
catching the blown-off material on pre-placed drop
cloths. Lightly sweep a soft sash paint brush across
the face of the wheel to remove any leftover residue. A
SLIGHT CLEANER SMELL MAY BE PRESENT FOR A
SHORT TIME AFTER THE UNIT IS TURNED BACK ON.
THIS SMELL WILL DISSIPATE QUICKLY.
Dedicated Outdoor Air Unit34
Page 35
Troubleshooting – Alarms
Several of the electronic controls in the unit monitor the
system for faults and will go into alarm, shutting down
the unit or a single function within the unit.
Microprocessor Controller
The microprocessor is located in the main control
center. If the microprocessor is in alarm condition,
the Alarm button will blink red. Press the Alarm
button to see the specific condition or to reset the
microprocessor. Refer to the microprocessor IOM for
detailed information on fault codes and see the unitspecific wiring diagram.
Phase Monitor
The phase monitor has two LED indicator lights, one
red and one green. Green indicates proper operational
status, red indicates the unit has detected a fault and is
in alarm condition. The alarm LED will blink to show the
specific fault and there is a chart printed on the monitor
that shows the code for the blinking light. The phase
monitor is self-resetting once the alarm condition is
corrected. It is located in the main control center.
Variable Frequency Drive (VFD)
Variable frequency drives have a display screen that will
show an alarm condition. If a fault such as a voltage
spike occurs, the VFD will go into alarm and will not
reset until a hard restart is performed. See the unitspecific manufacturer’s manual supplied with the unit.
VFDs are located in the main control center.
Optional Digital Scroll Compressor
Controller
Present only if packaged DX with digital scroll option is
selected. The controller has
three LED indicator lights.
One is green, indicating that
it has power, one is an alarm
indicator that will flash a code
for various alarm conditions
and the third indicates
whether the compressor
is operating in a loaded or unloaded condition. See
the manufacturer’s unit-specific manual for further
information.
See the Fault Code chart below. The Fault Code chart
is also printed on the back of the controller. Note that
if the controller generates either a Code 2 or a Code 4
Lockout, a manual reset must be performed. Manual
Reset is accomplished by shutting off main power to the
unit and then turning it back on.
Digital Scroll Compressor
Controller Fault Codes
Alert Code
Code 2*
Code 3
Code 4*Locked RotorBlinks 4 TimesLockout
Code 5
Code 6
Code 7FutureN/AN/A
Code 8
Code 9Low VoltageBlinks 9 TimesTrip Compressor
System
Condition
High Discharge
Temperature Trip
Compressor
Protector Trip
Demand Signal
Loss
Discharge
Thermistor Fault
Welded
Contactor
*Protective faults that require manual reset.
Diagnostic
Alert Light
Blinks 2 TimesLockout
Blinks 3 TimesLockout
Blinks 5 TimesLockout
Blinks 6 Times
Blinks 8 Times
Action
Reduce
Capacity
Unload
Compressor
®
Dedicated Outdoor Air Unit35
Page 36
®
Troubleshooting – Unit
SymptomPossible CauseCorrective Action
Blown fuse or open circuit breaker.Replace fuse or reset circuit breaker and check amps.
Blower fails
to operate
Motor
starters
“chatter” or
do not pull in
Motor over
amps
Low airflow
(cfm)
High airflow
(cfm)
Excessive
noise or
vibration
Defective motor or capacitor.Replace.
Motor overloaded.Reset VFD and check amps.
Electrical.
Control power (24 VAC) wiring run is too
long. (Resistance should not
exceed 0.75 ohms).
Check for On/Off switches. Check for correct supply
voltage. Check Control wiring.
Shorten wiring run to mechanical room or install a relay
to turn unit on/off. Consult factory for relay information.
Increase wire gauge size so that resistance is 0.75 ohms
or less.
Incoming supply power is less than
anticipated. Voltage supplied to starter
coil must be within +10% / -15% of
Need to increase supply power or use a special control
transformer which is sized for the actual supply power.
nominal voltage stated on the coil.
Static pressures are higher than design.Check for dirty filters. Improve ductwork.
Motor voltage incorrect.
Motor horsepower too low.
Check motor wiring. Check motor nameplate versus
supplied voltage.
See specifications and catalog for fan curves to
determine if horsepower is sufficient.
Shorted windings in motor.Replace motor.
Unit damper not fully open.Adjust damper linkage or replace damper motor.
System static pressure too high.
Improve ductwork to eliminate losses using good duct
practices.
Check maximum motor RPM and compare with catalog
Blower speed too low.
data. Verify that external control wiring is in place if
required.
Fan wheels are operating backwards.
Dirty filter.
For 3-phase, see Direction of Fan Wheel Rotation
Direction in Start-Up, Components section.
Replace filters or follow cleaning procedures in Routine
Maintenance section of this manual.
Leaks in ductwork.Repair.
Elbows or other obstructions may be
obstructing fan outlet.
Blower fan speed too high.
Correct or improve ductwork.
Check for correct maximum fan RPM. Decrease
maximum fan speed if necessary in the VFD.
Induce Ps into system ductwork. Make sure grilles
and access doors are installed. Decrease fan speed if
necessary.
Adjust wheel and/or inlet cone. Tighten wheel hub or
bearing collars on shaft.
Replace defective bearing(s). Lubricate bearings. Tighten
collars and fasteners.
Loose wheel on shaft.Tighten wheel hub.
Motor base or blower loose.Tighten mounting bolts.
Make sure ductwork is supported properly. Make sure
Noise being transmitted by duct.
ductwork metal thickness is sized for proper stiffness.
Check duct size at discharge to ensure that air velocities
are not too high.
Always have a completed Pre-Start-Up Checklist and Start-Up Checklist prior to requesting parts or service information.
Dedicated Outdoor Air Unit36
Page 37
Troubleshooting – Refrigeration Circuit
TROUBLESHOOTING NOTE
IMPORTANT
Do not release refrigerant to the atmosphere! If
Before any components are changed on the
refrigeration system, the cause of the failure must be
identified. Further problems will exist unless the true
cause or problem is identified and corrected.
required service procedures include the adding or
removing of refrigerant, the service technician must
comply with all federal, state and local laws. The
procedures discussed in this manual should only be
performed by a qualified EPA Certified Technician.
NOTE: Unit is equipped with a phase loss/phase reversal control. If system does not start, check phase of electrical
supply.
The first step in troubleshooting a refrigeration circuit is to examine the microprocessor controller and digital scroll
compressor controller (if present) and see if there is a fault code. The next step is to check airflow conditions
(e.g. improper ductwork, atypical wet bulb / dry bulb, etc.). After these steps have been eliminated, proceed with
troubleshooting by following this guide.
SymptomPossible CauseCorrective Action
Open disconnect switch or circuit
breaker.
Compressor contactor not closing.
Blown fuse or tripped breaker.
Close switch and/or breaker.
Check voltage to contactor coil, transformer, slave relay,
system. Replace parts as necessary.
Check for reason and repair. Replace fuse after correcting
problem.
Compressor
will not run
or does not
start
Compressor
starts but
cuts out on
low pressure
Low pressure
switch cuts
out at
50 PSIG (PDX)
or 25 PSIG
(ASHP)
Low line voltage.
Check line voltage. If more than 10% from compressor
marking, correcting is necessary.
Motor thermal protector automatically resets. Allow time
Compressor motor protector open.
(2 hours) for compressor to cool down so protector will
reset. Restart and check for reason overheat occurred.
Check motor for open circuit, short circuit, grounded
Compressor defective.
windings, or burn out. Compressor may be seized; check
refrigerant. If necessary, replace compressor.
High pressure switch open
or defective.
Low pressure switch open
or defective.
Open room thermostat or control.
(No cooling required).
If manual reset (high pressure), reset switch. (Switch
opens at 610 psi and will not reset above 420 psi for
R-410A). Replace if defective.
See switch label for setpoint.
Check room temperature. If temperature is proper, wait
for thermostat to close.
Loose wiring.Check all wire terminals and tighten as necessary.
Low or loss of refrigerant charge.
Check refrigerant pressures and temperatures
(subcooling.)
Check for dirty evaporator coil, dirty filters, dampers
Refrigeration undercharged.Check subcooling. Adjust charge, if necessary.
Dirty filter or evaporating coil.Check filter, coil and airflow.
Dirty or clogged condensing coil.Check coil and airflow.
Air or other non-condensables in
system.
Check equalized high side pressure with equivalent
outdoor temperature.
Restriction in suction and liquid line.Check for restrictions in refrigerant circuit.
Control contacts stuck.Check wiring.
Excessive load.Add more equipment or reduce room load.
Restriction in liquid line.
Insufficient evaporating coil airflow.
Malfunctioning or defective expansion
valve.
Hot gas bypass valve not functioning
properly (if equipped).
Manual hot gas bypass valve closed (if
equipped).
Clear restriction upstream of point of frosting. (Note:
liquid line frosting in normal on ASHP units).
Check airflow, check filters, check VFD control signal for
proper operation.
Check bulb of thermal expansion valve.
Check valve. If defective, replace.
Open valve.
Low load or airflow.Increase airflow, check filters.
Always have a completed Pre-Start-Up Checklist and Start-Up Checklist prior to requesting parts or service information.
Dedicated Outdoor Air Unit40
Page 41
Routine Maintenance
DANGER
Electric shock hazard. Can cause injury or death.
Before attempting to perform any service or
maintenance, turn the electrical power to the unit to
OFF at disconnect switch(es). Unit may have multiple
power supplies.
CAUTION
Use caution when removing access panels or other
unit components, especially while standing on a
ladder or other potentially unsteady base. Access
panels and unit components can be heavy and
serious injury may occur.
This unit requires minimal maintenance to operate
properly. Maintenance requirements for this model
vary for each installation and depend greatly on how
much the system is used and the cleanliness of the air.
Proper maintenance will both increase the life of the
system and maintain its efficiency. Maintenance must
be performed by experienced technicians and in the
case of refrigeration systems, must be done by an EPA
certified technician.
Maintenance frequency is based on a presumed
nominal use of the system. If the system is being
run constantly, the frequency should be adjusted
accordingly. If there is seasonal debris in the air which
can be drawn into the filters and the coils, they should
be checked more frequently. If the system is being
used for only a few hours per day, the frequency may
be reduced. Use the maintenance log at the end of
this manual to record each maintenance session
and observations and then establish a maintenance
schedule that is appropriate for the installation. The
following is provided as a guideline.
Annually
It is recommended that the annual inspection and
maintenance occur at the start of the cooling season.
After completing the checklist, follow the unit start-up
checklist provided in the manual to ensure the
refrigeration system operates in the intended matter.
1. Lubrication
Apply lubricant where required
2. Dampers
Check for unobstructed operation
3. Blower Wheel and Fasteners
Check for cleanliness
Check all fasteners for tightness
Check for fatigue, corrosion, wear
4. Door Seal
Check if intact and pliable
5. Wiring Connections
Check all connections for tightness
6. Cabinet
Check entire cabinet, inside and out, for dirt
buildup or corrosion. Remove accumulated dirt,
remove any surface corrosion and coat the area
with appropriate finish.
Adjust replacement schedule for MERV 13 and
MERV 14 or other filters as inspection requires.
Semiannually
1. Check motor and motor bearings
Check for excessive heat, vibration or noise.
Lubricate bearings in accordance with the
motor manufacturer’s recommendations.
2. Condensate Drain (if applicable)
Inspect and clean – refill with water
3. Heat Transfer Coils (if applicable)
Inspect for cleanliness – clean as required
4. Outdoor Fan Blades and Motor (if applicable)
Check for cleanliness
Check all fasteners for tightness
Check for fatigue, corrosion, wear
®
Dedicated Outdoor Air Unit41
Page 42
®
Filter
Routine Maintenance
Maintenance Procedures:
Lubrication - Check all moving components for
proper lubrication. Apply lubricant where required.
Any components showing excessive wear should be
replaced to maintain the integrity of the unit and ensure
proper operation.
Dampers - Check all dampers to ensure they open and
close properly and without binding. Backdraft dampers
can be checked by hand to determine if blades open
and close freely. Apply power to motorized dampers to
ensure the actuator opens and closes the damper as
designed.
Gas Furnace - Maintain furnace in accordance with
instructions in the Indirect Gas-Fired Heat IOM shipped
with this unit.
Fan Motors - Motor maintenance is generally limited
to cleaning and lubrication. Cleaning should be limited
to exterior surfaces only. Removing dust and grease
buildup on the motor housing assists proper cooling.
Never wash-down the motor with high pressure
spray. Greasing of motors is only intended when
fittings are provided. Fan motors typically have two
grease fittings. Each motor manufacturer has different
lubrication schedules for different models. Go to the
motor manufacturer’s website and download their
maintenance requirements. Do not over-lubricate motors or use an incompatible grease. Many
fractional motors are permanently lubricated for life and
require no further lubrication.
Fan Wheel and Fasteners - Wheels require very little
attention when moving clean air. Occasionally oil and
dust may accumulate on the wheel causing imbalance.
When this occurs, the wheel and housing should be
cleaned to assure smooth and safe operation. Inspect
fan impeller and housing for fatigue, corrosion, or wear.
Routinely check all fasteners, set screws and locking
collars on the fan, bearings, drive, motor base and
accessories for tightness. A proper maintenance
program will help preserve the performance and
reliability designed into the fan.
Coil Maintenance - Coils must be cleaned to maintain
maximum performance. Check coils once per year
under normal operating conditions and if dirty, brush
or vacuum clean. Soiled fins reduce the capacity of the
coil, demand more energy from the fan and create an
environment for odor and bacteria to grow and spread
through the conditioned zone. High pressure water
(700 psi or less) may be used to clean coils with a fin
thickness over 0.0095 inches thick. TEST THE SPRAY PRESSURE over a small corner of the coil to determine
if the fins will withstand the spray pressure.
For coils with fragile fins or high fin density, foaming
chemical sprays and washes are available. Many coil
cleaners use harsh chemicals, so they must be used
with caution by qualified personnel only. Care must be
taken not to damage the coils, including the fins, while
cleaning. Caution: Fin edges are sharp!
WARNING
REFER TO GENERAL SAFETY INFORMATION
Do not operate this unit without the filters and
birdscreen installed. They prevent the entry of foreign
objects such as leaves, birds, etc.
Do not remove access panels or other unit
components while standing on a ladder or other
unsteady base. Access panels and unit components
are heavy and serious injury may occur.
Internal Filter Maintenance - The unit will typically be
provided with 2-inch thick pleated paper filters in the
airstream. These filters should be checked according
to a routine maintenance schedule and replaced as
necessary to ensure proper airflow through the unit.
Replacement filters shall be of same performance and
quality as factory installed filters. Filter must be pleated
design with integral metal grid. Two acceptable filter
replacements are Aerostat Series400 or Farr 30/30®.
Filters upstream of the coil should be checked regularly.
If the filters are dirty, they should be cleaned or
replaced. It is important the filters stay clean to maintain
desired airflow.
thick filters are located in the supply weatherhood (if
the weatherhood option was purchased). These filters
should be checked and
cleaned on a regular basis for
best efficiency. The frequency
of cleaning depends upon the
cleanliness of the incoming
air. These filters should be
cleaned by rinsing with a mild
detergent in warm water prior
to start-up.
Outdoor Air Intake Hood
Mesh Filter Access
WARNING
Biological hazard. May cause disease. Cleaning
should be performed by qualified personnel.
Drain pans in any air conditioning unit will have some
moisture in them, therefore, algae and other organisms
will grow due to airborne spores and bacteria. Periodic
cleaning is necessary to prevent this buildup from
plugging the drain and causing the drain pan to
overflow. Inspect twice a year to avoid the possibility
of overflow. Also, drain pans should be kept clean to
prevent the spread of disease. Cleaning should be
performed by qualified personnel.
* Based upon a 30 / 36 in. energy wheel (16x25x2, quantity of 3 for 41 in. energy wheel)
** Based upon a 52 in. energy wheel (16x16x2, quantity of 8 for 58 in. energy wheel)
As a result of our commitment to continuous improvement, Greenheck reserves the right to change specifications
without notice.
Product warranties can be found online at Greenheck.com, either on the specific product page or in the literature
section of the website at Greenheck.com/Resources/Library/Literature.
Greenheck’s Model RV and RVE catalog provides additional
information describing the equipment, fan performance,
available accessories, and specification data.
AMCA Publication 410-96, Safety Practices for Users and
Installers of Industrial and Commercial Fans, provides
additional safety information. This publication can be obtained
from AMCA International, Inc. at www.amca.org.
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