AAON RZ Series Owner's manual

RZ SERIES
(45-240tons)
Packaged Rooftop Units & Outdoor Air Handling Units
Installation, Operation,
& Maintenance
oDo not store gasoline or other flammable
vapors and liquids in the vicinity of this or any
other appliance
oWHAT TO DO IF YOU SMELL GAS
Do not try to light any appliance.

Do not touch any electrical switch; do not
use any phone in your building.
Leave the building immediately.

Immediately call your gas supplier from a
phone remote from the building. Follow the
gas supplier’s instructions.

If you cannot reach your gas supplier, call
the fire department.
oStartup and service must be performed by a
Factory Trained Service Technician.
WARNING
FIRE OR EXPLOSION HAZARD
Failure to follow safety warnings
exactly could result in serious
injury, death or property damage.
Be sure to read and understand
the installation, operation and
service instructions in this manual.
Improper installation, adjustment,
alteration, service or maintenance
can cause serious injury, death or
property damage.
A copy of this IOM mustbe kept
with the unit.
WARNING

3
Table ofContents
Table of Contents
AAON® RZ Series Features and Options Introduction ............................................................. 7
Safety...................................................................................................................................... 8
RZ Series Feature String Nomenclature...................................................................................14
General Information ...............................................................................................................26
Codes and Ordinances.........................................................................................................27
Receiving Unit....................................................................................................................27
Storage...............................................................................................................................28
Access Doors......................................................................................................................28
Wiring Diagrams ................................................................................................................28
Installation .............................................................................................................................28
Locating Units....................................................................................................................28
Curb Installation .................................................................................................................29
Lifting the Unit...................................................................................................................30
Duct Connection.................................................................................................................33
Reassembling Split Units ....................................................................................................34
Refrigeration Split Installation Procedure.......................................................................35
Electrical Connection of Split Units................................................................................36
Outside Air Rain Hood .......................................................................................................36
End Flashing Installation.....................................................................................................36
Vestibule Exhaust Fan ........................................................................................................37
Electrical............................................................................................................................38
Variable Speed Compressors..........................................................................................40
Condensate Drain Piping.....................................................................................................41
Draw-Through Coils ...........................................................................................................41
Startup ...................................................................................................................................43
Filters.................................................................................................................................43
Cartridge Filter Installation...........................................................................................43
HEPA Filters.................................................................................................................43
Metal Mesh Filters.........................................................................................................43
Air Flow Monitoring...........................................................................................................44
Supply, Return, and Exhaust Backward Curved Fans ...........................................................44
Airflow Adjustment.........................................................................................................44
Back Draft Damper Setup ...................................................................................................46
Adjusting Refrigerant Charge..............................................................................................46
Before Charging ............................................................................................................46
Checking Liquid Sub-Cooling.........................................................................................47
Checking Evaporator Superheat.....................................................................................47
Adjusting Sub-cooling and Superheat Temperatures........................................................49
Freeze Stat Startup..............................................................................................................50
Refrigerant Filter Driers......................................................................................................50
Suction Filter Removal Instructions.....................................................................................51
VFD Controlled Condenser Fan Startup...............................................................................52

4
Low Sound Condenser Fan EC Motor Startup......................................................................52
Operation ...............................................................................................................................53
Packaged DX Cooling Operation.........................................................................................53
Indirect Gas Heater Operation .............................................................................................53
Electric Heating Operation..................................................................................................53
Steam or Hot Water Preheating and Heating Operation ........................................................53
Chilled Water or Non-Compressorized DX Cooling Operation.............................................53
Maintenance...........................................................................................................................54
Supply Fans........................................................................................................................54
Lubrication....................................................................................................................54
DX Cooling........................................................................................................................54
Condensate Drain Pans .......................................................................................................54
Filter Replacement..............................................................................................................54
Brazed Plate Heat Exchanger Cleaning................................................................................54
Air-Cooled Condenser ........................................................................................................55
E-Coated Coil Cleaning ......................................................................................................55
Microchannel Coil Cleaning................................................................................................57
Options ..................................................................................................................................59
Heating Coils......................................................................................................................59
Chilled Water Coil..............................................................................................................60
Packaged Direct Expansion (DX) Units...............................................................................60
Evaporator Coil.............................................................................................................61
Condenser Fans.............................................................................................................62
Evaporative Condenser .......................................................................................................62
Evaporative Condenser Location....................................................................................63
Evaporative Condenser Installation................................................................................64
Evaporative Condenser Operation..................................................................................64
Evaporative Condenser Sequence of Operation...............................................................66
Evaporative Condenser Maintenance..............................................................................67
Evaporative Condenser Water Quality............................................................................69
Energy Recovery Units .......................................................................................................71
Aluminum Energy Recovery Wheel.................................................................................71
Polymer Energy Recovery Wheel....................................................................................74
Energy Recovery Wheel General Cleaning......................................................................81
Energy Recovery Wheel Defrost Timer Setting...............................................................83
Gas or Electric Heating .......................................................................................................84
Gas Heating........................................................................................................................85
Piping Sizing Example ...................................................................................................86
Inlet and Manifold Pressures..........................................................................................86
Gas Pressure Regulator & Overpressure Protection Device............................................86
Piping Supports.............................................................................................................87
Additional Gas Piping Considerations............................................................................87
Leak Testing ..................................................................................................................88
Rain Hoods....................................................................................................................89
Gas Heater Operating Instructions.................................................................................90
Gas Heating Maintenance..............................................................................................91

5
Gas Heat Exchanger Removal........................................................................................91
Phase and Brownout Protection Module ..............................................................................92
UV Lights ..........................................................................................................................95
Filter Replacement..............................................................................................................95
Replacement Parts ..............................................................................................................97
Appendix A - Heat Exchanger Corrosion Resistance................................................................98
Appendix B - Thermistor Temperature vs. Resistance Values ................................................100
RZ Series Startup Form ........................................................................................................101
Maintenance Log (E-Coated Coil).........................................................................................108
Literature Change History.....................................................................................................109
G074290 · Rev. A · 220113
Index of Tables and Figures
Tables
Table 1 - Air-Cooled Condenser Unit Clearances 45-240 ton...........................................................29
Table 2 - Evaporative Condenser Unit Clearances 45-240 ton..........................................................29
Table 3 - Mounting Dimensions..................................................................................................33
Table 4 - Nameplate Voltage Markings & Tolerances.....................................................................38
Table 5 - RZ Variable Speed Compressor VFD Frequency Range....................................................40
Table 6 - Draw-Through Drain Trap Dimensions...........................................................................42
Table 7 - Blow-Through Drain Trap Dimensions...........................................................................42
Table 8 - Plenum Fan Set Screw Specifications .............................................................................45
Table 9 - Acceptable Fin & Tube Sub-Cooling and Superheat Temperatures......................................48
Table 10 - Acceptable Microchannel Air-Cooled Condenser Coil Liquid Sub-Cooling Values ..............48
Table 11 - R-410A Refrigerant Temperature-Pressure Chart............................................................50
Table 12 - Filter Drier Maximum Pressure Drop............................................................................50
Table 13 - EC Condenser Fan Cycling Options..............................................................................52
Table 14 - Hot Water Coil Connection Sizes.................................................................................59
Table 15 - Steam Distributing Coil Connection Sizes .....................................................................59
Table 16 - Chilled Water Coil Connection Sizes ............................................................................60
Table 17 - Energy Recovery Wheel Cleaning Frequency.................................................................81
Table 18 - RZ 45-140 ton Electric Heating Capacities ....................................................................84
Table 19 - RZ 145-240 ton Electric Heating Capacities...................................................................84
Table 20 - RZ 45-140 ton Gas Heating Capacities..........................................................................84
Table 21 - RZ 145-240 ton Gas Heating Capacities ........................................................................84
Table 22 - RZ 45-140 ton Unit Gas Piping Connections..................................................................85
Table 23 - RZ 145-240 ton Unit Gas Piping Connections................................................................85
Table 24 - Natural Gas Maximum Piping Capacities (ft3/hr)............................................................85
Table 25 - Propane (kBtu/hr) Maximum Piping Capacities ..............................................................86
Table 26 - Piping Support Intervals..............................................................................................87
Table 27 - Air Disinfection UV Information..................................................................................95
Table 28 - RZ Series Filter Sizes.................................................................................................96
Table 29 - Metal Mesh and HEPA Filter Sizes...............................................................................97

6
Figures
Figure 1 - Lockable Door Handles...............................................................................................28
Figure 2 - RZSeries Unit Orientation...........................................................................................29
Figure 3 - Base Rail Lifting Lug..................................................................................................30
Figure 4 - 4 Point Lift RZ Series Air-Cooled Condenser Unit ..........................................................31
Figure 5 - 8 Point Lift RZ Series Air-Cooled Condenser Unit ..........................................................32
Figure 6 - Curb Mounting ..........................................................................................................33
Figure 7 - Curb Detail................................................................................................................33
Figure 8 - Curb & Steel Mounting Rail with Dimensions ................................................................33
Figure 9 - Unit Base and Sides....................................................................................................34
Figure 10 - Unit Roof Flange Splice Detail ...................................................................................34
Figure 11 - Staggered assembly for refrigeration pipes....................................................................35
Figure 12 - Air Hood Shown in the Open Position .........................................................................36
Figure 13 - Factory Supplied End Flashings..................................................................................37
Figure 14 - Vestibule Exhaust Fan...............................................................................................37
Figure 15 - Motorized Exhaust....................................................................................................37
Figure 16 - Power Block............................................................................................................39
Figure 17 - Draw-Through Drain Trap.........................................................................................41
Figure 18 - Blow-Through Drain Trap..........................................................................................42
Figure 19 - Top Clip and Side Spring Fastener Securing Filters in Place............................................43
Figure 20 - Air Volume Band .....................................................................................................44
Figure 21 - Air Volume Band Tab Locations.................................................................................45
Figure 22 - Securing Air Volume Band Ends.................................................................................45
Figure 23 - Plenum Fan Gap Tolerances.......................................................................................45
Figure 24 - Closed Back Draft Damper ........................................................................................46
Figure 25 - Open Back Draft Damper...........................................................................................46
Figure 26 - Replaceable Core Liquid Filter/Driers Suction Filter......................................................51
Figure 27 - RPE-48-BD filter element..........................................................................................51
Figure 28 - Proper Unit Location.................................................................................................63
Figure 29 - Improper Unit Locations............................................................................................63
Figure 30 - Temporary Drain Components....................................................................................64
Figure 31 - Water Makeup Valve ................................................................................................66
Figure 32 - Evaporative condenser access door..............................................................................68
Figure 33 - Aluminum Energy Recovery Wheel............................................................................71
Figure 34 - Aluminum ERW Purge Sector Location.......................................................................72
Figure 35 - Polymer Energy Recovery Wheel................................................................................74
Figure 36 - Wheel Segment Removal Pattern................................................................................78
Figure 37 - Defrost Timer..........................................................................................................83
Figure 38 - Temperature Dial......................................................................................................83
Figure 39 - Gas Heater Rain Hood...............................................................................................89
Figure 40 - Gas Heater Rain Hood Screws....................................................................................89
Figure 41 - Gas Heat Exchanger..................................................................................................92

7
AAON® RZ Series Features and Options Introduction
EnergyEfficiency
Direct Drive Airfoil Plenum Supply Fans
Variable Speed R-410A Scroll
Compressors
AAON Evaporative Condenser
Airside Economizer
Factory Installed AAONAIRE®Energy
Recovery Wheels
Double Wall Rigid Polyurethane Foam
Panel Construction, R-13 Insulation
Modulating Natural Gas Heaters
Modulating/SCR Electric Heaters
Premium Efficiency Permanent Magnet
Motors
Variable Speed Supply/Return/Exhaust
Fans
Indoor Air Quality
100% Outside Air
Outside Airflow Monitoring
Economizer CO2Override
High Efficiency Filtration
Final Filters, including Gas Heat Systems
UV Lights for Single Pass 90% Air
Disinfection
Double Wall Rigid Polyurethane Foam
Panel Construction, R-13 Insulation
Interior Corrosion Protection
Humidity Control
High Capacity Cooling Coils
Variable Speed Compressors
Factory Installed AAONAIRE Total
Energy Recovery Wheels
Modulating Hot Gas Reheat
Safety
Burglar Bars
Freeze Stats
Phase and Brown Out Protection
Supply/Return Smoke Detectors
Supply/Return Firestats
Remote Safety Shutdown Terminals
Installation and Maintenance
Clogged Filter Switch
Color Coded Wiring Diagram
Compressors in Isolated Compartment
Compressor Isolation Valves
Convenience Outlet
Direct Drive Supply Fans
VFD Shaft Grounding
Hinged Access Doors with Lockable
Handles
Magnehelic Gauge
Service Lights
Sight Glasses
BACnet MSTP with Diagnostics
Remote Start-Stop Terminals
Access Door Windows
Motorized Fresh Air Service Vestibule
SystemIntegration
Chilled Water Cooling Coils
Electric/Natural Gas/LP Heating
Hot Water/Steam Heating Coil
Non-Compressorized DX Coils
Environmentally Friendly
Airside Economizers
Factory Installed AAONAIRE Energy
Recovery Wheels
R-410A Refrigerant
ExtendedLife
5 Year Compressor Warranty
25 Year Stainless Steel Heat Exchanger
Warranty
Interior Corrosion Protection
Polymer E-Coated Coils - 5 Year Coating
Warranty
Stainless Steel Coil Casing
Stainless Steel Drain Pans

8
Safety
ELECTRIC SHOCK, FIRE OR
EXPLOSION HAZARD
Failure to follow safety warnings
exactly could result in dangerous
operation, serious injury, death or
property damage.
Improper servicing could result in
dangerous operation, serious injury,
death, or property damage.
Before servicing, disconnect all
electrical power to the furnace.
More than one disconnect may be
provided.
When servicing controls, label all
wires prior to disconnecting.
Reconnect wires correctly.
Verify proper operation after
servicing. Secure all doors with
key-lock or nut and bolt.
WARNING
WHAT TO DO IF YOU SMELL GAS
Do not try to turn on unit.
Shut off main gas supply.
Do not touch any electric switch.
Do not use any phone in the
building.
Never test for gas leaks with an
open flame.
Use a gas detection soap solution
and check all gas connections and
shut off valves.
CAUTION
Electric shock hazard. Shut off all
electrical power to the unit to avoid
shock hazard or injury from rotating
parts.
WARNING
Attention must be paid to the following statements:
NOTE - Notes are intended to clarify the unit installation, operation and maintenance.
CAUTION- Caution statements aregiven to prevent actions that may result in equipment
damage, property damage, or personal injury.
WARNING - Warning statements are given to prevent actions that could result in
equipment damage, property damage, personal injury or death.
DANGER - Danger statements are given to prevent actions that will result in equipment
damage, property damage, severe personal injury or death.
Electric shock hazard. Before
servicing, shut off all electrical power
to the unit, including remote
disconnects, to avoid shock hazard or
injury from rotating parts. Follow
proper Lockout-Tagout procedures.
WARNING

9
FIRE, EXPLOSION OR CARBON
MONOXIDE POISONING HAZARD
Failure to replace proper controls
could result in fire, explosion or
carbon monoxide poisoning. Failure to
follow safety warnings exactly could
result in serious injury, death or
property damage. Do not store or use
gasoline or other flammable vapors
and liquids in the vicinity of this
appliance.
WARNING
During installation, testing, servicing,
and troubleshooting of the equipment
it may be necessary to work with live
electrical components. Only a
qualified licensed electrician or
individual properly trained in handling
live electrical components must
perform these tasks.
Standard NFPA-70E, an OSHA
regulation requiring an Arc Flash
Boundary to be field established and
marked for identification of where
appropriate Personal Protective
Equipment (PPE) be worn, must be
followed.
WARNING
ROTATING COMPONENTS
Unit contains fans with moving parts
that can cause serious injury. Do not
open door containing fans until the
power to the unit has been
disconnected and fan wheel has
stopped rotating.
WARNING
CARBON MONOXIDE POISONING
HAZARD
Failure to follow instructions could
result in severe personal injury or
death due to carbon-monoxide
poisoning, if combustion products
infiltrate into the building.
Check that all openings in the outside
wall around the vent (and air intake)
pipe(s) are sealed to prevent
infiltration of combustion products into
the building.
Check that furnace vent (and air
intake) terminal(s) are not obstructed
in any way during all seasons.
WARNING
Unit power supply wire must be only
copper or aluminum.
CAUTION

10
VARIABLE FREQUENCY DRIVES
Do not leave VFDs unattended in
hand mode or manual bypass.
Damage to personnel or equipment
can occur if left unattended. When in
hand mode or manual bypass mode
VFDs will not respond to controls or
alarms.
WARNING
GROUNDING REQUIRED
All field installed wiring must be
completed by qualified personnel.
Field installed wiring mustcomply with
NEC/CEC, local and state electrical
code requirements. Failure to follow
code requirements could result in
serious injury or death. Provide proper
unit ground in accordance with these
code requirements.
WARNING
Electric motor over-current protection
and overload protection may be a
function of the Variable Frequency
Drive to which the motors are wired.
Never defeat the VFD motor overload
feature. The overload ampere setting
must not exceed 115% of the electric
motors FLA rating as shown on the
motor nameplate.
CAUTION
UNIT HANDLING
To prevent injury or death, lifting
equipment capacity must exceed unit
weight by an adequate safety factor.
Always test-lift unit not more than 24
inches high to verify proper center of
gravity lift point to avoid unit damage,
injury or death.
WARNING
Failure to properly drain and vent coils
when not in use during freezing
temperature may result in coil and
equipment damage.
CAUTION
Rotation must be checked on all
MOTORS AND COMPRESSORS of 3
phase units at startup by a qualified
service technician. Scroll
compressors are directional and can
be damaged if rotated in the wrong
direction. Compressor rotation must
be checked using suction and
discharge gauges. Fan motor rotation
mustbe checked for proper operation.
Alterations must only be made at the
unit power connection
CAUTION
Do not use oxygen, acetylene or air in
place of refrigerant and dry nitrogen
for leak testing. A violent explosion
may result causing injury or death.
WARNING