AAON LZ Series Owner's manual

LZ Series
Chillers and Outdoor Mechanical Rooms
Installation, Operation,
& Maintenance
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 should be kept with
the unit.
Do not store gasoline or other
flammable vapors and liquids in the
vicinity of this or any other appliance.
WHAT 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 you 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.
Startup and service must be
performed by a Factory Trained
Service Technician.
WARNING
WARNING

Table of Contents
Codes and Ordinances............................................................................................................... 19
Receiving Unit........................................................................................................................... 19
Storage....................................................................................................................................... 20
Outdoor Mechanical Room....................................................................................................... 20
Wiring Diagrams....................................................................................................................... 21
General Maintenance................................................................................................................. 21
Chiller Primary Pumping .......................................................................................................... 21
Chiller Primary/Secondary Pumping ........................................................................................ 22
Condensing Boilers ................................................................................................................... 22
Makeup Water........................................................................................................................... 23
Compression Tank..................................................................................................................... 23
Pressure Relief Valve................................................................................................................ 24
Automatic Air Vent................................................................................................................... 24
Dual Pumps ............................................................................................................................... 24
Pressure Gauges and Thermometers ......................................................................................... 24
Pipe Insulation........................................................................................................................... 25
Outdoor Mechanical Room Placement...................................................................................... 25
Curb and Steel Mount Installation ............................................................................................ 25
Lifting and Handling................................................................................................................. 28
Vestibule Exhaust Fan............................................................................................................... 29
Water Connection...................................................................................................................... 30
Temporary Drain –Evaporative Condenser.............................................................................. 31
Access Doors............................................................................................................................. 31
End Flashing Installation........................................................................................................... 31
Boiler Gas Connection .............................................................................................................. 32
Boiler Air Intake / Vent Piping ................................................................................................. 32
Sidewall Direct Boiler Venting................................................................................................. 35
Vertical Direct Boiler Venting.................................................................................................. 37
Boiler Condensate Drain........................................................................................................... 41
Split Unit Assembly.................................................................................................................. 41
Unit Mounting Isolation............................................................................................................ 41
Low Ambient Operation............................................................................................................ 41
Electrical.................................................................................................................................... 42
Variable Speed Compressors .................................................................................................... 44
Condenser Fan Pitch Adjustment.............................................................................................. 47
Boiler System Startup................................................................................................................ 50
Boiler Sequence of Operations.................................................................................................. 51
General ...................................................................................................................................... 51
Refrigerant Suction Line Filter ................................................................................................. 51
Suction Filter Removal Instructions.......................................................................................... 52
Refrigerant Liquid Line Filter Driers........................................................................................ 52
Evaporator/Heat Exchangers..................................................................................................... 53
Adjusting Refrigerant Charge ................................................................................................... 53
Lubrication ................................................................................................................................ 57

4
Air-Cooled Condenser............................................................................................................... 57
E-Coated Coil Cleaning ............................................................................................................ 57
Microchannel Coil Cleaning ..................................................................................................... 59
Evaporative-Condensed Chiller ................................................................................................ 61
Severe Operating Conditions Service.................................................................................... 62
Safety..................................................................................................................................... 62
Performance........................................................................................................................... 62
Warranties.............................................................................................................................. 63
Condenser Tube Inspection ................................................................................................... 63
Freeze Protection ................................................................................................................... 63
Recirculating Water System .................................................................................................. 63
Startup.................................................................................................................................... 63
Cleanliness............................................................................................................................. 63
Storage................................................................................................................................... 63
Pump Operation..................................................................................................................... 64
Running.................................................................................................................................. 64
Condenser Fan Motors........................................................................................................... 64
Water Make Up Valve........................................................................................................... 64
Water Treatment System ....................................................................................................... 65
Sequence of Operation for LZ Series units without Diagnostics .......................................... 65
Sequence of Operation for LZ Series units with Diagnostics................................................ 66
Pump Maintenance ................................................................................................................ 67
Fan Motor Maintenance......................................................................................................... 67
Access Doors ......................................................................................................................... 67
Bearings - Lubrication........................................................................................................... 68
Recommended Monthly Inspection....................................................................................... 68
Mist Eliminators .................................................................................................................... 68
Air Inlet.................................................................................................................................. 68
Stainless Steel Base Pan ........................................................................................................ 68
Propeller Fans and Motors..................................................................................................... 68
Recommended Annual Inspection......................................................................................... 68
Cleaning................................................................................................................................. 68
Water Quality......................................................................................................................... 69
Mechanical Cleaning............................................................................................................. 70
Service....................................................................................................................................... 70
Replacement Parts..................................................................................................................... 70
Water Pressure Reducing Valve................................................................................................ 71
Water Pressure Relief Valve ..................................................................................................... 73
Automatic Air Vent Valves....................................................................................................... 73
Pumps - Installation and Operating Instructions....................................................................... 75
Pump Piping - General.............................................................................................................. 77
Pump Operation......................................................................................................................... 77
General Care.............................................................................................................................. 78
Dual Pump Specific Information............................................................................................... 80
Horizontal and Vertical Expansion Tanks ................................................................................ 85
Suction Guides .......................................................................................................................... 86

5
Glycol Auto Fill Unit ................................................................................................................ 87
Flo-Trex Combination Valve .................................................................................................... 89
Index of Tables and Figures
Tables:
Table 1 - Service Clearances......................................................................................................... 25
Table 2 - Unit Gas Pipe Information, Feature B4 = A-J............................................................... 33
Table 3 - Unit Gas Pipe Information, Feature B4 = K-N.............................................................. 34
Table 4 - Nameplate Voltage Markings........................................................................................ 42
Table 5- Tandem Circuited Variable Speed Compressor VFD Frequency Range....................... 44
Table 6 - Air-Cooled Condenser Fan Pitch................................................................................... 47
Table 7 - Evaporative-Condensed Chiller Fan Pitch .................................................................... 47
Table 8 - Condenser Fan Pin Location (Bushing Mount)............................................................. 49
Table 9 - Condenser Fan Pin Location (Rotation Direction)........................................................ 49
Table 10 - Fan Assembly Bushing Torque Specifications............................................................ 50
Table 11 - Filter Drier Maximum Pressure Drop.......................................................................... 52
Table 12 - Acceptable Refrigeration Circuit Values..................................................................... 54
Table 13 - R-134a Refrigerant Temperature-Pressure Chart........................................................ 55
Table 14 - R-410A Refrigerant Temperature-Pressure Chart....................................................... 56
Table 15 - Recirculating Water Quality Guidelines ..................................................................... 69
Figures:
Figure 1 - Backflow Preventer...................................................................................................... 23
Figure 2 - Pressure Relief Valve................................................................................................... 24
Figure 3 - Curb Mounting with Dimensions................................................................................. 26
Figure 4 - Curb End Detail............................................................................................................ 26
Figure 5 - Steel Mounting Rail with Dimensions......................................................................... 26
Figure 6 - Concrete Pad Mounting with Dimensions ................................................................... 27
Figure 7 - LZ Base........................................................................................................................ 27
Figure 8 - Lifting Points................................................................................................................ 28
Figure 9 - LZ Series Example Lifting Detail................................................................................ 29
Figure 10 - Vestibule Exhaust Fan................................................................................................ 29
Figure 11 - Water Pipe Flashing Installation................................................................................ 30
Figure 12 –Temporary Drain Components.................................................................................. 31
Figure 13 - Factory Supplied End Flashings................................................................................. 31
Figure 14 - Sidewall Vent Shipping Cover Removal ................................................................... 35
Figure 15 - Sidewall Vent Plate Installation................................................................................. 35
Figure 16 - Typical Air Intake Piping........................................................................................... 35
Figure 17 - Typical Flue Vent Piping........................................................................................... 36
Figure 18 - Sidewall Vent Base .................................................................................................... 37
Figure 19 - Sidewall Vent Cap...................................................................................................... 37
Figure 20 - Roof Air Intake and Vent Piping Shipping Covers.................................................... 37
Figure 21 - Typical Vertical Air Intake Piping............................................................................. 38

6
Figure 22 - Correct Joint Connection............................................................................................ 39
Figure 23 - Incorrect Joint Connection......................................................................................... 39
Figure 24 - Typical Vertical Vent Piping ..................................................................................... 40
Figure 25 - Vertical Termination of Air Intake and Vent Piping ................................................. 40
Figure 26 - Evaporative-Condensed Chiller Section Layout........................................................ 45
Figure 27 - Fan with the HUB on the top and RET on the bottom............................................... 48
Figure 28 - Bushing Mount Location............................................................................................ 48
Figure 29 - RET with Pin in Groove 4.......................................................................................... 48
Figure 30 - Fan HUB and RET Castings...................................................................................... 48
Figure 31 - Pitch Insert ................................................................................................................. 49
Figure 32 - Replaceable Core Filter Driers................................................................................... 52
Figure 33 - Proper Unit Location.................................................................................................. 62
Figure 34 - Improper Unit Locations............................................................................................ 62
Figure 35 - Water Makeup Valve ................................................................................................. 65
Figure 36 –Evaporative condenser access door........................................................................... 67
V45100 · Rev. A · 190515

7
AAON LZ Series Features and Options Introduction
Energy Efficiency
•Staged or Variable Speed R-410A Scroll
Compressors
•Oil-Free Magnetic Bearing R-134a
Turbocor Centrifugal Compressors
•High Efficiency Air-Cooled
Microchannel Condenser Coils
•AAON Evaporative-Condensed Chiller
•VFD Controlled Pumping Packages
•VFD Controlled Condenser Fan Head
Pressure Control
•ECM Low Sound Condenser Fan Head
Pressure Control
•98% Thermal Efficiency Boilers
•Waterside Economizers
•Factory Installed EXVs
Outdoor Mechanical Room
•Chilled Water Applications up to
540 tons
•Hot Water Applications up to
6,000 MBH
•Lighted Walk-In Service Vestibule
•Factory Engineered Primary or
Primary/Secondary Pumping Packages
•Factory Installed Three Chemical Water
Treatment
•Factory Installed Compression Tank
•Brazed Plate or Shell and Tube
Evaporators
•Factory Installed Option Boxes for Field
Installed Accessories
Safety
•Phase and Brownout Protection
•Single Point Non-Fused Disconnect
Power Switch
•Factory Installed Refrigerant Leak
Detector
•Water Piping Air Separator
•Waterside Thermometer and Pressure
Gauge
Installation and Maintenance
•Double Wall Rigid Polyurethane Foam
Injected Panel Construction
•Lighted Walk-In Service Vestibule
•Access Doors with Full Length Stainless
Steel Piano Hinges
•Zinc Cast Lockable Handles
•Factory Installed Convenience Outlet
•Service Vestibule Heating and Cooling
•Motorized Service Vestibule Fresh Air
•Controls Diagnostics
•Touchscreen Computer Controls
Interface
•Evaporative-Condensed Chiller De-
Superheater
•Evaporative-Condensed Chiller Sump
Heaters
•Liquid Line Sight Glass
•Compressor Isolation Valves
•Auto Glycol Feeder
•Color-Coded Wiring Diagrams
System Integration
•Complete System with AAON Chilled
Water Air Handling Units
•BMS Connectivity
•Grooved End Water Piping Connections
•Custom Color Paint Options
Environmentally Friendly
•R-410A or R-134a Refrigerant
Extended Life
•Optional 5 Year Compressor Warranty
•Condenser Coil Guards
•2,500 Hour Salt Spray Tested Exterior
Corrosion Protection
•10,000 Hour Salt Spray Tested Polymer
E-Coated Condenser Coils
•

8
Safety
Attention should be paid to the following statements:
NOTE - Notes are intended to clarify the unit installation, operation and maintenance.
CAUTION - Caution statements are given 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, 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 unit. 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
QUALIFIED INSTALLER
Improper installation, adjustment,
alteration, service or maintenance can
cause property damage, personal
injury or loss of life. Startup and
service must be performed by a
Factory Trained Service Technician. A
copy of this IOM should be kept with
the unit.
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

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
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
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 shall
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, should be
followed.
WARNING
GROUNDING REQUIRED
All field installed wiring must be
completed by qualified personnel.
Field installed wiringmust comply 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
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
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

10
UNIT HANDLING
To prevent injury or death lifting
equipment capacity shall 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
Always use a pressure regulator,
valves and gauges to control incoming
pressures when pressure testing a
system. Excessive pressure may
cause line ruptures, equipment
damage or an explosion which may
result in injury or death.
WARNING
Door compartments containing
hazardous voltage or rotating parts
are equipped with door latches to
allow locks. Door latches are shipped
with nut and bolts requiring tooled
access. If you do not replace the
shipping hardware with a pad lock
always re-install the nut & bolt after
closing the door.
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
PVC (Polyvinyl Chloride) and CPVC
(Chlorinated Polyvinyl Chloride) are
vulnerable to attack by certain
chemicals. Polyolester (POE) oils that
are used in R-410A and other
refrigerant systems will cause stress
cracking of PVC or CPVC piping, even
if only present in trace amounts. This
will result in complete piping system
failure.
CAUTION
COMPRESSOR CYCLING
3 MINUTE MINIMUM OFF TIME
To prevent motor overheating
compressors must cycle off for a
minimum of 3 minutes.
3 MINUTE MINIMUM ON TIME
To maintain the proper oil level
compressors must cycle on for a
minimum of 3 minutes.
The cycle rate must not exceed 6
starts per hour.
WARNING
To prevent damage to the unit, do not
use acidic chemical coil cleaners. Do
not use alkaline chemical coil cleaners
with a pH value greater than 8.5, after
mixing, without first using an
aluminum corrosion inhibitor in the
cleaning solution.
CAUTION