Aaon LZ-053 Installation Manual
LZ Series
Chillers and Outdoor Mechanical Rooms
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.
Installation, Operation,
& Maintenance
3
Table of Contents
Safety .............................................................................................................................................. 8
LZ Series Feature String Nomenclature ....................................................................................... 12
General Information ...................................................................................................................... 19
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 ........................................................................................ 21
Condensing Boilers ................................................................................................................... 22
Makeup Water ........................................................................................................................... 22
Compression Tank ..................................................................................................................... 23
Pressure Relief Valve ................................................................................................................ 23
Automatic Air Vent ................................................................................................................... 24
Dual Pumps ............................................................................................................................... 24
Pressure Gauges and Thermometers ......................................................................................... 24
Pipe Insulation ........................................................................................................................... 24
Installation..................................................................................................................................... 25
Outdoor Mechanical Room Placement ..................................................................................... 25
Curb and Steel Mount Installation ............................................................................................ 25
Lifting and Handling ................................................................................................................. 27
Water Connection ...................................................................................................................... 29
Boiler Gas Connection .............................................................................................................. 30
Boiler Air Intake / Vent Piping ................................................................................................. 30
Sidewall Direct Boiler Venting ................................................................................................. 32
Vertical Direct Boiler Venting .................................................................................................. 34
Boiler Condensate Drain ........................................................................................................... 38
Split Unit Assembly .................................................................................................................. 38
Unit Mounting Isolation ............................................................................................................ 38
Access Doors ............................................................................................................................. 38
Low Ambient Operation ............................................................................................................ 38
Electrical .................................................................................................................................... 39
Startup ........................................................................................................................................... 43
Condenser Fan Pitch Adjustment .............................................................................................. 44
Boiler System Startup ................................................................................................................ 47
Boiler Sequence of Operations .................................................................................................. 48
Maintenance .................................................................................................................................. 48
General ...................................................................................................................................... 48
Refrigerant Filter Driers ............................................................................................................ 48
Evaporator/Heat Exchangers ..................................................................................................... 49
Adjusting Refrigerant Charge ................................................................................................... 49
Lubrication ................................................................................................................................ 53
Air-Cooled Condenser ............................................................................................................... 53
E-Coated Coil Cleaning ............................................................................................................ 53
Recommended Coil Cleaner .................................................................................................. 54
Recommended Chloride Remover ......................................................................................... 54
Microchannel Coil Cleaning ..................................................................................................... 54
Evaporative-Cooled Condenser ................................................................................................. 56
Severe Operating Conditions Service .................................................................................... 57
Safety ..................................................................................................................................... 57
Performance ........................................................................................................................... 57
Warranties .............................................................................................................................. 58
Condenser Tube Inspection ................................................................................................... 58
Freeze Protection ................................................................................................................... 58
Recirculating Water System .................................................................................................. 58
Startup .................................................................................................................................... 58
Cleanliness ............................................................................................................................. 58
Storage ................................................................................................................................... 58
Pump Operation ..................................................................................................................... 59
Running .................................................................................................................................. 59
Condenser Fan Motors ........................................................................................................... 59
Water Make Up Valve ........................................................................................................... 59
Water Treatment System ....................................................................................................... 60
Sequence of Operation for LZ Series units without Diagnostics .......................................... 60
Sequence of Operation for LZ Series units with Diagnostics ................................................ 61
Pump Maintenance ................................................................................................................ 62
Fan Motor Maintenance ......................................................................................................... 62
Access Doors ......................................................................................................................... 62
Bearings - Lubrication ........................................................................................................... 62
Recommended Monthly Inspection ....................................................................................... 62
Mist Eliminators .................................................................................................................... 62
Air Inlet .................................................................................................................................. 62
Stainless Steel Base Pan ........................................................................................................ 62
Propeller Fans and Motors ..................................................................................................... 63
Recommended Annual Inspection ......................................................................................... 63
Cleaning ................................................................................................................................. 63
Water Quality ......................................................................................................................... 63
Mechanical Cleaning ............................................................................................................. 64
Service ....................................................................................................................................... 64
Replacement Parts ..................................................................................................................... 64
Appendix - Water Piping Component Information ...................................................................... 65
Water Pressure Reducing Valve ................................................................................................ 65
Water Pressure Relief Valve ..................................................................................................... 67
Automatic Air Vent Valves ....................................................................................................... 67
Pumps - Installation and Operating Instructions ....................................................................... 69
Pump Piping - General .............................................................................................................. 71
Pump Operation ......................................................................................................................... 71
General Care .............................................................................................................................. 72
Dual Pump Specific Information ............................................................................................... 74
4
5
Horizontal and Vertical Expansion Tanks ................................................................................ 79
Suction Guides .......................................................................................................................... 80
Glycol Auto Fill Unit ................................................................................................................ 81
Flo-Trex Combination Valve .................................................................................................... 83
LZ Series Startup Form ................................................................................................................. 88
Index of Tables and Figures
Tables:
Table 1 - Service Clearances ......................................................................................................... 25
Table 2 - Unit Gas Pipe Information, Feature B4 = A-J ............................................................... 31
Table 3 - Unit Gas Pipe Information, Feature B4 = K-N.............................................................. 32
Table 4 - Air-Cooled Condenser Fan Pitch ................................................................................... 44
Table 5 - Evaporative-Cooled Condenser Fan Pitch ..................................................................... 44
Table 6 - Condenser Fan Pin Location (Bushing Mount) ............................................................. 46
Table 7 - Condenser Fan Pin Location (Rotation Direction) ........................................................ 46
Table 8 - Fan Assembly Bushing Torque Specifications.............................................................. 47
Table 9 - Filter Drier Maximum Pressure Drop ............................................................................ 49
Table 10 - Acceptable Refrigeration Circuit Values ..................................................................... 50
Table 11 - R-134a Refrigerant Temperature-Pressure Chart ........................................................ 51
Table 12 - R-410A Refrigerant Temperature-Pressure Chart ....................................................... 52
Table 13 - Recirculating Water Quality Guidelines ..................................................................... 63
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 - Lifting Points ................................................................................................................ 27
Figure 8 - LZ Series Example Lifting Detail ................................................................................ 28
Figure 9 - Water Pipe Flashing Installation .................................................................................. 29
Figure 10 - Sidewall Vent Shipping Cover Removal ................................................................... 32
Figure 11 - Sidewall Vent Plate Installation ................................................................................. 32
Figure 12 - Typical Air Intake Piping ........................................................................................... 33
Figure 13 - Typical Flue Vent Piping ........................................................................................... 33
Figure 14 - Sidewall Vent Base .................................................................................................... 34
Figure 15 - Sidewall Vent Cap...................................................................................................... 34
Figure 16 - Roof Air Intake and Vent Piping Shipping Covers .................................................... 34
Figure 17 - Typical Vertical Air Intake Piping ............................................................................. 35
Figure 18 - Correct Joint Connection............................................................................................ 36
Figure 19 - Incorrect Joint Connection ......................................................................................... 36
Figure 20 - Typical Vertical Vent Piping ..................................................................................... 37
Figure 21 - Vertical Termination of Air Intake and Vent Piping ................................................. 37
Figure 22 - Evaporative-Cooled Condenser Section Layout ........................................................ 42
Figure 23 - Fan with the HUB on the top and RET on the bottom. .............................................. 45
Figure 24 - Bushing Mount Location............................................................................................ 45
Figure 25 - RET with Pin in Groove 4 .......................................................................................... 45
Figure 26 - Fan HUB and RET Castings ...................................................................................... 45
Figure 27 - Pitch Insert ................................................................................................................. 46
Figure 28 - Replaceable Core Filter Driers ................................................................................... 48
Figure 29 - Proper Unit Location .................................................................................................. 57
Figure 30 - Improper Unit Locations ............................................................................................ 57
Figure 31 - Water Makeup Valve ................................................................................................. 60
V45100 · Rev. A · 150715
6
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-Cooled Condenser
• VFD Controlled Pumping Packages
• VFD Controlled Condenser Fans
• 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-Cooled Condenser De-
Superheater
• Evaporative-Cooled Condenser 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
• 6,000 Hour Salt Spray Tested Polymer
E-Coated Condenser Coils
8
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
Failure to follow safety warnings
exactly could result in dangerous
operation, serious injury, death or
Improper servicing could result in
dangerous operation, serious injury,
Before servicing, disconnect all
electrical power to the unit. More
than one disconnect may be
When servicing controls, label all
wires prior to disconnecting.
Verify proper operation after
servicing. Secure all doors with
key-lock or nut and bolt.
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
A copy of this IOM should be kept
with the unit.
Do not use any phone in the
Never test for gas leaks with an
Use a gas detection soap solution
and check all gas connections
and shut off valves.
Safety
QUALIFIED INSTALLER
EXPLOSION HAZARD
property damage.
death, or property damage.
provided.
Factory Trained Service Technician.
WHAT TO DO IF YOU SMELL GAS
Do not try to turn on unit.
Shut off main gas supply.
Reconnect wires correctly.
Do not touch any electric switch.
building.
open flame.
9
FIRE, EXPLOSION OR CARBON
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.
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.
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
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.
All field installed wiring must be
completed by qualified personnel.
Field installed wiring must 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.
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.
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.
MONOXIDE POISONING HAZARD
GROUNDING REQUIRED
VARIABLE FREQUENCY DRIVES
perform these tasks.
10
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.
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.
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.
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.
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
To prevent motor overheating
compressors must cycle off for a
To maintain the proper oil level
compressors must cycle on for a
The cycle rate must not exceed 6
starts per hour.
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.
UNIT HANDLING
COMPRESSOR CYCLING
3 MINUTE MINIMUM OFF TIME
minimum of 3 minutes.
3 MINUTE MINIMUM ON TIME
minimum of 3 minutes.
11
Polyolester (POE) and Polyvinylether
(PVE) oils are two types of lubricants
used with R-410A and R134a
refrigeration systems. Refer to the
compressor label for the proper
compressor lubricant type.
CAUTION
Do not clean DX refrigerant coils with
hot water or steam. The use of hot
water or steam on refrigerant coils
will cause high pressure inside the
coil tubing and damage to the coil.
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
should be checked for proper
operation. Alterations should only be
made at the unit power connection.
Some chemical coil cleaning
Use
these substances only in accordance
with the manufacturer’s usage
instructions. Failure to follow
instructions may result in equipment
damage, injury or death.
WARNING
compounds are caustic or toxic.
1. Startup and service must be performed
by a Factory Trained Service
Technician.
2. The unit is for outdoor use only. See
General Information section for more
information.
3. Use only with type of the gas approved
for the boiler. Refer to the boiler rating
plate.
4. Provide adequate combustion ventilation
air to the boiler.
5. Every unit has a unique equipment
nameplate with electrical, operational,
and unit clearance specifications.
Always refer to the unit nameplate for
ratings unique to the model you have
purchased.
6. READ THE ENTIRE INSTALLATION,
OPERATION AND MAINTENANCE
MANUAL. OTHER IMPORTANT
SAFETY PRECAUTIONS ARE
PROVIDED THROUGHOUT THIS
MANUAL.
7. Keep this manual and all literature
safeguarded near or on the unit.
Model Options
:
Unit Feature Options
GEN
MJREV SIZE SERIES MNREV VLT A1
A2
A3
A4
A5 B1
B2
B3
B4 1 2
3A
3B
3C
3D 4A
4B
4C
4D 5A
5B
5C
5D 6 7
8A
8B
8C
LZ A -
140
- C - 0 - 3 - F A C 0
E
-
0 0 0 0 : E 0 - 0 0 0 0 - 0 0 0 0 - 0 0 0 0 - 0 0 - 0 0 0
0 - 0 E 0 0 - 0 0 C 0 0 - 0 J 0 0 0 - 0 0 0 0 0 - 0 0 0 0 0 0 - 0 0 0 0 0 - 0 0 D
B
9
10A
10B
10C
10D
11
12
13
14
15 16
17
18
19
20 21
22
23
24
25
26A
26B
26C
26D
26E
26F
27
28
29
30
31 32
33
34
35
12
Air-Cooled
Evaporative-Cooled
045 = 45 ton Capacity
053 = 53 ton Capacity
055 = 55 ton Capacity
061 = 61 ton Capacity
060 = 60 ton Capacity
069 = 69 ton Capacity
075 = 75 ton Capacity
078 = 78 ton Capacity
090 = 90 ton Capacity
090 = 90 ton Capacity
095 = 95 ton Capacity
106 = 106 ton Capacity
105 = 105 ton Capacity
120 = 120 ton Capacity
120 = 120 ton Capacity
121 = 121 ton Capacity
140 = 140 ton Capacity
134 = 134 ton Capacity
170 = 170 ton Capacity
150 = 150 ton Capacity
181 = 181 ton Capacity
161 = 161 ton Capacity
200 = 200 ton Capacity
180 = 180 ton Capacity
181 = 181 ton Capacity
193 = 193 ton Capacity
239 = 239 ton Capacity
240 = 240 ton Capacity
274 = 274 ton Capacity
300 = 300 ton Capacity
356 = 356 ton Capacity
360 = 360 ton Capacity
401 = 401 ton Capacity
441 = 441 ton Capacity
450 = 450 ton Capacity
478 = 478 ton Capacity
540 = 540 ton Capacity
Air-Cooled
A = 45-60 ton units
B = 75 ton unit
C = 95-140 ton units
D = 175-200 ton units
Evaporative-Cooled
A = 53-69 ton units
B = 78 ton unit
C = 106-161 ton units
D = 193-239 ton units
E = 274-319 ton units
F = 356-401 ton units
G = 441-478 ton units
Air-Cooled
H = 90-120 ton units
K = 181 ton unit
Evaporative-Cooled
H = 90-120 ton units
J = 150-180 ton units
K = 181 ton unit
L = 240 ton unit
M = 300-360 ton units
N = 450-540 ton units
LZ Series Feature String Nomenclature
MODEL OPTIONS
Series and Generation
LZ
Major Revision
A
Unit Size
Series - Scroll Compressor
LZ Series Feature String Nomenclature
Series - Turbocor Compressor
Minor Revision
0
Voltage
2 = 230V/3Φ/60Hz
3 = 460V/3Φ/60Hz
4 = 575V/3Φ/60Hz
8 = 208V/3Φ/60Hz
A1: Compressor Style
F = R-410A Tandem VFD Compatible Scroll
Compressor
H = R-134a Turbocor Centrifugal Compressor
J = R-134a Turbocor Centrifugal Compressor with
Economizer
A2: Condenser Style
A = Air-Cooled Microchannel Condenser
H = Evaporative-Cooled Condenser
A3: Evaporator Configuration
A = Brazed Plate
B = Oversized Brazed Plate
C = Shell & Tube
D = Oversized Shell & Tube
A4: Coating
0 = Standard
E = Polymer E-Coated Condenser Coil
A5: Staging
0 = Staged On/Off Compressors
E = All Circuits Variable Capacity Compressors
G = Half Circuits Variable Capacity Compressors
LZ Series Feature String Nomenclature
Model Options
:
Unit Feature Options
GEN
MJREV SIZE SERIES MNREV VLT A1
A2
A3
A4
A5 B1
B2
B3
B4 1 2
3A
3B
3C
3D 4A
4B
4C
4D 5A
5B
5C
5D 6 7
8A
8B
8C
LZ A -
140
- C - 0 - 3 - F A C 0
E
-
0 0 0 0 : E 0 - 0
0
0 0 - 0 0 0 0 - 0 0 0 0 - 0 0 - 0 0 0
0 - 0 E 0 0 - 0 0 C 0 0 - 0 J 0 0 0 - 0 0 0 0 0 - 0 0 0 0 0 0 - 0 0 0 0 0 - 0 0 D
B
9
10A
10B
10C
10D
11
12
13
14
15 16
17
18
19
20 21
22
23
24
25
26A
26B
26C
26D
26E
26F
27
28
29
30
31 32
33
34
35
13
B1: Type
0 = No Boilers
B2: Boiler Quantity
0 = No Boilers
B3: Type and Pipe Size
0 = No Boilers
B4: Boiler Capacity
0 = No Boilers
UNIT FEATURE OPTIONS
1: Unit Orientation
E = Walk-in Vestibule Left Access Left Water
Connections
F = Walk-in Vestibule Left Access Right Water
Connections
G = Walk-in Vestibule Left Access Bottom Water
Connections
J = Walk-in Vestibule Right Access Left Water
Connections
K = Walk-in Vestibule Right Access Right Water
Connections
L = Walk-in Vestibule Right Access Bottom Water
Connections
2: Pumping Style
0 = No Pumps
A = Const. Primary Pumping System Small Pipe Size
B = Const. Primary Pumping System Large Pipe Size
C = Var. Primary Pumping System Small Pipe Size
D = Var. Primary Pumping System Large Pipe Size
E = Primary/Secondary Pumping System Small Pipe
Size
F = Primary/Secondary Pumping System Large Pipe
Size
3A: Building Pump Configuration
0 = No Building Pumps
A = 1 Pump + High Eff Motor
B = 1 Dual Pump + High Eff Motors
C = 2 Single Pumps + High Eff Motors
D = 1 Pump + VFD + High Eff Motor
E = 1 Dual Pump + 2 VFD's + High Eff Motors
F = 2 Single Pumps + 2 VFD’s + High Eff Motors
K = 1 Pump + Field Installed VFD + High Eff Motor
L = 1 Dual Pump + 2 Field Installed VFD's + High
Eff Motors
M = 2 Single Pumps + 2 Field Installed VFD’s +
High Eff Motors
3B: Building Pump Series and RPM
0 = No Building Pumps
A = 4360 (1,200 nominal rpm)
B = 4360 (1,800 nominal rpm)
C = 4360 (3,600 nominal rpm)
D = 4380 (1,200 nominal rpm)
E = 4380 (1,800 nominal rpm)
F = 4380 (3,600 nominal rpm)
G = 4300 (1,200 nominal rpm)
H = 4300 (1,800 nominal rpm)
J = 4300 (3,600 nominal rpm)
K = 4382 (1,200 nominal rpm)
L = 4382 (1,800 nominal rpm)
M = 4382 (3,600 nominal rpm)
N = 4302 (1,200 nominal rpm)
P = 4302 (1,800 nominal rpm)
Q = 4302 (3,600 nominal rpm)
LZ Series Feature String Nomenclature
Model Options
:
Unit Feature Options
GEN
MJREV SIZE SERIES MNREV VLT A1
A2
A3
A4
A5 B1
B2
B3
B4 1 2
3A
3B
3C
3D 4A
4B
4C
4D 5A
5B
5C
5D 6 7
8A
8B
8C
LZ A -
140
- C - 0 - 3 - F A C 0
E - 0 0 0 0 : E 0 - 0
0
0 0 - 0 0
0 0 - 0 0 0 0 - 0 0 - 0 0
0
0 - 0 E 0 0 - 0 0 C 0 0 - 0 J 0 0 0 - 0 0 0 0 0 - 0 0 0 0 0 0 - 0 0 0 0 0 - 0 0 D
B
9
10A
10B
10C
10D
11
12
13
14
15 16
17
18
19
20 21
22
23
24
25
26A
26B
26C
26D
26E
26F
27
28
29
30
31 32
33
34
35
14
3C: Pump Size
0 = No Building Pumps
A = 1.5B
B = 2B
C = 2D
D = 3D
E = 1.5x1.5x6
F = 2x2x6
G = 3x3x6
H = 4x4x6
J = 6x6x6
K = 1.5x1.5x8
L = 2x2x8
M = 3x3x8
N = 4x4x8
P = 5x5x8
Q = 6x6x8
R = 8x8x8
S = 2x2x10
T = 3x3x10
U = 4x4x10
V = 6x6x10
W = 8x8x10
Y = 4x4x11.5
Z = 5x5x11.5
1 = 6x6x11.5
2 = 8x8x11.5
3 = 4x4x13
4 = 6x6x13
5 = 8x8x13
3D: Building Pump Motor Size
0 = No Building Pumps
A = 0.5 hp
B = 0.75 hp
C = 1 hp
D = 1.5 hp
E = 2 hp
F = 3 hp
G = 5 hp
H = 7.5 hp
J = 10 hp
K = 15 hp
L = 20 hp
M = 25 hp
N = 30 hp
P = 40 hp
Q = 50 hp
R = 60 hp
S = 75 hp
4A: Recirculating Pump Configuration
0 = No Recirculating Pumps
A = 1 Pump + High Eff Motor
B = 1 Dual Pump + High Eff Motors
C = 2 Single Pumps + High Eff Motors
4B: Recirculation Pump Series & RPM
0 = No Recirculating Pumps
A = 4360 (1,200 nominal rpm)
B = 4360 (1,800 nominal rpm)
C = 4360 (3,600 nominal rpm)
D = 4380 (1,200 nominal rpm)
E = 4380 (1,800 nominal rpm)
F = 4380 (3,600 nominal rpm)
G = 4300 (1,200 nominal rpm)
H = 4300 (1,800 nominal rpm)
J = 4300 (3,600 nominal rpm)
K = 4382 (1,200 nominal rpm)
L = 4382 (1,800 nominal rpm)
M = 4382 (3,600 nominal rpm)
N = 4302 (1,200 nominal rpm)
P = 4302 (1,800 nominal rpm)
Q = 4302 (3,600 nominal rpm)
LZ Series Feature String Nomenclature
Model Options
:
Unit Feature Options
GEN
MJREV SIZE SERIES MNREV VLT A1
A2
A3
A4
A5 B1
B2
B3
B4 1 2
3A
3B
3C
3D 4A
4B
4C
4D 5A
5B
5C
5D 6 7
8A
8B
8C
LZ A -
140
- C - 0 - 3 - F A C 0
E - 0 0 0 0 : E 0 - 0 0 0 0 - 0 0
0 0 - 0 0 0 0 - 0 0 - 0 0
0
0 - 0 E 0 0 - 0 0 C 0 0 - 0 J 0 0 0 - 0 0 0 0 0 - 0 0 0 0 0 0 - 0 0 0 0 0 - 0 0 D
B
9
10A
10B
10C
10D
11
12
13
14
15 16
17
18
19
20 21
22
23
24
25
26A
26B
26C
26D
26E
26F
27
28
29
30
31 32
33
34
35
15
4C: Recirculating Pump Size
0 = No Recirculating Pumps
A = 1.5B
B = 2B
C = 2D
D = 3D
E = 1.5x1.5x6
F = 2x2x6
G = 3x3x6
H = 4x4x6
J = 6x6x6
K = 1.5x1.5x8
L = 2x2x8
M = 3x3x8
N = 4x4x8
P = 5x5x8
Q = 6x6x8
R = 8x8x8
S = 2x2x10
T = 3x3x10
U = 4x4x10
V = 6x6x10
W = 8x8x10
Y = 4x4x11.5
Z = 5x5x11.5
1 = 6x6x11.5
2 = 8x8x11.5
3 = 4x4x13
4 = 6x6x13
5 = 8x8x13
4D: Recirculating Pump Motor Size
0 = No Recirculating Pumps
A = 0.5 hp
B = 0.75 hp
C = 1 hp
D = 1.5 hp
E = 2 hp
F = 3 hp
G = 5 hp
H = 7.5 hp
J = 10 hp
K = 15 hp
L = 20 hp
M = 25 hp
N = 30 hp
P = 40 hp
Q = 50 hp
R = 60 hp
S = 75 hp
5A: Boiler Building Pump Configuration
0 = No Boiler Pumps
5B: Boiler Building Pump Series & RPM
0 = No Boiler Pumps
5C: Boiler Building Pump Size
0 = No Boiler Pumps
5D: Boiler Building Pump Motor Size
0 = No Boiler Pumps
6: Refrigeration Options
0 = None
A = Hot gas bypass on non-variable capacity
compressor circuits
B = Hot gas bypass on all circuits
7: Refrigeration Accessories
0 = Standard
A = Sight Glass
B = Compressor Isolation Valves
C = Option A + B
8A: Unit Disconnect Type
0 = Standard Single Point Power Block
A = Single Point Power Non-fused Disconnect
8B: Disconnect 1 Size
0 = Power Block
N = 100 amps
R = 150 amps
U = 225 amps
Z = 400 amps
3 = 600 amps
5 = 800 amps
7 = 1200 amps
LZ Series Feature String Nomenclature
Model Options
:
Unit Feature Options
GEN
MJREV SIZE SERIES MNREV VLT A1
A2
A3
A4
A5 B1
B2
B3
B4 1 2
3A
3B
3C
3D 4A
4B
4C
4D 5A
5B
5C
5D 6 7
8A
8B
8C
LZ A -
140
- C - 0 - 3 - F A C 0
E - 0 0 0 0 : E 0 - 0 0 0 0 - 0 0 0 0 - 0 0 0 0 - 0 0 - 0
0
0
0 - 0 E 0 0 - 0 0 C 0 0 - 0 J
0 0 0 - 0 0 0 0 0 - 0 0 0 0 0 0 - 0 0 0 0 0 - 0 0 D B
9
10A
10B
10C
10D
11
12
13
14
15 16
17
18
19
20 21
22
23
24
25
26A
26B
26C
26D
26E
26F
27
28
29
30
31 32
33
34
35
16
8C: Blank
0 = Standard
9: Accessories
0 = None
B = Phase & Brown Out Protection
10A: Unit Control Sequence
0 = Standard AAON Controls
10B: Unit Control Supplier
E = MCS Controls
10C: Control Supplier Options
0 = None
A = Touchscreen Computer Interface
C = Modem
G = Option A + C
10D: BMS Connection & Diagnostics
0 = None
A = BACnet IP
B = BACnet MSTP
C = Modbus IP
D = Modbus RTU
E = LonTalk
H = No BMS Connection with Diagnostics
J = BACnet IP with Diagnostics
K = BACnet MSTP with Diagnostics
L = Modbus IP with Diagnostics
M = Modbus RTU with Diagnostics
N = LonTalk with Diagnostics
11: Cabinet Options
0 = None
B = Access Door Windows
12: Vestibule Accessories
0 = None
A = Refrigerant Leak Detector
B = Motorized Service Vestibule Fresh Air
C = Vestibule Heating (Electric)
D = Vestibule Cooling (Fan/Coil)
F = Option A + B
G = Option A + C
H = Option A + D
K = Option B + C
L = Option B + D
N = Option C + D
R = Option A + B + C
S = Option A + B + D
U = Option A + C + D
Y = Option B + C + D
3 = Option A + B + C + D
13: Maintenance Accessories
0 = None
A = 115VAC Convenience Outlet Factory Wired
B = 115VAC Convenience Outlet Field Wired
C = Service Lights
F = Option A + C
J = Option B + C
14: Option Boxes
0 = None
A = 2 ft Option Box
B = 4 ft Option Box
C = 6 ft Option Box
D = 8 ft Option Box
F = 10 ft Option Box
G = 12 ft Option Box
15: Code Options
0 = Standard ETL U.S.A. Listing
A = Chicago Code
B = ETL U.S.A. + Canada Listing
16: Shipping Splits
0 = One Piece Unit
A = Two Piece Unit
17: Air-Cooled Condenser Accessories
0 = None (No Air-Cooled Condenser)
H = Cond Coil Guards + 3Φ Condenser Fan Motor +
Fan Cycling (25°F)
J = Cond Coil Guards + 3Φ Condenser Fan Motor +
VFD Condenser Fan Head Pressure Control (0°F)
LZ Series Feature String Nomenclature
Model Options
:
Unit Feature Options
GEN
MJREV SIZE SERIES MNREV VLT A1
A2
A3
A4
A5 B1
B2
B3
B4 1 2
3A
3B
3C
3D 4A
4B
4C
4D 5A
5B
5C
5D 6 7
8A
8B
8C
LZ A -
140
- C - 0 - 3 - F A C 0
E - 0 0 0 0 : E 0 - 0 0 0 0 - 0 0
0 0 - 0 0 0 0 - 0 0 - 0 0
0
0 - 0 E 0 0 - 0 0 C 0 0 - 0 J 0 0 0 - 0 0 0 0 0 - 0 0 0 0 0 0 - 0 0 0 0 0 - 0 0 D
B
9
10A
10B
10C
10D
11
12
13
14
15 16
17
18
19
20 21
22
23
24
25
26A
26B
26C
26D
26E
26F
27
28
29
30
31 32
33
34
35
17
18: Evaporative-Cooled Condenser Accessories
0 = None (No Evaporative-Condenser)
A = No Sump Heat
B = Sump Heaters
19: Blank
0 = None
20: Blank
0 = None
21: Chiller Compression Tank
0 = None
A = AX-15V
B = AX-20V
C = AX-40V
D = AX-60V
E = AX-80V
F = AX-100V
G = AX-120V
H = AX-180V
J = AX-200V
K = AX-240V
L = AX-260V
M = AX-280V
22: Boiler Compression Tank
0 = None
23: Blank
0 = Standard
24: Chiller Accessories 1
0 = None
A = Glycol chiller
B = Air Separator
C = Thermometers & Pressure Gauges
D = Chemical Pot Feeder
E = Auto Glycol Feeder
F = Option A + B
G = Option A + C
H = Option A + D
J = Option A + E
K = Option B + C
L = Option B + D
M = Option B + E
N = Option C + D
P = Option C + E
Q = Option D + E
R = Option A + B + C
S = Option A + B + D
T = Option A + B + E
U = Option A + C + D
V = Option A + C + E
W = Option A + D + E
Y = Option B + C + D
Z = Option B + C + E
1 = Option B + D + E
2 = Option C + D + E
3 = Option A + B + C + D
4 = Option A + B + C + E
5 = Option A + B + D + E
6 = Option A + C + D + E
7 = Option B + C + D + E
8 = Option A + B + C + D + E
25: Blank
0 = Standard
26A: Blank
0 = Standard
26B: Blank
0 = Standard
26C: Blank
0 = Standard
26D: Blank
0 = Standard
26E: Blank
0 = Standard
26F: Blank
0 = Standard
27: Blank
0 = Standard
LZ Series Feature String Nomenclature
Model Options
:
Unit Feature Options
GEN
MJREV SIZE SERIES MNREV VLT A1
A2
A3
A4
A5 B1
B2
B3
B4 1 2
3A
3B
3C
3D 4A
4B
4C
4D 5A
5B
5C
5D 6 7
8A
8B
8C
LZ A -
140
- C - 0 - 3 - F A C 0
E - 0 0 0 0 : E 0 - 0 0 0 0 - 0 0 0 0 - 0 0 0 0 - 0 0 - 0 0 0
0 - 0 E 0 0 - 0 0 C 0 0 - 0 J 0 0 0 - 0 0 0 0 0 - 0 0 0 0 0 0 - 0
0 0 0 0 - 0 0 D B
9
10A
10B
10C
10D
11
12
13
14
15 16
17
18
19
20 21
22
23
24
25
26A
26B
26C
26D
26E
26F
27
28
29
30
31 32
33
34
35
18
28: Blank
0 = Standard
29: Blank
0 = Standard
30: Blank
0 = Standard
31: Blank
0 = Standard
32: Blank
0 = Standard
33: Warranty
0 = Standard Warranty
D = Compressor Warranty Years 2-5
34: Cabinet Material
D = Galvanized Cabinet 6” Base Rail + Double Slope
Roof
H = Galvanized Cabinet 8” Base Rail + Double Slope
Roof
35: Paint & Special Pricing Authorizations
B = Premium AAON Gray Paint Exterior
E = Premium AAON Gray Paint Exterior + Shrink
Wrap
X = Special Pricing Authorization + Premium AAON
Gray Paint Exterior
1 = Option X + Shrink Wrap
4 = Special Pricing Authorization + Special Exterior
Paint Color
7 = Option 4 + Shrink Wrap
19
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
Electrical raceways are located in the
upper wall sections of the unit. DO
NOT CUT OR DRILL into the wall
sections of the unit that are within 12
inches of the roofline.
The Clean Air Act of 1990 bans the
intentional venting of refrigerant as of
July 1, 1992. Approved methods of
recovery, recycling, or reclaiming
Coils and sheet metal surfaces
present sharp edges and care must
be taken when working with
equipment.
Failure to observe the following
instructions will result in premature
failure of your system and possible
voiding of the warranty.
General Information
AAON LZ Series chiller outdoor
mechanical rooms are complete selfcontained liquid chilling units. They are
assembled, wired, charged, and run-tested.
Models are available for air-cooled and
evaporative-cooled applications. Chiller
primary pumping packages,
primary/secondary pumping packages, and
boilers with pumping package are available
as optional features.
Factory Trained Service Technician.
Installation of LZ Series units must conform
to the ICC standards of the International
Mechanical Code, the International Building
Code, and local building, plumbing and
waste water codes. All appliances must be
electrically grounded in accordance with
local codes, or in the absence of local codes,
the current National Electric Code,
ANSI/NFPA 70 or the current Canadian
Electrical Code CSA C22.1.
must be followed.
RISK OF ELECTRICAL SHOCK
Codes and Ordinances
LZ Series units have been tested and
certified, by TL, in accordance with UL
Safety Standard 1995/CSA C22.2 No. 236.
System should be sized in accordance with
the American Society of Heating,
Refrigeration and Air Conditioning
Engineers Handbook.
Receiving Unit
When received, the unit should be checked
for damage that might have occurred in
transit. If damage is found it should be noted
on the carrier’s Freight Bill. A request for
inspection by carrier’s agent should be made
in writing at once. Nameplate should be
checked to ensure the correct model sizes
20
To prevent motor overheating
compressors must cycle off for a
To maintain the proper oil level
compressors must cycle on for a
The cycle rate must not exceed 6
starts per hour.
Before unit operation, the main power
switch must be turned on for at least
24 hours for units equipped with
crankcase heaters.
Rotation must be checked on all
MOTORS AND COMPRESSORS of
three phase units. All motors, to
include and not be limited to pump
motors and condenser fan motors,
should all be checked by a qualified
service technician at startup and any
wiring alteration should only be made
at the unit power connection.
Scroll compressors are directional
and will be damaged by operation in
the wrong direction. High pressure
switches on compressors have been
disconnected after factory testing.
Rotation should be checked by a
qualified service technician at startup
using suction and discharge pressure
gauges and any wiring alteration
should be made at the unit power
connection.
and voltages have been received to match
the job requirements.
Storage
If installation will not occur immediately
following delivery, store equipment in a dry
protected area away from construction
traffic and in the proper orientation as
marked on the packaging with all internal
packaging in place. Leave all internal
packaging in place and secure all looseshipped items.
Outdoor Mechanical Room
COMPRESSOR CYCLING
3 MINUTE MINIMUM OFF TIME
Never turn off the main power supply to the
unit, except for complete shutdown. When
power is cut off from the unit, any
compressors equipped with crankcase
heaters cannot prevent refrigerant migration.
This means the compressor will cool down,
and liquid refrigerant may accumulate in the
compressor. The compressor is designed to
pump refrigerant gas and damage may occur
when power is restored if liquid enters the
compressor.
minimum of 3 minutes.
3 MINUTE MINIMUM ON TIME
minimum of 3 minutes.
Failure to observe the following instructions
will result in premature failure of your
system, and possible voiding of the
warranty.
Always control the system from the building
management system, or control panel, never
at the main power supply (except for
emergency or for complete shutdown of the
system).
21
Some units may require field wired
connections. Refer to the wiring
diagrams contained within the unit to
identify any components or controls
requiring additional wiring in the field
before placing the unit into service.
All additional field wiring should be
performed by a Factory Trained
Service Technician.
CAUTION
Scroll compressors must be on a minimum
of 3 minutes and off for a minimum of 3
minutes. The cycle rate must be no more
than 6 starts per hour.
The chiller is furnished with a flow switch
installed on the outlet of each heat
exchanger. This sensor must not be
bypassed since it provides a signal to the
unit controller that water flow is present in
the heat exchanger and the unit can operate
without the danger of freezing the liquid.
Compressor life will be seriously shortened
by reduced lubrication, and the pumping of
excessive amounts of liquid oil and
refrigerant.
Wiring Diagrams
A complete set of unit specific wiring
diagrams in both ladder and point-to-point
form are laminated in plastic and located
inside the control vestibule.
FIELD WIRED CONNECTIONS
General Maintenance
When the initial startup is made and on a
periodic schedule during operation, it is
necessary to perform routine service checks
on the performance of the chiller and boiler.
This includes reading and recording suction
pressures and checking for normal subcooling and superheat. See the evaporative-
cooled condenser and air-cooled condenser
sections in this manual for specific details.
Chiller Primary Pumping
Primary pumping uses a single pump to
move water (or glycol) through the chiller
evaporator and back to the building. This
pumping package provides a constant or
variable flow of water to the building. The
pump is activated whenever the chiller is
given a run signal.
Water enters the unit through the return
water piping, and then travels through an air
separator to remove any air that is entrapped
in the water. Following this, the water flows
through a suction guide with an integral
strainer. The end of the suction guide is
removable for strainer access. The strainer
assembly is composed of two parts, the
operational strainer and the startup strainer,
(located inside the operational strainer)
which is to be removed 24 hours after
startup.
The pump is installed after the suction
guide, and before a combination valve (FloTrex). This combination valve acts as an
isolation valve, check valve, and flow
balancing valve. The evaporator is placed
after the combination valve in the water
circuit, with a flow switch installed at its
inlet and outlet. This pressure switch closes
when the velocity is above .7 feet per
second. The closing flow switch signals the
control system to indicate flow through the
heat exchanger and allow cooling to activate
as required to maintain the setpoint. The
water exiting the chiller evaporator leaves
the unit through the water out connection.
Chiller Primary/Secondary Pumping
Primary/secondary pumping option provides
variable flow to the system. It consists of a
constant flow pump for the chiller heat
exchanger and a variable flow pump for the
22
building. The controls package senses
differential pressure across the pump with
pressure transducers installed at the suction
and discharge, and varies the speed of the
pump using a VFD in order to maintain a
given differential pressure across the pump.
The primary/secondary pumping package is
essentially composed of two piping loops
coupled together. The primary loop has a
constant flow rate in order to keep the chiller
heat exchanger from freezing, and the
secondary, variable flow loop, provides
water to the building. The two loops are
coupled via a water line that compensates
for excess flow in either loop. As the flow in
the secondary loop decreases below the flow
in the primary loop, excess flow bypasses
the building loop and circulates through the
bypass water line. On the other hand, as the
flow in the secondary loop increases above
the flow in the primary loop, excess flow
bypasses the chiller and circulates through
the bypass water line.
The secondary pump has its own suction
guide, combination valve, and isolation
valve, similar to the primary pump, with the
addition of an air separator to remove any
air that is entrapped in the water.
Condensing Boilers
AAON LZ chillers are available with factory
installed condensing boilers. All boiler
systems will include either fixed or variable
speed building pumps. All boiler building
pumps will be supplied with a suction guide
with a strainer and triple duty valve. The
suction guide contains both an operational
strainer and a startup strainer. The startup
strainer should be removed 24 hours after
startup. The triple duty valve functions as
an isolation valve, check valve, and flow
balancing valve.
The condensing boilers will be a water tube
design or a fire tube design. In a water-tube
boiler, the water flows through tubes with
the combustion products heating from the
outside. These boilers require a constant
water flow and will be provided with a
primary pump for each heat exchanger.
Some boilers have two heat exchangers and
will have two primary pumps. The primary
pump is controlled by the boiler and will
only come on when it has a call for heat.
Water-tube boilers are provided with flow
switches, which must make before the boiler
can operate.
In fire-tube boilers water flows through a
tank, with the combustion products inside
tubes. These boilers are capable of
significant water flow turn-down and do not
require individual primary pumps. A
control valve, operate by the boiler controls,
is provided with each boiler. A water flow
switch is not required with fire-tube boilers.
A low-level cutoff switch is used which will
prevent the boiler from operating when there
is not a sufficient water level present. Upon
initial startup, the boiler may have to be
cycled several times to generate an adequate
water level.
Makeup Water
A city make up water connection is provided
to replace water that is lost from the system.
Glycol units require a glycol feeder
(optional factory installed or field installed)
to replace fluid that is lost in the system.
Water should not be directly added to glycol
applications as this would dilute the glycol
concentration and thereby increase the
freezing temperature of the fluid.
The makeup water connection is provided
with a backflow preventer that has isolation
valves on the inlet and outlet for service.
23
Figure 1 shows the pressure drop versus
flow rate for the backflow preventer.
Figure 1 - Backflow Preventer
There is a pressure-reducing valve after the
backflow preventer. This valve reduces the
city water pressure to maintain the operating
pressure of the system. This valve is
adjustable from 10-35 psig with a factory
setting of 30 psig. The system pressure
varies with the height of the system. The
pressure-reducing valve setting should be set
so that the pressure at the high point in the
system is high enough to vent air from the
system (usually 4 psig). There should be air
vents at all parts in the system where air
could be trapped. If the pressure is not high
enough throughout the system, flashing
could occur in the piping or the pump could
cavitate. There is an isolation valve on the
inlet and outlet of the pressure-reducing
valve for service.
The pressure reducing valve fills the system
at a reduced rate. There is a bypass around
the pressure reducing valve for the initial fill
of the system to increase the initial fill
speed. After the initial system fill, this valve
should be closed.
Compression Tank
As the water temperature in the system
increases, the volume that water displaces
increases. In order to compensate for these
expansion forces, a compression or
expansion tank must be used. The factory
installed tank option includes a pre-
pressurized diaphragm compression tank
that is preset for 12 psig.
The factory pre-charge pressure may need to
be field adjusted. The tank must be precharged to system design fill pressure before
placing into operation. Remove the pipe
plug covering the valve enclosure. Check
and adjust the charge pressure by adding or
releasing air.
If the system has been filled, the tank must
be isolated from the system and the tank
emptied before charging. This ensures that
all fluid has exited the diaphragm area and
proper charging will occur.
If the pre-charge adjustment is necessary, oil
and water free compressed air or nitrogen
gas may be used. Check the pre-charge
using an accurate pressure gauge at the
charging valve and adjust as required. Check
air valve for leakage. If evident, replace the
Schrader valve core. Do not depend on the
valve cap to seal the leak. After making sure
the air charge is correct, replace the pipe
plug over the charging valve for protection.
Purge air from system before placing tank
into operation. All models have system
water contained behind the diaphragm.
It is recommended that the pre-charge be
checked annually to ensure proper system
protection and long life for the vessel.
Pressure Relief Valve
Required pressure relief valve is installed in
the unit. This valve is set at 125 psig. Figure
2 shows inlet pressure versus capacity for
this pressure relief valve. See appendix for
additional information.
24
Figure 2 - Pressure Relief Valve
Automatic Air Vent
There is an automatic air vent installed at the
high point of the system inside the pumping
package compartment. The air vent valve
must be in the proper position for operation.
Ensure that the small vent cap is loosened
two turns from the closed position, allowing
air to be vented from the system. It is
advisable to leave the cap on to prevent
impurities from entering the valve. See
appendix for additional information.
Dual Pumps
When redundant pumping is required,
factory installed dual pumps or two single
pumps can be ordered. A dual pump is a
pump with two independent motors and
impellors in a single casing. This dual pump
has a swing split-flapper valve in the
discharge port to prevent liquid recirculation
when only one pump is operating. Isolation
valves in the casing allow one pump to be
isolated and removed for service while the
other pump is still operating.
When redundant pumping is required with
high flow rates, two independent pumps
may be installed in parallel. Each pump will
have its own suction guide/strainer,
combination valve, and isolation valves.
The controls package will activate the pump
when the unit is given a run command. If the
controls do not recognize flow in 60 seconds
(factory default), the second pump will be
activated and an alarm signal will be
generated. If the second pump does not
activate, the cooling will be locked out. See
Appendix - Water Piping Component
Information for additional information.
Pressure Gauges and Thermometers
Pressure gauges and thermometers are
available as a factory installed option.
Thermometers are installed on the inlet and
outlet of the unit. One pressure gauge is
installed at each pump. This pressure gauge
is connected in three places to the water
piping before the suction guide/strainer,
after the suction guide and before the pump,
and after the pump. There is also a valve at
each of these points to isolate the pressure.
To measure the pressure at any given point,
open the valve at that point and close the
other two valves. One gauge is used so that
the calibration of the pressure gauge is
irrelevant in the calculation of the
differential pressure.
Pipe Insulation
The water piping and components on units
with pumping packages are not insulated at
the factory. Insulation should be installed on
the water piping after the system has been
checked for leaks.
25
Location
Unit Size
45-540 tons
Left
96”
Right
Compressor End
72”
Chiller HXC End
Top
Unobstructed
All roofing work should be performed
by competent roofing contractors to
Installation
Outdoor Mechanical Room Placement
The AAON LZ Series is designed for
outdoor applications and can be mounted at
ground level or on a rooftop. It must be
placed on a level and solid foundation that
has been prepared to support its weight.
The placement relative to the building air
intakes and other structures must be
carefully selected. Be sure to observe the
dimensions that are on the rating plate of the
chiller for operational and service
clearances.
Table 1 - Service Clearances
Condenser coils and fans must be free of any
obstructions in order to start and operate
properly with a correct amount of airflow.
For proper unit operation, the immediate
area around condenser(s) must remain free
of debris that may be drawn in and obstruct
airflow in the condensing section.
Consideration must be given to obstruction
caused by snow accumulation when placing
the unit.
Curb and Steel Mount Installation
Make openings in the roof decking large
enough to allow for water piping, electrical,
and gas penetrations and workspace only.
Do not make openings larger than necessary.
Set the curb to coincide with the openings.
Make sure curb is level.
Unit specific curb drawing is included with
job submittal. See SMACNA Architectural
Sheet Metal Manual for curb installation
details.
avoid any possible leakage.
When installed at ground level, a one-piece
concrete slab should be used with footings
that extend below the frost line. Care must
also be taken to protect the coil and fins
from damage due to vandalism or other
causes.
If unit is elevated a field supplied catwalk is
recommended to allow access to unit service
doors.
This unit ships with a curb gasket that is
1¼” wide and 1½” tall. It is recommended
that this or another similar gasket be used
between the curb and the unit to reduce
vibration transmission from the unit to the
building.
26
Figure 3 - Curb Mounting with Dimensions
Figure 4 - Curb End Detail
Figure 5 - Steel Mounting Rail with Dimensions
27
Figure 6 - Concrete Pad Mounting with Dimensions
Lifting and Handling
If cables or chains are used to hoist the unit
they must be the same length and care
should be taken to prevent damage to the
cabinet. See Figure 8 for additional
information.
Before lifting unit, be sure that all shipping
material has been removed from unit. Secure
hooks and cables at all lifting points/ lugs
provided on the unit.
Hoist unit to a point directly above the curb
or mounting rail. Be sure that the gasket
material has been applied to the curb or
mounting rail.
Carefully lower and align unit with utility
openings. Lower the unit until the unit skirt
fits around the curb. Make sure the unit is
properly seated on the curb and is level.
Do not push, pull or lift the unit from
anything other than its base.
Figure 7 - Lifting Points
28
Figure 8 - LZ Series Example Lifting Detail
Lifting slot locations are unit specific.
Unit must be rigged at all marked lifting points.
29
The chiller must be operated only
with liquid flowing through the
evaporators.
Boilers must be operated only with
liquid flowing through the boiler.
PVC (Polyvinyl Chloride) and CPVC
(Chlorinated Polyvinyl Chloride) are
vulnerable to attack by certain
chemicals. Polyolester (POE) oils
used with R-410A and other
refrigerants, even in trace amounts,
in a PVC or CPVC piping system will
result in stress cracking of the piping
and fittings. This will result in
complete piping system failure.
Installing Contractor is responsible
for proper sealing of the water piping
and electrical entries into the unit
Failure to seal the entries may result
in damage to the unit and property.
Water Connection
Remove the shipping cover from the water
connection cutout in the post. Connect the
supply and return water lines. The standard
water connection is grooved end pipe. The
connection size is listed on the unit rating
sheet along with the designed volumetric
flow rate. The maximum operating pressure
for AAON LZ Series unit is 125 psi. Install
the flashing provided by AAON according
to the steps in Figure 9. Finished water
connection will be water tight.
Figure 9 - Water Pipe Flashing Installation
30
Failure to apply sealing compound as
detailed can result in property
damage, personal injury, or death.
DO NOT use matches, candles, open
flames, or other ignition sources to
check for gas leaks. Use only
approved leak detection methods.
Failure to comply with this warning
can result in property damage,
personal injury, or death.
Failure to provide a properly installed
vent and air system can result in
property damage, personal injury, or
death.
Boiler Gas Connection Before making gas connection, make sure the boiler is being supplied with the type of fuel shown on the boiler nameplate.
Table 2 and Table 3 show the gas
connection size and type (NPT or flanged)
provided along with the required inlet gas
pressure for the unit. Refer to feature B on
the LZ Series unit feature string to
determine which line of the table to use. For
example, a unit with feature B = A3CC will
have a 2” NPT gas connection and require
an inlet gas pressure in the range of 6-14”
W.C.
Use only pipe sealing compound that is
compatible with propane gases on all
threaded connections. Apply sparingly only
to the male threads of the pipe joints so that
the pipe sealing compound does not block
any gas flow.
Before being placed in operation, the boiler
and all gas piping connections must be
checked for leaks. The boiler must be
disconnected from the gas supply piping
system during any pressure testing of the
system at pressures in excess of .5 psig (14”
W.C.). The boiler must be isolated from the
gas supply piping system by closing the
manual shutoff valve during any pressure
testing of the system at pressures equal to or
less than .5 psig (14” W.C.).
Some leak test solutions, including soap and
water, may cause corrosion. These solutions
should be rinsed off with water after testing.
Boiler Air Intake / Vent Piping Each boiler requires the installation of air intake and vent piping. This piping has been removed for shipping purposes. All piping must be reinstalled according to the instructions provided in this section prior to boiler operation.
All boilers must be vented and supplied with
combustion and ventilation air as described
in this section and in the Lochinvar
Installation & Operation Manual included
with the boiler. Ensure the vent and air
piping and combustion air supply comply
with instructions regarding vent system, air
system, and combustion air quality.
Inspect finished vent and air intake piping
thoroughly to ensure all are airtight and
comply with the instructions provided and
with all requirements of applicable codes.
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