Aaon LL-035 Installation Manual

LL Series

Chillers and Outdoor Mechanical Rooms

Installation, Operation

& Maintenance

WARNING

FIRE OR EXPLOSION HAZARD

Failure to follow safety warnings exactly could result in serious injury, death or property damage.

Be sure to read and understand the installation, operation and service instructions in this manual.

Improper installation, adjustment, alteration, service or maintenance can cause serious injury, death or property damage.

A copy of this IOM should be kept with the unit.

WARNING

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.

Table of Contents
Safety ..............................................................................................................................................	7
LL Series Feature String Nomenclature .......................................................................................	11
General Information......................................................................................................................	19
Codes and Ordinances...............................................................................................................	19
Receiving Unit...........................................................................................................................	19
Storage.......................................................................................................................................	19
Outdoor Mechanical Room .......................................................................................................	20
Wiring Diagrams .......................................................................................................................	21
General Maintenance.................................................................................................................	21
Chiller Primary Pumping ..........................................................................................................	21
Chiller Primary/Secondary Pumping ........................................................................................	21
Boiler System ............................................................................................................................	22
Boiler Primary/Secondary Pumping..........................................................................................	22
Make Up Water .........................................................................................................................	23
Compression/Expansion Tank...................................................................................................	23
Pressure Relief Valve ................................................................................................................	24
Automatic Air Vent...................................................................................................................	24
Dual Pumps ...............................................................................................................................	24
Pressure Gauges and Thermometers .........................................................................................	24
Pipe Insulation...........................................................................................................................	25
Installation.....................................................................................................................................	26
Outdoor Mechanical Room Placement......................................................................................	26
Curb and Steel Mount Installation ............................................................................................	26
Lifting and Handling .................................................................................................................	27
Water Connection......................................................................................................................	28
Gas Connection .........................................................................................................................	29
Boiler Exhaust Connection........................................................................................................	29
Boiler Intake Connection ..........................................................................................................	31
Mounting Isolation ....................................................................................................................	31
Access Doors.............................................................................................................................	31
Low Ambient Operation............................................................................................................	31
LAC Valve.............................................................................................................................	31
OROA Valve .........................................................................................................................	32
ORI/ORD Valves...................................................................................................................	33
Condenser Flooding...............................................................................................................	34
Electrical....................................................................................................................................	35
Startup...........................................................................................................................................	38
Axial Flow Condenser Fans ......................................................................................................	39
General ......................................................................................................................................	42
Compressors ..............................................................................................................................	42
Refrigerant Filter Driers ............................................................................................................	42
Evaporator/Heat Exchangers.....................................................................................................	42
Adjusting Refrigerant Charge ...................................................................................................	42
Lubrication ................................................................................................................................	47
Air-Cooled Condenser...............................................................................................................	47

E-Coated Coil Cleaning ............................................................................................................	47
Recommended Coil Cleaner ..................................................................................................	48
Recommended Chloride Remover.........................................................................................	48
Evaporative-Cooled Condenser.................................................................................................	48
Severe Service .......................................................................................................................	49
Safety .....................................................................................................................................	49
Performance...........................................................................................................................	50
Warranties..............................................................................................................................	50
Condenser Tube Inspection ...................................................................................................	50
Freeze Protection ...................................................................................................................	50
Recirculating Water System ..................................................................................................	50
Startup....................................................................................................................................	50
Cleanliness.............................................................................................................................	50
Storage ...................................................................................................................................	50
Pump Operation .....................................................................................................................	51
Running..................................................................................................................................	51
Condenser Fan Motors...........................................................................................................	51
Water Make Up Valve ...........................................................................................................	51
Water Treatment System .......................................................................................................	52
Sequence of Operation for LL Series units without Diagnostics ..........................................	53
Sequence of Operation for LL Series units with Diagnostics................................................	53
Pump Maintenance ................................................................................................................	54
Fan Motor Maintenance.........................................................................................................	54
Access Doors .........................................................................................................................	54
Bearings - Lubrication ...........................................................................................................	54
Recommended Monthly Inspection.......................................................................................	54
Mist Eliminators ....................................................................................................................	55
Air Inlet..................................................................................................................................	55
Stainless Steel Base Pan ........................................................................................................	55
Propeller Fans and Motors.....................................................................................................	55
Recommended Annual Inspection.........................................................................................	55
Cleaning.................................................................................................................................	55
Water Quality.........................................................................................................................	55
Mechanical Cleaning .............................................................................................................	56
Service.......................................................................................................................................	56
Replacement Parts .....................................................................................................................	57
AAON Warranty, Service and Parts Department......................................................................	57
Appendix - Water Piping Component Information ......................................................................	58
Water Pressure Reducing Valve................................................................................................	58
Water Pressure Relief Valve .....................................................................................................	60
Automatic Air Vent Valves.......................................................................................................	60
Pumps - Installation and Operating Instructions .......................................................................	62
Pump Piping - General ..............................................................................................................	64
Pump Operation.........................................................................................................................	64
General Care..............................................................................................................................	65
Dual Pump Specific Information...............................................................................................	67
4

Horizontal and Vertical Expansion Tanks ................................................................................	72
Suction Guides ..........................................................................................................................	73
Glycol Auto Fill Unit ................................................................................................................	74
Flo-Trex Combination Valve ....................................................................................................	76
LL Series Startup Form.................................................................................................................	81
Maintenance Log ..........................................................................................................................	87
Literature Change History.............................................................................................................	88
R10100 · Rev. B · 140226

Index of Tables and Figures
Tables:
Table 1 - Service Clearances.........................................................................................................	26
Table 2 - Mounting Dimensions ...................................................................................................	27
Table 3 - Boiler Rated Input Capacity ..........................................................................................	29
Table 4 - Condenser Flooding.......................................................................................................	35
Table 5 - Return/Exhaust Fan Pin Location..................................................................................	40
Table 6 - Return/Exhaust Fan Pin Location..................................................................................	40
Table 7 - Fan Assembly Bushing Torque Specifications..............................................................	41
Table 8 - Filter Drier Maximum Pressure Drop............................................................................	42
Table 9 - Acceptable Refrigeration Circuit Values.......................................................................	44
Table 10 - R-134a Refrigerant Temperature-Pressure Chart........................................................	45
Table 11 - R-410A and R-22 Refrigerant Temperature-Pressure Chart .......................................	46
Table 12 - Recirculating Water Quality Guidelines .....................................................................	55
Figures:
Figure 1 - Backflow Preventer......................................................................................................	23
Figure 2 - Pressure Relief Valve...................................................................................................	24
Figure 3 - Curb Mounting with Dimensions.................................................................................	26
Figure 4 - Steel Mounting Rail with Dimensions .........................................................................	27
Figure 5 - Marked Lifting Points ..................................................................................................	27
Figure 6 - LL Series Lifting Detail ...............................................................................................	28
Figure 7 - Boiler Vent Shipping Covers .......................................................................................	29
Figure 8 - Boiler Vent Components..............................................................................................	30
Figure 9 - Correct Vent Pipe Connection .....................................................................................	30
Figure 10 - Incorrect Vent Pipe Connection.................................................................................	31
Figure 11 - Piping Schematic of Example System using the LAC Valve. ...................................	32
Figure 12 - Piping Schematic of Example System using the OROA Valve.................................	33
Figure 13 - Piping Schematic of Example System using the ORI/ORD Valve............................	34
Figure 14 - Terminal Block...........................................................................................................	36
Figure 15 - Evaporative-Cooled Condenser Section Layout ........................................................	37
Figure 16 - Fan with the HUB on the top and RET on the bottom...............................................	39
Figure 17 - Bushing Mount Location............................................................................................	39
Figure 18 - RET with Pin in Groove 4..........................................................................................	39
Figure 19 - Fan HUB and RET Castings ......................................................................................	40
Figure 20 - Pitch Insert .................................................................................................................	41
Figure 21 - Replaceable Core Filter Driers...................................................................................	42
Figure 22 - Proper Unit Location..................................................................................................	49
Figure 23 - Improper Unit Locations............................................................................................	50
Figure 24 - Water Makeup Valve .................................................................................................	52

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.

WARNING

ELECTRIC SHOCK, FIRE OR

EXPLOSION HAZARD

Failure to follow safety warnings exactly could result in dangerous operation, serious injury, death or property damage.

Improper servicing could result in dangerous operation, serious injury, death, or property damage.

Before servicing, disconnect all electrical power to the furnace. More than one disconnect may be provided.

When servicing controls, label all wires prior to disconnecting.

Reconnect wires correctly.

Verify proper operation after servicing. Secure all doors with key-lock or nut and bolt.

WARNING

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.

CAUTION

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.

WARNING

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 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.

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.

CAUTION

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.

WARNING

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.

CAUTION

Door compartments containing hazardous voltage or rotating parts are equipped with door latches to allow locks. Door latch 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.

WARNING

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.

CAUTION

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 and complete piping system failure.

CAUTION

Rotation must be checked on all

MOTORS AND COMPRESSORS of

3 phase units at startup by a qualified service technician. Scroll compressors are directional and can be damaged if rotated in the wrong direction. Compressor rotation must be checked using suction and discharge gauges. Fan motor rotation should be checked for proper operation. Alterations should only be made at the unit power connection

CAUTION

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.

WARNING

Some chemical coil cleaning compounds are caustic or toxic. Use these substances only in accordance with the manufacturer’s usage instructions. Failure to follow instructions may result in equipment damage, injury or death.

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.

WARNING

COMPRESSOR CYCLING

5 MINUTE MINIMUM OFF TIME To prevent motor overheating compressors must cycle off for a minimum of 5 minutes.

5 MINUTE MINIMUM ON TIME To maintain the proper oil level compressors must cycle on for a minimum of 5 minutes.

The cycle rate must not exceed 6 starts per hour.

CAUTION

Polyolester (POE) and Polyvinylether

(PVE) oils are two types of lubricants used in hydrofluorocarbon (HFC) refrigeration systems. Refer to the compressor label for the proper compressor lubricant type.

CAUTION

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 specific 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.

LL Series Feature String Nomenclature

Model Options

Unit Feature Options

GEN

SIZE

VLT

CONFIG

A1 A2 A3 A4

B1 B2 B3

1A 1B 1C 1D

2 3 4

5A 5B 5C

6A 6B 6C

7 8 9 10 11 12 13

14A 14B

15 16 17 18 19 20 21 22 23

LL – 0 7 5 – 3 – 0 – DB 0 A – A 2 C : CR J G – 0 F B – K 5 E – K J G – A 0 C 0 CBA – E C – 0 F AA 0 0 B 0 B

BASE MODEL		VOLTAGE
SERIES AND GENERATION		2	= 230V/3Φ/60Hz
LL		3	= 460V/3Φ/60Hz
		4	= 575V/3Φ/60Hz
UNIT SIZE		8	= 208V/3Φ/60Hz
035 = 35 ton Capacity		BLANK
050 = 50 ton Capacity
055 = 55 ton Capacity		0	= Standard
060	= 60 ton Capacity	MODEL OPTION A: COOLING
067	= 67 ton Capacity
075	= 75 ton Capacity	A1: COOLING STYLE
085	= 85 ton Capacity	B = R-134a Variable Capacity Oil-Free Magnetic
090	= 90 ton Capacity	Bearing Centrifugal Compressors
092	= 92 ton Capacity	D = R-410A Dual Circuited Scroll Compressors
104	= 104 ton Capacity	E = R-410A Independently Circuited Scroll
105	= 105 ton Capacity	Compressors
115	= 115 ton Capacity	M = R-410A VFD Compatible Scroll Compressors
118	= 118 ton Capacity
120	= 120 ton Capacity	A2: COOLING CONFIGURATION
125	= 125 ton Capacity	0	= Air-Cooled Condenser, Low Water Flow
140 = 140 ton Capacity		A = Air-Cooled Condenser, High Water Flow
150 = 150 ton Capacity		B = Evap-Cooled Condenser, Low Water Flow
170 = 170 ton Capacity		C = Evap-Cooled Condenser, High Water Flow
180 = 180 ton Capacity		A3: COOLING COATING
181 = 181 ton Capacity
185 = 185 ton Capacity		0	= Standard
210 = 210 ton Capacity		1	= Polymer E-Coated Condenser Coil
230 = 230 ton Capacity		2	= Stainless Steel Condenser Coil Casing
240 = 240 ton Capacity		A4: COOLING STAGING
245 = 245 ton Capacity
275 = 275 ton Capacity		A = Shell and Tube Heat Exchanger
300 = 300 ton Capacity		C = Oversized Shell and Tube Heat Exchanger
335 = 335 ton Capacity		(Glycol)
360 = 360 ton Capacity		V = Shell and Tube Heat Exchanger + All Variable
365 = 365 ton Capacity		Speed Compressors
450 = 450 ton Capacity		W = Oversized Shell and Tube Heat Exchanger
540 = 540 ton Capacity		(Glycol) + All Variable Speed Compressors

LL Series Feature String Nomenclature

Model Options

Unit Feature Options

GEN

SIZE

VLT

CONFIG

A1 A2 A3 A4

B1 B2 B3

1A 1B 1C 1D

2 3 4

5A 5B 5C

6A 6B 6C

7 8 9 10 11 12 13

14A 14B

15 16 17 18 19 20 21 22 23

L L – 0 7 5 – 3 – 0 – DB 0 A – A 2 C : CR J G – 0 F B – K 5 E – K J G – A 0 C 0 CBA – E C – 0 F AA 0 0 B 0 B

MODEL OPTION B: HEATING

B1: HEATING TYPE

0 = No Boiler

A = Natural Gas Fired Boiler

B = Propane Fired Boiler

B2: BOILER QUANTITY

0 = No Boiler

1 = 1 Boiler

2 = 2 Boilers

3 = 3 Boilers

4 = 4 Boilers

B3: BOILER HEATING CAPACITY

0 = No Boiler

A = 500 MBH Modulating High Flow B = 750 MBH Modulating High Flow C = 1,000 MBH Modulating High Flow D = 1,500 MBH Modulating High Flow E = 500 MBH Modulating Low Flow F = 750 MBH Modulating Low Flow G = 1,000 MBH Modulating Low Flow H = 1,500 MBH Modulating Low Flow

FEATURE 1: BUILDING PUMPING

1A: PUMP OPTIONS

0 = Standard - No Building Pump

A = Common Water Connections

B = Primary Pumping System

C = Primary/Secondary Pumping System

1B: PUMP CONFIGURATION

0 = Standard - No Building Pump

D = 1 Pump - Prem Eff, 1170 RPM

E = 2 Single Pumps - Prem Eff, 1170 RPM F = dualArm Pump - Prem Eff, 1170 RPM G = 1 Pump w/ VFD - Prem Eff, 1170 RPM

H = 2 Single Pumps w/ 2 VFDs - Prem Eff, 1170 RPM

J = dualArm Pump w/ 2 VFDs - Prem Eff, 1170 RPM N = 1 Pump - Prem Eff, 1760 RPM

P = 2 Single Pumps - Prem Eff, 1760 RPM Q = dualArm Pump - Prem Eff, 1760 RPM R = 1 Pump w/ VFD - Prem Eff, 1760 RPM

S = 2 Single Pumps w/ 2 VFDs - Prem Eff, 1760 RPM

T = dualArm Pump w/ 2 VFDs - Prem Eff, 1760 RPM

Y = 1 Pump - Prem Eff, 3520 RPM

Z = 2 Single Pumps - Prem Eff, 3520 RPM 1 = dualArm Pump - Prem Eff, 3520 RPM 2 = 1 Pump w/ VFD - Prem Eff, 3520 RPM

3 = 2 Single Pumps w/ 2 VFDs - Prem Eff, 3520 RPM

4 = dualArm Pump w/ 2 VFDs - Prem Eff, 3520 RPM

LL Series Feature String Nomenclature

Model Options

Unit Feature Options

GEN

SIZE

VLT

CONFIG

A1 A2 A3 A4

B1 B2 B3

1A 1B 1C 1D

2 3 4

5A 5B 5C

6A 6B 6C

7 8 9 10 11 12 13

14A 14B

15 16 17 18 19 20 21 22 23

L L – 0 7 5 – 3 – 0 – DB 0 A – A 2 C : CR J G – 0 FB – K 5 E – K J G – A 0 C 0 CBA – E C – 0 F AA 0 0 B 0 B

	1C: PUMP SIZE	1D: PUMP MOTOR
	0 = Standard - No Building Pump	0=Standard - No Building Pump
	A = Pump 4360 1.5B	A = 0.5 hp
	B = Pump 4360 2B	B = 0.75 hp
	C = Pump 4360 2D	C = 1 hp
	D = Pump 4380 1.5x1.5x6	D = 1.5 hp
	E = Pump 4380 2x2x6	E = 2 hp
	F = Pump 4380/4382 3x3x6	F = 3 hp
	G = Pump 4380/4382 4x4x6	G = 5 hp
	H = Pump 4380 1.5x1.5x8	H = 7.5 hp
	J = Pump 4380 2x2x8	J = 10 hp
	K = Pump 4380/4382 3x3x8	K = 15 hp
	L = Pump 4380/4382 4x4x8	L = 20 hp
	M = Pump 4380 5x5x8	M = 25 hp
	N = Pump 4380/4382 6x6x8	N = 30 hp
	P = Pump 4380 2x2x10	P = 40 hp
	Q = Pump 4380/4382 3x3x10	Q = 50 hp
	R = Pump 4380/4382 4x4x10	R = 60 hp
	S = Pump 4380/4382 6x6x10	S = 75 hp
	T = Pump 4380/4382 8x8x10	FEATURE 2: WATER CONNECTION
	U = Pump 4380 4x4x11.5	FEATURE 2: WATER CONNECTION
	V = Pump 4380 5x5x11.5	LOCATION
	W = Pump 4380 6x6x11.5	0 = Back Water Connections
	Y = Pump 4380 8x8x11.5	0 = Back Water Connections
	Y = Pump 4380 8x8x11.5	A = Front Water Connections
	Z = Pump 4380 4x4x13	A = Front Water Connections
	Z = Pump 4380 4x4x13	B = Bottom Water Connection
	1 = Pump 4380 6x6x13	B = Bottom Water Connection
	1 = Pump 4380 6x6x13
	2 = Pump 4380 8x8x13	FEATURE 3: CHILLER
	3 = Pump 4382 6x6x6	FEATURE 3: CHILLER
	4 = Pump 4382 8x8x8	ACCESSORIES
	5 = Pump 4360 3D	0 = Standard
		A = Glycol System
		D = Air Separator
		E = Options A + D
		F = Thermometers & Pressure Gauges + Option D
		G = Thermometers & Pressure Gauges + Option E

LL Series Feature String Nomenclature

Model Options : Unit Feature Options

GEN

SIZE

VLT

CONFIG

A1 A2 A3 A4

B1 B2 B3

1A 1B 1C 1D

2 3

L L – 0 7 5 – 3 – 0 – DB 0 A – A 2 C : CR J G – 0 F

FEATURE 4: LOW AMBIENT

0 = Standard - None

A = One Refrigerant Circuit

B = Two Refrigerant Circuits

C = Three Refrigerant Circuits

D = Four Refrigerant Circuits

E = Five Refrigerant Circuits

F = Six Refrigerant Circuits

G = Seven Refrigerant Circuits

H = Eight Refrigerant Circuits

FEATURE 5: RECIRCULATING PUMP

5A: PUMP CONFIGURATION

0 = Standard - No Recirculating Pump

D = 1 Pump/Barrel - Prem Eff, 1170 RPM

E = 2 Single Pumps/Barrel - Prem Eff, 1170 RPM F = dualArm Pump/Barrel - Prem Eff, 1170 RPM G = 1 Pump/Barrel w/ VFD - Prem Eff, 1170 RPM H = 2 Single Pumps/Barrel w/ 2 VFDs - Prem Eff, 1170 RPM

J = dualArm Pump/Barrel w/ 2 VFDs - Prem Eff, 1170 RPM

N = 1 Pump/Barrel - Prem Eff, 1760 RPM

P = 2 Single Pumps/Barrel - Prem Eff, 1760 RPM Q = dualArm Pump/Barrel - Prem Eff, 1760 RPM R = 1 Pump/Barrel w/ VFD, Prem Eff, 1760 RPM S = 2 Single Pumps/Barrel w/ 2 VFDs, Prem Eff, 1760 RPM

T = dualArm Pump/Barrel w/ 2 VFDs, Prem Eff, 1760 RPM

Y = 1 Pump/Barrel -Prem Eff, 3520 RPM

Z = 2 Single Pumps/Barrel - Prem Eff, 3520 RPM 1 = dualArm Pump/Barrel - Prem Eff, 3520 RPM 2 = 1 Pump/Barrel w/ VFD - Prem Eff, 3520 RPM 3 = 2 Single Pumps/Barrel w/ 2 VFDs - Prem Eff, 3520 RPM

4 = dualArm Pump/Barrel w/ 2 VFDs - 3520 RPM

5B: PUMP SIZE

0 = Standard - No Recirculating Pump

A = Pump 4360 1.5B

B = Pump 4360 2B

C = Pump 4360 2D

D = Pump 4380 1.5x1.5x6

E = Pump 4380 2x2x6

F = Pump 4380/4382 3x3x6

G = Pump 4380/4382 4x4x6

5A 5B 5C

6A 6B 6C

7 8 9 10 11 12 13

14A 14B

15 16 17 18 19 20 21 22 23

B – K 5 E – K J G – A 0 C 0 CBA – E C – 0 F AA 0 0 B 0 B

H = Pump 4380 1.5x1.5x8

J = Pump 4380 2x2x8

K = Pump 4380/4382 3x3x8

L = Pump 4380/4382 4x4x8

M = Pump 4380 5x5x8

N = Pump 4380/4382 6x6x8

P = Pump 4380 2x2x10

Q = Pump 4380/4382 3x3x10

R = Pump 4380/4382 4x4x10

S = Pump 4380/4382 6x6x10

T = Pump 4380/4382 8x8x10

U = Pump 4380 4x4x11.5

V = Pump 4380 5x5x11.5

W = Pump 4380 6x6x11.5

Y = Pump 4380 8x8x11.5

Z = Pump 4380 4x4x13

1 = Pump 4380 6x6x13

2 = Pump 4380 8x8x13

3 = Pump 4382 6x6x6

4 = Pump 4382 8x8x8

5 = Pump 4360 3D

5C: PUMP MOTOR

0=Standard - No Recirculating Pump A = 0.50 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

LL Series Feature String Nomenclature

Model Options

Unit Feature Options

GEN

SIZE

VLT

CONFIG

A1 A2 A3 A4

B1 B2 B3

1A 1B 1C 1D

2 3 4

5A 5B 5C

6A 6B 6C

7 8 9 10 11 12 13

14A 14B

15 16 17 18 19 20 21 22 23

L L – 0 7 5 – 3 – 0 – DB 0 A – A 2 C : CR J G – 0 F B – K 5 E – K J G – A 0 C 0 CBA – E C – 0 F AA 0 0 B 0 B

FEATURE 6: BOILER BUILDING PUMP

6A: PUMP CONFIGURATION

0 = Standard - No Boiler

D = 1 Pump - Prem Eff, 1170 RPM

E = 2 Single Pumps - Prem Eff, 1170 RPM F = dualArm Pump - Prem Eff, 1170 RPM G = 1 Pump w/ VFD - Prem Eff, 1170 RPM

H = 2 Single Pumps w/ 2 VFDs - Prem Eff, 1170 RPM

J = dualArm Pump w/ 2 VFDs - Prem Eff, 1170 RPM N = 1 Pump - Prem Eff, 1760 RPM

P = 2 Single Pumps - Prem Eff, 1760 RPM Q = dualArm Pump - Prem Eff, 1760 RPM R = 1 Pump w/ VFD - Prem Eff, 1760 RPM

S = 2 Single Pumps w/ 2 VFDs - Prem Eff, 1760 RPM

T = dualArm Pump w/ 2 VFDs - Prem Eff, 1760 RPM

Y = 1 Pump - Prem Eff - 3520 RPM

Z = 2 Single Pumps - Prem Eff, 3520 RPM 1 = dualArm Pump - Prem Eff, 3520 RPM 2 = 1 Pump w/ VFD - Prem Eff, 3520 RPM

3 = 2 Single Pumps w/ 2 VFDs - Prem Eff, 3520 RPM

4 = dualArm Pump w/ 2 VFDs - Prem Eff, 3520 RPM

6B: PUMP SIZE

0 = Standard - No Boiler

A = Pump 4360 1.5B

B = Pump 4360 2B

C = Pump 4360 2D

D = Pump 4380 1.5x1.5x6

E = Pump 4380 2x2x6

F = Pump 4380/4382 3x3x6

G = Pump 4380/4382 4x4x6

H = Pump 4380 1.5x1.5x8

J = Pump 4380 2x2x8

K = Pump 4380/4382 3x3x8

L = Pump 4380/4382 4x4x8

M = Pump 4380 5x5x8

N = Pump 4380/4382 6x6x8

P = Pump 4380 2x2x10

Q = Pump 4380/4382 3x3x10

R = Pump 4380/4382 4x4x10

S = Pump 4380/4382 6x6x10

T = Pump 4380/4382 8x8x10

U = Pump 4380 4x4x11.5

V = Pump 4380 5x5x11.5

W = Pump 4380 6x6x11.5

Y = Pump 4380 8x8x11.5

Z = Pump 4380 4x4x13

1 = Pump 4380 6x6x13

2 = Pump 4380 8x8x13

3 = Pump 4382 6x6x6

4 = Pump 4382 8x8x8

5 = Pump 4360 3D

6C: PUMP MOTOR

0 = Standard - No Boiler A = 0.50 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

FEATURE 7: SERVICE OPTIONS

0 = Standard

A = 115V Outlet, Factory Wired

B = 115V Outlet, Field Wired

LL Series Feature String Nomenclature

Model Options

Unit Feature Options

GEN

SIZE

VLT

CONFIG

A1 A2 A3 A4

B1 B2 B3

1A 1B 1C 1D

2 3 4

5A 5B 5C

6A 6B 6C

7 8 9 10 11 12 13

14A 14B

15 16 17 18 19 20 21 22 23

L L – 0 7 5 – 3 – 0 – DB 0 A – A 2 C : CR J G – 0 F B – K 5 E – K J G – A 0 C 0 CBA – E C – 0 F AA 0 0 B 0 B

FEATURE 8: REFRIGERATION

OPTIONS

0 = Standard

B = VFD Controlled Condenser Fans (Air-Cooled)

D = Hot Gas Bypass - All Circuits

E = Options B + D

FEATURE 9: REFRIGERATION

ACCESSORIES

0 = Standard

A = Sight Glass

B = Compressor Isolation Valves

C = Options A + B

FEATURE 10: POWER OPTIONS

0 = Standard Power Block

A = Power Switch (225 Amps)

B = Power Switch (400 Amps)

C = Power Switch (600 Amps)

D = Power Switch (800 Amps)

E = Power Switch (1200 Amps)

F = Dual Point Power Block (2)

G = Dual Point Power Switch (2 x 225 Amps) H = Dual Point Power Switch (2 x 400 Amps) J = Dual Point Power Switch (2 x 600 Amps) K = Dual Point Power Switch (2 x 800 Amps) L = Dual Point Power Switch (2 x 1200 Amps)

FEATURE 11: SAFETY OPTIONS

0 = No Boiler

A = Standard, Boiler w/ UL/FM/CSD-1 Certification B = Boiler w/ IRI Gas Train

C = Boiler w/ IRI Gas Train and Proof of Closure D = Boiler w/ Low Water Cutoff

E = Options B + D

F = Options C + D

FEATURE 12: CONTROLS

0 = Standard

A = Touchscreen Unit Controls Interface

B = Phase and Brown Out Protection

F = Options A + B

FEATURE 13: SPECIAL CONTROLS

0 = MCS Magnum Controller A = w/ Diagnostics

C = w/ Diagnostics and Modbus Connection D = w/ Diagnostics and N2 Connection

E = w/ Diagnostics and LonTalk Connection G = w/ Modem

H = w/ Diagnostics and Modem

K = w/ Diagnostics, Modbus Connection and Modem L = w/ Diagnostics, N2 Connection and Modem

M = w/ Diagnostics, LonTalk Connection and Modem

Q = w/ Modbus Connection R = w/ N2 Connection

S = w/ LonTalk Connection

V = w/ Modbus Connection and Modem W = w/ N2 Connection and Modem

Y = w/ LonTalk Connection and Modem 1 = w/ BACnet IP Connection

2 = w/ Diagnostics and BACnet IP Connections

3 = w/ Diagnostics, BACnet IP Connection and Modem

4 = w/ BACnet IP Connection and Modem

5 = w/ BACnet MS/TP Connection

6 = w/ Diagnostics and BACnet MS/TP Connection

7 = w/ Diagnostics, BACnet MS/TP Connection and Modem

8 = w/ BACnet MS/TP Connection and Modem

LL Series Feature String Nomenclature

Model Options

Unit Feature Options

GEN

SIZE

VLT

CONFIG

A1 A2 A3 A4

B1 B2 B3

1A 1B 1C 1D

2 3 4

5A 5B 5C

6A 6B 6C

7 8 9 10 11 12 13

14A 14B

15 16 17 18 19 20 21 22 23

L L – 0 7 5 – 3 – 0 – DB 0 A – A 2 C : CR J G – 0 F B – K 5 E – K J G – A 0 C 0 CBA – EC – 0 FAA 0 0 B 0 B

FEATURE 14: COMPRESSION TANK

14A: CHILLER COMPRESSION TANK

0 = No Chiller Compression Tank

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

N= 1000-L

P= 1200-L

Q= 1600-L

R= 2000-L

14B: BOILER COMPRESSION TANK

0 = No Boiler Compression Tank

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

N= 1000-L

P= 1200-L

Q= 1600-L

R= 2000-L

FEATURE 15: OPTION BOXES

0 = Standard

A = 2ft Option Box B = 4ft Option Box C = 6ft Option Box D = 8ft Option Box E = 10ft Option Box F = 12ft Option Box

FEATURE 16: CABINET OPTIONS

0 = Standard

A = Electrical Vestibule Heating

B = Fan/Coil Vestibule Cooling

F = Options A + B

FEATURE 17: CABINET OPTIONS

0 = Standard

A = Access Door Windows

FEATURE 18: CUSTOMER CODE

0 = Standard

A = Second to Fifth Year Extended Compressor Warranty

LL Series Feature String Nomenclature

Model Options

Unit Feature Options

GEN

SIZE

VLT

CONFIG

A1 A2 A3 A4

B1 B2 B3

1A 1B 1C 1D

2 3 4

5A 5B 5C

6A 6B 6C

7 8 9 10 11 12 13

14A 14B

15 16 17 18 19 20 21 22 23

L L – 0 7 5 – 3 – 0 – DB 0 A – A 2 C : CR J G – 0 F B – K 5 E – K J G – A 0 C 0 CBA – E C – 0 F AA 0 0 B 0 B

FEATURE 19: CODE OPTIONS

0 = Standard - ETL U.S.A. Listing A = M.E.A. (New York)

B = Chicago - Cool + Gas

H = ETL U.S.A. + Canada Listing

FEATURE 20: UNIT

CONFIGURATION

0 = Standard (One Piece Unit)

A = Two Piece Unit

FEATURE 21: EVAPORATIVE-

COOLED CONDENSER

0 = Standard - No Evaporative-Cooled Condenser

A = No Sump Heater

B = Sump Heater

FEATURE 22: BLANK

0 = Standard

FEATURE 23: TYPE

B = Standard Paint

U = Special Price Authorization and Special Paint

X = Special Price Authorization and Standard Paint

General Information

AAON LL 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 and primary/secondary pumping packages and boilers with pumping package are available as optional features.

WARNING

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.

Codes and Ordinances

LL Series units have been tested and certified, by ETL, 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.

Installation of LL 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.

CAUTION

The Clean Air Act of 1990 bans the intentional venting of refrigerant as of

July 1, 1992. Approved methods of recovery, recycling, or reclaiming must be followed.

WARNING

Coils and sheet metal surfaces present sharp edges and care must be taken when working with equipment.

WARNING

Failure to observe the following instructions will result in premature failure of your system and possible voiding of the warranty.

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 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. Secure all loose-shipped items.

Outdoor Mechanical Room

WARNING

COMPRESSOR CYCLING

5 MINUTE MINIMUM OFF TIME To prevent motor overheating compressors must cycle off for a minimum of 5 minutes.

5 MINUTE MINIMUM ON TIME To maintain the proper oil level compressors must cycle on for a minimum of 5 minutes.

The cycle rate must not exceed 6 starts per hour.

Failure to observe the following instructions will result in premature failure of your system, and possible voiding of the warranty.

CAUTION

CRANKCASE HEATER

OPERATION

Units may be equipped with compressor crankcase heaters, which should be energized at least

24 hours prior to cooling operation, to clear any liquid refrigerant from the compressors.

Never turn off the main power supply to the unit, except for complete shutdown. When power is cut off from the unit, any compressors using 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.

CAUTION

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.

Before unit operation, the main power switch must be turned on for at least 24 hours for units with compressor crankcase heaters. This will give the crankcase heater time to clear any liquid accumulation out of the compressor before it is required to run.

CAUTION

Scroll compressors are directional and will be damaged by operation in the wrong direction. Low 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 only be made at the unit power connection.

Never cut off the main power supply to the unit, except for complete shutdown. 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).

Scroll compressors must be on a minimum of 5 minutes and off for a minimum of 5 minutes. The cycle rate must be no more than 6 starts per hour.

The chiller is furnished with a pressure differential switch that is factory installed between the chilled water supply and return connections. 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 compartment door.

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 evaporativecooled 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 barrel and back to the building. This pumping package provides a constant flow of water to the system. 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 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 isolation valve, check valve, and flow balancing valve. The evaporator barrel is placed after the combination valve in the water circuit, with a differential pressure switch installed across its inlet and outlet. This pressure switch closes when the differential pressure increases above the setpoint, which should be set 1-2 psig below the pressure drop across the heat exchanger at design flow rate. The closing differential pressure 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 barrel 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 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.

Boiler System

Optional boilers and pumping packages are factory installed. The boiler system uses a primary/secondary pumping package. There can be 1-4 boilers in parallel and each boiler has its own primary pump. The heating loop must be designed to return at least 120°F water to the boiler during normal operation. Failure to return 120°F water to the boiler will create condensation, which will reduce the life of the heat exchanger and void the boiler warranty. See unit submittal for unit specific piping schematics. See the Thermal Solutions Boiler “Installation, Operating, and Service Instructions” that are included with the unit for additional information about the boiler.

Once the boiler is given a run signal, the boiler secondary pump will be activated and the controls package will stage boilers as necessary to maintain the leaving water temperature setpoint.

The controls package will also control the speed of the secondary pump in the boiler system to maintain differential pressure across the pump similar to the chiller secondary pump.

Boiler Primary/Secondary Pumping

Water enters the unit through the return water piping, and then travels through a suction guide with 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 primary/secondary pumping package provides variable flow to the system. It consists of a constant flow pump for the boiler, and a variable flow pump for the 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 maintain water temperature through the boiler, 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 boiler and circulates through the bypass water line.

The secondary pump includes suction guide, combination valve, and isolation valve with the addition of an air separator to remove any air that is entrapped in the water.

See appendix for additional information on the installation, operation and maintenance of pumps.

Make Up 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. 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/Expansion 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 prepressurized 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.

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 pumps 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, 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 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 needle valve at each of these points to isolate the pressure. To measure the pressure at any given point, open the needle valve at that point and close the other two needle 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.

Installation

Outdoor Mechanical Room Placement

The AAON LL Series is designed for outdoor applications and mounting 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

	Location	Unit Size
	Location	35-540 tons
		35-540 tons
	Front -	100”
	(Controls Side)	100”
	(Controls Side)
	Back	100”
	Ends	100”
	Top	Unobstructed

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 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.

CAUTION

All roofing work should be performed by competent roofing contractors to avoid any possible leakage.

Units require rail support along all four sides of the unit base.

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 from the unit to the building.

Figure 3 - Curb Mounting with Dimensions

Figure 4 - Steel Mounting Rail with Dimensions

Table 2 - Mounting Dimensions

Tons	A	B	C	D
35-115	100”	96”	92”	97”
(Scroll)	100”	96”	92”	97”
(Scroll)
125-365
(Scroll)	142”	138”	134”	139”
90-540	142”	138”	134”	139”
90-540
(Centrifugal)

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 6 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 and duct 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 5 - Marked Lifting Points

Figure 6 - LL Series Lifting Detail

Lifting slot locations are unit specific. Unit must be rigged at all marked lifting points.

Water Connection

Connect the supply and return water lines. The connection size is listed on the unit rating sheet, along with the designed volumetric flow rate. The maximum operating pressure for AAON LL Series units is 125 psi.

WARNING

The chiller must be operated only with liquid flowing through the evaporators.

CAUTION

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