Mueller E-Star OESE User manual

Part No. 8828748
Effective June 16, 2020
E-Star® OESE
Condensing Unit
7.5 and 9 HP HFC
INSTALLATION AND OPERATION MANUAL

E-Star OESE Condensing Unit
7.5 and 9 HP HFC
INSTALLATION AND OPERATION MANUAL
Section 1.0 – Introduction
1.1 General Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Table 1: Dimensions and Weight ............................................................................................1
Figure 1: Dimensions and Weight. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
1.2 Technical Support ......................................................................................................... 2
1.3 Installation Information ................................................................................................... 2
Section 2.0 – Installation
2.1 Inspection .................................................................................................................. 3
2.2 Handling .................................................................................................................... 3
2.3 Location..................................................................................................................... 3
2.4 Refrigeration Piping and Evacuation ..................................................................................... 3
Table 2: Liquid Line Sizing................................................................................................. 4
Table 3: Suction Line Sizing................................................................................................ 4
Table 4: Discharge Line Sizing To and From the Fre-Heater®........................................................... 4
Table 5: Condensing Unit Connection Sizes .............................................................................. 4
2.5 Electrical Connections .....................................................................................................5
2.6 Compressor Rotalock Torque Specifications ..............................................................................5
2.7 Oil Sight Glass Torque Specifications......................................................................................5
Section 3.0 – Refrigerant Charging
3.1 EPA Refrigerant Regulations .............................................................................................. 6
3.2 Initial Refrigerant Charge ................................................................................................. 6
Table 6: Recommended Startup Refrigerant Charge ..................................................................... 6
3.3 Weigh-In Refrigerant Charging ........................................................................................... 6
3.4 Final Operating Charge .................................................................................................... 7
3.5 Refrigerant Testing ........................................................................................................ 7
3.6 Safety Alert ................................................................................................................. 7
Section 4.0 – Operating Features
4.1 Refrigerant Cycle .......................................................................................................... 8
4.2 Oil Return .................................................................................................................. 8
4.3 Increased Operating Efficiency ........................................................................................... 8
Figure 2: Refrigerant Piping Schematics ................................................................................. 9
Table of Contents
Mueller E-Star OESE 7.5 and 9 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828748 Effective June 16, 2020

Section 5.0 – Expansion Valve
5.1 Thermal Expansion Valve (TEV) Selection and Installation ..........................................................10
Table 7: Thermal Expansion Valve Selection ............................................................................10
Figure 3: Thermal Expansion Valve Installation ........................................................................10
5.2 Checking and Adjusting Superheat ...................................................................................... 11
Figure 4: Checking and Adjusting Superheat ............................................................................ 11
Section 6.0 – Accumulator Heat Exchanger
6.1 Accumulator Heat Exchanger Functions ................................................................................12
Figure 5: Accumulator Heat Exchanger..................................................................................12
Section 7.0 – Electrical
7.1 E-Star OESE Condensing Unit Electrical Wiring .......................................................................13
7.2 CoreSense Diagnostics™ Module for 7.5 and 9 HP Compressors .......................................................13
7.3 CoreSense LED Status ....................................................................................................13
7.4 CoreSense Diagnostic Fault Code Details ...............................................................................13
7.5 CoreSense Protection Module Connection Wiring...................................................................... 14
7.6 CoreSense Protection Module Voltage Troubleshooting................................................................14
7.7 CoreSense Product Specifications .......................................................................................14
7.8 Copeland Scroll Compressor Functional Check ......................................................................... 15
Section 8.0 – Electrical Schematics
8.1 OESE 7.5 and 9 HP, 200–220/50/3, 208–230/60/3...................................................................... 16
8.2 OESE 7.5 and 9 HP, 380/50/3, 460/60/3, 575/60/3 ...................................................................... 17
Section 9.0 – Pressure Switches and Fan Control
9.1 Low-Pressure Switch with Auto Reset...................................................................................18
9.2 High-Pressure Switch with Auto Reset ..................................................................................18
9.3 RGE Electronic Fan Pressure Control ...................................................................................18
9.4 RGE Electronic Fan Pressure Control Setpoint Adjustment ...........................................................19
Figure 6: RGE Electronic Fan Pressure Control.........................................................................19
9.5 Off-Cycle Fan Pressure Switch...........................................................................................19
9.6 Schrader Core Identification .............................................................................................20
Section 10.0 – Equipment Sound Level
10.1 Sound Testing Equipment ................................................................................................21
10.2 Sound Measurement ......................................................................................................21
Figure 7: Sound Measurement ............................................................................................21
Section 11.0 – Maintenance
11.1 E-Star OESE Refrigeration Survey.......................................................................................22
11.2 Maintenance Procedures .................................................................................................23
11.3 Safety Alert ................................................................................................................23
Table of Contents
Mueller E-Star OESE 7.5 and 9 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828748 Effective June 16, 2020

Section 12.0 – Disposal
12.1 General ....................................................................................................................24
12.2 Compressor Refrigerant Oil .............................................................................................24
12.3 Metal Components ........................................................................................................24
Section 13.0 – Equipment Markings
13.1 Label No. 8820454, Dry Nitrogen Holding Charge ......................................................................25
13.2 Label No. 8824716, HFC Refrigerant.....................................................................................25
13.3 Label No. 8824497, E-Star Data Tag .....................................................................................25
13.4 Label No. 8822574, Inspection Card. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
13.5 Label No. 8820155, Wiring Connections for Three-Phase Scrolls......................................................26
13.6 Label No. 8822225, CE Data Tag (UK Models Only). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
13.7 Label No. 8822232, Warning Symbol: Hot ...............................................................................26
13.8 Label No. 8820623, Warning Symbol: Electrical ........................................................................26
13.9 Label No. 8822226, Warning: Screen Guard Removal ..................................................................27
13.10 Label No. 8822141, Warning: Risk of Electric Shock, Disconnect All Remote Power Supplies Before Servicing ....27
13.11 Label No. 8820764, Warning: Disconnect Power Before Screen Guard Removal .....................................27
13.12 Label No. 8820768, Warning: Place Screen Guard Before Unit Operation .............................................27
13.13 Label No. 8820769, Warning: Fan Will Start Automatically ...........................................................28
13.14 Label No. 8824383, Mueller Logo.........................................................................................28
13.15 Label No. 8822705, CSA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Section 14.0 – Safety
14.1 Safety Alert ................................................................................................................29
14.2 Refrigerant Health Hazards ..............................................................................................29
14.3 First Aid ...................................................................................................................29
14.4 Personal Protective Equipment...........................................................................................29
Section 15.0 – Technical Data
15.1 E-Star OESE Electrical Data .............................................................................................30
15.2 E-Star OESE Refrigerant Data ...........................................................................................30
15.3 E-Star OESE Expansion Valve Selection ................................................................................30
Section 16.0 – Data Charts
16.1 ZB58K5E-TFC 3-Phase, 7.5 HP, 208–230 V Compressor Data Chart .................................................. 31
16.2 ZB58K5E-TFD 3-Phase, 7.5 HP, 460 V Compressor Data Chart........................................................32
16.3 ZB66K5E-TFC 3-Phase, 9 HP, 208–230 V Compressor Data Chart....................................................33
16.4 ZB66K5E-TFD 3-Phase, 9 HP, 460 V Compressor Data Chart .........................................................34
Section 17.0 – R-507 Pressure Temperature Chart ...............................................................35
Section 18.0 – E-Star OESE Installation Survey. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table of Contents
Mueller E-Star OESE 7.5 and 9 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828748 Effective June 16, 2020

Mueller E-Star OESE 7.5 and 9 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828748 Effective June 16, 2020
1.1 GENERAL SPECIFICATIONS
Mueller® E-Star® OESE condensing units are engineered to maximize the energy efficiency and cooling capacity of
a milk cooling system. Custom and specialized components consist of the following:
• A quiet, energy-efficient Copeland® “ZB” scroll refrigeration compressor, designed for commercial
refrigeration service rather than air conditioning, provides improved performance over the entire milk cooling
temperature range. An oil sight glass, oil fill/drain port, and screw electrical terminals are added bonuses that
ensure long-term reliability and serviceability.
• An accumulator heat exchanger with a proprietary subcooling coil maximizes refrigeration capacity while
protecting the compressor from liquid refrigerant.
• A custom tube-and-fin condenser with rifled tubing and integral subcooling loop provides an enhanced heat
exchange surface. The subcooling loop maintains subcooled liquid refrigerant to the thermal expansion valve,
ensuring maximum evaporator efficiency.
• A single, variable speed, high-efficiency fan motor provides maximum condensing efficiency over a wide range
of ambient temperatures.
• An electrical enclosure is designed for safety, ease of installation, and serviceability. A resistive heater is
included for reliable operation during colder ambient temperatures.
• The three-piece galvanized steel cover with an attached steel grill provides safe operation plus offers easy
access for service..
• Rust-resistant brass service valves are located for easy access without removing the cover.
TABLE 1: DIMENSIONS AND WEIGHT FIGURE 1: DIMENSIONS AND WEIGHT
1
Section 1.0 – Introduction
7.5 and 9 HP
Width 118.11 cm 461⁄2in
Depth 85.09 cm 331⁄2in
Height 107.95 cm 421⁄2in
Approximate Weight 204 kg 450 lb
461⁄2˝
331⁄2˝
42
1⁄2˝

Mueller E-Star OESE 7.5 and 9 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828748 Effective June 16, 2020
1.2 TECHNICAL SUPPORT
This manual provides basic installation and operating information for Mueller E-Star OESE condensing units.
Please contact your local Paul Mueller Company Sales and Service Representative if you require additional
technical assistance pertaining to installation or operating procedures.
Manufacturer’s support is available by contacting the following:
Paul Mueller Company
Dairy Farm Equipment Service Department
1600 West Phelps Street
Springfield, Missouri 65802
Direct Telephone: [phone]
Facsimile: 1-800-436-2466
Email: [e-mail]
1.3 INSTALLATION INFORMATION
Electrical and refrigeration installation and service must be performed by an authorized service technician who
has the proper training to install and service refrigeration and electrical equipment.
Local, state, and/or country electrical and refrigeration regulations must be followed during installation, service,
and/or operation of this equipment.
United States Environmental Protection Agency (EPA) regulations require that any technician performing
refrigerant installation or service on a high-pressure appliance be certified as a Type II Technician in accordance
with Section 608 of the Clean Air Act. Clean Air Act regulations may change or differ, depending on locality. It is
the responsibility of the technician performing the refrigerant service and/or installation to abide by all regulatory
requirements and procedures for the locality, state, and country.
2

Mueller E-Star OESE 7.5 and 9 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828748 Effective June 16, 2020
2.1 INSPECTION
Each shipment should be carefully checked for shortages or concealed damage. Any shortage or damage must be
reported to the delivery carrier at the time of delivery.
Damaged material becomes the delivery carrier’s responsibility and should not be returned to the manufacturer
unless prior approval is obtained.
2.2 HANDLING
IMPORTANT: Equipment used to move or lift this equipment must be rated for the weight of the
equipment. See Table 1 for equipment weight.
2.3 LOCATION
When choosing a location for the Mueller E-Star OESE condensing unit, consider these items:
• Environment: The unit must be located where it is protected from extreme temperatures of –30°F (–34.4°C)
and below or 115°F (46.1°C) and above.
• Condenser Air Flow: Ensure proper provisions for adequate air flow to the condenser. When installing the
condenser facing a wall, the distance to the wall must be a minimum of 24 in (61 cm) with non-restricted
air flow at the top, left, and right sides. Be especially cautious of installation methods that would allow the
condenser air flow to recirculate and conditions that would allow dust or oil to enter the condenser.
• Serviceability: The condensing unit should be located with the compressor and electrical enclosure
accessible for service. Do not pipe refrigerant lines in front of the electrical enclosure.
• Efficiency: Locate the condensing unit as close to the evaporator as possible. This will improve efficiency by
reducing pressure drop in the refrigerant piping.
• Lubrication: For proper oil return, do not install the condensing unit above the height of the evaporator, and
ensure the suction line returning from the evaporator is sloped towards the condensing unit.
2.4 REFRIGERATION PIPING AND EVACUATION
Refrigeration lines should be purged with dry nitrogen when brazing connections to prevent internal oxide
formation. Proper refrigerant practices as outlined in ASHRAE 15-1994 should be followed.
The refrigerant line set must be insulated to reduce heat gain, prevent sweating and condensation, and ensure
subcooled liquid refrigerant to the evaporator.
Refrigerant piping should be installed with long-radius bends or fittings.
E-Star condensing units are shipped with a dry nitrogen holding charge. The unit, refrigerant lines, and evaporator
circuit will require a triple system evacuation to 500 microns prior to refrigerant charging. The system must hold
below 1,000 microns in a standing vacuum test, ensuring that it is leak free.
NOTE: Installation technicians must follow proper refrigerant practices as outlined in ASHRAE 15-1994.
3
Section 2.0 – Installation

Mueller E-Star OESE 7.5 and 9 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828748 Effective June 16, 2020
TABLE 2: LIQUID LINE SIZING
Paul Mueller Company recommends the shortest pipe run possible.
TABLE 3: SUCTION LINE SIZING
Paul Mueller Company recommends the shortest pipe run possible.
TABLE 4: DISCHARGE LINE SIZING TO AND FROM THE FRE-HEATER
Paul Mueller Company recommends the shortest pipe run possible.
TABLE 5: CONDENSING UNIT CONNECTION SIZES
4
Compressor
Horsepower
Equivalent Length of Pipe (Feet)
< 30ˇ 30ˇ – 50ˇ 50ˇ – 100ˇ
3.5 1⁄21⁄21⁄2
51⁄21⁄25⁄8
7.5 5⁄85⁄85⁄8
95⁄85⁄87⁄8
Compressor
Horsepower
Equivalent Length of Pipe (Feet)
< 30ˇ 30ˇ – 50ˇ 50ˇ – 100ˇ
3.5 7⁄811⁄811⁄8
5 11⁄811⁄813⁄8
7.5 11⁄813⁄815⁄8
9 13⁄815⁄821⁄8
Compressor
Horsepower
Equivalent Length
of Pipe (Feet)
0ˇ – 50ˇ
3.5 7⁄8
57⁄8
7.5 11⁄8
9 11⁄8
Compressor
Horsepower Liquid Line Suction Line
Discharge Line
(Fre-Heater®)
3.5 1⁄27⁄81⁄2
55⁄87⁄81⁄2
7.5 5⁄815⁄811⁄8
95⁄815⁄811⁄8

Mueller E-Star OESE 7.5 and 9 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828748 Effective June 16, 2020
2.5 ELECTRICAL CONNECTIONS
Prior to installation, verify equipment is compatible with site electrical requirements (e.g., voltage, phase, and
hertz). Ensure that all electrical connections are secure and correspond with wiring schematics.
Following local and NEC (National Electrical Code) regulations and procedures, connect a fused disconnect power
supply of the proper voltage and phase to the E-Star OESE condensing unit’s electrical enclosure.
The control circuit is designed to be operated by a 24-VAC supply. Read the warning statement below.
Refer to the electrical schematics in Section 8.0 for connection details.
WARNING: Mueller E-Star OESE condensing units are prewired for low-voltage, 24-VAC control
circuit input. Connecting high-voltage control to this circuit will cause equipment failure and a possible
electrical hazard.
2.6 COMPRESSOR ROTALOCK TORQUE SPECIFICATIONS
During shipment, threaded fittings under tension may stretch and relax. Copeland Corporation recommends
inspecting and retorquing the Rotalock fittings on compressors.
The Rotalock fittings need to be checked after installation and the compressor has been in operation, due to the
changes in temperature that could reduce the torque from the original setting. The compressor Rotalock torque
specifications are as follows:
2.7 OIL SIGHT GLASS TORQUE SPECIFICATIONS
The scroll compressor’s sight glass may be susceptible to leakage due to shipment or a temperature change during
operation. However, this fitting has a thread sealer that can crack after curing if re-torque is attempted.
The sight glass should be checked for leaks; if it is not leaking, do not attempt to re-torque. If the sight glass is
leaking, the refrigerant must be recovered and the oil removed below the sight glass by utilizing the oil fill/drain
port. Remove the sight glass and clean the threads. Apply Loctite anaerobic PST No. 12928/12929 Teflon sealer.
Apply sealer sparingly to the threads only; do not apply to the end surface. Reinstall the sight glass and torque to
these specifications:
Add new refrigerant oil through fill/drain port to the same level as before sight glass removal.
5
Discharge Rotalock 11⁄4Nut 1,106–1,195 inch pounds or 89–100 foot pounds
Suction Rotalock 13⁄4Nut 1,195–1,416 inch pounds or 100–120 foot pounds
Oil Sight Glass Torque 200 inch pounds or 20 foot pounds

Mueller E-Star OESE 7.5 and 9 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828748 Effective June 16, 2020
3.1 EPA REFRIGERANT REGULATIONS1
Mueller OESE condensing units are designed to operate with R-507 refrigerant. R-507 refrigerant is specified by
ASHRAE Standard 34 Safety Classification as an “A-1” refrigerant with low flame propagation and low toxicity.
EPA regulations require that any technician performing refrigerant installation or service on a high-pressure
appliance be certified as a Type II or Universal Technician in accordance with Section 608 of the Clean Air Act.
1As adopted for the United States and Canada. These regulations may change or dier for your locality. It is the responsibility of the
technician performing the refrigerant service and/or installation to abide by all regulatory requirements for the installation locality,
state, and country.
3.2 INITIAL REFRIGERANT CHARGE
IMPORTANT: Mueller E-Star condensing units must be triple evacuated to 500 microns before
refrigerant charging.
The most efficient and reliable method to charge the condensing unit is to weigh in the charge, ensuring it matches
the startup charge recommendation in Table 6. The refrigerant charge should be adjusted for the final operating
charge, as described in Section 3.4.
TABLE 6: RECOMMENDED STARTUP REFRIGERANT CHARGE
NOTE: R-507 is recommended for use with Mueller E-Star OESE condensing units; however, other refrigerants
may be compatible. Contact the Mueller Dairy Farm Equipment Service Department for more information.
IMPORTANT: The compressor is equipped with Rotalock suction and discharge service valves intended
for ease of compressor change-out only. At no time during operation should these valves be closed.
3.3 WEIGH-IN REFRIGERANT CHARGING
The following steps will outline the procedure to weigh in the refrigerant startup charge:
1. With a clean and evacuated system, connect the manifold gauges to P2, suction charging access port, and P6,
high-side service valve.
2. Connect the center charging hose to a cylinder of new or reclaimed ARI 700-88 specifications refrigerant.
3. Weigh and record the gross weight of the refrigerant cylinder.
4. Purge any air from the manifold gauge hose as specified by EPA Section 608, de-minimus release.
5. Break the refrigeration system’s vacuum with liquid refrigerant, charging into the Schrader port at P2, suction
charging access port.
6
Section 3.0 – Refrigerant Charging
Recommended Startup Charge
Condensing Unit Size Milk Cooler Chiller
7.5 HP 25 lbs / 11.34 kg 23 lbs / 10.43 kg
9 HP 25 lbs / 11.34 kg 23 lbs / 10.43 kg

Mueller E-Star OESE 7.5 and 9 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828748 Effective June 16, 2020
3.3 WEIGH-IN REFRIGERANT CHARGING (CONTINUED)
6. When the system pressure equalizes with cylinder pressure, energize the compressor.
7. Monitoring the gross weight of the refrigerant cylinder, weigh in the remaining refrigerant charge in liquid
state at P2, suction charging access port (up stream of accumulator).
IMPORTANT: Liquid refrigerant must always be charged upstream of the accumulator heat exchanger to
ensure the compressor is protected against liquid refrigerant.
3.4 FINAL OPERATING CHARGE
The refrigerant charge should be fine-tuned for the best operating efficiency of the cooling system. The exact
charge will vary depending on the evaporator size and refrigerant line length.
1. With the evaporator completely covered with milk/water or with the chilled solution circulating through the
chiller, operate the cooler or chiller with the startup refrigerant charge until the product is cooled below 45°F.
2. Check the evaporator superheat and ensure that it is properly adjusted. Milk cooler evaporator superheat
should be set at 4–6°F and chiller evaporator superheat should be set at 10–12°F. Refer to Section 5.0 for the
superheat adjustment.
3. Check the sight glass installed at the TEV inlet. If the sight glass shows vapor refrigerant (bubbles), go to step
4. If the sight glass is clear with liquid refrigerant, slowly recover refrigerant from the system at P6, high-side
service valve, until an occasional bubble of vapor is seen in the sight glass.
4. Slowly add refrigerant at P2, suction charging access port, until the sight glass becomes clear with liquid
refrigerant.
5. Check the superheat a second time to ensure the proper setting.
IMPORTANT: Liquid refrigerant must always be charged upstream of the accumulator heat exchanger,
access ports P2 or P3, to ensure the compressor is protected against liquid refrigerant slugging.
3.5 REFRIGERANT TESTING
When removing refrigerant from a system which has had a compressor failure, the refrigerant should be tested for
acid to ensure that it has not been contaminated by a burnout. If any contamination is found, recover the entire
refrigerant charge, replace the filter-drier, triple evacuate, and recharge with new or recycled refrigerant to meet
ARI 700-88 specifications.
3.6 SAFETY ALERT
Technicians should wear side-shielded safety glasses and butyl-lined gloves when handling refrigerants.
Liquid refrigerant will cause frostbite.
When refrigerants come in contact with an open flame or a high heat source, dangerous gases will form.
This is characterized by a strong acidic odor. Immediately vacate the area and ventilate prior to reentry.
7
!

Mueller E-Star OESE 7.5 and 9 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828748 Effective June 16, 2020
4.1 REFRIGERANT CYCLE
The E-Star OESE refrigeration system utilizes an expansion valve (TEV) that controls the evaporator superheat.
The expansion valve must be field adjusted to maintain the milk cooler evaporator’s superheat at 4–6°F (2.2–3.3°C)
or the chiller evaporator’s superheat at 10–12°F (5.6–6.7°C).
Refer to Figure 2, “Refrigeration Piping Schematics.” Subcooled liquid refrigerant leaves the condenser coil and
flows through the heat exchanger coil in the accumulator, where it is subcooled an additional 5–15°F (2.7–8.5°C).
This heat exchange also evaporates any liquid refrigerant in the suction accumulator, protecting the compressor
against liquid flood-back.
As the liquid refrigerant, now subcooled a total of 10–25°F (5.5–13.8°C), passes through the expansion valve, its
pressure is reduced to an evaporative pressure. Since the liquid refrigerant was subcooled in the accumulator heat
exchanger coil before entering the evaporator, there will be less flash gas at the inlet of the expansion valve.
Any liquid refrigerant returned from the evaporator is evaporated into vapor when it contacts the warmer heat
exchanger coil in the bottom of the suction accumulator. Vapor leaving the accumulator heat exchanger will be
superheated an additional 2–5°F (1.1–2.75°C) prior to entering the compressor’s suction intake. This minimal
superheat provides protection against liquid refrigerant entering the compressor while providing exceptional
refrigerant cooling of the compressor.
4.2 OIL RETURN
Refrigerant oil returning from the evaporator drops into the accumulator where the oil separates from the
refrigerant and settles to the bottom of the accumulator. This oil is metered back into the compressor through
the oil pickup orifice located in the bottom of the accumulator’s suction outlet “J” tube. Reference Section 6.0,
“Accumulator Heat Exchanger.”
4.3 INCREASED OPERATING EFFICIENCY
Mueller E-Star OESE condensing units incorporate a receiver and condenser subcooling loop to maintain properly
subcooled liquid refrigerant to the TEV, which ensures optimum evaporator efficiency.
8
Section 4.0 – Operating Features

Mueller E-Star OESE 7.5 and 9 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828748 Effective June 16, 2020
T1: Product Temperature
Liquid Refrigerant
Liquid-Vapor Refrigerant
Vapor Refrigerant
T2
P3
P4
P2
P6
T4 T6
T3
T5
P5
P1
DFE0117
60 psig
40°F T7
Subcooling Loop
Fan
Scroll
Compressor
Ambient Air
Receiver
This is a custom-designed
accumulator heat exchanger.
To ensure proper system operation,
a genuine Mueller accumulator
heat exchanger must be used.
Accumulator Heat Exchanger
Fan
ControlFP
(O-Cycle)
HP
LP
FIGURE 2: REFRIGERANT PIPING SCHEMATICS
IMPORTANT: When charging the system with liquid refrigerant, always charge upstream of the
accumulator heat exchanger, charging access port P2, to ensure the compressor is protected against
damage caused by liquid refrigerant slugging.
9
Example (R-507):
• 60 psig converted to saturation temperature on refrigerant pressure temperature table equals 34°F.
• Actual suction line temperature equals 40°F.
Results:
• 40°F – 34°F = 6°F (4.4°C – 1.1°C = 3.3°C) superheat at evaporator.

Mueller E-Star OESE 7.5 and 9 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828748 Effective June 16, 2020
5.1 THERMAL EXPANSION VALVE (TEV) SELECTION AND INSTALLATION
The condensing unit’s TEV must be field adjusted to maintain the milk cooler evaporator’s superheat at 4–6°F
(2.2–3.3°C) or the chiller evaporator’s superheat at 10–12°F (5.6–6.7°C). Proper location and sizing of the thermal
expansion valve is critical. Refer to Section 5.2 for the superheat adjustment procedure.
An externally equalized TEV must be used on Mueller milk cooling applications. A sight glass must be installed at
the TEV inlet.
See Table 7 for expansion valve selection.
TABLE 7: THERMAL EXPANSION VALVE SELECTION
FIGURE 3: THERMAL EXPANSION VALVE INSTALLATION
10
Section 5.0 – Expansion Valve
No. Description Specifications
Part No. for Milk
Cooler Applications
Part No. for
Chiller Applications
1 R-507 TEV (7.5 HP) 1⁄2" ODF inlet x 7⁄8" ODF outlet 8825838 N/A
2 Sight Glass (7.5 HP) 1⁄2" ODF inlet x 1⁄2" ODF outlet solder 8824494 N/A
3 R-507 TEV (9 HP) 5⁄8" ODF inlet x 7⁄8" ODF outlet 8825840 8825850
4 Sight Glass (9 HP) 1⁄2" ODF inlet x 1⁄2" ODF 9813636 9813636
The TEV sensing bulb should be located
a minimum of 10 tube diameters away
from any fittings or bends.
Example: 7/8" suction line (x) 10 = 83/4".
Securely mount and insulate the TEV sensing
bulb at a 4-o’clock position on the copper
suction line. Horizontal mounting is always
recommended when possible. If vertical
mounting is required, maintain the minimum
dimensions as stated above.
4 o'clock
12 o'clock
1
2

Mueller E-Star OESE 7.5 and 9 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828748 Effective June 16, 2020
5.2 CHECKING AND ADJUSTING SUPERHEAT
Take the following readings with the evaporator completely covered with milk/water or with the chilled solution
circulating through the chiller, at a temperature below 45°F.
1. Take an accurate suction pressure at the evaporator outlet.
IMPORTANT: The suction pressure must be taken at the evaporator outlet, rather than the suction access
port, due to unknown pressure drop in the refrigerant line between the evaporator and compressor. The
technician should also ensure the system is properly charged with refrigerant as described in Section 3.
2. Use an accurate electronic thermometer to take the actual suction line temperature near the TEV sensing bulb.
3. Utilizing the appropriate pressure temperature chart, convert the suction pressure reading from step 1 to the
saturation temperature. (See Section 17 for the pressure temperature chart.)
4. The superheat is calculated by subtracting the saturation temperature (dew point) determined in step 3 from
the actual suction line temperature taken in step 2.
5. If the superheat is not in the proper range of (e.g., 4–6°F for milk coolers, 10–12°F for chillers) at conditions as
described above, adjust the TEV.
6. If superheat is below the proper range, turn the TEV’s adjustment stem clockwise 1⁄8to 1⁄4of a turn. Allow the
system to operate for 5 minutes before repeating test.
7. If superheat is above the proper range, turn the TEV’s adjustment stem counterclockwise 1⁄8to 1⁄4of a turn.
Allow the system to operate for 5 minutes before repeating the test.
8. Any time adjustment is made to the TEV, the refrigerant charge should be checked, as described in Section 3.
9. Check the superheat setting and make final adjustments at a product temperature near the setpoint for the
best performance.
FIGURE 4: CHECKING AND ADJUSTING SUPERHEAT
11
40°F
60 PSIG
Example (R-507):
• 60 psig converted to saturation temperature on
refrigerant pressure temperature table equals 34°F.
• Actual suction line temperature equals 40°F.
Results:
• 40°F – 34°F = 6°F (4.4°C – 1.1°C = 3.3°C)
superheat at evaporator.

Mueller E-Star OESE 7.5 and 9 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828748 Effective June 16, 2020
6.1 ACCUMULATOR HEAT EXCHANGER FUNCTIONS
The accumulator heat exchanger performs several functions on the OESE system.
• Additional Subcooling: High-pressure liquid refrigerant from the condenser is subcooled 5–15°F (2.7–8.5°C)
as it passes through the heat exchanger coil in the bottom of the accumulator which is submerged in cold liquid
refrigerant that has returned from the evaporator.
• Vapor Return to the Compressor: The accumulator heat exchanger evaporates accumulated liquid
returning from the evaporator, providing cool vapor refrigerant to the suction inlet of the compressor.
• Oil Return to the Compressor: Oil settles to the bottom of the accumulator and is returned to the
compressor through an orifice in the accumulator’s suction outlet.
IMPORTANT: The custom Mueller accumulator heat exchanger utilizes a special “pancake” heat
exchange coil. The use of a generic (spiral) accumulator heat exchanger will severely reduce cooling
capacity of the E-Star OESE condensing unit and may cause premature compressor failure. Use genuine
Mueller replacement parts only.
FIGURE 5: ACCUMULATOR HEAT EXCHANGER
12
Section 6.0 – Accumulator Heat Exchanger
15∕8" Suction Connections
7∕8" Liquid Connections
Fuseable Plug
Oil Return Orifice

Mueller E-Star OESE 7.5 and 9 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828748 Effective June 16, 2020
7.1 E-STAR OESE CONDENSING UNIT ELECTRICAL WIRING
Authorized personnel, in accordance with the National Electrical Code (NEC) and/or local and state codes, must
perform all wiring. Refer to Section 16.0 for electrical requirements and Section 8.0 for wiring schematics.
A fused disconnect must be provided of adequate size, voltage, and phase for the incoming power supply to the
E-Star OESE condensing unit.
7.2 CORESENSE DIAGNOSTICS™ MODULE FOR 7.5 AND 9 HP COMPRESSORS
A Copeland CoreSense module is installed in the electrical box of all 7.5 and 9 HP K5 Scroll compressors. The
CoreSense module can accurately detect the cause of electrical and system related issues by monitoring and
analyzing data from K5 compressors via module power, discharge line thermistor, and the current transducer (CT).
A flashing LED indicator displays alert, fault, and trip conditions.
IMPORTANT: When servicing or replacing the CoreSense module, it is imperative that bit switch 6 of the
compressor operation switch block be turned on; all other switches remain off.
7.3 CORESENSE LED STATUS
7.4 CORESENSE DIAGNOSTIC FAULT CODE DETAILS
The LEDs will flash a number of times consecutively, pause, and then repeat the process. To identify an alert code
number, count the number of consecutive flashes. Detailed descriptions of specific alert codes are shown below.
1 Code 8 displays for 24 hours after last detection. With Terminal D energized, the M1–M2 relay will open during a protection shutdown.
To reset module, cycle module power.
13
Section 7.0 – Electrical
Fault
Code Color Code Description
Protection
Shutdown
Protection
Off Time
Consecutive Detections
Until Lockout
1 Red/Yellow High Discharge Line Temperature Yes 20 Min. 4
2 Yellow Excessive Limit Trips Yes 5 Min. No Lockout
3 Green Excessive Demand Cycling NO N/A N/A
4 Red/Yellow Locked Rotor Yes 20 Min. 4
5 Green Demand Present- No Current Present No N/A N/A
6 Red/Yellow Phase Loss Detected Yes 20 Min. 10
7Red Reversed Phase Detected Yes Reset Required 1
8 Green Welded Contactor No1— —
9 Yellow Low Module Voltage Yes 5 Min. No Lockout
10 Green Module Communications Error No — —
11 Green Discharge Temperature Sensor Error No — —
12 Green Current Transducer Error No — —
CORESENSE MODULE DIAGNOSTICS
LED Color Solid Light Flashing Light
Green Normal Alerts
Yellow Demand/No Current Trip (Auto Reset)
Red — Lock Out (Manual Reset)

Mueller E-Star OESE 7.5 and 9 HP HFC Condensing Unit
Installation and Operation Manual, Part No. 8828748 Effective June 16, 2020
14
7.5 CORESENSE PROTECTION MODULE CONNECTION WIRING
The CoreSense operates on constant power of 240 volts at terminals L1–L2. When a 120-volt run signal is applied
to terminal D, and if there are no protective faults detected within the CoreSense, the M1–M2 control circuit
contacts will close. The compressor will run with no external faults present. If the CoreSense detects a problem, the
M1–M2 contacts will open, de-energizing the compressor.
7.6 CORESENSE PROTECTION MODULE VOLTAGE TROUBLESHOOTING
1. Verify that all wire connectors are maintaining a good mechanical connection. Replace any connectors that
are loose.
2. Measure the voltage across L1–L2 to ensure the proper supply voltage and the demand voltage at terminal D is
present.
3. Measure the control voltage (24 VAC) across the M1–M2 contacts:
a. If the measured voltage is equal to the control voltage, then the M1–M2 contacts are open.
b. If the measurement is less than one volt and the compressor is not running, then the problem is external
to the motor protector module.
IMPORTANT: Do not run a Copeland Scroll compressor in a deep vacuum. Failure to heed this advice can
result in arcing of the Fusite pins and permanent damage to the compressor.
IMPORTANT: Scroll compressors (as with any refrigerant compressor) should never be used to evacuate
a refrigeration system.
The compressor leads must be routed through the holes in the current transducer (CT) module marked T1, T2, and
T3. Only the compressor lead wires should be placed through the CT module.
Directional Dependence of Three-Phase Scroll Compressors: Scroll compressors are directionally dependent
and will compress in one rotational direction only. The CoreSense module will provide reverse rotation protection.
7.7 CORESENSE PRODUCT SPECIFICATIONS
Operating Temperature: –40° to 150°F (–40° to 65°C)
Storage Temperature: –40° to 175°F (–40° to 80°C)
Power Supply Range: 85–265 VAC, 50–60 Hz
Working Amperage for CT Module: 3–200 A
NOTE: The CoreSense module is not accurate below 3 A. If the current drawn by the compressor during operation
falls below 3 A, the module may indicate a fault condition and alarm.
Maximum continuous contactor coil current is 2 A with a maximum in rush current of 20 A.