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
Control
FP
(Off-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.
