Liquid Line; Refrigeration Cycle - Hussmann Proto-Aire EZ Manual Del Usuario

Proto-Aire EZ I/O Manual 13

Liquid Line

Take-offs to evaporators must exit the bottom of the liquid line.

Refrigeration Cycle

Beginning with Compressors, refrigerant vapor is compressed into the Discharge Header.
The oil separator effectively divides the refrigerant from the lubricant in the system. The
lubricant is then returned to the compressors. The Condenser dissipates the unwanted heat from
the refrigerant into an air-cooled condenser.
The receiver acts as a vapor trap and supplies the Liquid Line with quality liquid refrigerant.
A Liquid Line Filter/Drier removes water and other contaminants from the refrigerant.
The liquid branch line supplies liquid refrigerant to the Thermostatic Expansion Valve (TXV),
which in turn feed refrigerant to the cases (evaporator coils). These coils pick up heat from the
product stored in the cases. A Suction Filter removes system contaminants from return vapor,
which is factory supplied but field installed. It is also a good idea to install isolation valves for
ease of service.
The mechanical ORI valve (Open on Rise of Inlet pressure) should be set to start opening at 70F
equivalent pressure from T/P chart. This will allow bypass after fans have been cycled off. To set
the valve, install pressure gauge on the inlet tap of the valve and artificially lower the pressure to
when the valve starts to open. The valve comes factory set from Sporlan to open at 120 psi. For
initial start-up, turning the adjustment screw IN approximately * turns should give a starting
point and make it easier to verify proper operation.
*ORI-6 = 1 turn = 27 lbs
*ORI-10 = 1 turn = 17 lbs
70° F equivalent pressure = (X) turns + 120 psi
The mechanical bypass CRO valve (Close on Rise of Outlet pressure) should be set to start
closing at 2 psi above the low temperature satellite compressor suction pressure set-point. This
will prevent the low temperature satellite compressor from short cycling. The valve comes
factory set from Sporlan to close at 15 psi. For initial start-up, turn the adjustment screw either
clockwise to increase the setting or counterclockwise to decrease the setting approximately *
turns. The valve has an adjustment range of 0 to 20 psi.
*CRO-4= 1 turn = 3.3 psi
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