Hoshizaki 73168 service manual Refrigeration System Pump‑Down Procedure

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2.Refrigeration System PumpDown Procedure

1)Remove the front panel. Move the power switch to the "OFF" position, then unplug the unit.

2)Remove the left side panel.

3)Connect the gauge manifold hoses to the receiver service valve (high-side) and the rail low-side access valve. See Fig. 1.

Note: Be sure the high-side gauge manifold hose is on the receiver service valve before opening the receiver service valve.

4)Run in the receiver service valve stem all the way until tight.

Note: Be sure the receiver service valve stem is seated all the way in and tight.

5)Plug the unit back in, then move the power switch to the "ON" position.

6)Move the rail switch to the "NORMAL" position. There is a 2-minute delay before the compressor starts. Once the compressor starts, the system pump-down begins.

7)When the low-side gauge indicates a vacuum, close the high and lowside rail service valves completely. Run in the rail service valve stems all the way until tight.

Note: Be sure the rail high and low-side service valve stems are seated all the way in and tight.

8)Move the power switch to the "OFF" position, then unplug the unit.

9)Back out the receiver service valve stem all the way until fully seated. Remove the highside gauge manifold hose.

Note: Be sure the receiver service valve stem is backseated all the way out and tight.

10)Use a backup wrench and disconnect the rail refrigerant tubes from the rail high and low-side service valves. Use a backup wrench when loosening the fittings. See Fig. 1.

11)Remove the screw securing the rail service valve bracket.

12)Disconnect the power supply cord connector, rail thermistor connector, and perimeter heater/rail fan connector.

13)Remove the wire cover below the control box.

14)Remove the upper and lower attachment nuts and washers from the control box and the hex head bolt from the base of the refrigeration system cartridge. See Fig. 1.

15)Slide the refrigeration cartridge forward. Support the evaporator as it clears the evaporator case. See Fig. 2.

CAUTION

1.Be careful when handling the cabinet evaporator assembly. This assembly includes a defrost heater sheathed in a glass tube. This sheathing can be easily damaged and may also cause cuts if broken. The defrost heater will also be hot after a defrost. Use gloves when handling and avoid touching the glass directly. Also prevent the defrost heater from touching other parts.

2.To avoid refrigerant leaks, be sure to prevent the refrigeration piping from coming into contact with the frame when removing and replacing the refrigeration cartridge.

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Contents Superior Degree Reliability Number Issued Revised Hoshizaki AMERICA, INC Contents Page Page Important Safety Information Serious injuryIndicates important information about the use and care UnitSpecifications Nameplate Ratings DimensionsII. General Information Construction Sequence of Operation Power Switch ON, Rail Cooling Switch OFFPower Switch ON, Rail Cooling Switch Normal or LOW Cool Down Restart Cabinet DefrostCabinet Defrost Power Switch ON, Rail Cooling Switch OFF Rail DefrostPower Switch ON, Rail Cooling Switch OFF Cabinet OperationPower Switch ON, Rail Cooling Switch Normal or LOW Position Rail CoolingCabinet and Rail Cooling Control Board Control Board LocationFront Rear Control Board LayoutLED Display and Service Lock-Out Alarm SignalService Menu Compressor Short Cycle ProtectionTemperature Display Controls and AdjustmentsSwitch Settings Cabinet Defrost Temperature SetpointEnergy Saving Mode Temperature Correction Factor Service Menu Service Menu AccessService Menu Chart Control Board Replacement Alarm SignalsControl Board Check Procedure Compressor Protector Thermistor CheckPerimeter Heater III. Service Diagnosis Alarm SignalsAlarm Priority Problem Reset, Corrections, and Adjustments High Temperature Alarm E1 Reset OptionsLow Temperature Alarm E2 Cabinet Defrost Alarm E3 High Condenser Temperature Alarm clogged filter E7 5a. Secondary Defrost Thermistor Rail, not used Defrost Thermistor cabinet Malfunction Alarm E8Possible Causes Condenser Thermistor Malfunction Alarm E9 No Operation Service ChartControl Board Alarms EA and ED Cabinet Cooling Problem Possible Cause Remedy Rail Cooling Cabinet Defrost Other Refrigerant Recovery IV. Removal and Replacement of ComponentsService for Refrigerant Lines Brazing Evacuation and Recharge R-404APage Removal and Replacement of Refrigeration System Cartridge Refrigerant Recovery ProcedurePage Refrigeration System Pump‑Down Procedure Page Defrost Thermistor Rail Thermistor Removal and Replacement of Compressor Removal and Replacement of Cabinet Evaporator Removal and Replacement of Expansion Valve Removal and Replacement of Liquid Line Valve Removal and Replacement of Condenser Defrost Thermistor Removal and Replacement of Thermistors and ThermostatCabinet Thermistor Defrost Thermostat Rail ThermistorRemoval and Replacement of Defrost Heater Condenser Thermistor clogged filterRemoval and Replacement of Fan Motors Cabinet Fan MotorCondenser Fan Motor Rail Fan MotorRemoval and Replacement of Door Gasket Door Re-Hinging and Drawer ConversionCleaning and Maintenance Instructions Work SurfaceRail and Rail Cover ExteriorCabinet Interior Door/Drawer GasketsMaintenance Power Supply ConnectionRail Condensate Pan Air FilterShutdown and Long Storage Refrigeration Circuit VI. Technical Information HPR100A-DWiring Diagrams HPR46A-D2a. HPR72A-D Auxiliary Code U-5 and Earlier 2b. HPR72A-D Auxiliary Code U-6 and Later Awaiting Data