Hoshizaki 73180 service manual Brazing, Evacuation and Recharge R-134a

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2. Brazing

WARNING

•R-134a itself is not flammable at atmospheric pressure and temperatures up to

212°F (100°C).

•R-134a itself is not explosive or poisonous. However, when exposed to high temperatures (open flames), R-134a can be decomposed to form hydrofluoric acid and carbonyl fluoride both of which are hazardous.

•Do not use silver alloy or copper alloy containing arsenic.

•Use an electronic leak detector or soap bubbles to check for leaks. Add a trace of refrigerant to the system (if using an electronic leak detector), and then raise the pressure using nitrogen gas (140 PSIG). DO NOT use R-134a as a mixture with pressurized air for leak testing.

1)Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4 PSIG.

NOTICE

•Always install a new drier every time the sealed refrigeration system is opened. Do not replace the drier until after all other repair or replacement has been made.

•When brazing, protect the drier by using a wet cloth to prevent the drier from overheating. Do not allow the drier to exceed 250°F (121°C).

2)Use an electronic leak detector or soap bubbles to check for leaks. Add a trace of refrigerant to the system (if using an electronic leak detector), and then raise the pressure using nitrogen gas (140 PSIG). DO NOT use R-134a as a mixture with pressurized air for leak testing.

3.Evacuation and Recharge (R-134a)

1)Attach a vacuum pump to the system. Be sure the high-side charging hose is connected to the field-installed high-side access valve.

NOTICE

The vacuum level and vacuum pump may be the same as those for current refrigerants. However, the rubber hose and gauge manifold to be used for evacuation and refrigerant charge must be exclusively for POE oils.

2)Turn on the vacuum pump, then open the high-side valve on the gauge manifold. Never allow the oil in the vacuum pump to flow backwards.

3)Allow the vacuum pump to pull down to a 29.9" Hg vacuum. Evacuating period depends on pump capacity.

4)Close the high-side valve on the gauge manifold.

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Contents 100BAF-DS 100BAF-AD 100BAF-ADDS Hoshizaki AMERICA, INC Contents Page Important Safety Information Page Specifications 100BAF Auxiliary Codes A-1 and EarlierAuxiliary Codes A-2 and Later 100BAF-DS 100BAF-DS, 2. Auxiliary Codes A-2 and Later 100BAF-AD 100BAF-AD, 2. Auxiliary Codes A-2 and Later 100BAF-ADDS 100BAF-ADDS, 2. Auxiliary Codes A-2 and Later Auxiliary Codes Rear II. General Information ConstructionFront Auxiliary CodesIcemaking Unit Sequence of Operation Freeze CycleFill Cycle Auxiliary Codes A-1 and Earlier Auxiliary Codes A-2 and Later Wiring Diagram Auxiliary Codes A-2 and LaterIcemaker with Optional Drain Pump HS-0248 Performance Data 100BAF SeriesIce Production Check IV. Service DiagnosisDiagnostic Procedure Page Auxiliary Codes A-2 and Later Bin Control Check Float Switch Check Float Switch Cleaning Lower Float white Plastic Retainer ClipDrain Pump Check Optional Drain Pump HS-0248Overview Priming Instructions Float Switch Cleaning Diagnostic Charts No Ice Production Possible Cause StartupShutdown Fill Cycle and Refill Cycle Shutdown Refrigerant Recovery Removal and Replacement of ComponentsService for Refrigerant Lines Brazing Evacuation and Recharge R-134aImportant Notes for Component Replacement ComponentRemoval and Replacement of Evaporator Assembly Components Upper Bearing Wear Check Removal and Replacement of Extruding Head Removal and Replacement of Auger Removal and Replacement of Evaporator Page 5b. Lower Housing Page VI. Maintenance Maintenance Schedule Frequency Area TaskCleaning and Sanitizing Instructions Cleaning SolutionPage Sanitizing Solution Page Cleaning Solution Page Sanitizing Solution Storage Bin Drain Condenser VII. Preparing the Icemaker for Periods of Non-Use Auxiliary Codes A-1 and Earlier Skip to stepVIII. Disposal
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