Removal And Replacement Of Expansion Valve - Hoshizaki KMD-450MAH Service Manual

9) Place the compressor in position and secure it using the bolts and washers.
10) Place the new drier in position.
11) Remove the plugs from the suction, discharge, and process pipes.
12) Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4 PSIG.
13) 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-404A as a mixture with
pressurized air for leak testing.
14) Evacuate the system and charge it with refrigerant. For air-cooled and water-cooled
models, see the nameplate for the required refrigerant charge. For remote air-cooled
model, see the rating label inside the icemaker.
15) Connect the terminals and replace the terminal cover in its correct position. On remote
air-cooled model, connect the crankcase heater.
16) Replace the panels in their correct positions.
17) Turn on the power supply.
C. Removal and Replacement of Expansion Valve
Moisture in the refrigeration circuit may exceed drier capacity and freeze up at the
expansion valve.
1. Always install a new drier every time the sealed refrigeration system is
opened.
2. Do not replace the drier until after all other repair or replacement has been
made. Install the new drier with the arrow on the drier in the direction of the
refrigerant flow.
3. When brazing, protect the valve body and drier by using wet cloths to
prevent the valve body and drier from overheating. Do not allow the valve
body or drier to exceed 250°F (121°C).
1) Turn off the power supply.
2) Remove the panels.
3) Recover the refrigerant and store it in an approved container.
4) Remove the insulation and the expansion valve bulb on the suction line.
5) Remove the expansion valve cover and disconnect the expansion valve. Place the new
expansion valve in position.
6) Remove the drier, then place the new drier in position.
7) Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4 PSIG.
8) 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-404A as a mixture with
pressurized air for leak testing.
CAUTION
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