Expansion Valve - Hoshizaki TM-500AAE Service Manual

5. EXPANSION VALVE

Sometimes moisture in the refrigerant circuit exceeds the Drier capacity and
freezes up at the Expansion Valve. 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.
1) Disconnect the power source.
2) Remove the panels.
3) Recover the refrigerant and store it in a proper container, if required by an applicable law
(See "1. [b] REFRIGERANT RECOVERY").
4) Remove the Expansion Valve Bulb at the Evaporator outlet.
5) Disconnect the Expansion Valve using brazing equipment.
6) Braze the new Expansion Valve with nitrogen gas flowing at the pressure of 0.2 - 0.3 bar.
Always protect the valve body by using a damp cloth to prevent the valve from
overheating. Do not braze with the valve body exceeding 100°C.
7) Install the new Drier (See "4. DRIER").
8) Check for leaks using nitrogen gas (10 bar) and soap bubbles.
9) Evacuate the system, and charge it with refrigerant. See the Nameplate for the required
refrigerant charge (See "1. [c] EVACUATION AND RECHARGE").
10) Attach the Bulb to the suction line. Be sure to secure the Bulb using a wire or clamp and
replace the insulation.
11) Refit the panels in their correct position.
12) Connect the power source.
IMPORTANT
WARNING
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