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7. EVAPORATOR
IMPORTANT
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) Turn off the power supply.
2) Remove the panels and the front and top insulation.
3) Remove the refrigerant from the unit and then any residual refrigerant still existing in the
unit to allow welding process. (See “2. WELDING REPAIR FOR R290 REFRIGERATION
CIRCUIT”.)
4) Remove the spray tubes. Remove the insulation at the "U" shaped notch where the
refrigeration tubing passes through the molded chassis.
5) Disconnect the evaporator tubing.
6) Remove the pop rivets securing the evaporator, then lift out the evaporator.
7) Install the new evaporator.
8) Remove the drier, then place the new drier in position.
9) Braze all fittings while purging with nitrogen gas flowing at a pressure of 20 to 30 kPa.
10) 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 (970 kPa). DO NOT use R290 as a mixture with
pressurized air for leak testing.
11) Evacuate the system, and charge it with refrigerant. For air-cooled and water-cooled
models, see the nameplate for the required refrigerant charge.
12) Replace the removed parts in the reverse order of which they were removed.
13) Replace the insulation and the panels in their correct positions.
14) Turn on the power supply.
