Refrigerant Recovery; Brazing; Evacuation And Recharge (R-404A) - Hoshizaki KM-230BAJ Service Manual

1. Refrigerant Recovery

The icemaker is provided with a low-side refrigerant access valve. Using proper
refrigerant practices, recover the refrigerant from the access valve and store it in an
approved container. Do not discharge the refrigerant into the atmosphere. After recovery
is complete, install a proper, permanent high-side access valve.

2. Brazing

• R-404A itself is not flammable at atmospheric pressure and temperatures up to
176°F (80°C).
• R-404A itself is not explosive or poisonous. However, when exposed to high
temperatures (open flames), R-404A 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.
1) Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4
PSIG.
Note: Because the pipes in the evaporator case are specially coated to resist
corrosion, it is important to make connections outside the evaporator case
when possible. If it is necessary to braze inside the evaporator case, use
sandpaper to remove the coating from the brazing connections before
unbrazing the components.
• 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.
Install the new drier with the arrow on the drier in the direction of the refrigerant
flow.
• 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-404A as a mixture with
pressurized air for leak testing.

3. Evacuation and Recharge (R-404A)

1) Attach a vacuum pump to the system. Be sure to connect the charging hoses to
both the low-side access valve and the field-installed high-side access valve.
WARNING
NOTICE
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