Filter
Top Products
45
2. Brazing
WARNING
• R-404A itself is not ammable 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 ames), R-404A can be decomposed to form hydrouoric
acid and carbonyl uoride 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-404A as a mixture with
pressurized air for leak testing.
1) Braze all ttings while purging with nitrogen gas owing 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.
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.
Install the new drier with the arrow on the drier in the direction of the refrigerant
ow.
• 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)
The condensing unit is provided with refrigerant shutoff valves and the icemaker is
provided with refrigerant service valves. Evacuation and recharge via the condensing unit's
refrigerant shutoff valves is recommended.
1) Attach a vacuum pump to the system. Be sure to connect the charging hoses to both
high and low-side refrigerant shutoff valves.
IMPORTANT
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 should be exclusively for POE oils.